Moorhens and More

Kingdom: Animalia

Family: Rallidae

Species: Gallinula chloropus

The common moorhen, also known as the swamp chicken (not a nice nickname really is it?), is a species of bird found widely across the Old World: the parts of the world known to Europeans before the discovery of the Americas, including Europe, Asia and Africa. Although they are birds, they are better at swimming and walking than they are flying, and are often seen swimming bobbing their heads back and forth.

Moorhens are found in well-vegetated marshes, ponds and other wetlands. I found a few when walking along a river somewhere on the UEA campus behind the lake... However, I am not sure exactly where this is as I did get a bit lost! The moorhen is distinctly recognisable because of its dark plumage with a white under tail and stripes on the flanks, yellow legs and red bill with a yellow tip. Younger moorhens are brown and lack the red frontal shield. They grow to 12-15 inches with a wingspan of just under 2 feet. Their feet are not webbed - they have long chicken-like toes (hence the nickname) which enable them to walk on top of the floating vegetation and the mud.

They consume a variety of vegetables and small aquatic animals, foraging either in the water or on land. They are quite secretive, although this one was tame enough to let me close enough to get some pics, even if they are a little blurry. This may be because I took these before breeding season had started - this takes place from mid-March to mid-May in the Northern hemisphere, and usually in lowland areas in the UK in central and eastern England, which the UEA campus is a clear example of!

During the breeding season the birds can get very territorial. The male moorhen courts the female by bringing her water weeds and fanning out his tail. They form a monogamous pair and build their nests on the ground in dense vegetation, in a bowl shape and made of twigs, cattail, grass and sedges. Usually the male gathers the twigs and the female builds the nest among vegetation in the water. 

About 8 eggs are laid per female early on in the season, at a rate of about 1 egg per day, although this may be slightly less later on. The eggs are smooth and glossy, of a greyish-white to green colour with reddish-brown or grey markings, measuring about 43mm by 31mm. Incubation lasts about 3 weeks and is done by both parents, showing the high parental investment typical of birds. Young moorhens are precocial, and can therefore leave the nest and feed themselves within a few days of birth. They then fledge after 40-50 days. If the young fee threatened, they cling to their parents' body and the adults carry them, flying away to safety. 

Moorhens are often confused with coots, but although coots are similar, they have a white beak, and have no red mark. This can be remembered by thinking R is for red, and there are no "R"s in coot! Another way is to think CO reminds you of a cold and white frost, or OO reminds you of snowballs which are white - these can be related to the white beak!

The moorhen population began declining in the 1970s and 80s but has recovered since. This was thought to be because of a result of reduced clutch size caused by the spread of the American mink, which predates the birds' nests along waterways. The moorhen is considered now to be a species of Least Concern by the IUCN, so we don't need to be bidding farewell to the moorhens on our waterways for hopefully a very long time!

Field Trip - Ancient Woodlands and Dog's Mercury

Ancient woodlands provide a rich and unique community of plants and animals, as they have been around long enough for the ecosystems to develop into complex and irreplacable habitats. Plants and animals depend on the stable habitat the woodland provides due to the relatively undisturbed soils. Ancient woodland is any woodland that has been around since 1600AD (1750AD in Scotland) or earlier; some woodland in the UK has been around since the last Ice Age approximately 10,000 years ago! 1600 was when planting of new woodland became more common and so woodland established before this time is likely to have developed naturally.

They also indicate to us signs of history that allow us to trace backwards throughout the woodland's lifetime, giving them cultural value as well as conservational. Medieval boundary banks, old coppice stools - all tell a story about an England very different to the one we now know. Ancient woodland can be characterised as 

Semi-natural woodland: Mainly made up of trees and shrubs native to the site, arising from natural generation in most cases.

or

Plantations on ancient woodland sites: Areas of ancient woodland where the former native tree cover has been felled and replaced by planted trees, typically not native to the area. Planted Ancient Woodland Sites (PAWS) can be restored to give rise to Restored Native Woodland on Ancient Sites (RNWAS).

Foxley Wood: Photo by Richard Osbourne

Foxley Wood is Norfolk's last remaining ancient woodland, and it contains a number of ancient woodland indicator species (AWI's), including:

Wood anemone (Anemone nemorosa)

Wood sorrel (Oxalis acetosella)

Honeysuckle (Lonicera peliclymenum)

Common dog violet (Viola riviniana)

Dog's Mercury (Mercurialis perennis): A case study

Kingdom: Plantae

Family: Euphorbiaceae

Species: Mercurialis perennis

Dog Mercury: Photos from naturessecretlarder.co.uk

The name 'dog's mercury' is said to originate from the messenger of the gods, Mercury, who is the one to discover it. 'Perennis' is used to distinguish it from the 'annua' species, which was used as a diuretic (to increase urine production) and as a purgative (to give a laxative effect). 'Dog's' is a term used to describe a plant with no medicinal uses (in the sense of 'false' or 'bad', as even though recently it has been harvested to use as a laxative this is discouraged by herbalists due to its cumulative effect.

Dog's mercury can quickly colonise and spread throughout an area by using underground rhizomes. The plant favours alkaline soils and is found in abundance in suitable habitats in limestone regions. It is present in neutral soils too, but not acidic soil. This can lead to crowding out of other, rarer, species such as Fly orchids, or even Ash seedlings, which we saw are already under threat due to Ash dieback diseases, present on some of the trees in Foxley Wood. The plant is characterised by its spear-shaped, toothed fresh green leaves, upright set, small, greenish flowers, and a foul and rotten smell that it produces. By coppicing at Foxley Wood, the woodland floor is exposed to sunlight which helps other flowers and plants to thrive and thus keeping others that spread easily under control: preventing the Dog's Mercury takeover. In other areas of East Anglia where coppicing as ceased, Dog's Mercury has been observed to be increasing in abundance.

Dog's mercury is highly poisonous, due to the combination of methyl amine  trimethylamine, a volatile oil and saonins. It is diuretic purgative, and emetic, meaning it causes diarrhoea and vomiting after consumption. Larger doses also lead to lethargy, jaundice, painful urination, gastric and kidney inflammation, inflammation of the cheeks and jaw, and potentially a coma which leads to death. Yep, that's enough to keep me well away.

The leaves often poison sheep or cattle, but no incident of severe human poisoning has been reported since the 1980s when a couple ate the plant after boiling it, thinking it to be a green vegetable: they recovered within 2 days. The first case of human poisoning was reported in 1693, when a family of five ate it and one of the children died. For some reason though, some people still think it's worth a try! One woman wrote on 09/02/17 when commenting on a blog about Dog's Mercury: "I picked some dog mercury and ate it on a salad. I thought I'd read a small amount was ok to eat... was enough to cause my lips, mouth and throat to burn. This was followed by a feeling of shaky weakness and a need for the toilet". 

Why you would want to risk it I do not know, but I guess it goes to show that you should double check if something is safe before you try eating it! All in all, this is a pretty nasty plant from anyone's point of view. So by all means, look out for it the next time you think you might be in an ancient woodland, as well as the other AWI's, but don't get too close!

Field Trip - Sampling leaf miners

As part of our Issues and Approaches in Ecology module we went on an on-campus field trip, and one of the things we did was sampling leaf miners on holly bushes (Ilex aquifolium). A leaf miner is the larva laid on a leaf by an insect, which lives within the leaf and eats the plant tissue. Insects which do this include moths (Lepidoptera) and flies (Diptera). This protects the larva from many predators, and provides them with a source of food. The miner leaves a discoloured blotch on the leaf, which is usually green with some brown marks within, as below:

Photo by David Fenwick

This pest has little impact on the health of the holly bush, and is difficult to control as insecticides are relatively ineffective due to the thick, glossy protective layer the surface of the holly leaf provides. On other plants which are less well protected, however, they can reduce the economical value of a crop, causing problems for farmers, so in this context control of leaf miners is more of a pressing issue.

The task we were set seemed relatively simple, to conduct an experiment to estimate the population of holly bushes and the number of these affected by leaf miners. We began designing our experiment, and in our group of 5 we found that we could easily identify new growths from the last season as it leaves a scar on the branch. Therefore we could estimate the number of leaf miners left in the last growing season, between May and June.

We conducted our survey as follows. We divided the area of woodland we had been given into five separate areas by pacing out five paces along the path, and five paces away from the path, giving us each an area of approximately 25m squared. We decided to sample the holly bushes by taking a measurement of a new growth at a high, medium, and low level (above the head, just below head height, and about knee height). We measured new growths as it would give us flexibility with the data as we would know the average number of leaves on a new growth, whereas measuring the number of leaves would not give us this flexibility and would also be more time consuming. We each aimed to sample 50 new growths.

Bias was an issue we would ideally have overcome by using a random number generator of some sort, but this was not available to us as we were making it up on the spot. The approached this by using a rather amateur method, which included closing our eyes and randomly holding our finger out and sampling the branch we were pointing at. This is a flawed method as it is still subject to bias and means we may not have been pointing at a plant at the right height, but it was the best we could do with the resources available to us.

After sampling at the three heights we moved around the holly bush until we had gone all the way around, measuring each about 5 times, and then moving on to the next one. We recorded the number of leaves on the new growth, and the number of leaves infected by leaf miners. We could then use this information to calculate the percentage of the holly bushes that were infected with leaf miners.

To take this further, we could have used the information to calculate the number of holly bushes infected in the entire wood. To do this we would need to know the area of the wood, but this posed the issue of variation. For example, on one side of the path where we were sampling, there were many holly bushes. On the other side, there were next to none. We would therefore need a larger sample area to calculate the average percentage of woodland covered by holly bushes, and we could then times this by the proportion of leaves that were infected to see how many new growths throughout the wood were infected. However, this would take much more time and planning than just this one field trip allowed.

Crows - unlucky or just super smart?

Kingdom: Animalia

Family: Corvidae

Genus: Corvus

Crows are species of birds in the genus Corvus, and have a shiny jet black plumage and a high level of intelligence. They are widely regarded as a bad omen, and are often brushed aside as a simple nuisance, rather than recognised for the intelligent animals that they are. They are actually very interesting creatures, but many people do not give them the credit they deserve due to the bad luck associated with them.

What’s so great about them?

They are incredibly intelligent! They have the biggest brain to body ratio among all bird species, with a highly developed forebrain which is associated with intelligence. They are cleverer than parrots, and Bonobo chimpanzees, which makes them the second most intelligent creatures, beaten only by humans! This has given them the name ‘feathered apes’. For example, if a crow is unable to crack a nut, then it puts it on a highway so a vehicle will pass over it and crack it open, and they prefer to put it under smaller vehicles so the kernel is not completely squashed.

Crow meat is edible for humans and is served in Western parts of the globe, and is healthier than other meats such as pork.

They can be used by humans to destroy pests of crops and can form bonds with humans due to their social nature.

They have an excellent memory and can stash food in places, sometimes moving it several times, and remember exactly where it is stored.

They are migratory birds, and gather together in autumn and winter to migrate.

They have a characteristic “cawing” and have developed a sophisticated form of language to communicate with one another. The caws have different meanings at different times and can mimic sounds of other animals. They can also associate different commotions to different events. They also express emotions vocally, such as happiness, anger and sadness.

When another crow is dying, a group of crows flock around it and peck it aggressively to death, which is why a group of crows is called a murder.

Crows mate for life, and after hatching (usually 4-7 eggs) the male and female take it in turns to incubate the eggs. Some of the offspring remain after they developed to assist in co-operative breeding.

They can make tools for food, a behaviour only otherwise shown in apes and humans. The New Caledion crow can develop knife-like tools from stiff leaves and stiff stalks of grass. The crows of Queensland, Australia have learned the skill of grabbing and eating the toxic cane frog. The crows flip the frog at its back and start stabbing its throat with their long and sharp beaks, thus consuming the non-toxic innards.

They can imitate human voice, like parrots. Some have even been taught to recite opera.

So why are they considered to be bad omens?

They are associated with bad omen, death, and dark witchcraft, as well as with the ability to manipulate physical appearances, and magic in general.  It is said that if a black crow lands on a home’s roof, the inhabitants will suffer bad luck or face death. This perhaps comes from a crow’s scavenger personality, which leads to them hanging around human residences, and even places like graveyards. For example, after Hiroshima, there was a famous plague of crows on the city. 

There are different crow superstitions in different places all over the world. In Wales, the idea was that if one crow crossed your path it was bad luck, whereas if two crows crossed your path then it was good luck. They’re also considered good luck if you find one dead on the road. The French had a saying that evil priests became crows, and bad nuns became magpies. In Somerset, England, people used to carry an onion with them for protection from crows. In New England, to see two crows flying together from the left was bad luck. A general superstition was releasing two crows together at a marriage ceremony, and if they flew away together then it would be a long and happy marriage. If the crows separated, the couple would part soon too. Sounds risky to me!

Personally, I think it’s high time that these superstitions were forgotten, and let’s recognise crows for the incredibly intelligent, and sociable, animals that they are. Although I perhaps won’t be saying that if one now crosses my path or lands on the roof of my house…

Are swans aggressive? Or just overprotective dads?

Kingdom: Animalia

Family: Anatidae

Species: Cygnus olor

The mute swan, Cygnus olor, is a species of swan found frequently throughout the UK. It is recognised for its white plumage, orange beak and long neck, and is called 'mute' due to it being less vocal than other swan species. They are some of the heaviest flying birds in the UK and have a  wingspan of up to 2.4 m. They possess an oil-producing gland at the base of their tail and use their bills to spread this oil throughout their feathers to keep them waterproof, which is why they are sometimes seen wiggling about in an odd fashion. They regularly bathe by opening their wings and diving underwater, and then flapping their wings and shaking to dry off. Mute swan sub fossils which are 6000 years old have been found in post-glacial peat beds right here in East Anglia!

However, what mute swans are most well known for is not their looks, or their history with Norfolk, but their attitude. Swans have bit of a rep for being aggressive. Previously, someone has died from drowning as a result of a swan attack, and most people you speak to have stories about someone they know being attacked by a swan. Every day when walking to school when I was in sixth form, I had to walk past 'Asbo' - the well known swan in my home town who everyone knew to stay way from due to numerous attacks. I certainly know that when I was taking these pictures, I was feeling pretty nervous and  remained ready to run upon attack. But is there any truth behind this bad name this species have earned for themselves? Or is Asbo just a bad egg, dirtying the name up for all the others, along with a few others?

The aggressive behaviour is usually displayed in late spring, from April to June, and is done because males are defending their nests to protect their young. They typically hiss and busk (where they flap their wings and curve their neck back), but the danger is apparently overrated and it is a myth that they will break your leg or arm with their wings. However, they will use their wings to attack rather than their beak if you provoke them. The behaviour is primarily for show, as they are not actually that strong, it is simply their size which makes them an intimidating animal. They may be able to harm the elderly or very young, but to an adult? They pose no real threat. The number of reported incidents compared to the number of swans living in the UK means the threat is minimal. To be safe, stand your ground and don't overstep the line into their territory, and you should be safe to go for walks around the UEA broad with no fear.

'Sea' gulls? Not necessarily

Kingdom: Animalia

Family: Laridae

Species: Larus argenatus

 



















The typical noises of a day at the beach: Shrieks of girls being splashed by their little brothers, the whirring of the ice cream van engine, crying overtired children, and the all too familiar sound of the caws of sea gulls. Sea gulls in the UK consist of black-backed gulls and herring gulls (the latter is what I have observed here). They're the nuisance behind every day at the seaside, but they are becoming an even bigger issue away from the shoreline, despite having lived there for so long to be close to the water (they evolved 15 million years ago, so that's very very long!). In 2009 the herring gull was added to the Red List of Birds of Conservation Concern. Red is the highest conservation priority, with urgent action deemed to be necessary to protect the species. One of the main reasons for the falling numbers is that changes to fishing practices in the UK have resulted in food shortages for rural gulls. This has lead to a division of the herring gulls into two groups: urban and rural, and it is urban which are the problem to us.

Numbers of urban sea gulls have quadrupled in the last 15 years, and numbers of attacks on humans have also increased. However, it is humans who are partially to blame for this aggression. People are throwing increased amount of litter on the streets, attracting gulls to urban areas. They also encourage the aggressive behaviour shown by urban sea gulls by feeding them, which leads to attacks on humans with food. The gulls are also attracted to cities as they can nest on the roofs of office blocks and houses (and libraries and lecture theatres...) which means they can avoid predators such as foxes and, as a result, more chicks survive, meaning urban environments are less hostile to the gulls.

The prevalence of urban gulls in cities (or in our case, universities) can be mitigated through actions of individuals. This includes seemingly small things like not littering, and aiming to reduce the amount of organic waste taken to landfill sites. Urban gulls can also be repelled through the actions of governments and local councils who can make public waste bins, domestic and business waste containers, and collection arrangements 'gull-proof'. Gulls may be annoying but they are very intelligent and will find a way to get into wheelie-style bins. Nothing stops them from getting their food! So here we have a conflicting issue - we need to protect the herring gulls but also stop feeding them, as it is causing problems with aggression. Research into management strategies is what is really needed, so the correct precautions can be taken to protect these interesting birds.

The world of a wagtail

Kingdom: Animalia

Family: Motacillidae

Species: Motacilla alba

The pied wagtail is a small, spritely, black and white bird found throughout the UK. The species is partly migratory - it is permanently resident in England, but may spend summer in northern Scotland when it is warmer. Some parts of the population migrate southwards to France, Spain and Morocco during winter. They are pretty common - about 10% of gardens have them as regular visitors, so it's no wonder that they like UEA so much as the place is one massive garden! They are slender, with mostly black upperparts and white underparts. It is often overlooked compared to its more well known garden friends, such as the robin and the blackbird, but in truth these birds are very endearing and sweet.

They are often found near water, although they have been found to nest in urban areas too. They are given their name based on their long-feathered tails which they repeatedly wag up and down (not very imaginative, I know). No one knows why they do it exactly, but it fits in with their restless nature which is what enables them to be such effective predators of insects, such as caterpillars, flies and worms. They feed on particularly small ones, which other larger, birds usually look over. The wagtails dart about, and if they are in a natural environment where something is fast moving, such as by a stream, it makes them quite tricky to spot. They combine quick scurrying around on the ground with twisting flight patterns. However, in the open area by Nelson Court, they do stand out - although are still tricky to get a decent picture of!

They tend to nest in reef beds, holes or crevices of buildings, or dense bushes, as they keep their nests warm and defends them from ground predators. In their nests they lay three to eight eggs at a time, which both sexes incubate for 11 to 16 days. They are very social birds and flock together to share their warmth and feel safer as it acts as an information exchange; the birds who have difficulty finding food can follow the ones who know their way around. It also means more eyes to watch out for predators. On a winter evening, the wagtails are known to take part in an unusual social activity, where they gather together in enormous, noisy roosts - up to hundreds of them on one roof in a shopping mall or industrial estate, to gain further protection from predators overnight.

Although they are sociable, the males can be very territorial, and take up a position on a tiled roof and chase away intruders with a twisting, acrobatic flight, letting out a harsh and urgent flight call to keep predators away. If a bird sees its own reflection in a mirror or in a car window, it may attack it - and get a sore head by doing so. It is usually not a very vocal bird, but can be heard to be singing out a shrill, clear and happy chirp from perches or close to the nest. 

These sweet little birds have been declining since the 1970s due to degradation and habitat loss, but luckily the species is able to adapt fairly well, but is not classed as threatened, and is of least concern. This is reassuring, as I don't want to say goodbye to these little fellows any time soon.

Some very blurry photos of some very fidgety wagtails!!

Cenhinen pedr

Kingdom: Plantae

Family: Amaryllidaceae

Genus: Narcissus

While the snowdrop signals the end of winter, the daffodil is the beginning of spring. As someone who is half-Welsh, the daffodil has been prevalent throughout my childhood, as the daffodil is the national flower of Wales, and it translates to Cenhenin pedr in the Welsh language. It is traditional to wear a daffodil on Saint David's Day, March 1st, and a Welsh myth claims that if you spot the first daffodil of the season, your next 12 months will be filled with wealth. Clearly I need to keep a better eye out, as that student budget is still hitting me hard. Daffodils grow perennially from bulbs, often in large clusters, brightening up the countryside with their bright, yellow, sunny colour. The plants have a single central leafless hollow flower stem, with several green strap-shaped leaves arising from the bulb. Closest to the stem is a floral tube above the ovary, then an outer ring of six tepals, which may hang down or be erect.

The daffodil has many myths surrounding it, with different symbolisms in different times and cultures. It is also known as Narcissus, which is a Classical Greek name in honour of a beautiful youth who became so entranced by his own reflection that he pined away and the gods transformed him into this flower. The Romans cultivated them, and then they were forgotten until 1600. Around 1629, Englishmen reintroduced it to gardens because their sap was thought to have healing flowers. However, it actually contains crystals which can irritate the skin - hardly what I would call healing. Due to their long association with Lent, they are known as the "Lent Lily", and symbolise happiness as a gift, although they must be given as a bunch as one on their own can foretell misfortune. It is also the 10th wedding anniversary flower. Lots of meanings!

Daffodils are known as the flowers of March, and usually bloom between March and late April, meaning they are early in mid-February this year. Phenology describes the timing of critical events, such as when flowers bloom, birds migrate or trees shed their leaves. These processes are closely linked to environmental conditions, including temperature. Therefore, the increase in the Earth's climate is having effects on the life cycles of various plants including the daffodil, which consequently affects its fitness. For example, earlier flowering means that they are more exposed to frost conditions which has knock-on effects for seed production. It also leads to mismatches with pollinators, meaning less pollination takes place. Therefore, the daffodils this year at UEA may be exposed to tricky conditions in the next couple of weeks.