Biology Department Newsletter Issue 20: Autumn term, 2021
‘The Birds of Christmas’ with Mr Glanville Did you know that there are a total of 184 birds in ‘The Twelve Days of Christmas’? Six different species are represented, and whilst we are all pretty familiar with geese and swans, we might be less aware about the others. A Partridge in a Pear Tree
Red-legged partridge (Alectoris rufa)
There are 2 species of partridge in the UK: the grey partridge (Perdix Perdix) and the red-legged partridge (Alectoris rufa). Partridges are small game birds and are members of the pheasant family. Although the grey partridge does fly, it is strictly a ground bird whereas the red-legged partridge is known to roost in orchards, making it the most likely contender for the true love’s first gift!
Two turtle doves Turtle doves are only summer visitors to the UK and their population has undergone a huge 98% population decline since 1970. There are now less than a thousand pairs breeding in the UK. This decline is believed to be due to habitat loss, hunting pressure during the migration, especially on Mediterranean islands including Malta, and lack of food including weed seeds during the breeding season. Four Calling birds Three French hens There are lots of French chicken breeds. One of the most distinct is the Houdan.
The calling birds are “colly” birds in the original version of the song. Colly (or collie) is from “colliery,” an Old English word for coal mines. It was also used when referring to blackbirds, as in “black like coal.” Blackbirds are common woodland and garden birds in the UK and on the continent, where they are known as the black thrush. At Habs blackbirds are common throughout the school grounds but they tend to be fairly inconspicuous. The male bird is black whilst the female is mainly brown. Many people think that the blackbird has one of the most beautiful songs of all the British birds. Blackbirds are one of the only native birds that feeds regularly on earthworms. Many of the Blackbirds that are found in the winter in the UK have migrated from the continent to avoid the colder weather.
‘The Birds of Christmas’ with Mr Glanville Six geese-a-Laying All domestic geese are domesticated from the greylag goose. There are wild greylag geese in Scotland but the majority of the greylag geese in the UK are descended from a feral population and do not migrate.
Seven Swans a Swimming There are three species of swan native to the UK. Only the Mute swan is resident, the other two species migrate to the UK for the winter to avoid the cold weather of the near Artic, which is where they breed. Aristotle, Plato and Socrates all believed that swans’ singing prowess was heightened as death approaches, giving rise to the idea of the swan song, or the final performance. Swans and the Queen During the Middle Ages, the mute swan was considered to be a valuable commodity and was regularly traded between noblemen. The owners of swans were duty-bound to mark their property by way of a succession of unique nicks in the beaks of their birds. It was the duty of the Royal Swanmaster to organise the annual swan-upping, a tradition that survives to this day.
The role of swan-upping was to round up unmarked cygnets and once the parentage of the cygnets had been established to the Swanmaster's satisfaction, the birds could be marked appropriately and returned to the wild. The ceremony exists these days in a largely symbolic form, although as an exercise it is useful in monitoring the condition and number of swans on the Thames. The only two companies that still observe the tradition of owning swans on the Thames are the Worshipful Companies of Vintners and Dyers. The Royal swans are no longer marked, but an unmarked mute swan on the Thames is regarded as belonging to the Queen by default. The Queen still maintains an officially appointed Swan Keeper, and the ceremony still takes place on the Monday of the third week in July.
‘Looking after wildlife this winter’ with Dr Randall We all struggle a bit when the weather gets darker and colder and most of us would prefer the spend the day snuggled up in a onesie, keeping warm. Our wildlife friends, however, don’t have this luxury so it is up to us to see if we can make this time of year more comfortable for them. See below how you can give wildlife a helping hard Feeding the birds
Help the squirrels with their cache
Many of us took to doing this during lockdown and enjoyed viewing the birds as they came to feed in our gardens. During the colder months, and once the berries have gone from the bushes, many birds find it much more difficult to find enough nutrients to sustain them. Leaving out some extra food at this time of year will help them enormously. It’s not just nuts and seeds that they enjoy. Many birds are also partial to bacon rind, grated cheese and even fresh fruit. Remember, if you have cats to place the food high and in a safe place where the birds are safe to feed without predation. Check out this handy guide.
During autumn, squirrels store food such as acorns to eat during winter when it is more scarce. However, they aren’t known for their memory and often can’t remember where the food is stored. Leaving out a selection of nuts, chopped apple, carrots and spinach will help these furry favourites during the winter freeze.
Melting frozen ponds
Create bundles of stems and other habitats
Toxic gases can build up under the ice of a frozen pond, killing the fish and frogs that live there. If you have a pond, make sure you check it every day. If it is frozen, hold a saucepan of hot water on the surface to make a hole in the ice. Never tip boiling water into the pond as it can kill the aquatic residents.
If you prune your herbaceous perennials, bundle together the stems and leave them in a secluded place. Many minibeasts and small mammals will shelter there during the cold months. Similarly, collect fallen leaves and pile them up to make a cosy hiding place for insects and hedgehogs. Don’t forget to leave a bowl or dish of fresh water out for the animals too, and remember to break the ice if it freezes over!
‘Galivanting Gauntlett: Arctic Circle and Reindeer’ with Mr Gauntlett As the cold weather closes in and we move further into winter, I’m reminded of my travels in the Arctic circle. In early March 2020 as coronavirus was spreading around the world, I was in fact a few degrees north of the 66th parallel in the most northerly point of Europe. I was travelling from Tromsø in Norway to Lapland in Finland for an important meeting with Father Christmas. Energised from a week of husky sledding, cross country skiing and glimpses of the Northern Lights, I boarded the ‘Arctic Express’ on a 12‐hour journey through pristine winter wilderness. This part of northern Scandinavia is largely inaccessible in the winter months, but this was beefed‐up bus ready to take on the arctic conditions. I spent pretty much the whole journey staring out of the window taking in the landscape. As we neared Lapland, I was lucky enough to catch a brief glimpse of a wild reindeer. There is no shortage of reindeer in Norway or Finland, but most are in fact semi‐domesticated and managed by indigenous herders who farm them for meat, fur, and tourism. Wild reindeer are relatively rare and tend to be confined to mountainous regions, so I was quite excited by my brief encounter.
View from the Arctic Express
Reindeers have become synonymous with Christmas, and popular culture would have us think of them as cartoonish animals with a magical ability to fly. Cleary reindeer can’t fly, that’s just silly, but they do have some fascinating real‐life adaptations that I think are worth sharing. Forget about red noses, reindeer have colour‐changing eyes that transform with the seasons. That’s right. If you were to look inside the eye of a reindeer in the summer, you would see that it is a golden/yellow colour. Look inside the same eye in the winter and it would be a shimmering blue. Why is this? Due to their northerly location, reindeer must cope with extremes of daylength, living through both the polar night in the winter and the midnight sun in the summer. This might mean up to three months of almost constant daylight or darkness depending on the time of year. Scientists think this adaptation helps them to cope with this changing environment. The colour is caused by a layer of tissue called tapetum lucidum (TL) which is located behind the retina (which contains the light sensitive cells in the eye). The role of the TL is to reflect light back through the retina which can help enhance night vision. This adaptation is shared by many mammals in fact, and is the reason why some animals’ eyes appear to ‘glow’ when a light is shone at them. The same principal is exploited for making ‘cat’s eyes’ on roads, a good example of biomimicry (get your dictionary out). Contrasting colours of the TL (credit: National Geographic)
‘Galivanting Gauntlett: Arctic Circle and Reindeer’ with Mr Gauntlett
A reindeer
In the summer, most light is reflected back through the reindeer’s retina creating a golden/yellow colour. However, the change in colour in the winter means that different wavelengths of light are reflected, in this case blue, and this means that less light is reflected out of the eye. As a result, more light is scattered through photoreceptors increasing the sensitivity of the retina in the murky light of winter. It’s thought that this gives reindeer an advantage in being better able to spot predators in the dark.
How does this happen? Scientists think that the colour transformation is caused by a change in the pressure in the eye. In the winter, the pupils are permanently dilated to maximise light entering the eye which prevents fluid in the eyeballs draining and thus creates a higher pressure. This in turn forces liquid out of the tapetum lucidum causing the collagen fibres of which it is mostly comprised to squeeze closer together. This conformational change is what alters the colour of the eye. Pretty nifty. Furthermore, it’s also been discovered that reindeer eyes are sensitive to ultraviolet which is abundant in the arctic light. Reindeer have many other adaptations, but one more is worth a mention. They may not have a ‘very shiny nose’, in fact they’re quite furry, but they do have a built‐in heat exchange system. Reindeer have to cope with temperatures as low as ‐40°C and breathing in air this cold poses a serious problem as it would damage the delicate structures of the lungs, not to mention lowering their core temperature. What’s the solution? Reindeer have an impressively large surface area in the internal structures of their noses which in turn have an extensive network of blood vessels. This allows for an exchange of heat between the cold air and the warm blood. Scientists at the Arctic University of Norway in Tromsø found that when reindeer breathed in air that was ‐40°C it was 38°C by the time it reached the lungs. That’s an incredible change of 78°C, and all in less than one second! When breathing air out, they are also able to rapidly cool it, so that any heat is retained and not lost to the surrounding air. Pretty incredible. I’m not sure that ‘Rudolf the furry, rapid heat exchange‐nosed reindeer’ has quite the same ring to it though!
Here’s a little rhyme to help you remember: Noses aren’t red, Eyeballs change hue, In summer they’re yellow, In the winter they’re blue
‘Winterwatch*’ with Mr Coleman Winter brings with it a whole host of magical wildlife! Over the holidays, can you find any of the following to provide you with some inspiration when out walking? Robin singing - Robins are one of the few birds that sing over winter because they defend their territories all year round. They’ll even sing after dark under streetlights, long after every other songbird has settled down for the night. Compared to the loud, rich and varied song that they sing in spring, the winter song is much weaker and more melancholy. Corvid Roost - Corvids, such as jackdaws, rooks and crows can be seen gathering in spectacular numbers at roost sites throughout the country. The roosts are dominated by mainly juvenile and other non-breeding birds. This gathering is thought to act as a way to exchange information about the best feeding sites in the area. Smell of Gorse Flowers - In a bid to avoid predation on its seeds during the spring and summer, gorse flowers all year round, even in the depths of winter. Its flowers have a wonderful, distinctive, coconut scent. Jelly ear/Oyster fungus Jelly ear fungus is common across the UK and grows on deadwood in damp, shady corners. Hazel Flowers - Distributed all over the UK, the first hazel flowers of the year typically appear in January, before the leaves. Hazel trees are ‘monoecious’ which means male and female flowers occur on one tree. Look out for the yellow male catkins glowing in the low winter sunlight, and then get up close and search for the beautiful and tiny pink female flowers. Greater Spotted Woodpecker drumming - Great spotted Woodpeckers will visit peanut feeders during the winter. You may start to hear them drumming on trees. The thumping sound echoes out across the forest and is the start of the Woodpeckers establishing breeding territories and trying to attract a mate. *in meteorological terms, Winter starts on the 1st December but astronomically speaking, it starts on the solstice, December 21st. Of course, the natural world doesn’t recognise these specific dates and the signs of seasonal change are all around us if you get outside and notice them!
‘Winterwatch*’ with Mr Coleman Winter Migrant gatherings (Fieldfare, Redwing, Brambling, Waxwing) - In Winter, the UK gets an influx of winter migrants that are often seen together in groups. They come here usually to escape the colder harsher weather of further north. Fieldfare, Redwings and Waxwings can be seen feeding ferociously on berry trees, while Bramblings can be seen in large mixed flocks often with Chaffinches as they search the forest floor for seeds. Redwing and Fieldfare are both a similar size and shape to song thrushes. You can tell them apart using the bold cream-coloured stripe across the Redwing’s eyebrow, and it’s rusty red underwing. Fieldfares on the other hand, have white underwings and a grey head. Winter Moth - The Winter Moth is one of the few moths that can cope with the low temperatures of winter and can be seen as adults from October to January. The males and females look very different though as unlike the male, the females of the species cannot fly, having only stumpy wings. To attract a mate then, the female must crawl up a tree, instead of fly. They then give off pheromones that attract the males to them. Hair Ice – Hair ice is a rare phenomenon which requires very specific conditions to form, but is instantly recognisable when it does appear. It only materialises in association with a fungus called Exidiopsis effusa which grows on moist, rotting, deadwood, and on days when the weather is humid and the temperature dips just below 0 degrees Centigrade.
Mistle Thrush guarding berries - During the winter, Mistle Thrushes exhibit an unusual behaviour; guarding berry bushes, including holly, yew and mistletoe. This tactic should hopefully insure they have a larder full of berries ready to eat all through the toughest winter months. Glue Crust Fungus - Widespread across the UK but more common on the damper west coast, Hymenochaete corrugata has a very clever way of travelling - it traverses the canopies of Hazel trees by glueing branches together! As well as allowing the fungus to spread, its welding abilities allow it to ‘catch’ dead branches and other woody material in the canopy and effectively store it to feed on.
‘Winterwatch*’ with Mr Coleman Overwintering Insects Unlike mammals and birds, butterflies and moths rely mainly on external sources of heat to warm their bodies so that they can be active. Although many are adept at increasing their body temperature way above ambient air temperature by basking in sunshine or shivering (vibrating their flight muscles), when their surroundings are really cold, most butterflies and moths are forced to remain inactive. Other insects, such as Ladybirds huddle together for warmth in sheltered spots such as inside empty seed heads, under bark or in forgotten corners of houses and sheds, often congregating in large numbers. Solitary bees and wasps seal themselves away inside hollow plant stems, underground chambers or in bug hotels. So, not surprisingly, winter poses a problem for butterflies and (most) moths in temperate climates such as ours. It is difficult for them to get warm and, therefore, be active and so they have evolved ways of dealing with this unfavourable season. Most species enter a dormant phase. This can be as an egg, larva, pupa or adult insect, dependent upon species. The majority of butterflies and moths overwinter in the larval stage, with pupae being the next most common choice, followed by eggs and adults. A few are capable of overwintering in more than one stage. The Speckled Wood butterfly for example can overwinter as a caterpillar (larva) or a pupa. Strictly speaking, insects don’t hibernate but enter a period of dormancy but the species that overwinter as dormant adults include the butterflies Brimstone, Small Tortoiseshell, Peacock and Comma and moths such as the Twenty-plume Moth, Redgreen Carpet, Tissue, Sword-grass, Herald and Bloxworth Snout. Among the butterflies, it is only the Small Tortoiseshell and Peacock that regularly overwinter inside houses. They come in during late summer/early autumn when it is still warm outside and our houses appear to provide suitably cool, sheltered dry conditions. However, come Christmas, when the central heating is cranked up, such butterflies may be awoken prematurely by high indoor temperatures. This presents a major problem for the butterfly as the outside weather conditions may be very hostile and there is little nectar available in gardens. It is a problem for the concerned householder too. How best to help these poor confused butterflies and moths unwittingly tricked into thinking spring has come early. The best solution is to rehouse them into a suitable location. Catch the butterfly or moth carefully and place it into a cardboard box or similar, in a cool place for half an hour or so to see if it will calm down. Once calmed down you might be able to gently encourage the sleepy creature out onto the wall or ceiling of an unheated room or building such as a shed, porch, garage or outhouse. Just remember that they will need to be able to escape when it awakens in early spring. If you have no options at all for suitable hibernation places, then it would be best to keep the butterfly or moth as cool as possible, to minimise activity, and then to release it outside during a spell of nice weather. My thanks to BBC Winterwatch and Butterfly Conservation for images and copy
‘Oh Christmas Tree’ with Mrs Oatridge The traditional Christmas tree used in the UK is the Norway spruce. Its scientific classification is: Kingdom: Plantae Phylum: Coniferophyta Class: Pinopsida Order: Pinales Family: Pinaceae Genus: Picea Species: abies The Norway spruce is found in cold climates with heavy snowfall. In these conditions, water in the soil freezes during the winter months. How is it adapted for this climate? Thick layer of bark to provide insulation against the freezing temperatures. The bark reduces heat loss from the tree to the surroundings.
Needle-like leaves have a smaller surface area than broad leaves and a waxy coating which reduces the volume of water lost by transpiration.
The flexible branches allow snow to easily slide off, preventing the branches from breaking due to the weight of settling snow.
The cone shape means that the bottom branches of the tree are not shaded by the higher branches which increases the amount of sunlight the leaves can absorb.
Hours of sunlight
The growing season is short so plants need to make the most of the sunlight hours. By keeping their leaves all year round, the plants are able to photosynthesise whenever there is sufficient sunlight, taking advantage of the shorter growing season.
Christmas Quiz (courtesy of SAPS: www.saps.org.uk) Write down your answers then check your score at the end!
Question 1 The common holly (Ilex aquifolium) is often used to decorate homes during the Christmas festivities and holly trees are well known for their spiny leaves. Choose a reason why it is generally accepted that the higher up the leaves, the less spines they will have. A) The spines grow due to reduced daylight B) The spines deter small mammals from consuming the leaves of the plant lower down
C) Humans have bred the spikes in this way so they can walk past the trees without getting hurt
Question 2 Mistletoe berries have a lovely appearance and an association with a warm gesture at Christmas. Mistletoe berries are actually: A) Full of anti-oxidants
B) A staple part of the diet of a hedgehog C) Toxic to humans
Question 3 Currants, raisins and sultanas are dried fruits often used in Christmas cakes but what are they before they are dried?
A) Grapes
B) Olives
C) Figs
Question 4 Look at this painting of a nativity scene. Name items which could have derived from plants.
Christmas Quiz Question 5 Sulforaphane is a compound and has the formula C6H11NOS2 Which item commonly found in a traditional Christmas dinner contains sulforaphane? A) Cranberry (sauce) B) Brussel spout C) Roast potato
Question 6 In which part of the plant does a Christmas tree (fir tree) store its seeds? A)
Cone
B) Needle
C) Trunk
Question 7 There is only one plant mentioned in the song ‘The 12 days of Christmas’, which fruit grows on it? A)
Apple
B) Raspberry
C) Pear
Question 8 Where is Myrrh extracted from?
A)
The roots of a herb
B)
Sap secreted from wounded trees
C)
Fungus found on bushes
Question 9 Name the type of spruce which is commonly used as a Christmas tree across Europe. A) Norway
B) Sweden
C) Finland
Question 10 Often known as the Christmas Flower, the Poinsettia has become a symbol of the festive season due to a Mexican legend where a poor girls gave Jesus a bunch of weeds that transformed into a bright red bouquet. The colourful parts of the poinsettia are the: A) Flowers
B) Leaves
C) Fruit
Answers: 1-A; 2-C; 3-A; 4-Frame, sandal, gift, roof, straw, gift; 5-B; 6-A; 7-C; 8-B; 9-A; 10-B