Beginner's Birds: Great Blue Coal

This mini feeding station at the rear of the Health and Safety Service building on the Science Site has attracted 14 different species of birds ( and a squirrel). These photos show the commonest 3 visitors - from the top, great tit, blue tit and coal tit.

Although these are common birds around the campus, identification does still confuse people who take only a passing interest in birds.

Here are some key identification pointers:-

Great tit: the chunkiest of the three; very bold white cheeks; strong black mark down the centre of its chest

Blue tit: daintier and...well...blue-ish on its head and back

Coal tit:: dainty - like the blue tit: white cheeks but never as clean and bold as the great tit. Also - look on the back of the head where there is an extra white patch.

Hazel and Alder Catkins

Alder has been planted as an amenity tree at numerous locations on the university estate and its long, pendulous catkins (above) appear very early in February. By the end of summer it develops globular, woody cones that release vast numbers of small, winged seeds that are an important food resource for finches like siskins and redpolls in winter.

Hazel catkins are paler yellow and shorter than alder catkins, and usually open to shed pollen at the end of February. Hazel was planted at several locations on the Science Site in the early 1980s so that its nuts could provide a food resource for red squirrels, which were still common there at that time. At the end of the 1970s it was quite common to see half a dozen red squirrels siting on the wall beyond Hollingside House eating hazel nuts from the small patch of coppiced hazel near the lower end of the Botanic Garden. Sadly, red squirrels are now extinct in almost all of County Durham and the hazel nuts are taken by grey squirrels before they even have a chance to ripen...

Maybugs

About once every three or four years students living in college are sometimes alarmed by these large beetles that fly in through open windows on late spring evenings in Easter term. They're maybugs, also known as cockchafers, and their grubs feed on the roots of grasses in lawns, taking three or four years to reach maturity, so batches of eggs all tend to reach adulthood at the same time. Maybugs fly with their hard wing covers outstretched and their beating wings make a loud buzz as they clatter around rooms, where they're attracted to lights at dusk. The adults feed on flowers and can be notoriously destructive in orchards in Europe. You can find out more about this large beetle and find photos of its subterranean larva here.

Heron

You are probably most likely to spot a heron by the two ponds at the back of the Mountjoy buildings but they turn up from time to time at most of the other ponds on the university estate - in the Botanic Garden, on Van Mildert lake and Trevelyan college pond, for example. Herons are early nesters and will be feeding young in March... and the frogs that breed in all the above ponds are favourite food items. Once they find a good hunting ponds they'll return regularly, usually early in the morning before sunrise. They can spot the glint of water while flying over and that probably accounts for the arrival of the heron below on the roof of the Maths department - because there's a small pond in the courtyard next to lecture theatre CG91, just below its roof-top perch...

Photo coutesy of Michael Coxon

Photo courtesy of Stephen Applegarth

 

Photo courtesy of Stephen Applegarth

Photo courtesy of Stephen Applegarth

Gorse

I suspect that many University staff and students are not fully aware of the extent of the University Estate - for example - Whinney Hill. Here, it's gorse patch is in full bloom.

One of the pleasures to be had from a close encounter with gorse is the wonderful vanilla/coconut smell of the blossom. Another good reason to have a closer look is the flowers themselves. A member of the pea family, the flower structure is typical with a broad petal at the back and a sort of keeled structure in front which holds the reproductive parts of the flower (the male stamens which produce the pollen and the female stigma/style/ovary combination which produce the fruit.)

The flowers need a reasonably heavy insect to operate the pollination process. A bumblebee is ideal. As it lands on a flower and pushes its way in to reach the nectar reward (it's a con trick - there is none!), the bee's weight releases of a sort of trigger mechanism and the stamens spring up under the body of the bee and coat it with pollen. The bee then carries this off to the next flower and the pollination is done.

You can tell which flowers have been visited if you look closely. The left hand flower below remains untouched but the one on the right has been had. Try it with your finger next time you pass a gorse bush.

Wood anemones

Wood anemones are the first wild flowers to bloom in Durham University's woodlands, often in early March, long before the bluebells flower. There are some particularly fine patches of wood anemone in Little High Wood, on the hill to the south of the Science Site.

The Roman naturalist Pliny the Elder, writing in his Naturalis Historia, recorded the ancient Greek belief that the winds that blew in spring brought these flowers into bloom - which is how anemones came to be named after the Greek word for wind, anemos, and why they are still sometimes known as windflowers. The flowers are carried on very slender stalks and tremble in the slightest breeze.

Wood anemones grow very slowly, from a creeping rhizome that extends just a centimetre or two each year, so some of the large patches in Little High Wood are likely to decades old.

Kestrel

Although birds of prey are frequently seen flying over the Science Site (red kites have been seen overhead during the last couple of years) the raptor that you are most likely to encounter there is the kestrel. You'll often see one hovering over the grassland just north of Hollingside Wood, behind the Mountjoy Buildings, hunting mice and voles. From time to time they also breed in Hollingside Wood.... which is good news, since kestrels have been declining in some parts of Britain.

The little feather that you can see sticking out of the leading edge of each wing, about half way along, is the alula, which allows the bird to hang in the wind motionless, while it scans the ground below for prey. Anatomically, the alula is the bird's thumb and the feather controls airflow across the leading edge of the wing when it's held at a high angle attack, generating maximum lift without stalling. Leading edge slats on short take-off and landing aircraft serve the same purpose.

Bluebells

Hollingside Wood hosts one of the finest displayed of bluebells in North East England. In late April and early May, take a lunchtime walk to the end of Hollingside lane, beyond the Botanic Garden, descend the steps into the wood and follow the footpath back towards Houghall. You'll find yourself amongst a sea of bluebells, in a woodland that's as fragrant as a florist's shop. If you sign up to the free e-news service provided by the Botanic Garden, you'll receive notice of the best time to see the bluebell display, as well as other events in and around the garden. Details are at  http://www.dur.ac.uk/botanic.garden/whatson/enews/

All the flowers that you can see were formed inside the bulbs early last summer, before last year's foliage died down, and they've been sitting there, primed and ready to grow, all through winter. By July the flowers will have set seed, the leaves will have withered away and the spectacle will be over for another year.

There's also a fine display of bluebells in Little High Wood, behind the Calman learning centre and below the School of Biological and Biomedical Sciences. Biology and Psychology students, labouring up the infamous 'Cardiac Hill', can console themselves with the thought that there are few other university campuses where the path to enlightenment is strewn with bluebells.  

Yellow Brain Fungus

The Yellow Brain Fungus (Tremella mesenterica) is the best known of a small group of fungi with a jelly-like texture commonly found throughout Britain. It first appears in the shape of a disc and then quickly forms contortions that make it look like the surface of a brain.

It is mainly seen in winter when it grows on the fallen timber of most broadleaf trees, and is usually found in wet weather as it becomes a small, hard, orange bracket during dry spells. This was growing on a dead beech branch found near the Botanic Garden in Hollingside Lane.

Steve Ansdell

Winter Thrushes

The arrival of the winter thrushes from the far north of Europe is one of our great annual bird events. Driven south and west from their breeding grounds as the temperatures drop in the northern latitudes they arrive in the region in huge numbers, especially in colder winters like this year.

The large car park on the Science Site (on the road up to Mountjoy) has a couple of rowan trees just by the entrance and at lunchtime on the last day before the christmas holiday break they were absolutely covered in yellow berries and absolutely heaving with 4 of the members of the thrush family that can be seen in Durham during winter (fieldfare, redwing, mistle thrush and blackbird). By 5pm the trees were stripped bare and the birds long gone.

The fieldfare (above) and the redwing (below) only visit us in winter.

Although the blackbird, mistle thrush (below) and song thrush can be seen all year round in Durham, our resident birds are joined by huge numbers that migrate here, like the fieldfare and redwing, and swell the local population during winter.

The British Trust for Ornithology has tracked the arrival of fieldfares through its birdtrack scheme and published a graph for the last three years on it web site (click here). This shows a remarkable consistency in arrival dates and numbers. The peak in 2010 records coincided with my sightings in Durham.

Identification is fairly straightforward if you can get close to feeding birds or have binoculars. Fieldfares are exceptionally beautiful with distinctive grey heads. Redwings can be identified by the creamy eye stripe. They do also show a russett red patch on their sides.

The mistle thrush and the song thrush are similar but the mistle is bigger with cleaner-looking spots on a whiter breast than the song thrush.

There are size differences too if you see them together. Fieldfares and mistle thrushes are bigger and chunkier than redwings and song thrushes.

Harlequin Ladybird

Harlequin ladybirds Harmonia axyridis were first found in Durham in November 2009, feeding on ivy flowers near the entrance to Durham University Botanic Garden. On that occasion they were just nibbling harmlessly at the nectar on the surface of an ivy flower, but this is a carnivorous species that has been introduced into Britain and is spreading rapidly. It eats the eggs of many of our native insect species, including other ladybirds, moths and butterflies and could have a significant impact on native insect species biodiversity in Britain. The wing case colour patterns on the harlequin ladybird are astonishingly varied - the example above is the multi-spotted orange morph of the species. A national survey plotting the spread of this invasive species is currently underway and you can confirm identifications and record sightings on-line or by mobile phone by visiting http://www.harlequin-survey.org/default.htm#

Most of the specimens found so far in Durham have been of the red-spotted black form, shown above. The larval stages are larger than other ladybird larvae and have spines on their back. When they are ready to pupate they attach themslves to a leaf by their tail, as the example below has done.

If you spot harlequin ladybirds, which are noticeably larger than most of our native species and have a more rounded outline, Dr. Phil Gates in the School of Biological and Biomedical Sciences p.j.gates@durham.ac.uk would like to hear from you.........

Grassland butterflies

Ringlet

Small Skipper

Small Copper

Wall Brown

Meadow Brown

These are all grassland butterflies, all photographed this summer, that have bred in the area of grassland between Mountjoy 2 and Hollingside wood, on the southern edge of the science site. The ringlet butterflies, whose caterpillars feed on grasses, are fairly recent colonists in the North East, apparently extending their range northwards in response to climate change, and produce one generation per year in late July and early August. The meadow brown – the commonest species here – begins to emerge in late June and has a flight season that extends into early September. The small skipper (seen as an adult butterfly in July) and wall brown butterflies also have larvae that feed on common grass species. The wall browns have two generations, flying in late May and in August and the small coppers, whose caterpillars feed on sorrel leaves, sometimes have three, flying in May, July and early October. So if you take a lunchtime walk through this grassland at any time between May and October there’s a good chance that you’ll see at least one of these species.

Toadstools

Every autumn there are some fine specimens of fungi to be found growing in the Botanic Gardens and around the Science site. These fly agarics (Amanita muscaria) were growing amongst the birches near the stream on the southern edge of the Botanic Garden. Fly agaric forms a close mutually beneficial relationship with the roots of birch, helping the tree to acquire minerals like phosphorus from the soil in exchange for sugars provided by the tree.

These shaggy ink caps (Coprinus comatus) often appear in the grass beside the main road through the science site that leads to Mountjoy.

Within a few days of emergence ink caps begin to dissolve into a gooey mass of black spores, starting at the edge of the cap, until all that is left is a dark stain on the grass.

The university woodlands provide a wonderful habitat for fungi. These parasol mushrooms Lepiota procera (above and below) were growing in Little High Wood, just to the right of the infamous 'Cardiac Hill' that leads up to Biological Sciences.

Parasol mushrooms also turn up frequently in the Botanic Garden in autumn, associated with the cypresses growing on the conifer lawn. This one (below) is shaggy parasol Lepiota rhacodes, photographed earlier this week.

There are also some fine bracket fungi in the newly-opened nature trail in the woodland at the bottom of the Botanic Garden. These magnificent specimens of the bracket fungus Ganoderma adspersum, growing on a beech stump, were almost certainly the cause of the tree's death. This parasitic fungus weakens the tree and infected trunks typically snap somewhere above head height during gales. The fungus is perennial, so each year the bracket develops a new zone of spore-producing tissue around its periphery and generates so many spores that they cover the vegetation below with what looks like a layer of cocoa powder. You can estimate the age of the bracket by counting the number of ‘steps’ on its upper surface; each marks the end of a year’s growth. During their ten years of existence, these brackets must have produced billions of spores.

Poplar Hawk-moth

This well-camouflaged poplar hawk-moth  Laothoe populi was found roosting on the wall of the Biological Sciences building. Its caterpillars feed on poplar and willow, which are both present nearby on land surrounding the Mountjoy site, so it's likely that this is a breeding species here. For more information on this species visit http://ukmoths.org.uk/show.php?id=28