Biology Newsletter - Issue 17

Biology Department Newsletter Issue 17: Second half of Spring term, 2021

International Dawn Chorus Day 2021 Who knew?! An entire day dedicated to the celebration of nature’s great symphony. On 2nd May 2021 (get the date in your diary), people around the world will be rising early to listen to the sweet sound of birdsong as the dawn chorus kicks in. From March to July, our songbirds rise before dawn to defend their territories and sing to attract a mate. Robins, great tits, blackbirds and wrens, to name but a few, will all be serenading the females, hoping to win her attention.

The singing starts about an hour before sunrise. Different birds start before others with species such as blackbirds, skylarks and song thrushes getting going the earliest. Smaller birds like the wren and some warblers join the party a little later, possibly because their small size makes them more susceptible to the coldness of dawn. At this time of day the air is still and the sound of the bird song travels further than later on when background noise is more distracting. Another advantage is that the dim light of dawn makes the birds harder to see by their natural predators.

You don’t have to live in the countryside to enjoy the sound of birdsong. Many of our most vocal birds live happily in urban areas so you can still enjoy their singing. So, set your alarm, throw open your window and enjoy nature’s orchestra.

Not sure what you’re listening out for? The RSBP has a helpful bird song ID playlist including many of the common birds that you can expect to find in your local area.

See how many you can learn to identify. Click here to find out more Don’t forget ‘Tweet of the Day’ on BBC Radio 4. Each Tweet of the Day begins with a call or song, followed by a story of fascinating ornithology inspired by the sound. Well worth a few minutes of your time.

Biology Department Newsletter Issue 17: Second half of Spring term, 2021

‘Biology in the News’ with Mrs Oatridge A year without flu. That’s not all good news…

The past year has seen an extraordinarily quiet flu season, but scientists have warned that this may not be as promising as it sounds. In Britain, seasonal flu normally kills between 10,000-30,000 people per year; but flu deaths over the past 12 months have barely registered. This silence is being explained by mask wearing, social distancing, and other measures in place to mitigate COVID-19. While this has helped the health services cope with the current pandemic, it has also reduced immunity levels to flu which could result in an extreme outbreak next season. “We have effectively missed out on flu this winter, so levels of immunity are less than are typical,” says Professor John Edmunds, of the London School of Hygiene & Tropical Medicine. “In fact, it is not impossible that we will have an out-of-season epidemic, perhaps in the autumn rather than winter”. As well as this, this year’s low flu levels have made it harder for epidemiologists to predict the next strain and so develop an effective vaccination.

So, should we brace ourselves for a dramatic resurgence of flu? Or should we continue to social distance and wear masks to prevent it?

The birds that are forgetting their song A critically endangered songbird, the regent honeyeater, is now so threatened that it is losing its song. Songbirds use their song to communicate, find a mate and to establish their territory and young birds learn to sing by listening to older males and repeating their songs.

However, with only 300 individuals spread across a vast area of south-eastern Australia, young males are simply unable to find a male to learn from. An expert in animal communication , Dr Zollinger likened this way of learning to human development: “human children need a rich linguistic experience when young in order to speak fluently as adults". In the absence of males, the young regent honeyeater has begun “learning the songs of other species” with the honeyeater’s natural song “disappearing” in 12% of the population. Conservationists are now using recordings of wild birds to try to teach captive honeyeaters their own song, but whether females will respond to these captive-learnt tunes remains unknown.

Biology Department Newsletter Issue 17: Second half of Spring term, 2021

‘How eggs have evolved to avoid bacterial contamination’

by Mr Glanville From Tim Birkhead’s book ‘The most perfect thing - Inside (and outside) a Bird’s Egg’ Did you know that in the past (1960s) chicken eggs were sometimes stored for up to a year without going off.

Viruses, bacteria and fungi can all potentially invade eggs, but birds have evolved mechanisms to prevent the eggs being infected by microbes. This is especially a problem for water birds that have nests which often get wet and muddy: ideal conditions for microbes.

An egg is a rich source of nutrients but it has no immune system, so it is important that there are mechanisms to prevent it being infected by pathogens. Birds’ eggshells must contain pores to allow oxygen to diffuse into the egg. The eggs must be waterproof but permeable to oxygen, rather like Gortex. The eggs of waterbirds cover the pores with a layer of waterproof spheres that makes the egg waterproof but allows oxygen in.

The inner shell membrane acts as the second line of defence which has a mesh-like structure to catch the microbes.

Possibly the most important adaptation for antibacterial defence is the egg white, albumen. Amazingly, if you leave a blob of egg white in a dish for three months it remains free of bacteria. It was Louis Pasteur who discovered that albumin contained a bacteria-destroying protein called lysozyme. We now know that there are over one hundred antibacterial proteins in albumen.

Albumen contains no nutrients that microbes can feed upon and hence they cannot cross the albumen and reach the nutritious yolk. The albumen is alkaline pH9 or 10 which denatures the enzymes in most microbes.

Why are the eggs of birds that nest in holes usually white?

How is the yolk kept in place? Can you work out how the chalaza keeps the embryo in the centre of the egg even when the egg is turned?

Biology Department Newsletter Issue 17: Second half of Spring term, 2021

‘How to make rubber eggs!’by Mr Glanville Take an egg, a glass and some vinegar (any type will do) Place the egg in the glass and cover with vinegar.

Leave for 3 days.

The shell will dissolve in the acetic acid (vinegar). The egg will be rubbery and larger than when it contained the shell.

Why has the egg increased in size?

‘Springwatch*’ with Mr Coleman It was on the Spring Equinox, Friday March 20th, 2020 that schools across the country closed prior to the first national lockdown. Now that Spring 2021 has sprung (the hours of daylight are longer than 12 hours and the nights shorter), the signs of seasonal change are all around us once again. Small birds are even now crossing the Mediterranean to be with us and they have but one thing on their minds!

If you have access to a garden, park or any green space; why not try to spot some of the harbingers of Spring left…

Write to reply

In response to my previously published article, ‘If a tree falls in the woods and there is no one around, does it make a sound?’, our very own Reverand Brandon has contributed this deep and meaningful philosophical musing…

‘The answer to this question is like parking a car in the lowest storey of a carpark. I cannot see the top storey but that doesn’t mean it doesn’t exist. Many people don’t like car parks. They consider them unsightly. Does this mean they don’t exist or that they should all be turned into candy stores?’

*in meteorological terms, Spring starts on March 1st but astronomically speaking, it started on the Vernal equinox, March 20th. Of course, the natural world does not recognise these specific dates and the signs of seasonal change are all around if you get outside and notice them!

Biology Department Newsletter Issue 17: Second half of Spring term, 2021

‘Springwatch’ with Mr Coleman ‘In the Green’

If in doubt, the soft, outer tissues that were underground will be white so you should see a tiny bit of white peeping above the soil after planting. Leave plenty of room between bulbs for them to form clumps in the future. Let the foliage die back naturally after flowering so the nutrients in the leaves and fading flowers can be transported down into the bulb and stored for next year’s display.

What with the snowdrops and crocuses almost over, now is the best time to plant these bulbs for more early Spring colour next year. Dig up, divide and replant them at their most verdant or simply buy and plant some more of these bulbs to create some delightful patterns in and around your lawn.

Bulbs ‘in the green’ are ones in leaf and growing (before, during or after flowering). Their treatment is different from most spring-flowering bulbs which are planted while dormant in the autumn.

Snowdrops, crocuses and bluebells are among the few species that are best transplanted this way. Bulbs planted in the green establish and flower faster than the same variety planted in autumn. However, because the green parts of the bulb are still photosynthesising, they are delicate and need careful handling.

Plant them in their new location as quickly as possible to about the same depth they were at before lifting (too shallow is better than too deep).

Now it won’t be long until the woodlands are carpeted with one of the natural wonders of late Spring, the Bluebell. Late April to May is usually the best time to see Bluebells as the brightest leaves begin to be seen in the tree canopy above. Traditionally, they grow under Beech trees, but they tend to thrive in forest floor areas of leaf mulch that retain moisture and minerals.

Biology Department Newsletter Issue 17: Second half of Spring term, 2021

‘Springwatch’ with Mr Coleman OED Words of 2020 Continuing with the retrospective and literary theme of this edition of Springwatch, I look back on some of the Oxford English Dictionary’s words of 2020.

Ordinarily, the OED only selects one word to reflect the year’s "ethos, mood, or preoccupations".

However, to sum up last year being… (insert your own word here dear reader) ... a list of over 50 words was compiled to reflect the year gone by and I have chosen a few personal favourites with a scientific connection. Just for fun - can you guess the word from one of its definitions below?

1.

2.

3.

4.

5.

6.

a fire in scrub or a forest, especially one that spreads rapidly. a person who transmits an infectious disease or agent to an unexpectedly or unusually large number of other people. (of a disease) prevalent over a whole country or the world the rarefied gaseous envelope of the sun and other stars the global slowdown of travel and other human activity and the subsequent welcome consequences, such as a decrease in light and noise pollution an extremely ambitious and innovative project.

Bird of the Month - Chiffchaff

The Chiffchaff (Phylloscopus collybita) is a thrilling birdsong to pick out from amongst mature trees as it is normally the first migratory bird to return from overwintering in southern Europe.

These small, olive-coloured warblers sing out their name on warm sunny days and whilst not the most inventive of songs, its two-note refrain tells us that Spring is getting serious. Unlike the similar looking Willow Warbler, Chiffchaff numbers are on the increase as some have started to reside in Southern England and so their simple song is becoming more widely heard. This week in fact, I could hear a distinctive ‘chiff-chaff, chiff-chaff, chiffchaff’ from amongst the trees down on North drive.

Biology Department Newsletter Issue 17: Second half of Spring term, 2021

‘Springwatch’ with Mr Coleman

To help develop your bird identification skills to distinguish between Chiffchaff and Willow Warbler, watch this Natureguides video from the British Ornithology Trust.

The Wildlife Trusts and the RHS set up Wild About Gardens to celebrate wildlife gardening and to encourage people to use their gardens to take action to help support nature. Many of our common garden visitors – including hedgehogs, house sparrows and starlings – are increasingly under threat. This year the focus is on bringing back the beetles!

With over 4,200 species in the UK, beetles range in size, colour and shape but all have biting or chewing mouthparts and hardened wing cases with wings folded beneath. Around 1,000 beetle species rely on trees and woodland habitats, from decaying wood to breed in, to carrion to feed on.

Beetles play a vital part in any wildlife garden. They will munch on garden insects like aphids and snails, whilst acting as food for our larger garden visitors such as hedgehogs and birds. Unfortunately, beetle populations are threatened by things like pesticides, habitat loss and climate change - but you can help by burying a bucket for a beetle!

Take a plastic bucket, make some holes in the sides, and fill it with a mix of woodchips and soil. Leave it in peace and remember to top up the soil every now and then. It will be more than just beetles who take advantage of a home like this – plenty of other insects will love it too.

Answers: 1. Bushfire, 2. Superspreader, 3. Pandemic, 4. Corona, 5. Anthropause, 6. Moonshot

Biology Department Newsletter Issue 17: Second half of Spring term, 2021

‘Galivanting Gauntlett: The bats of Battambang’ with Mr Gauntlett In a new series of articles, our very own Mr Gauntlett will regale us with tales of his recent travels. I have decided to name this column ‘Galivanting Gauntlett’! – The Editor I have been fortunate enough to observe all manner of interesting wildlife on my travels around the world, but one of the most impressive things that I’ve witnessed was in Cambodia. In November 2019, I visited the small city of Battambang in the north west of the country in search of bats. I’d heard about a spectacle involving these animals from fellow travellers a week or so earlier. I arrived after a slightly stressful nine-hour journey, on a rather rickety old bus, weary and feeling lucky to have made it there alive. On the way from the bus depot into town, I made friends with my tuk tuk driver, Polo, who agreed to take me to see the bats that afternoon.

Later that day Polo picked me up and we drove out of town to a large rocky outcrop called Phnom Sampeou that rose from the jungle. This rocky hill contained a network of caves which housed the bats I was after. Having spent some time climbing to the top and making friends with some monkeys, I returned to the road where Polo picked me up in his tuk tuk and whisked me off down a bumpy side road telling me we had to hurry. After just a few minutes he pulled over abruptly and he instructed me to climb up a steep bank onto some rocks where a small handful of fellow bat enthusiasts had gathered.

I wasn’t entirely sure what to expect, but the sense of excitement and anticipation was palpable. The sun was setting over the jungle, slowly making its way towards the horizon and a picture-perfect sunset was taking shape. A faint mist was rising from the trees and the distant mountains formed silhouettes in the fading light. The scene reminded me somewhat of watching a winter sunset from the staff room balcony at the end of the school day, only this time it was the gentle hum of the jungle I could hear and not the sound of the speaking clock on loudspeaker.

Biology Department Newsletter Issue 17: Second half of Spring term, 2021

‘Galivanting Gauntlett: The bats of Battambang’ with Mr Gauntlett We waited. After a while, amongst the quiet chatter there were one or two gasps as a few bats suddenly flew overhead, circling once or twice as if to check for the all-clear before fluttering off into the distance. And then, within a moment or two, what can only be described as an eruption of bats came pouring out from the hill side. The small cave opening was only a little further up from where I stood. The torrent of bats snaked off into the distance above the jungle for as far as the eye can see forming what looked like an ethereal black smoke trail, continuously shape shifting and dancing its way through the air.

Not being much of a wordsmith, it is hard to convey quite how impressive a sight this was, but I hope the photos give some impression.

Besides the visual spectacle, what was really impressive was the sheer number of bats.

They leave the cave at a rate of what appears to be hundreds a second and a continuous stream emerges from the caves for over an hour. It was hard to get an exact number, and I'm not sure that anyone precisely knows, but it’s thought that between 10 and 30 million bats that leave the caves every evening.

Where do they go? Well, not all to the same place. Many head for a large lake around 10 miles away where they feed on the many insects flying close to the water’s surface, and others will spread out into the surround areas some travelling as far as 30 miles away.

They feed all through the night before returning to the caves in a similar fashion at dawn.

These particular bats are Wrinkle-lipped free tail bats (try saying that after a shandy) and are about the size of your hand. They are found in many parts of Asia and are named as such for obvious reasons. I was actually told they are considered local delicacy and are often trapped, and then used to make a ‘tasty soup’. Not something I tried, nor would I recommend given recent events.

Bat portrait pic is © Merlin Tuttle

Biology Department Newsletter Issue 17: Second half of Spring term, 2021

‘Galivanting Gauntlett: The bats of Battambang’ with Mr Gauntlett The entrances to the caves are carefully guarded. Not to protect the inhabitants, but to prevent people getting to the precious commodity that is found within. Not precious metals, but guano (faeces). It turns out that bat poo makes a very effective manure that can fetch a good price for the locals who venture in to retrieve it. You’ll have to use your imagination but just consider for a moment how much faeces 30 million bats produce. I was told the man who guards the caves is a very wealthy person.

It’s precisely these kinds of practices however, that increase the risk of the Zoonotic diseases (diseases transmitted from animals to humans) occurring. Something that has been highlighted by the current pandemic. As human populations have grown, they have increasingly come into closer contact with animal species that they previously may not have encountered. This only increases the chances of that further diseases emerging in the future.

So, if you do ever find yourself in Cambodia and want to see something truly spectacular then I highly recommend going to watch the bats of Battambang…. but don’t eat them!

‘Grow your own vegetables’ with Mrs Shiradski Now is the perfect time to decide what fruit or vegetables you would like to grow as the frost is hopefully over and we can see buds on the trees! Growing your own vegetables from seed is immensely rewarding as you can eat the fruits of your labour.

Step 1: Obtain seeds either by going to a supermarket, gardening centre or from online.

Remember to look at what time of the year the seeds should be sown and whether they should be kept indoors or outdoors. An alternative is to be creative and use the seeds that you already have in your house: seeds from a tomato - carefully scoop them out from the tomato and put them on damp kitchen paper so they can start to germinate or put them straight into a pot of compost on your windowsill.

Biology Department Newsletter Issue 17: Second half of Spring term, 2021

‘Grow your own vegetables’ with Mrs Shiradski Step 2: Plant seeds - arrange some small pots, yoghurt pots work well. Fill with compost and plant the seeds according to the instructions on the packet. If you are using beans from the kitchen cupboard then plant them approx. 1 cm below the top of the soil.

If the seeds are smaller then they should be closer to the surface.

Interesting fact: The seed contains a store of energy as starch in its cotyledon, the endosperm.

When the conditions are right for germination (warmth and moisture both needed for enzyme activity) the seeds will germinate using their food store to grow until the leaves are produced above ground. Only then will the plant be able to photosynthesis and make its own food.

As we approach April, it is a good time to sow cucumber seeds as well as tomatoes, courgettes and herbs in pots on the windowsills. When they get large enough to handle, put the pots outside to ‘harden off’ before planting them in the garden in your own vegetable plot. When the frost is over, plant your carrot seeds in thin rows – they will grow in the ground outside straight away. You just need to rake some soil over the carrot seeds for them to grow, as well as water them well.

Don’t forget Gardener’s World with Monty Don is back on again on Friday evening on BBC2!

Year 9’s half term project was to plant some seeds in a pot indoors and identify the stages of germination. Alex (9C1) wrote in with the following: ‘After I saw that my plant’s leaves go up during the daytime and go down during the night, I decided to create a time-lapse of the bean growing over 2.5 days, setting a camera to take a photo every 2 minutes and compressing the result into a video’. Watch here to see his stunning result! If you are equally inspired, do send your pictures/videos of your germinating or growing plants to your biology teacher!