HOW TO TRAIN YOUR DRAGON

An inside look at the training methods used by Chester Zoo.

Komodo dragons can be some of the most ferocious reptiles on the planet. As apex predators capable of hunting water buffalo, working with these animals can be challenging. We spoke to Matt Cook, Lead Keeper of Reptiles and Amphibians at Chester Zoo about how experts at the zoo train komodo dragons.

Life will find a way

Komodo Dragons are fierce Varanids from East Indonesia. These giant lizards inhabit the islands of Flores, Rinca and Komodo (as well as a few small neighbouring islands). Throughout the years, scientists have made countless discoveries relating to the dragon’s natural history. From misconceptions around their hunting techniques and venom glands, to better understanding their habitat requirements and distribution. Much of these breakthroughs were the result of collaborative efforts between zoos and local rangers in these extremely remote areas.

Matt Cook is the lead keeper of the komodo dragons at Chester Zoo. He has completed various field work projects across Komodo and Flores, most recently supporting projects which outlined the Komodo Dragons natural distribution. “Working with Komodo Dragons is a privilege” explained Matt. “I’ve worked with numerous Varanids but Komodo Dragons are so unique in how they move, the way they look and their characteristics. Even the Salvador monitors (Varanus salvadorii) in Papua New Guinea are beautiful animals with a similar appearance, they’re huge, but they’re not Komodo Dragons.”

The temperament of Komodo Dragons both in captivity and in the wild can be somewhat misleading. Tourists visiting Komodo have returned with anecdotes of lazy, unthreatening animals. Some international zoos also walk their dragons around the park, to get closer to visitors. Yet, zoologists throughout the centuries have reported violent aggression particularly around breeding season. Both narratives seem true, and Chester Zoo chooses not to take any chances. Matt continued: “Dragons are very calm a lot of the time but it’s when they turn into feed mode that they turn into a genuine threat to humans. You would never want to be in a situation where a dragon could mistake a human for food. For this reason, we don’t use contact when working with komodo dragons. One weird smell, one weird movement or one weird sight such as gloves etc can cause the dragon to associate it with food, and that can be dangerous.”

With most reptiles in the herpetoculture hobby posing very little risk to humans, it’s easy to underestimate the day-to-day tasks involved in caring for an apex predator. Therefore, training is crucial to allow keepers to manage their animals in the safest and most stress-free situation for both the animal and keeper.

Training methods

Various training techniques are used in zoos across the world for animals for a huge range of taxa. Some private keepers also try to implement many of these target training practices with their own animals, particularly the large clever ones, such as monitor lizards.

“Training dragons is not unlike training a lot of our other animals” explained Matt. “Komodo dragons will respond really well to training as they’re an intelligent animal. The best advice I can give is to keep it basic. Most of the training we do is target training or using a sound.”

“If you can get a dragon to stay still, that’s exactly what you want. So, for x-rays, weighing, any data collection on the animal, you’ll want it to station in an area. This can be done with a target, which is what we’re doing with the komodo dragons here at Chester Zoo.”

“It is just about associating the target with food. Just a yellow ball on the end of a stick, then click, reward, click, reward, click, reward.

The idea is that the animal pairs up the target with food. Obviously, dragons are a little different with their feeding habits. If a dragon’s really full and it’s eaten well, it won’t respond particularly well to a little treat. When I say little, I mean tiny. However, dragons are scavengers. When you see a giant animal in the wild turning its huge head to pick up a tiny bit of meat, you know you’re dealing with a scavenger. This can make things easier for us when it comes to training, compared to other animals that won’t respond to small items at all.”

Training Varanids

For private keepers, training their own Varanids can be challenging. Naturally, the physical resources of private keepers can be much more limited than those in zoos. For example, even the largest enclosures are unlikely to provide enough space for a keeper to stand within, but that is not to say that training is impossible.

Matt continued: “There is use for training Varanids. It’s a little trickier as you need to use a lot of space and I wouldn’t encourage anyone to just do it without thinking it through as you can develop bad habits and you can put yourself in a worse situation.

“Obviously, if you’re starting to build a feed and training response with your target and your animal is loose with you, the worst thing you can do is not realise that the animal doesn’t understand that the target is where you want it to go. You might think it’s coming to the target but it’s actually coming to you, so it could think you’re the target, and if it thinks you’re the food you can put yourself in a dangerous position. Even the smaller Varanids can give a nasty bite. Keepers often feed with tongs, so it might have already associated the keeper with food, but you really want to give a bit of distance between yourself and the target to make sure the target is the focus of attention.”

Target training is certainly the most widely used training methods for reptiles and possibly a good start for keepers of Varanids to experiment with. However, anyone aiming to train their own Varanids can find that it could be detrimental to the keeper/ animal relationship without prior research. Just like the training methods of dogs, if mistakes are made early on and continually reinforced, the animal will not behave in the desired way.

Matt told us some of his top tips for anyone aiming to train their own monitor lizards: “Firstly, you want to distance yourself away. For some of the really small dragons we have a huge pole, made from a lot of piping with a yellow ball on the end. That helps the animal go towards the target, you need to give the animal some leeway.”

“The other mistake I see is when people hold the target out and also has a pair of tongs with the food. Although they look very different to you, to a monitor lizard it doesn’t look all that different. You’re not making it easy for the animal.”

“I would urge caution when it comes to training and maybe even learn a bit from dog trainers, even just the principals. It’s about positive reinforcement, ignoring the negative responses, eventually the animal will pick up on what it’s supposed to do, but the best tip is to make it easy for the animal. When we first started, we used a target and then threw the food, so there was no connection to the keeper.”

Komodos in captivity

The first Komodo dragons to be exhibited in a zoo were a pair on display at London Zoo’s Reptile House in 1927. Since then, various collections have exhibited these animals in a bid to inspire people of all ages and interests to care for and understand reptiles. Having bred successfully in captivity now for many decades, Komodo Dragons are increasingly popular in zoos across the world.

Many people do question why the animals in zoos typically look much smaller than their wild counterparts. Though extensive DNA analysis and research has not taken place yet, experts are beginning to theorise their own ideas.

Water buffalo and deer were introduced to the islands of Komodo and Rinca by early Dutch settlers for farming and agriculture. These large prey items required an equally large predator to hunt them and thus natural selection may have swayed the survival odds in favour of the largest dragons. However, the animals on Flores are typically smaller and leaner, as their largest prey items are fruit bats and arboreal mammals. Eventually this could have created contrasting morphological differences between the two. As Flores is the largest of the islands with much better infrastructure, it is thought that the dragons that first entered zoos were possibly sourced from this locale. Although none of this theory has been scientifically documented or published and researchers have confirmed that all locales belong to the same nominate species Varanus komodoensis, it is an interesting and little-known theory about Komodo dragon adaptability.

Threats facing dragons

This year, the Komodo Dragon was recategorized as ‘Endangered’ after more than 20 years of the species being considered ‘Threatened’. This poignant chapter was marked by the IUCN at the World Conservation Congress in September 2021. Research suggests that rising sea levels are a major threat to the dragons who only inhabit islands at low elevation. This is also paired with habitat fragmentation due to agriculture which is in-turn affecting the genetic diversity of these already extremely limited populations.

Although the remoteness and limited range of the Komodo dragon makes it much more vulnerable than widespread species, it also means conservation efforts can be concentrated on the individual communities that can protect the dragons. “All zoos that manage dragons are working under the same breeding programme” explained Matt.

“Obviously each zoo can manage komodo dragons in their care how they like to an extent, but everyone is working together and collaborating. One of those collaborations is funding so everybody is putting money together per year that goes directly to the Komodo Survival Programme. Having dragons in zoos is directly funding the conservation work in Indonesia, which is incredible. It doesn’t work like that with every species, but the money from Komodo Dragons is literally impacting the wild populations. Anyone who loves animals should want to see them here long term and the work that zoos do impacts on their numbers. Not just their numbers, but their habitats and the people. The people that live on Komodo and Flores don’t have a vast income as it’s not a hugely wealthy country, and, in the past, they have exploited dragons. Their farming is hugely important to their livelihoods, but dragons do eat their livestock, and that’s a massive problem for them. You can’t just tell them to look after the dragons after the equivalent to a burglar has just come in and stolen their livestock. So, the Komodo Survival Programme helps the local people create other ways to build income. One of them is eco-tourism, another is creating wooden dragons, there’s snorkelling and guides etc. They’re all trying to generate money for these people and if the people that live alongside dragons care about them, that’s going to help protect them. By generating that income, we protect the entire ecosystem in that part of Indonesia.”

For more information on how Chester Zoo keep their Komodo Dragons, a video interview and enclosure tour with Matt Cook can be found on the Exotics Keeper YouTube Channel.

Hogging The Limelight

Is this the world’s most charismatic snake?

It is impossible to turn your nose up at the downright adorable face of a hognose snake. Their timid nature and dramatic personalities make them one of the most appealing groups of snakes for people to keep. Combined with straightforward care requirements and a rich scene of morph breeding, the hognose snakes are responsible for a whole sector of exotics keeping, brimming with passionate hobbyists and doting pet owners alike.

Species spectrum

The term ‘hognose snake’ refers to thirteen species from three separate genera of snakes, all with upturned noses designed for burrowing and all rear fanged. However, these genera are widespread across three separate continents; Heterodon are from North America and contain the most popular species within the hobby, Xenodon (formerly Lystrophis) are much less popular in the hobby and widespread across South America and Leioheterodon are found in Madagascar with very small amounts in captivity.

The western hognose snake (Heterodon nasicus) is by far the most popular. Being a terrestrial, burrowing snake that stays relatively small and has a “showy” yet docile temperament, the western hognose has become a very popular pet. As such, dedicated breeders have discovered many co-dominant genes, the most popular of which are the ‘anaconda’ and ‘arctic’ variants, but also include a handful of others. There are also further dominant forms, which combine to produce incredible morphs. This has created a rich network of professional breeders and subsequent resources for first-time keepers which has accelerated the popularity of these animals in captivity.

Devonshire hognoses

Emily Reed is a hognose snake breeder and runs Devonshire Hognoses. After finishing her course in Zoology with Herpetology at Bangor University, she embarked on a hognose breeding project. Emily keeps 5 species of hognose snake, spanning two of the three genera. This year she has successfully hatched 54 eggs. She shared some of her young snakes at the Doncaster IHS Show in September. “It’s the attitude and the wide range of morph combinations that I love” explained Emily.

One defining feature for hognose snakes, particularly “Westerns” is their charismatic behaviour. As a snake that will often ‘feign death’ in the wild, their defensive strategy is extremely submissive. They will sometimes puff out their necks to appear bigger and even ‘fake strike’ despite rarely being able to latch onto the handler.

Emily added: “Although some of them don’t have it, a lot of them do. My Mexican hognose is 100% sassy, she’ll never change. They cobra up and fake strike and it’s so cute. I find myself doing baby talk when they do it. When I was at the end of my first year, me and my friend had a plan that she would buy a female and I would buy the male. I kind of just got carried away from there and now I have loads!”

Heterodon husbandry

Hognoses in the Heterodon genus are very hardy animals. They will typically awake from brumation in early spring in relatively cool temperatures around 20°C, but with low lying vegetation and open areas of hard soil, the ground temperatures will be much hotter, well up to 26°C. Throughout summer these ambient temperatures reach upwards of 30°C, with ground temperatures even hotter.

Recent research suggests that western hognose snakes adapt their behaviour as temperatures increase. They will leave the hot prairies they usually inhabit and instead visit wetland environments where it’s cooler and where they switch their diet from rodents to amphibians. Keepers should understand during the hottest summer months is when hognose snakes are at their most fussy. This could be attributed to a shift in natural diets in the wild.

Emily continued: “Westerns are the top ones to keep. I don’t personally keep any Easterns, because although they are brilliant once you get them onto mice, their diet is really comprised of frogs, which is difficult to find in the UK. While they are beautiful, breeding them can be a complete pain!

The Westerns, on the other hand, you can try all kinds of fish to help scent the food. Anything from trout, whitebait, salmon and I’ve even heard people use hot dogs! With all hoggies, once they’re on certain categorise hognoses as ‘intermediate’ level snakes. However, Emily disagrees as she claims “In my own opinion, any animal can be a starter animal as long as you have done all the research.”

“The best advice I could really give is to talk to the breeder you’re getting the snake from. Although shops are great, the person that bred the snake will know if the animal goes because hopefully that breeder will want the animal to be cared for in the best way possible.”

There are lots of ways to keep a Western hognose successfully. The biggest challenges tend to arise when caring for a youngster, but this can also be the most rewarding time to get to know the snake. While Exotics

Keeper Magazine always recommends going for the largest sized enclosure possible, young snakes (particularly hognoses) can benefit from a smaller, easier to manage environment.

Emily continued: “If someone is looking to buy a baby, I would first recommend that they recreate the enclosure that they are in now. So, my babies are currently in 1.3 litre Braplast tubs. Then I use tealight holders as a water bowl and a heat mat with thermostat. A thermostat is a big thing! A lot of people won’t check that the new owner has a thermostat. You want it between 31 and 33 degrees. Any colder and they won’t eat, any hotter and it could cause burns.”

Once the animal reaches a suitable size and is feeding well, the keeper can find great enjoyment in setting up a naturalistic vivarium for their animal. Keepers should pick an enclosure that holds heat efficiently but also facilitates a deep layer of substrate which will allow the snake to burrow and provide greater enrichment. Ultimately, the snake should have plenty of space to explore the enclosure and should be provided with the best burrowing opportunities possible.

Feeding schedules for hognoses can be dependent on the animal and the keeper should feed each animal on a case-by-case basis. “My juveniles and adults are once every 7 days, unless the females have just laid eggs then I feed them a smaller meal once every 4-5 days to build their weight back up” explained Emily. “My biggest girl eats large mice normally or mediums once she lays. The size can depend as I have small females and big females, so anything from small mice to large mice. The males, it’s between a Hopper or small mice to get their animals feeding, it is possible to provide a varied diet too. Although it is not easy to source frogs and toads, it is possible to buy frogs legs, quail eggs and whole fish which can be fed as a supplementary food to provide a varied diet. As with all species, providing as much variation to the lives and diets of captive animals as possible is a great way to ensure high standards of animal welfare.

Being a diurnal species, hognose snakes should be kept with UV and a basking lamp. For breeders working with many animals and often temporarily, this can sometimes prove challenging to facilitate. Although in the wild they will spend much of their time in burrows, they do hunt for prey above the ground during the day. Providing Ferguson Zone 2 (UVI 0.7-1.1) lighting is crucial to ensuring they have good circadian rhythms and mimics the wild conditions they would usually experience. Young snakes should ideally be moved into a large enclosure, fitted with appropriate lighting as soon as the keeper is confident that the animal is healthy and feeding properly.

The final consideration for husbandry, which may be slightly more complex than other more popular snake species is brumation. All species of Heterodon will enter a state of brumation as the winter arrives. Across their natural range temperatures will drop remarkably low. In the wild, Western hognoses will typically enter brumation for around three months, whilst Southern (Heterodon simus), Eastern (Heterodon platyrhinos) and Mexican hognoses (Heterodon kennerlyi) will experience a shorter brumation (around 2 months). While there are many ways to simulate this period, Emily uses her own house conditions to her advantage, encouraging brumation alongside the natural

Venomous and poisonous?

Funnily enough, one of the most docile and timid snakes on the planet is both venomous and possibly poisonous. Their diet in the wild consists heavily of toxin-ridden toads as well as other amphibians. Whether they can retain this poison efficiently for a long period is yet to be discovered, but this diet likely influences the defensive ‘feigning death’ smell that hognose snakes use to deter predators.

Hognoses are also mildly venomous. They are opisthoglyphous, which essentially means ‘rear-fanged’. Just like mangrove snakes (Boiga dendrophilia), false water cobras (Hydrodynastes gigas) and a few other species, hognose snakes are required to chew on their prey to push their toxic saliva from their duvernoys glands, down grooves in their teeth and into the prey. This explains largely why hognose snakes are such fussy eaters in captivity. Their highly specialised hunting methods are adapted for a diet of toads. Once a toad is caught by the snake, it will instantly puff up to avoid being eaten, consequently puncturing itself with the hognose’s rear fangs. Even though their toxic saliva may be adapted to amphibians, in the wild these snakes will still eat rodents, small birds and eggs.

Hognoses also have a list of defence mechanisms that make them such charismatic snakes. Emily added: “At first, it’s going to be scary if they’re hissing and fake striking but once you know they’re not going to bite you, you can just pick them up. Babies are more likely to musk on you and that does stink, but the adults really don’t do it. A few of my animals think it’s always feeding time, but it’s just about knowing the individual. Some people ask what the temperament of a baby snake is, but they all have good days and bad days, so it really is about getting to know them. Some of my loudest snakes are also the easiest to handle, I just pick them up, which people find strange when they’re hissing at me. As soon as they’re in my hands though, they really calm down.”

“Of course, if you give the snake the opportunity to bite properly, people do get bitten. I had a female named Red who properly chewed on me, but I had no reaction which was nice. It’s not the first time I’ve been bitten, it’s actually quite funny to watch. I do have some people who ask me about bites. I would say just take off any jewellery and keep an eye on any swelling, it’s rare that there are any ill effects.”

Just like any venom, hognose snake bites can cause an allergic reaction. These bites can be likened to bee stings. Even though most people will be absolutely fine, individuals who are prone to allergic reactions from bites and stings should avoid keeping all rear-fanged snakes.

Breeding hognoses

Western hognose snakes have had a firm hold on the herpetoculture hobby in recent years. With variable colours and a rich morph market forming, breeders are continuing to produce unique animals. This often gives already passionate individuals further incentive to dedicate so much time and resources into captive breeding. With new VAT costs impacting exports from Europe, ensuring the UK has enough breeders to meet the demand for hognose snakes in the UK is more important than ever. However, responsible breeding is paramount to ensure that welfare standards are met.

Emily added: “My favourite morph for the Westerns is the super arctics. In hognoses there’s one gene that can be lethal and that’s the recessive pink pastel albino gene, so you do need to be responsible with breeding. I have two of these myself and so far, they haven’t shown any neurological issues, but of course you can’t breed a visual to a visual with those because when they come out, they can have serious problems.”

“I started off with the lower cost morphs like the anaconda and the albino genes. While most hognose genes are recessive there are only a handful of co-dominant genes. The most popular are the arctic and anaconda forms. So, you need to play the long game and work with your hets.

As well as commercial breeding, Emily is embarking on a breeding project which may benefit research and conservation in the future. The Malagasy giant hognose (Leioheterodon madagascariensis) is one of three species native to Madagascar. Shrouded in superstition throughout its native range, it is not well documented and rarely bred in captivity. Although several zoos now exhibit these animals, Emily is hoping to breed this species next year.

Emily concluded: “Giants are very heavy breathing animals, when you have them out it sounds like they’re hissing which can be intimidating but they’re actually just breathing. My giants are in 5 ft tanks (1.5 X 2 width and height). For a giant burrowing species, you’d be surprised how much they climb! Soon I will be adding UV to their enclosures, but this will be after brumation this year. I have tried my giants on sand and topsoil. Even though it was a natural look, it was hard to find their poo and clean, so I put them back onto lignocel. When they were on the topsoil sand mix, I would spray them once a week. Now, I just spray the cork bark to stop the lignocel bunching up.”

EK experts

Our resident Madagascar Expert and Herpetologist, Aimee Jones has worked with Malagasy giant hognoses (Leioheterodon madagascariensis) in the wild. She writes:

Leioheterodon madagascariensis, the Malagasy giant hognose, is a real joy to see in its natural habitat. The largest of the three Malagasy species reaching 1.51.8 metres, the giant hognose stands out due to its striking black shaded colouring with yellow contrasting markings. This coloration is surprisingly good at breaking up the snake’s outline in dark leaflitter.

We commonly encountered this species emerging to bask when the sun had been up for a few hours in the morning. They emerge from covered refugia such as natural burrows beneath trees and thick foliage or holes in the ground. They are quite widespread in Madagascar, even settling on the smaller islands such as Nosy Be. Individuals in the Mahamavo region aren’t afraid to live near human settlements and this may unfortunately also fuel some human/snake conflict.

Like many snakes, they will act opportunistically and eat eggs if given the chance. Many Malagasy