Exotics Keeper Magazine June 2022

HAND-REARING LOVEBIRDS

THE BIGGEST FISH IN THE POND

LIFE IN THE TREES

Every effort is made to ensure the material published in EK Magazine is reliable and accurate. However, the publisher can accept no responsibility for the claims made by advertisers, manufacturers or contributors. Readers are advised to check any claims themselves before acting on this advice. Copyright belongs to the publishers and no part of the magazine can be reproduced without written permission.

Exotics keeping is a dynamic field that has seen loads of major advancements over recent decades. In the last few months several organisations have publicised their thoughts on addressing potentially problematic areas within herpetoculture. These include minimum enclosure sizes, wild-caught animals, online animal sales and many more. Regardless of people’s opinions on these topics, it is vitally important that we are honest with ourselves within our own community to consistently push for the highest standards. Exotics Keeper Magazine was founded with a clear vision to improve the welfare of captive animals by educating keepers, as well as fundraise for important conservation causes and inspire a new generation of herpetologists. We, as keepers, rely on the wider industry and are part of a huge network of herpetoculturists across the world that have different visions for the future of the hobby. Now is an important time to be vocal about the excellent things private keepers do, but also question outdated methods and practices.

This month we speak to several keepers of tree monitors and discuss the importance of enrichment. We were also lucky

side, we also dive into the world of koi and investigate where they get their colour. Finally, Teresa Masuet teaches us how to successfully hand-rear baby lovebirds. Last month we also donated to ‘Save Vietnams Wildlife’ an extremely worthy cause using hands-on rescue and rehabilitation to protect endangered Vietnamese species.

We will have a presence at several conferences this year. There are some great line-ups this year, with presentations from a variety of guest speakers. It will be nice to catch up with like-minded

EXOTICS NEWS

The latest from the world of exotic animals

retirement home for elderly female Asian elephants, some which had come from difficult backgrounds, but the decision has now been made to redevelop the area in the future. EAZA are assisting the zoo in finding another suitable home for the elephants, but no timescale for the move has been given as yet.

the Wild Camel Breeding Centre at Zakhyn-Us in Mongolia, and this year marks their 25th anniversary.

Blackpool Zoo`s Oldest Resident

Sadly Blackpool Zoo`s eldest resident –the male Aldabran giant tortoise called “Darwin”, who came to the U.K. prior to the zoo opening in 1972, has died. He was estimated to be around 105 years old, as there are no detailed records of his history. Following a progressive and deteriorating leg condition the decision was taken to euthanase him on veterinary welfare grounds.

Wild Wolverine

A wolverine has been born at the Wild Place Project in Bristol. This is the first born at the park which is owned by the Bristol Zoological Society.

The zoo have also bred two rare Francois`s leaf monkeys, and a female two-toed sloth named “Priscita” has arrived from Straubing Zoo in Germany to hopefully pair up with the resident male.

There are 34 captive-bred camels at the centre, with two new male calves being born recently. Last year five calves were born. All the camels underwent a sedation for a health check, ear-tagging, microchipping and blood sampling with the help of veterinary surgeon Dr Khatnaa from the Mongolian University of Agriculture, two assistants – Bridget and Jen from the UK`s Knowsley Safari Park and the staff of the centre. This work provides information to better understand the captive population and how best to manage them for the future survival of the species. A handful of UK zoos cooperate in the work of this facility.

Elephants Pack Their Trunks

At Belfast Zoo the two elderly female Asian elephants “Dhunja” and “Yhetto”, are to be rehomed after several years living at the zoo. The zoo had been providing a comfortable

New Invertebrate Park to Open

Called “BugzUK”, the new facility, based in Lenwade in Norfolk, and operated by invertebrate breeder Martin French, will feature a gift shop and café, as well as housing over 200 species. The park will be opening on the 28th May.

The 8th Most Endangered Large Mammal

It is said that the “wild Bactrian camel” (Camelus ferus) is the 8th most endangered large mammal on the planet, with less than 1,000 wild camels left they are critically endangered. The Wild Camel Protection Foundation runs

Six Tiny New Mexican Frogs

Tom Jameson, a researcher at the University of Cambridge’s Department of Zoology and University Museum of Zoology, who led the study which involved gathering almost 500 frog specimens from museums around the world, which had been collected in Mexico, and using new methods to categorise the relationships between them.

“Their lifestyle is utterly fascinating,”

Unlike this corn snake, we have sliding scales...

©www.cam.ac.uk Craugastor cueyatl on a Mexican coin

©Blackpool Zoo

©BugzUK

©Belfast Zoo

adds Jameson. “These frogs live in the dark, humid leaf litter of the forests, which is like a secret world - we don’t really know anything about what goes on there. We don’t understand their behaviour, how they socialise, or how they breed.”

Using DNA sequencing, the team sorted the frogs into groups based on how similar their genes were. Then CT-scanning was used to create 3D models of the frogs’ skeletons, so that physical details could be compared. These two very different lines of evidence revealed six new species of frog. The six new species have been named; Craugastor bitonium, Craugastor candelariensis, Craugastor cueyatl, Craugastor polaclavus, Craugastor portilloensis, and Craugastor rubinus.

A few specimens of Craugastor portilloensis were smaller, but they were not sure if these were fully grown adults. One of the smallest frogs are the Paedophryne amanuensis, a frog from Papua New Guinea, which are even smaller – the adult males don’t even reach 8mm in size.

The newly discovered species are known as ‘directdeveloping’ frogs: rather than hatching from eggs into tadpoles like most frogs, they emerge from the eggs as perfect miniature frogs. And they're so small that they’re right at the bottom of the forest food chain.

“With millions of these frogs living in the leaf litter, we think they’re likely to play a hugely important role in the ecosystem as a source of food for everything else, from lizards to predatory birds,” says Jameson.

Possible Come Back for Extinct Woodpecker?

The last confirmed sighting of the ivory-billed woodpecker (Campephilus principalis) was in 1944, although it was not widely accepted, but the last known photograph was in April 1935 when a pair were seen in Louisana. Since 1944 there have been a string of unverified sightings. This species was once fairly widely distributed across the southern US states in lowland mature forested areas, including in Cuba with the last accepted sighting there relatively late in 1987.

The ivory-billed woodpecker was one of the first animals to be recognized by the Endangered Species Act in 973.

With a call that has been described as that of a “tin trumpet” and making a double tap sound with its long bill, the ivory-billed woodpecker is the third largest woodpecker in the world and the largest north of Mexico.

Deforestation and hunting were a major contributing

factors in the species' demise throughout the 1800s, and this declining population was only enhanced its popularity with collectors, leading to further declines. They were once found in mature forests the Ohio River Valley down into Florida and into Cuba. Apparently another sighting was in the Big Woods of eastern Arkansas in 2004, but despite this the bird was still determined to be extinct by the U.S. Fish and Wildlife Service (FWS) in 2021. However, it appears that the FWS spoke too soon when they determined there were no more ivory-billed woodpeckers in existence. A research team from the National Aviary and Project Principalis went on a years-long search for the woodpecker and, using trail cameras and drone videos, accumulated evidence that at least three ivory-billed woodpeckers are living in the bottomland forests of the researchers’ study site in Louisiana, the National Aviary said. Director of conservation at the National Aviary in Pittsburgh Mr Steven C. Latta, who led the search and was co-author of the paper, observed an ivory-billed woodpecker fly. “It flew up at an angle and I watched it for about six to eight seconds, which was fairly long for an ivory-billed woodpecker,” Latta said. “I was surprised. I was visibly shaking afterwards. You realize you’ve seen something special that very few people had the opportunity to see.”

Latta said that the size and markings in the photos of the bird recorded by the researchers indicated that it was an ivorybill and not another type of woodpecker. After having been hunted for decades, the woodpecker became understandably wary of people, and avoided them by flying high into the trees, said biologists at Auburn University Geoffrey Hill, who participated in a search for the ivory-billed woodpecker in Florida in 2005.

Although these photos are of a poor quality and from a distance so they are not good enough to guarantee the existence of the species at this time. But generally, researchers are more optimistic that the species may continue to thrive in remote Hispaniolan forests than in southern US states.

©Sparsholt College

Dingo DNA Study

A new study has, for the first time, sequenced the genome of the Australian desert dingo, a wild dog that has been geographically isolated from both wolves and domestic dogs for thousands of years. Researchers, led by La Trobe University’s Professor Bill Ballard, showed that there are structural differences that separate the dingo genome from that of domestic breed dogs and that those changes have implications for the dingo’s physiology and even its gut microbiome.

For many years the origin of Australia`s dingo has been the subject of continued debate. Confused, to a degree, by the potential hybridization with feral wild dogs. In 2011 some 357 wild “dingos” were tested and the results showed only 20% of those animals were “pure dingo”. Despite this there was very little evidence of hybridization.

A more recent analysis tested several dead dingos, shot by farmers, hanging from a tree near Winton in Western Queensland. They were DNA tested and identified as being 99.9% “pure dingo”, which ties in with previous data suggesting that most dingos found specifically in

ON THE WEB

Queensland were said to be pure dingo.

The analysis showed that the dingo genome, isolated from other canids in Australia, had diverged from domestic dog breeds, showing up to 24 million unique bases as compared to domestic breeds. The genome was then compared to that of five breed dogs that represent the spectrum of domesticated canids: the German Shepherd, Boxer, Labrador, Basenji and Great Dane. To create an evolutionary tree involving domestic dogs and the dingo, a reference genome is needed that is genetically different from the animals under study—this is called an “outgroup”. Here, the authors picked the Greenland Wolf as outgroup—a subspecies that predates both dogs and Eurasian wolves and has mixed very rarely. There are still unanswered questions about the dingo. Ultimately, the authors concluded that their evidence suggests the dingo genome has “diverged substantially” from that domestic dog, although they note that these canids all remained relatively similar when compared to the Greenland Wolf.

Collated and written by Paul Irven.

A movement of enthusiasts and professionals, scientists and hobbyists, who know and understand the needs of amphibian and reptile husbandry. www.responsibleherpetoculture.com.ua

LIFE IN THE TREES

The natural history and captive husbandry of tree monitors.

Emerald tree monitor (Varanus prasinus)

Varanids, monitor lizards or ‘goannas’ are some of the most interesting reptiles on the planet. Members of this family of lizards can be found throughout Africa, Asia and Oceania. From three-meter long Komodo dragons (Varanus komodoensis) to 25cm short-tailed monitors (V. brevicauda), morphologically, this is one of the most diverse genera on the planet. They inhabit a range of environments from the canopies of tropical rainforests to underground burrows in dry deserts. Despite these vastly different characteristics, they are united by their incredible cognitive ability, superhero senses and prehistoric natural history.

Varanidae

Over half of all 80+ species of Varanid (comprised of the genera Varanus and Odatria) are found in Australia, making Oceania a hotspot for this genus. Not only are the large landmasses of Australia and New Guinea brimming with monitor lizards, but the fragmented islands across the wider region have fuelled incredible speciation. North of Timor-Leste lies “Wallacea”, a zoogeographical area comprised of many islands between Borneo and New Guinea, which provides a haven to a whole spectrum of unique monitor lizards. This region of the Pacific produces some startlingly unique taxa and is generally considered the location where Alfred Wallace first described the theory of evolution (which Darwin would later build upon in the Galapagos). Here, the reptiles exhibit stunning colouration from the blue vipers (Cryptelytrops insularis) of Komodo, to the ‘biak’ green tree pythons (Morelia azurea) of Papua, each species has evolved distinct ‘locale’ forms and in many cases, entirely different species.

There are currently around eight species belonging to the Emerald tree monitor (V. prasinus) species group. This ‘complex’ was formed to describe a group of different species which researchers previously thought were subspecies of the emerald tree monitor. One example, the ‘mysterious’ tree monitor (V. telenestes) has never been seen alive. A holotype of this animal discovered on the island of Rossel has had scientists scratching their heads since 1991. The yellow tree monitor (V. reisengeri) is also data deficient in almost all research and is only found on the remote island of Misool. Other species, such as the canopy monitor (V. keithhornei) are common and frequently studied in their home range of North Australia. All tree monitors vary in their morphology but are generally slim-bodied, medium-sized lizards that thrive at low elevations across dense woodlands, tropical forests and in some cases, plantations. Of these species, only three are being regularly bred in captivity and frequently exhibited in zoos. These are the emerald, black and blue-spotted tree monitors.

Emerald tree monitor (Varanus prasinus)

The emerald or green tree monitor is widespread through lowland tropical rainforests and mangroves across New Guinea and the Torres Strait Islands. Unconfirmed sightings (most recently in 2017) suggest that this species might also be present in the Cape York Peninsula in Far North Queensland, Australia. They have the largest distribution of all tree monitors, which explains why for decades, V. prasinus was thought to be the only tree monitor species. V. prasinus is also extremely variable in colour considering its distinct common name. Animals can range in hues of green, yellow and turquoise with unique patterns across their entire body.

They are one of the smaller tree monitors, reaching up to 80cm. Much of this length is comprised of a prehensile tail, a trait unique to tree monitors which facilitates their highly arboreal life. In fact, of all the Prasinus complex, few rarely

venture to the forest floor. They are primarily insectivorous but will opportunistically feed on eggs, chicks and small rodents and have been observed smashing small vertebrates and snails against hard surfaces before devouring them.

Adam Radovanovic is a keeper at Birmingham Wildlife and Conservation Park and has been working with tree monitors for six years. He told Exotics Keeper Magazine: “Generally, I have found tree monitors to be very intelligent. I think their high activity levels play into this more than V.albigularis, for example. I’m sure this species has the same intellectual/learning capabilities as the tree monitor complex, but it’s not always so visible.”

“To provide mental enrichment we interact a lot with our prasinus. He came to us from another zoo and was already nearly a year old at the time and wasn’t handled much, making him quite skittish. We had our black tree monitors

Emerald tree monitor (Varanus prasinus

from hatchlings and they were fantastic as I could let them sit on my shoulder and handled them on a regular basis. I wouldn’t go in to pick them up, I’d just offer them my hand and they’d walk on to me, up my arm onto my shoulder. We also use sections of hollow bamboo with various sized holes in (being careful that the lizards can’t get their heads stuck) and use them as a feeder by putting crickets, locust, pachnoda etc in there. It’s amazing how much time they spend trying to grab out invertebrates with their hands. We also use deeper substrates with lots of dried bamboo so any that escape can hide amongst the floor and you see the lizards wandering around foraging sticking their nose into the substrate. We often change up the exhibit so it’s “different” with branching, adding different leaves to the bottom of the enclosure etc. Sensory enrichment is very important not only for tree monitors but for all varanids due to their acute sense of smell.”

Although several tree monitors have been kept by hobbyists for decades now, they have always been regarded as a very specialised species that requires expert knowledge to maintain. Previously, they were widely considered a fragile species but are now kept successfully in many zoos. Adam continued: “I don’t think V.prasinus or even V.beccarii (only two I’ve worked with) are fragile species and captive individuals do very well on display and demonstrate natural behaviours in front of the public. However, it is important to use the available space properly. You can really maximise the space of an enclosure and make it heavily complex for the individual(s) by using lots of branches and cork bark hides/tubes at all different levels

which allows multiple platforms for basking/uptake of UVB at different parameters etc.”

Varanids have been maintained in captivity since the 1800s, with Alfred ‘Gogga’ Brown pioneering their husbandry following his publications dating back to 1834. However, the first official captive breeding of a Varanus species did not happen until 1941 when a Komodo dragon (V. komodoensis) produced surprise offspring, having dug her nest, laid her eggs and incubated the clutch completely unbeknown to keepers. Over that time, husbandry methods have improved but it is only very recently that successful clutches are being produced. In fact, reproductive failure is widespread across many monitor lizards.

Keepers are becoming more and more successful with just about every Varanid species in captivity. Yet, there is still a lot to learn despite more captive-bred animals being produced by zoos and private breeders. “Varanus prasinus is part of an ESB (European studbook) but it’s not too active at the moment, mainly due to so few females around” explained Adam. “Some collections have been exceptional with breeding prasinus but that has over-represented certain genetics. The breeding of this species still hasn’t been fully explored or understood and more breeding attempts are needed to really map out this species and have a better understanding of not only breeding parameters but also environmental parameters, nutrition and overall husbandry which plays a huge part in conditioning for these animals.”

Black tree monitor (Varanus beccarii)

Jamie Gilks is Head of Reptiles at Crocodiles of the World. The Zoo, which (unsurprisingly) specialises in large reptiles has been breeding black tree monitors (Varanus beccarii) for three years. He told Exotics Keeper Magazine: “Black tree monitors are of the subgenus Hapturosaurus, which quite fittingly translates to “grasp tail lizards”. This subgenus is also largely referred to as the V.prasinus complex. Black tree monitors were first described in the late 1800s and are endemic to the Aru Islands of Indonesia. The Aru Island Regency is made up of around 95 low-lying islands. These islands have central habitats that largely consist of moist lowland rainforest, whereas coastal areas of the islands have mangrove forests. Unfortunately, a majority of the black tree monitors’ suitable habitat has already been lost.”

The black tree monitor is one of the larger tree monitors, with adults reaching around 120cm in length. Males are generally slightly bigger than females but both display an entirely black colouration. Currently, the IUCN lists this species as ‘Data Deficient’ meaning that despite clear threats of deforestation across Aru, there is more to learn about the conservation status of the species. As such, captive breeding is considered an important part of conservation. Although there are a handful of zoos and private hobbyists that have been successful with green tree monitors and more recently, blue-spotted tree monitors, black tree monitors are still reasonably uncommon in a captive setting. Jamie continued: “I would say most of our visitors haven’t heard of a black tree

monitor before visiting, so just raising general awareness about the species (although very basic) is a great start. Being such an active and outgoing species, they have proven to be a great conversation starter with our visitors and receive a huge amount of dwell time. This really allows us to speak in detail about some of the threats they face such as fragmentation, collection for the international pet trade and threats from development and agricultural industries. As little is known about the wild populations it’s difficult to know exactly what damage is being caused by international trade. Gaining more experience and knowledge in the care and breeding of this species as a community will be hugely important and will hopefully help reduce a bit of pressure from wild collection in the future.”

Monitor species are widely regarded as the most intelligent reptiles on earth and require constant mental stimulation. Studies at San Diego Zoo discovered that some are even capable of counting. Keepers would provide a set number of snails each day and on occasion provide slightly less. This prompted the lizards to continue searching for the missing snails. It is also widely understood that monitor lizards will recognise their keepers and build a specific bond with an individual person. Add to this that tree monitors are both arboreal and have extremely dextrous appendages and the opportunities and necessity for good enrichment are huge.

Jamie continued: “Feed-based enrichment is probably our most frequently used method, but we try to change the way

Black tree monitor (Varanus beccarii)

this is presented as often as we can to avoid the animals getting overly familiar with particular enrichment feeders. Of course, it’s not all food-related. We’ve found that frequent and seasonal décor changes such as thin twisted willow branches work well for getting the monitors to shift their weight and use their tails a bit more whilst climbing. I’d also like to work a bit more with vines and swinging branches to help improve muscle tone. I think any of these examples could be used or adapted by private keepers to suit their set up and species, I would just make sure you know where your materials have come from, and that they are safe and suitable for the animal.”

Since maintaining the species, keepers at Crocodiles of the World have made some very interesting observations. Jamie continued: “When we moved a group of forktail rainbow fish into the exhibit we began to find our female sitting under a cork piece that hung over the water’s edge, she would sit there from evening to late morning and this pattern continued for a couple of weeks before stopping. In hindsight, it would have been nice to make a few more observations later in the evenings and earlier in the mornings to see if she was just resting there coincidentally at the same time fish were introduced, or if she was attempting to catch the fish at first and last light. Also, It may just be the animals we house but our V.beccarii are seemingly more confident and inquisitive than our V.prasinus. Unfortunately, I haven’t had the opportunity to work with other members of the complex to compare.”

Crocodiles of the World received international praise earlier this year for breeding the first Giant Galapagos tortoises (Chelonoidis niger) in a UK zoo. Whilst these charismatic chelonians may have caught the attention of the general public, there are a wealth of important breeding projects that the establishment is involved in, including one for the black tree monitor. Jamie continued: “Luckily, we haven’t had many issues with the general husbandry side of things. Our team are really good when it comes to researching and setting up for any new species coming into the collection. Paying close attention to seasonal parameters and dietary changes sounds obvious but if these aren’t correct the breeding project will always be on the back foot. The main challenge we’ve faced has probably been improving our incubation techniques. We lost our entire first clutch after about 70 days of incubation, since then we’ve made a few adjustments to temperature and increased airflow in the egg chambers and now we have close to a 90% success rate.”

Blue-spotted tree monitor (Varanus macraei)

The blue-spotted tree monitor is an arboreal species from the remote Indonesian island of Batanta, just off the coast of West Papua. The entire island is just 453km2. The fragility of this tiny island contributes to the species’ ‘endangered’ status. V. macraei was only discovered in 2001, by Duncan Macrae, founder of the Rimba Reptile

Blue-spotted tree monitor (Varanus macraei)

Centre in Bali. Since its discovery, it was widely exported into the international pet trade. This demand was potentially very dangerous, as at the time we knew very little about the natural history of the species. Whilst we still continue to know very little about these highly localised species in the wild, concerted efforts from hobbyists and zoos are starting to turn that notion around.

Now, the species is frequently bred in captivity with zoos basing much of their breeding practices on research conducted by private hobbyists who had imported them in the previous decade. Bristol Zoo was the first UK establishment to successfully breed V. macraei in 2019 and several others quickly followed suit. Daniel Kane is a Senior Reptile Keeper who maintains the species at ZSL London Zoo. He told Exotics Keeper Magazine: “The exhibit we have is very large, as they’re such an active species. 2.5 x 2.5 x 2.5 meters. If you look at the palms of their hands and the soles of their feet, they have these hard rubbery scales that give them extra grip. They have long claws and a prehensile tail, but those specialised scales also give them extra grip. One of their trademark things is extractive foraging, so we ensure our cork tubes have holes to stick their hands and noses in. They also do this with tree bark, so they’ll stick their noses under the bark and if they can’t quite get their full head inside, they’ll open their mouth to lift the bark up, then reach their hand in there. We also have ledges up high so she can be completely out of view of visitors if she wishes.”

“They do seem to require stimulation and prasinus are no different. When we started putting in lots of bigger

live plants, you’d see them shredding the leaves up. As a keeper we think, c’mon, don’t do that. But, the more we observed, the more we identified a pattern. What this particular lizard would be doing is shredding a leaf off and holding it with her front feet to tear it up. Or, she would take it up to the highest ledge in the exhibit, drop it and race it down to the bottom to try and catch it. We ran this behaviour through play criteria and together with Bristol Zoo, we have written a paper on play behaviour in tree monitors. We can now definitively say tree monitors in zoos and other collections do play!”

As such closely related species, the tree monitors often have similar traits and behaviours. It is only when working with many individuals of two or more species that herpetoculturists can begin to theorise behavioural differences in captivity. However, anecdotes can certainly identify potential differences to explore. Dan continued: “In terms of individuals, this macraei can eat loads and not put on any weight. However, this prasinus, if she ate the same as the macraei, she’d be the size of the exhibit! We feed our macraei three times a week, varying types of prey. I would say it’s about 90% insectivorous, but they also get the odd quail egg. They also have a weird fondness for shellfish. I can’t imagine how much seafood they’re eating in the wild, but they absolutely love it here. They’ll have entire tiger prawns which takes them a while to get through. It’s not quite a carcass feed but having those bits that they must tear into simulates wild behaviours. Sometimes we’ll get stick insects too, like Eurycantha. They’re a Papuan species, so it’s nice to provide something they would naturally take out of the wild.”

Emerald tree monitor (Varanus prasinus)

Enrichment for lizards

Although monitor lizards are famed for their problem solving and high cognitive ability, enrichment is important for all captive animals. Not all species will respond in the same way, but even novice reptile keepers can implement strategies to exercise their animal’s minds and improve captive welfare.

A recent paper published by researchers at Chester Zoo analysed enrichment methods of three Southeast Asian Varanids. These were the terrestrial Komodo Dragon of Indonesia and the arboreal green tree monitor and crocodile monitor (Varanus salvadorii) of New Guinea. It states: “There are five main ways in which environmental enrichment may be provided: by (1) creating and managing a dynamic habitat, (2) encouraging social interactions between individuals, (3) encouraging foraging, (4) introducing novel objects and (5) training. These methods aim to increase behavioural diversity, reduce abnormal behaviours, increase the range of natural behaviours demonstrated, increase the positive use of the environment, and increase the animal’s ability to cope with challenges in a more natural way.”

The researchers published many observations of enrichment techniques that typically contrast our general understanding of enrichment methods for reptiles. For example: “The provision of food- versus scent-based enrichment did not result in differences in enrichment engagement across the three species, suggesting that scent is just as effective in increasing natural behaviours.” Scent trails are widely used as enrichment strategies for snake species. Experienced keepers of all snake species

should be using scent trails within the enclosure. Those that handle their animals can create elaborate play areas outside of the vivarium and include scent trails too. Whilst most lizard species will rely much more on visual cues for hunting, introducing new smells, puzzle boxes, gradual feeding methods, etc could be beneficial. The paper continues: “Lizards exhibited significant increases in exploratory behaviour in response to hanging feeders, scent piles and scent trails. Contrary to our predictions, we found that engagement with these different enrichment types diminished more or less equally over time.” This period averaged out at around two and a half hours for each method of enrichment.

“Our results confirm that the most effective enrichment types may be those that mimic natural challenges routinely faced by lizards in the wild.”

Glossary

Prasinus complex: Refers to one of eight different species of arboreal Varanid lizard.

Monitor lizard: Refers to any member of the Varanidae family of lizards.

Wallacea: The zoological area between Borneo and Papua New Guinea comprised of Indonesian, Papuan and independent island nations.

Komodo

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SPECIES SPOTLIGHT

The wonderful world of exotic animals

Yemen Chameleon (Chamaeleo calyptratus)

As the name suggests, Yemen chameleons are from the Middle East. They inhabit mostly dry areas at elevations of up to 950m and as such, have evolved large crests to help channel precious water droplets into their mouths. Interestingly, both males and females exhibit this crest which has given them their other common name, the veiled chameleon.

As water is scarce in the environments they inhabit, older chameleons will eat plants and vegetation to ensure they are hydrated. They do very well in a live planted enclosure and many keepers recommend providing Epipremnum aereum which is non-toxic, fast growing and provides perfect climbing opportunities and even an occasional snack.

Because of the harsh conditions on the plateaus and mountainous regions they inhabit, Yemen chameleons can tolerate a range of temperatures. This makes them one of the hardier species of chameleon and has allowed them to become established in Florida as an invasive species.

Interestingly, Yemen chameleons are some of the only reptiles that can be sexed almost immediately after hatching. The males possess spurs on their legs which means breeders can quickly identify hatchlings. This species also grows quickly and males can reach a size of up to 60cm. Both sexes will also develop colourful patterns as they mature. Males will usually develop yellow bands that stretch down their dorsum, while females will have a sporadic spots of yellow, orange or black.

These chameleons should be housed separately where possible. This is particularly important for males which will actively harass the female and can lead to extremely high levels of stress. This territorial attitude makes chameleons a more specialist species for breeders. Although considered one of the more docile chameleons, they can appear aggressive or shy and should not be handled too frequently. Keepers should be able to recognise signs of stress or aggression in the colouration of their animal. In extreme cases this species may curl up and discolour to play ‘opossum’.

Enclosures can vary but a well-ventilated repti-breeze enclosure tends to be the “go-to”. These make drainage easier and provide good climbing opportunities for the animals. Keepers should provide a hot spot of up to 32°C at the top of the enclosure (with an ambient temperature of around 24°C). This should allow for the animal to move closer or further away from the heat source at will. Temperatures should drop to below 22°C at night.

To mimic wild conditions, a fogger should be used at night. As reptiles see light differently to us, sitting water is often difficult to distinguish so droplets of condensation are crucial. In the wild, moisture levels are much higher at night, peaking just before sunrise, so one minute of misting before lights turn on is a natural way to provide water. This should take humidity up to almost 100% at night and down to around 50% in the day. Yemen has very distinct seasons, so replicating these conditions throughout the year is advised.

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THE BIGGEST FISH IN THE POND

An introduction to prize-winning koi.

Koi keeping is big business and represents some of the most dedicated keepers in the aquarist hobby. Prized for their incredibly vibrant colouration, the science behind koi aesthetics is one which is well-documented and truly fascinating.

Koi-keeping: the basics

Koi were originally bred in Japan from common carp in the 1700s. Rice farmers would select the most attractive carp to breed, often selecting animals with red or white colouration, both of which are culturally significant in the country and represent joy and peace. Over several hundred years, a spectrum of over 120 varieties of koi have been produced. As koi-keeping became wellrespected in Japan and the fish became intrinsically tied to wealth, only the best koi were bred. A ‘good’ koi (which is most likely to be bred) is one which has healthy skin, a robust body shape, moves gracefully through the water and reaches an impressive size. However, a ‘winning’ koi must also have bold and distinct colouration. Whilst each variety will have different traits that are favourable to the keeper, the most impressive koi belong to the Gosanke (big three), comprised of Kohaku, Sanke and Showa

Kohaku: White (haku) base with vibrant red (ko) markings across the entirety of the body. This variety was one of the first consistently bred and has remained popular since the

1890s. The red colouration in this type of koi is thought to have originated from a natural colour mutation that would have likely been wiped out in the wild.

Sanke: This variety is characterised by white, red and black markings. These markings should all be above the lateral line, so the fish has a pure white underside. The most prized fish have small black markings, large red patterns and no gaps revealing the white colouration. There should be no black markings on the head and just a small stripe on the fins. This variety was introduced to the Tokyo Exhibition in 1914.

Showa: The specific tail patterns of this breed are important. They are generally a mix of red, white and black and must exhibit watercolour/painting style patterning. The tails must end in a pure white and there must be a visible line between the colour and the white. This variety is also judged heavily on its dorsal fin, as impeccable examples are rare.

These varieties are mostly bred in Japan, with international buyers exporting particular blood lines from the country. In the UK, it is possible to buy a whole spectrum of koi fish, including Kohaku, Sanke and Showa. However, like many aspects of exotics keeping, hobbyists must do a bit of digging to find the very best animals. Many aquatics shops and specialist breeders will sell koi valued between £100 and £600 which, whilst very impressive, are not considered ‘prize winning’ by international standards.

Koi colouration

The colouration of a koi is primarily produced by three colour pigments which are largely contained within cells called Chromatophores. The three pigments are Erythrin (Red), Melanin (Black), and Xanthin (Yellow) each of which occurs in different chromatophores. Complementing the colour pigments are irridocytes, which are best described as tiny reflective spheres within the skin. All the colours presented by koi are a mixture of these components. For

on tinfoil barbs or hatchet fish. If the irridocytes are in the lower layers of the skin the fish have a matte white colour. In certain cases, the irridocytes can combine with the chromatophores to produce reflective colours. Irridocytes

Other varieties

As well as the ‘big three’ Gosanke varieties, there are several more which can still claim huge amounts of money. The price of each koi is highly dependent on the individual. For example, a good-looking Asagi can be more valuable than an average Kohaku. Other highlyprized varieties of koi include:

Tancho Doitsu Ogon

Matsuba Asagi Utsuri

of the skin. The irridocytes interfere with the light to give a blue colour.

The chromatophores may be positioned on the surface of the skin (above the scales), immediately under the scales or deeper in the skin. If the chromatophores are very dense the colour will also appear dense, with the chromatophores on the surface of the skin blocking those below.

The position and density of the chromatophores affects the stability of the colour. The colouration and pattern of koi is known to change significantly as the fish grows, with colour ‘patches’ appearing and or disappearing as the fish ages. The chromatophores on the surface of the skin tend to be less stable due to them being more easily removed (by rubbing against underwater objects) or spreading as the fish ages and grows. Those deep in the skin are more stable and less likely to break up. Prize-winning koi have dense colour pigments in all layers of the skin as this results in both dense and stable colouration.

of chromatophores, with this number remaining relatively constant throughout its life. As the fish ages and grows, these chromatophores must cover a larger area of skin and therefore with some fish, there is a tendency for the colour to become paler (due to the chromatophores becoming less dense) or to fragment. Some young fish appear stunning with intense colouration on their bodies. As they grow bigger, this colouration fades and may disappear. Sourcing young koi from a ‘high quality bloodline’ usually means the keeper is buying fish which are likely to have denser chromatophores, resulting in more stable colouration as they grow. In some koi varieties (eg Showa and Sanke), it is common for the colour patterns to change considerably, with surface colouration fragmenting, revealing a deeper, different colour. Both koi and goldfish tend to become paler as they age. This is a sign of the chromatophores both spreading over the body surface which reveals the paler colour underneath, as well as the cells holding less pigment.

cell with finger like projections, within which the colour pigment can be moved. for the pigment to spread throughout the chromatophore, in which case the cell is the colour of the pigment; and b. for the pigment to be concentrated into one area within the cell, which results in the background colour showing through (usually pale or dark). The distribution of this pigment is affected by several things:

• The nervous system and hormonal system. In some fish species there is evidence that they can control the distribution of pigment in the chromatophores, allowing them to change their colour for camouflage or display.

• Water quality. Different conditions can have a marked impact on the distribution of colour pigment. Raised levels of pollutants such as ammonia, nitrite and chlorine tend to cause the pigment to concentrate, resulting in the fish becoming paler or darker. The pH

and hardness of the water can also have an impact. Black pigment in koi and possibly other fish tends to spread in harder water, making them appear a more intense black colour.

• Background colour. Fish tend to adjust their colour intentionally or unintentionally to be less conspicuous against the background. The flatfish species that live around the British coast are a great example of this, with many adjusting their colour to mimic the substrate. Aquarists who show their fish recognize this and will, where possible, avoid having ‘colourful’ fish in a pale container. Showing the fish against a black background and with dark coloured gravel ensures they look at their optimum.

• Treatments. When added to a pond or aquarium, many medications will result in a noticeable change in the colour of a fish. Adding salt is a good example and, for freshwater fish that can tolerate it, will result in the colouration fading.

DID YOU KNOW

THE MOST EXPENSIVE KOI EVER SOLD

A Kohaku Koi named S Legend fetched an immense $1.8 million after winning the All Japan Show 2017. As a nine-year-old female fish, with impeccable colouration, she is considered to be the most expensive koi ever sold. Her lineage ‘Neo Universe’ has previously won many shows, but as more hobbyists enter the fray, the price of koi continues to rise.

For example, a huge 76cm Showa koi won the All Japan Show in 1976, 1977, 1979 and 1980, making it the champion of all koi. In 1982, at the height of its fame, the fish was sold for ¥17 million (£60,000). Whilst this may still be an eye-watering price for a fish, it is just a fraction of what a multiaward winning koi would fetch today.

• Algae. Koi and goldfish which have lived in an algae rich green pond for some time are usually intensely coloured due in part to the lower light conditions and partly to the impact the algae have on the water.

• Temperature. Koi are usually at their best colour in the autumn and winter when the cold temperature causes the pigment in a chromoatophore to spread throughout the cell. In the middle of summer when temperatures are warmer, the reverse occurs and the fish appear less intensely coloured.

The genetics of any fish plays perhaps the major role in what colour the fish will appear, but there are other variable factors which can have an influence – and which we can adjust. Hopefully this article will have given you some insight into why your koi are the colour that they are – and why that colour can change in some instances.

Natural koi diets

Koi cannot make their own colour pigment so they must consume it in their diet. In the wild, these pigments would originate from eating algae, shrimps, snails, etc. In the confines of an aquarium or pond there is not enough algae or other natural supplies of pigment, so it must be included in the feed. As with all foods, the colour enhancing elements must be high quality to ensure that the pigments are in a form that the koi can absorb. If foods containing colour enhancers are not given, the chromatophores may not be filled with pigment and the koi may look pale or poorly coloured. When the chromatophores are filled with pigment, any excess will circulate through the body before being passed out in the faeces. When strong colour-enhancing foods are fed over a long period, the white colouration of the skin can start to turn pink. If the colour enhancing foods are stopped the white colour will return after a few days.

‘Koi’ is a variety of common carp (Cyprinus carpio) much like those that coarse anglers will fish for here in the UK. In the wild, these fish are opportunists that eat a wide variety of food items. They will consume anything from plants and algae to bacteria-rich sediment, as well as snails, insects and leftover picnics. Carp quickly locate areas where food is abundant. Sometimes this is naturally occurring, such as shallow areas where plants, algae and the associated insects thrive. Or it could be an area where people feed the ducks and the fish have learnt that bread is available

on a regular basis. However, their main diet comprises plant and algae material along with snails and insect larvae. Their intestine is designed for this omnivorous diet, being almost twice as long as their body length, which provides plenty of time to digest fibrous, plant material. Just because carp are opportunists that will eat anything, doesn’t mean that everything is good for them, or should form the basis of a healthy long-term diet.

Koi, like many pond fish, will experience seasonality in their diets. Warmer weather influences their behaviour but also affects the ecosystems beneath the water, changing the abundance of food throughout the year. In a lake, these fish will be found in shallow water in the summer months where there is a high concentration of protein-rich snails, insect larvae and algae. In the winter they may favour deeper water where they concentrate on molluscs, bloodworms and plants. They will consume fish eggs and fry in late spring when other fish (and other koi). However, they are not designed, either internally or externally to be fish eaters.

Koi competitions

Across the world, koi competitions are held annually. The ‘All Japan Koi Show’ is considered the most prestigious in the world, where breeders and hobbyists from across the world display their very best fish. Around 1,500 koi are displayed each year and these will range from tiny 10cm juveniles, right up to 1m long goliaths. Breeders are able to purchase a vat for around £1000 to exhibit their fish which can then be sold to customers. Naturally, some of the larger-scale and most in-demand breeders can spend tens of thousands of pounds entering and displaying their fish. However, it is not uncommon for some fish to be valued at well over one million US dollars.

In the UK, The British Koi Keepers Society is the largest organisation championing all aspects of Nishikigoi. Under the BKKS banner are several individual societies and associations. These are designed to bring hobbyists together to share information and tips on koi maintenance as well as building collections and entering competitions. The National Show is being held on the 2nd and 3rd July near Coventry. Although exhibitor vats cost a much more modest £45-£65 each, judging criteria operates in much the same way as the Japanese shows. There are 15 categories which are more accessible including ‘best newcomer’ and ‘young champion’ but can give new hobbyists an introduction to this competitive aspect of aquaculture.

TitleLOVE IS IN THE AIR

Hand-rearing love birds.

Lovebirds are some of the most appealing of all Psittacine birds. They belong to the Agapornis genus, a group of around nine species of African parrot. As well as having all the key characteristics of larger parrots including beautiful colouration and high intelligence, this group also exhibits many more desirable traits as a pet. Their adorable personalities make them ideal as a companion bird and with recent advancements in hand-rearing, many keepers are choosing to develop their bond right from the egg.

Species of lovebird

There are several species of lovebird which are often kept in captivity. The most popular of these is the rosey-faced lovebird (A. roseicollis). Sometimes referred to as the ‘peach-faced’ lovebird, this species is characterised by its pink face and chest against a uniform green plumage, with blue tail feathers. Males tend to be much more vibrant and slightly smaller than females. The rosey-faced lovebird can be found across Southwest Africa, through Namibia and Angola and typically live in groups of around five to 20 animals. In the wild, this species forms pairs very young, sometimes at just two months of age. Dominant females assume a ‘fluffed’ position to show approval of a male, who will then slide sideways towards her in a process known as ‘sidling’. If she appears receptive, he will sidle closer.

The courtship routine is anthropomorphically intimate and delicate which helped coin the name ‘love’ bird. He will also scratch her head, especially the area closest to the beak in a kissing gesture. Males are extremely attentive,

regularly feeding their partner and bobbing their head to exhibit their feeding behaviour. The rosey-faced lovebird is also a prolific breeder. Although they are generally considered seasonal breeders in the wild, in captivity they can breed year-round. Each ‘season’ four to six eggs are laid (usually a single egg every other day) which hatch after just 23 days of incubation. This, combined with the fact they have been kept in captivity since 1869, means they are well-established in aviculture today.

Selecting a lovebird

As with any pet, there is a lot of responsibility on the keepers’ shoulders when selecting a lovebird. Although not as long-lived as other parrots, these tiny birds can live for up to 15 years in captivity. The keeper must have a strong idea of how they will care for and house the birds before they acquire the animals. For example, keepers will most likely want to train their animals from a young age, whereas

breeders will perhaps have better success with a bird that has had less human interaction. However, all keepers should seriously consider getting more than one lovebird. Even hand-reared companion animals will benefit from being part of a small group.

Teresa Masuet and Xavier Viader have been breeding and handrearing parrots since 1991. Their experience led them to develop their internationally renowned brand Psittacus Foods. “The hand-rearing of psittacine birds is a resource that we currently have at our disposal” explained Teresa. “Although in the

80s and the 90s this was not a risk-free practice, the resources that we have now allow us to tackle it successfully and with excellent results. However, this is a huge responsibility and it is essential that the keeper has the necessary tools and the adequate information to be successful.”

Keepers should ensure that their birds come from healthy breeding pairs to prevent any inherited diseases that might develop later in life. Developing a relationship with a reputable breeder before acquiring the chick is vital. As well as providing healthy animals, this breeder could become a safety

net should the keeper require any unexpected advice. Once a breeder has been chosen, it is important to pick a good quality species-specific hand-rearing formula and familiarise oneself with all the equipment. Keepers should practice making up the formula and cleaning their equipment before they bring the bird home. While there is likely to be unexpected challenges throughout, it is important the keeper is as prepared as possible before they begin caring for the lovebird. The hand-rearing process should begin at around three weeks of age, at which time the lovebird will already have some early feathers.

Love is in the Air

Hand-rearing protocol

The ‘hand-rearing protocol’ requires the keeper to consider adequate temperatures, humidity, container choice, number of feeds per day and the volume of food to be administered. All these elements are closely entwined and can have a direct impact on the development of the bird. Although there are no hard and fast rules and each chick will develop at a slightly different rate. This should be in line with nature, overfeeding will not encourage the bird to develop faster. Here, advice from other breeders and hobbyists can be very helpful and provide some reassurance to new aviculturists.

Teresa explained: “A three-week-old lovebird should be fed three times a day (morning-noon-night). We recommend using a soft latex tube with a rounded tip to administer the formula because it is the safest and cleanest method and lets the keeper know with certainty, the amount of formula consumed. This method is far from being invasive - probing is practical and friendly for everyone involved, humans and parrots. Lovebirds, like other parrots, learn to grasp

and swallow the probe by themselves voluntarily. It is very important that the soft-tube material is natural latex. Other materials harden with time and washing and can be the cause of crop injuries. Keepers should use a soft tube with a rounded tip. Probing prevents the lovebird from getting dirty which stops the feathers from being damaged from constant washing of the plumage. Other, messier methods require this and can cause harm to the bird over time.”

Lovebirds should be fed a ‘Minor’ hand-rearing formula which meets the nutritional requirements of birds that eat seeds, berries, buds and invertebrates. Lovebirds should be fed around 10-16ml of formula per 100g of body weight in each feeding, although different formulas may vary slightly. This is created by mixing lukewarm water with the powder to a concentration of around 20-25%. This will change slightly across species and should be guided by the bird. The keeper should pay very close attention to its development, as opposed to timescales published online. As a rough guide, most hand-reared lovebirds will be less responsive to three meals at around four to five

weeks of age. However, this should be guided by careful observations. Teresa added: “When the bird is no longer gaining weight, the midday meal will be removed and solid adult food will be made available to encourage the chick to start eating on its own. At this time, it is important to offer it a complete food and get the bird used to it from an early age. There are complete foods that guarantee lovebirds’ optimal nutritional care for life.”

Eventually, the young lovebird will be weaned completely from the hand-rearing formula. This usually comes at about six weeks of age. Teresa added: “The morning feeding bout can be eliminated when the lovebird no longer shows interest in the soft tube. He's already eating alone! Despite this, we recommend keeping the night feeding bout for a while. You don't have to worry about calculating how many days you must keep it, let the bird set the pace.” By this point, the lovebird chick should be feathered and beginning to show some exploratory behaviours. “This stage of development is one of the most pleasant moments” added Teresa. “The lovebird is already jumping around and when it sees us appearing with the soft tube, it quickly approaches us ready to receive its nocturnal share. This is an excellent opportunity to use this trick to start the training of this new member of the family.”

Once the baby birds begin developing feathers, they will require an enclosure upgrade. “It is neither necessary nor advisable to keep the feathered lovebirds in the brooder” added Teresa. “If the ambient temperature of the room is between 22-25°C it is enough. Clean room air is preferable to a brooder with overheated animals. This habit of keeping the chicks overheated is always a potential source of trouble.”

“According to the age of the chick, the most suitable container should be selected. In phases in which the chick does not move from the nest, a small container will suffice. Gradually, when it begins to interact with the environment, we recommend using "generous" size containers that allow him to explore the elements that are at his disposal: food, toys, branches for them to climb.” Once acclimatised to room temperature, the keeper can judge when is appropriate to introduce the bird to its adult enclosure. It is important that the keeper provides the most amount of space possible whilst also maintaining high levels of care. For example, an outdoor aviary may be ideal for a pet bird if enough shelter and heating is also available. On the contrary, if a keeper is going to allow their bird to free-fly around the house for several hours a day, an indoor cage might be the better choice.

Socialisation

Hand-rearing, particularly amongst less experienced keepers, generally begins as the bird starts to develop its feathers. This is the common recommended age as it means the lovebird has shared its first neonatal stages of development with its parents and has become imprinted with its species. If they are removed from the nest at this moment, it is vitally important to continue rearing them in contact with other individuals, preferably with members of their own species.

Love is in the Air

A lovebird chick at three days old

Lovebirds chicks at 14 days old

Lovebirds chicks at 17 days old

Love is in the Air

“Coinciding with the feathering stage, is the socialization phase” explained Teresa. “It is at this stage of development when the young parrots learn that the stimuli of their environment is considered "normal". In the absence of being with their parents, who would be their guardians, the other individuals of the same species act as a model. So, let's forget the practice of keeping them locked up in a small facility to facilitate the process of emancipation. We must be aware of the importance of creating a facility in which they can develop their locomotor skills: go up, down and even flutter (or allow them to fly around the house every day).”

“Coexistence with people at this stage will allow them to assume their relationship with humans as something "normal". We should abandon the common idea that for a parrot to be tame it must be raised in isolation. If all companion birds were only allowed contact with humans, this would lead to emotionally unstable and often hyperdependent animals. Lovebirds in nature live in groups and move around together. This social need is indelibly etched in their genes. If we can raise a small group of lovebirds, we will observe that they act in a clique in their movements. If one of them flies away to a far point, soon the rest of the group will fly to him. There is a reason they are called inseparable in many languages! It is very fun to play little flying games with them and teach them, for example, to fly up to our arm in an impeccable formation!”

Lovebirds, being such intelligent animals, can be trained. Handrearing without the appropriate management will not lead to a tamed bird. “Appropriate management“ means teaching the lovebird positive behaviours as it begins to develop its curiosity. Training doesn’t mean to teach it to do tricks. Instead, we should reward certain actions such as going in and out of the cage, responding to calls, approaching the keeper and letting us inspect its body for injuries. At the same time, keepers must ignore undesired behaviours such as biting, being destructive or landing in inappropriate areas (such as people’s heads, or potentially dangerous spots around the house). This is how one establishes a common “communication language” between the parrot and the keeper.

Cage birds should be trained, to allow them to freely fly and gain adequate exercise outside of the cage. Encouraging the bird to return to the cage after a period of freeflight will make this process much less stressful for both the keeper and the bird. Teresa continued: “There are many specific training methods but, in our opinion, the best way to train a lovebird and animals in general

is by operant conditioning, where the consequences of a behaviour determine the probability of it being repeated. Therefore, if a behaviour is followed by positive reinforcement, it will occur more frequently.” Often, providing healthy treats is a great way to train parrots.

Is hand-rearing right for you?

All pet birds demand a huge amount of time and attention. Although the hand-rearing process may be a daunting task for a new keeper, with the right advice and equipment, it can be a very rewarding process. Hand-rearing a bird allows for an easier bond and one which has been built from birth. Although it is possible to tame an already grown-on parrot, this can be much more difficult and requires a lot of patience. Ultimately, anyone looking for a companion bird must be willing to invest lots of time and effort into raising the bird. For some keepers, the hand-rearing process is an easier option that requires lots of knowledge but is less frustrating. For others, a dedicated training regime with an older, juvenile bird is a better option, but is not guaranteed to produce the very best companion animal. It should be considered like buying a young puppy or adopting an older dog. Both can make excellent pets, but the keeper must decide how they want to dedicate most of their time and at which stage of development.

SEEING AMPHIBIANS IN A NEW LIGHT

How biofluorescence is changing our perception of the natural world.

Cranwells Frog (Ceratophrys cranwelli)

Biofluorescence is a natural phenomenon previously thought to be restricted to invertebrates and marine environments. It happens when high-energy wavelength light is absorbed and then re-emitted by a living organism at a lower wavelength, thus resulting in a glowing animal. Although this has been well documented in corals for decades, an accidental discovery in 2015 by David Gruber recorded biofluorescence in a species of marine eel. Since then, several species including hawksbill turtles (Eretmochelys imbricata) were confirmed to biofluoresce. Why? The answer still is not clear. However, a discovery by Drs Jennifer Lamb and Mathew Davis in 2020 gave research legs when they published their findings that most amphibians possess this same ability. Exotics Keeper Magazine caught up with Dr Jennifer Lamb to learn what this means for our understanding of the natural world.

Background and interests

Dr Lamb is a Herpetologist and Professor at St Cloud State University in Minnesota USA. “I grew up overseas but came to the states for college and university” explained Dr Lamb “This is where I was introduced to the idea of teaching and research as a career and the class that actually caught my interest was ‘reproductive ecology’ where we learnt all about how amphibians breed and reproduce and care for young and I thought that was really interesting. I continued at the University of Mississippi for my PhD. I studied the ecology and genetics of a group of salamanders called the lungless salamanders. The lungless salamanders are the most species-rich group of salamanders. Plethodontidae have primarily a holarctic distribution. This region includes North America but also Northern Asia and Europe, although most of the diversity is found in the Southeast United States. I’m a scientist that is really interested in Organismal Biology, so understanding the organisms, how they behave, how they

function and how they interact with their environment and that’s what inspires the questions I like to ask.”

What is biofluorescence?

Many people are aware of the otherworldly abilities of deep-sea creatures to produce light for hunting or communication methods. They are capable of creating enticing light displays in a completely light-less world and this is called bioluminescence. Biofluorescence is a very different process with potentially very different purposes. Dr Lamb added: “The difference kind of boils down to what is generating the light. So, with bioluminescence the organism, either through its own tissues or with symbiotic relationships with bacteria, produces the light. Things like fireflies have chemical reactions in their abdomen that produces

bioluminescence. Or, the angler fish, which is another common example has an esca (protruding dorsal fin) that actually houses symbiotic bacteria. Biofluorescence, on the other hand, is when an organism absorbs light from its environment and then emits that back at a different wavelength. Basically, it is absorbed, changed, then re-emitted so if you remove a light source from a biofluorescent animal it won’t biofluoresce.”

It was previously thought that biofluorescence was restricted to ocean life. Most wavelengths of light are filtered out after around 10m in depth. However, blue light can reach up to 1000m deep into the ocean, so it made sense that oceandwelling lifeforms would surely utilise biofluorescence more than those on land. “The research in marine

environments focuses on fluorescence in response to blue light, because blue light will penetrate much deeper. A lot of the research on terrestrial animals focuses primarily on ultraviolet light but the reality is and what we found is that amphibians will fluoresce from both ultraviolet and blue light.”

The hawksbill turtle discovery was exceptionally important, not just for highlighting the scope of potential research, but for contextualising how little we know about critically endangered species. By seeing the turtle in a new light, the research suggested that the complex glowing patterns may have significant value to the species. Although a finite answer is yet to be uncovered, these applications could include finding a mate, identifying others, traversing the globe and much more.

Biofluorescence in salamanders

Building on this research and delving deeper into pandora’s box, Dr Lamb and Dr Davis attempted to document biofluorescence in amphibians. After discovering this incredible phenomenon in Eastern tiger salamanders (Ambystoma tigrinum), the researchers continued recording more and more instances of biofluorescence in other amphibians. It was previously unheard of that a terrestrial tetrapod would have this remarkable ability and if it did, what other questions would that pose for our understanding of the natural world and evolutionary history? Dr Lamb continued: “Right now we’re at a really early stage in researching biofluorescent animals with vertebrae that we have a lot of questions, but really not a lot of answers. Potential

Dwarf Siren (Pseudobranchus striatus)

Dwarf Siren (Pseudobranchus striatus)

Alpine newt (Ichthyosaura alpestris) Alpine newt (Ichthyosaura alpestris)

avenues for further research include things like the potential role of fluorescence as camouflage and also the potential role of fluorescence in visual signalling or communications. There has been some research with birds that suggest biofluorescence and reflectance together might be important for communication, but we would need to look further into that for reptiles and amphibians.”

As research progressed, the scientists discovered that all species in the study were capable of biofluorescence. “In the paper, we had a little over 30 species, only one caecilian and a handful of frogs. We were able to survey across eight of the 10 families of salamanders, but I expect the remaining two to fluoresce as well. We have found that an organism with bright yellows, oranges, reds or whites, those areas of the skin tends to fluoresce strongly compared to the dark patches. That is, in part due to the pigments in those areas. We’ve begun documenting that those areas that lack white pigments or have lots of melanin, don’t fluoresce as brightly. Tadpoles do fluoresce, but similar patterns apply. So, it’s the light patches on the tadpoles that fluoresce the most. Species within the mole salamander family (Ambystomidae) and the newt family (Salamandridae) fluoresce really brightly. In particular, newts with their bright ventral patterns, fluoresce really

brightly. The ones that fluoresce less brightly are the more drab amphibians such as Amphiuma and Sirens were still fluorescing but it wasn’t as strong.

“There are lots of cool labs doing excellent research, looking into amphibian vision right now. What they’re starting to discover is that some amphibian groups are better able to distinguish between colours in dim-light scenarios than we previously expected. It is feasible that fluorescence could have contributed to speciation through differential communication or signalling. We’re just learning these things about fishes, yet we’ve known about fluorescence in marine environments a lot longer. I anticipate a similar trajectory in understanding these things about tetrapods.”

Implications for conservation

Although it might be some time until we fully understand why each species is capable of glowing with incredible patterns. We can implement this knowledge in our own conservation practices, something which has instantly excited researchers around the world. Dr Lamb continued: “There’s two ways that this kind of research really excites me in terms of conservation. One, which has been picked

“Often our understanding of the world is limited, at least initially, by our own perception” –Dr Jennifer Lamb

Tiger salamander (Ambystoma tigrinum)

up most by herpetologists, after we published our paper about 75-80% of the emails I got were from people who wanted to try using fluorescence as a tool in nocturnal surveys. I think that is potentially promising, especially for really small frogs that are hard to spot in complex microhabitats. Imagine you’re trying to find these tiny frogs, males and females, in grasses that are really hard to see them. If you were to be doing a biofluorescent survey, the plants would be fluorescing red, whereas amphibians tend to show up green. So that contrast between a green frog and a red leaf could be very helpful! Another avenue is just from drawing attention to the group. We tend to allocate funds and effort and public attention when taxa are charismatic and being able to talk about glowing frogs and glowing salamanders just draws them in. From there you can talk about other aspects of conservation.”

Inspiring others to participate in science and conservation is a crucial element of lots of zoological and biological research. This seems to have already happened in many scientific circles across the world as more and more people attempt to document cases of biofluorescence in other species. “There has been a boon in people documenting biofluorescence” added Dr Lamb. “Every month we’re adding new species to the list and that’s really exciting. I’ve seen reports from multiple species of geckos and some species of snakes. There was a really cool paper that came out talking about the tips of the tails of Viperid snakes. They had a neat approach by comparing the fluorescence to the colours we think these tails are mimicking which would be invertebrates such as worms or caterpillars.”

The process

As well as ground-breaking discoveries, documenting biofluorescence also produces some stunning images. Although Dr Lamb’s lab has state of the art equipment that captures crisp photos, the concept is actually very similar to recording the biofluorescence of scorpions, but requires a few extra steps to see the intricate patterns. “We actually use equipment that will be familiar to people who do scuba diving and underwater photography. We’ve known about fluorescence in coral reefs for a long time, so we buy all our equipment from a company that makes all the technology, so the lights, filters, camera equipment etc. You can do it at home though, you can use your phone. You need your excitation light which you shine at your organism, but you’re going to get a lot of that reflected straight back at you, so sometimes that can swamp the fluorescence. That’s why we place what we call a ‘barrier filter’ which is just a piece of plastic that will filter out the light that’s being bounced back at you. That’s why in the images, you’re just seeing that fluoresced light. There are some groups where fluorescence is strong enough that even without a filter you can see what is being fluoresced, but most will require a filter. That’s a major step that people miss when trying to document fluorescence in the field. Because they’re not viewing things through a filter, they are underestimating how much light is actually being fluoresced.”

“UV blacklights are often used to see fluorescence in scorpions and arthropods. It’s likely that these would work on amphibians with a good filter. Assuming that someone has an intense enough blacklight, with the right filter you should be able to see some fluorescence.”

Seeing Amphibians in a New Light

Cranwells Frog (Ceratophrys cranwelli)

The future is bright

As researchers continue to explore these marvels, it is expected that many more interesting discoveries will be uncovered which could pave the way for a variety of new advancements in herpetology. Not only will it help us better document the natural world but could have practical implications for veterinary practice too. Dr Lamb continued: “Since that, my lab has started to investigate individual variation in fluorescence and what might impact that, but we’re working with species that we had already previously identified as fluorescening. Two directions where we’re taking this work is to document variation between sexes and ages in individuals. We’re also documenting how we can use it practically. For example,

keratin-rich areas around the feet of frogs or the mouthparts of tadpoles don’t fluoresce. So we’re hoping we can use this to document potential damage to these areas in animals which may have undergone trauma.”

The study of biofluorescence represents one of the biggest cornerstones in the rise of ‘science’ as a discipline – that some things, we just don’t know. People have been studying amphibians for centuries and with such advanced scientific methods, we know how axolotls (Ambystoma mexicanum) regenerate limbs, how wood frogs (Rana sylvatica) can survive being frozen and even identify locales of subspecies of newly discovered animals in the most remote corners of

the world. Yet adopting a new approach and looking at things differently means that perhaps we know very little about life on earth. It is not until we look at amphibians through an amphibian eye that we can even begin to understand their relationship with the world around us. Dr Lamb concluded: “When we’re making these observations of the natural world, we need to keep our own perceptions in check. We have awesome eyes that can see a lot of wavelengths and pick up lots of details, but the eyes of lots of organisms are extremely variable. We need to keep in mind that the way things look to us, might be how they look to other critters. In reality, what we’ve done is really open up a box of lots of neat natural stories

need investigating.”

that

“When we’re making these observations of the natural world, we need to keep our own perceptions in check. We have awesome eyes that can see a lot of wavelengths and pick up lots of details, but the eyes of lots of organisms are extremely variable. We need to keep in mind that the way things look to us, might be how they look to other critters. In reality, what we’ve done is really open up a box of lots of neat natural stories that need investigating.”

– Dr Jennifer Lamb

KEEPER BASICS: GOING BIOACTIVE

Basics: Going Bioactive

Bioactive setups are characterised by a self-maintaining ecosystem which demands the breakdown of detritus such as animal waste, and in turn, creates fertile soil for plant growth. Despite a surge in popularity in recent years, these enclosures are nothing new. They have been widely used by herpetoculturists for decades before the sterile keeping trends of the 90s and 00s. Nowadays, creating a bioactive enclosure is much less specialist, with dedicated products available in most shops and a whole spectrum of clean up crews to choose from. A basic understanding of the components required to build a bioactive enclosure is required, but once established, they offer a rewarding approach to animal care.

Step 1: Layers

A ‘drainage layer’ is an area at the bottom of the enclosure that can hold water without flooding the substrate. This hidden reservoir of water is important for plant growth and encourages plants to grow their roots downwards in a natural direction. They can be created using a variety of mediums such as clay balls, volcanic substratum, sand or aquarium foam. A drainage medium with lots of holes for beneficial bacteria to grow will help maintain the water quality and prevent any nasty smells, but each medium has its advantages and disadvantages. For example, aquarium foam can be cut into the perfect shape to create pools of water and will host a whole spectrum of aesthetically pleasing mosses. However, clay balls will provide more room to collect water, reducing the frequency that the keeper needs to empty the tank. All drainage mediums should be rinsed with water to allow them to absorb water

and remove any dust or debris. In a tropical enclosure, a deep drainage layer (several inches thick) will add to humidity, particularly if heated with an aquatic heating cable. In arid enclosures, usually hosted in a wooden vivarium, the drainage layer needs to be completely water-tight and only a few centimetres deep. This is usually achieved by using silicon or resin and supported with a plastic sheet to capture all water, as leaks will soon damage the woodwork.

Depending on the drainage layer, the keeper will most likely need to add some fine mesh to stop the substrate from falling into the drainage layer. Some keepers will also add charcoal or slate before adding their substrate. This helps with the gas exchange through wet or damp substrates. By creating pockets of air, it provides a haven for clean up crews and allows easy passage for rooting plants.

Step 2: Substrate and leaf litter

Once the drainage layer has been established and an appropriate barrier has been installed, it’s time to add the substrate. This will vary across species and enclosure set up but must be comprised of several natural components. For example, arid setups may require a mostly sand-based substrate, but soil and coir will assist in plant growth.

Tropical substrates are much more soil-based, but with orchid bark and charcoal to aerate the layer, whilst using moss and coir to retain water. Many keepers will mix their own substrates, but Bio Life Forest and Bio Life Desert are excellent store-bought blends with great component ratios.

A key component that should be used in every tropical set up and should be utilised in many arid setups is leaf litter. All terrestrial rainforest species will encounter leaf litter at some point. It provides microclimates and shelter for small animals, as well as sensory enrichment and burrowing opportunities for larger animals. Leaf litter also

helps provide higher humidity and contributes to a natural looking biome. However, the most important function of leaf litter within a bio-active enclosure is to feed the cleanup crew. Without organic matter for the clean-up crew to feed on, they will soon perish.

Step 3: The clean-up crew

To establish a functioning ecosystem, clean-up crew are required to break down waste to a suitable size for microorganisms to break it down completely. There are a vast array of species that fill this niche, but for beginners springtails (Collembola sp.) and isopods tend to be the go-to. Advanced keepers can utilise millipedes, beetles, earthworms and various other detritivores (waste munchers) to do the job. Some of these species will breed prolifically, consume waste at different rates, or become food for the inhabitants so it’s best to have a bit of experience tending a bioactive setup before these are used.

Springtails (Collembola sp.)

These are tiny hexapods that are found across the world. Collembola is actually one of the ancient lineages, that are no longer considered ‘insects’ and date back almost 400 million years. Because they are found all over the world, they are extremely adaptable and excellent for both tropical and arid setups. They can be cultured within a pot of charcoal and water and provided with grains of dry rice (which then produce mould for the springtails to eat). Of course, if a bioactive set up is healthy with a good amount

Lighting and heating

Lighting and heating are both very important components for any set up. These have been covered in much more depth in past ‘Keeper Basics’, but there are some key considerations when applying them to a bioactive setup. Firstly, plants photosynthesise best under red and blue light, meaning LED lighting is almost essential for good plant growth. UVB and spot bulbs will also naturally dry out an area in the enclosure, so this should be considered when flora is being planted. Heating should always come from above, or, if a heat mat is used, try to install this to the side of the terrarium. A heat mat sitting underneath a drainage layer will not fare well once the drainage layer fills with water. In this instance, heat cables are sometimes installed behind the artificial background to raise ambient temperatures slightly. This will require a good amount of planning before creating the enclosure to ensure the electricals can be changed and replaced if needed.

of leaf litter or fungus, a single colony of springtails should thrive for many generations. A common issue brought up with those new to bioactive setups is the worrisome appearance of fungus or moulds. This is a normal part of the cycle that springtails will quickly take care of. What’s more, mushrooms in the soil are seen as healthy soil indicators and they will die off and break down for your clean-up crew in a short amount of time.

Isopods

There are various genera of isopods readily available as clean up crews but not all will flourish in all environments. They will generally thrive off the detritus build up in the enclosure, but to get isopods extra healthy and breeding, they should be given small amounts of a calcium and protein source. These include high protein vegetables, good quality fish flakes, sheds/waste, and cuttlebone or crushed eggshell 1 – 2X per week. In some cases, the inhabitants will also benefit from these, but for more sensitive species maintaining a separate isopod colony in a plastic terrarium can be an easier option. This prevents them being preyed upon too quickly, as they can be gradually added to the bioactive enclosure.

Clown isopod (Armadillidium klugii)

Clown isopods are easily recognised for their bright markings which are thought to be a form of mimicry of the Mediterranean black widow, to deter predators. They come from the coastal areas along the Adriatic Sea, notably Croatia and Montenegro. They are usually found beneath stones and in crevices, where they seek humidity. That being said, these isopods are generally considered a good all-round generalist species, so long as a humid area is available in your bioactive somewhere – which is usually the case even in an arid setup. They reach a maximum size of 21mm and will eat pretty much any organic material available.

Springtail (Collembola sp.)

Granulated isopod (Armadillidium granulatum)

This species is also a safe choice for almost any bioactive, favouring a 50:50 dry and moist environment. Keeping the humid area of your enclosure maintained will provide a good refuge for these isopods. They don’t like to be too wet, so they likely won’t be ideal for a tropical setup that needs frequent heavy misting. Younger individuals may be eaten by inhabitants, but they are a large species when adults. They also sport quite an appealing colouration of yellow splotches.

Pill isopod (Armadillidium vulgare)

These are the common woodlice we see in Europe and the UK. They are hardy and tolerant of some dry conditions, so they should establish well in a tropical or arid setup as long as conditions aren’t too extreme on either end. While the wild type is a bland slate grey, there are a few colour morphs now available thanks to captive breeding, including red, yellow, albino, “orange dalmatian”, or “magic potion”. Whatever the colour, they will all do the same job in the end.

Dwarf tropical white isopod (Trichorhina tomentosa)

These are usually said to be the most common species chosen for tropical setups with high humidity. Dwarf whites are soft-bodied isopods that do not roll into a ball and reproduce asexually. They are small, but hard workers; efficiently cleaning up detritus from the soil and other areas of the environment. T. tormentosa are most popular for keeping alongside amphibians such as poison frogs.

Giant canyon isopod (Porcellio dilatatus)

These are an excellent choice for arid setups, so long as a small humid retreat is available. P. dilatatus come from Western Europe and North America, and they grow quite

large, owing to their name. They eat organic matter like most other isopod species and reproduce at a moderate rate. They don’t have a flashy appearance but are a good choice for their hardiness in drier setups and affordability.

Speckled isopod (Porcellio scaber) P. scaber is another common species found throughout Europe and with different colour morphs – such as the popular orange and “dalmatian” varieties. These isopods need 70-80% humidity to thrive and therefore will not do well in an arid environment with low humidity levels. They eat and breed well in captivity.

Dairy cow isopod (Porcellio laevis)

The dairy cow isopods are some of the most popular and voracious of all the isopods. They will quickly eat large amounts of detritus, including shed skin, making them ideal for setups with larger inhabitants such as colubrids.

Maintenance

Although bioactive enclosures are supposed to be a self-maintaining ecosystem, there are a few things a keeper should do to ensure they have a healthy enclosure. The most important thing (aside from the general upkeep of the inhabitants) is to keep an eye on waste build up. Sometimes clean up crew cultures can ‘crash’, meaning they are no longer reproducing. This can be combatted by introducing more custodians, commonly referred to as a ‘bio shot’. Of course, plants will need to be watered and pruned depending on the type of set up. Tropical set ups should always have some water in the drainage layer to feed the roots. Increased spraying or pouring water directly into the drainage layer will support this.

FASCINATING FACT

World’s highest reptile

Liolaemus tacnae is a species of ‘tree iguana’ thought to be able to withstand the highest altitudes of any reptile. The Liolaemus genus contains more than 220 species, which are distributed across most of South America. Despite often being referred to as ‘tree iguanas’ they are extremely diverse, with most species living terrestrially. Although another population the Liolaemus were recorded nearby at elevations of around 4000m, L. tacnae has set a new record.

Last year, researchers managed to photograph this species at 5400m elevation, high in the Peruvian Andes. At this elevation, oxygen levels are extremely low, UV is intensely high and temperatures can be unstable, with volatile weather conditions. Zoologists, José Cerdeña and

colleagues photographed the animal on the Chachani volcano which rises to a total of 6,057m above sea level.

At high altitudes, ectotherms are extremely vulnerable to drastic temperature changes. Researchers believe that climate change is likely to have played a major role in the lizards’ ability to colonise previously harsh environments. However, it is not unheard of for lizard species to thrive high in the mountains. Previously, a species of toadheaded agama (Phrynocephalus erythurus) was recorded at 5,300m on the Tibetan Plateau. The new photograph of Liolaemus tacnae has beaten this record by 100m.

View of the new record location, on the route of ascent from 5,000 m to the summit of Chachani mountain, south-western Peru.

ENRICHMENT IDEAS

Turtle enrichment

Novel objects

Turtles are very inquisitive animals and the inclusion of novel objects can provide a lot of fun for both the keeper and the kept. Appropriately sized cork tubes, brightly coloured stones, artificial plants and novelty décor can be introduced periodically and rotated over time. Items that float, such as ping pong balls, are even better. It might be a step away from the natural enrichment they would receive in the wild, but it does provide some excellent mental stimulation. Turtles are not renowned for their problemsolving skills but incorporating a tasty treat into a floating play item is another good idea.

Moving water

More natural enrichment opportunities include pumps and jet streams to add movement to the water. Some filters come equipped with ‘turtle nozzles’ to create a cascade effect. These are simply secured to the side of the tank to create an instant water feature, which turtles will frequently investigate and interact with. Similarly, air stones can be added to oxygenate the water and provide some bubbles for the animal to chase. Jet stream units can be installed within the water to simulate water movement. As most pet turtle species will inhabit ponds or lakes, this unit does not need to create a current, but instead mimic the natural movements of a large body of water.

Live food

Live food is essential for insectivorous (and insect-eating omnivore) species. Even complete turtle pellets, which are renowned for having exceptional nutrient-profiles cannot simulate the movements of live insects. Throwing a few insects into the water will encourage the turtle to chase

Brushes

Tortoise keepers are familiar with ‘brushes’ as enrichment, but these can also be used in turtle tanks. Some bottle brushes with suction cups can be stuck to the glass wall, close to the floating platform to allow the animal to clean itself. Viral videos of turtles rubbing against the brush and shaking their posterior prompted the influx in popularity of this novel idea. Providing the brush does not obstruct the important parts of the setup, this tactile enrichment method (however obscure), certainly appears enjoyable for many pet turtles.

Calcium blocks and cuttlefish bones

The provision of extra calcium is recommended for all turtles and tortoises. Whilst ‘complete’ diets remove the necessity of dusting food items, the addition of a “Dr Turtle Calcium Block” allows turtles to consume extra calcium, whilst also conditioning the water in the enclosure. It is no secret how much tortoises love calci-blocks, but turtles can now sharpen their beaks, gain important nutrients, and interact with these novel items too. For a more traditional and natural-looking method, cuttlefish bones can be used.

Substrate

Substrate also provides vital enrichment amongst its many benefits. Keepers should choose pebbles that are rounded to ensure that the animals do not hurt themselves when swimming. These can be combined with finergrained gravel or riverbed sand to create a natural look. Each species will have slightly different requirements. For example, sand is fundamental to the wellbeing of softshell turtles (Apalone sp.) and beneficial to snake-necked turtles (Chelodina sp.) but is likely to just get messy for musk turtles (Sternotherys sp.) or map turtles (Graptemys sp.), where a

In the wild, many turtle species will spend huge amounts of time basking. They will enter the water to feed and thermoregulate as they see fit. By staggering the lighting to simulate a natural day/night cycle, the turtle can exhibit natural behaviours. For example, gradually turning the room lights, followed by the spot bulb, followed by the T5/ T8 (or whichever combination of electricals fits your turtles’ needs) over the space of an hour, then off again in the opposite order, will simulate the sunrise and sunset. This will give the turtle plenty of opportunities to move between basking and swimming as they would in a normal 24 hour cycle.