Mass Migration

Think of mass migration and the movement of a million Wildebeest across the Serengeti will probably come to mind. However, an equally impressive migration of around 600,000 birds has been taking place into the UK, and particularly over Durham, during the last few days.  

Wildebeest in East Africa - probably the best known mass migration event (Photo: Steve Willis)

Having said that, it probably passed most people by – largely because it is occurring at night, and a few hundred feet above our heads. Over the last couple of foggy nights there has been a large migration of Redwings, a thrush species, from their breeding grounds in the Arctic to the UK . They leave the Arctic in autumn to spend their winter in warmer climates. The huge migration over Durham during the last couple of evenings has probably been prompted by the very cold arctic weather that is currently heading our way from the north. These birds will have crossed the North Sea after leaving mainland Europe and arrived on a broad front along the east coast  of the UK.

If you can find a quiet area outside, away from traffic, and listen for 5-10 minutes one evening, you will have a good chance of hearing their characteristic, thin ‘tseep’ call as they pass overhead.

This amazing natural phenomenon happens every year at about this time but goes largely undetected.

Redwing

From now onwards it is worth looking out for Redwing (a small thrush with a white eye-stripe and an orange-red patch under it’s wing - see above) foraging on the ground under trees in Great and Little High Wood and through the Botanical Gardens.

Nocturnal activity

Badgers are relatively common, though seldom seen, around the university. At this time of year you are very unlikely to see a badger in daylight but they are still very active at night. In September and October they spend more of their time than usual collecting bedding to take down into their setts, in preparation for winter. They also increase their feeding rates to put on sufficient fat to survive the winter.

The photo above was taken on an infra-red, motion triggered camera that is being used to monitor wildlife around the Durham campus.

First and last of the summer butterflies?

After an especially dreary summer for butterflies across the university estate, the better weather of the last couple of weeks produced a flurry of last minute activity, albeit with species occurring in very low numbers compared to most years. The wet summer has caused large population declines in the commoner butterflies such as Peacock and Small Tortoiseshell (below), which can usually be seen in good numbers on Buddleia plants around the botanic gardens.

Small Tortoiseshell (Photo: Steve Willis)

Late flying second and third brood butterflies started to emerge in late August and include recently emerged Comma, Speckled Wood (below) and Peacock; the former two only having colonised Durham from further south in recent decades in response to changing climate.

Speckled Wood (Photo: Steve Willis)

Uncommon Waterside Warblers

Two of the least common birds around the university, both of which often have an affinity for water, are the sedge warbler and the grasshopper warbler. The grasshopper warbler is named after its insect-like song. Click on play in the link below to hear this unusual song:

http://www.rspb.org.uk/wildlife/birdguide/name/g/grasshopperwarbler/

It has been allocated a red-list conservation status in the UK, indicating a species of high conservation concern due to a long-term population decline. Listen for the reeling song of the grasshopper warbler in thick vegetation along the Durham riverbanks and in dense hedgerows.

Sedge Warbler (Photo: Steve Willis)

The sedge warbler is a very rare breeder on the university estate, with the small reedbed near the Mountjoy buildings being the only site to regularly hold a breeding pair. Although rarely seen, its grating and scratchy warble usually gives away its presence:

http://www.rspb.org.uk/wildlife/birdguide/name/s/sedgewarbler/

St Mark's Fly

Walk almost anywhere where there is rough grassland on the University estate right now and you will see the air full of jet black flies with long dangling legs. This is the St Mark's fly, so called because it is supposed to appear on St Mark's day (April 25th).  Take this with a pinch of salt however.  This year, the long cold Spring seems to have held them back.  

The dangling leg flight is thought to be all about finding a mate. This settled fly is a male - they have larger eyes that meet together on top of the head. 

Phil Gates' blog  - Beyond the Human Eye (click here) has some excellent close up shots and more information.

Tawny Owl Treat

Participants on today's lunchtime biodiversity programme guided walk led by Allan Watson -  'Birdsong for Beginners' were treated to this fine sight from the footpath into Great High Wood.



Photo: Allan Watson


Tawny Owls are the most nocturnal of the three species of owl recorded on the University estate. Of the other two, Barn Owls are fairly regularly seen in daylight towards the end of the day and Little Owls are almost completely daytime birds.  To see a tawny owl right out in the open in full view and in broad daylight is relatively unusual.  They almost always hunt between dusk and dawn but they are recorded hunting in the open during daylight when they have young in the nest - as is the case now. (For a photo of a young tawny taken in the botanic garden, click here)

'Tu-whit, tu-who' as Shakespeare wrote in Loves Labour's Lost.  Except that William got it famously wrong. Both male and female make the typical 'hu....huhuhuhoo' call and both make a separate contact call, a sharp 'kee-wick' but neither does one straight after the other.  You might get close to the bard's description if you happen to catch a 'kee-wick' from one bird followed by a 'hoo-hoo' from the other.

However, this one did not seem to realise that we were on an aural exploration and stayed resolutely silent.

Reed-bed Birds

With Spring well and truly underway, now is the best time for seeing or hearing many of the bird species around the university. Two species currently singing from the small Reedbed by the Mountjoy buildings are the appropriately named Reed Bunting and Sedge Warbler. Several pairs of Reed Bunting, an uncommon local breeding species, have territories around the Mountjoy fields - some nesting in the scattered patches of bramble and willowherb. The unmanaged rough grassland here is a vital habitat for these breeding pairs.

Male Reed Butning. Mountjoy Reedbed

The male Reed Bunting (above) is easily identified by its black head and white moustache. One can often be heard singing its simple repeated song from the top of reeds in the reedbed. The song has been likened to a child learnng to count, but continually forgetting where it has got to and having to start again ('one ... one, two, ... one, two three, ... one, two ...').

Female Reed Bunting/ Mountjoy Reedbed

The female Reed Bunting (above) is more cryptic, and well camouflaged, looking like a well-marked sparrow, and it usually requires sharp eyes to spot her moving through the lower level vegetation.

A Wealth of Warblers

The university estate supports a high diversity of breeding birds, including a wide range of migratory warbler species. Now is the ideal time of the year to look for these often elusive birds, as they become more obvious when setting up a breeding territory and singing.

Seven species of warblers breed on the university estate in most years, including Willow Warbler, Chiff-chaff, Blackcap, Garden Warbler, Whitethroat, Sedge Warbler and Grasshopper Warbler. Most of these species are now back from their wintering grounds and are singing around the university grounds.

Whitethroat - doing a good job of hiding its white throat.
Photo: Phil Gates

Blackcaps and Chiff-chaffs are very common around Durham this year. There aren't many sections of the University woodlands in which you cannot currently hear the rhythmical song of the chiff-chaff (http://www.rspb.org.uk/wildlife/birdguide/name/c/chiffchaff/).

Chiffchaff. Photo: Allan Watson

Similarly, most bushy areas and woodland margins have the warbling song of a male black-cap emanating from them at present (http://www.rspb.org.uk/wildlife/birdguide/name/b/blackcap).

Blackcap. Photo: Steve Willis

The populations of these two species, both of which migrate relatively short distances for warblers (most of our birds probably spent the winter in Spain or North Africa), have increased considerably across the whole of the UK in recent years.

Marsh Marigold

If you take a stroll up to Mountjoy you will see these cheerful plants around the edges of the pond. They have been in flower for well over a month now and provide early sources of nectar for bees.

Its Latin name, Caltha, is derived from the Greek for ‘goblet’, giving it another common name ‘Kingcup’.

This commonly found plant is a member of the buttercup family and can be successfully grown in the garden in damp spots or, like these ones, on the edges of ponds.

(Text and photo: Steve Ansdell)

King Alfred's Cakes

There is a dazzling array of different fungi to be found around the estate as the photo above shows. King Alfred’s Cakes (Daldinia concentrica) is commonly found on the dead wood of ash as this specimen was. It was photographed at the edge of Blaid’s Wood, just past the sewerage works at the bottom of Hollingside Lane.

The name comes from the legend that King Alfred, who was hiding from the Danes, once burnt some cakes by failing to take them out of the oven. The fungal growths, which look as if they have been burned, are a reminder of his poor cooking skills!

For the bushcraft fans amongst us – the dried inner flesh of the fungus can easily be lit, a bit like a barbeque briquette, and then laid on some dry grass or twigs and before you know it, you have a fire going.

Please don’t try this in the University woodland though!

(Text and Photograph by Steve Ansdell)

Know your onions … and cabbages

The damper areas of the University woods are currently ablaze with the white flowers of the Wild Garlic, the leaves from which are great in salads and soups (pick a few of the fresh green leaves but leave the bulbs in the ground), having a similar but milder flavour to domestic garlic bulbs. The link below links to some recipe suggestions:

http://uktv.co.uk/food/ingredient/aid/585886

A rarer form of the onion family, and one without any culinary appeal is the Few-flowered Leek (below), which has become naturalised in only a few places in County Durham. One such site lies close to the University Botanic gardens, though you would have to be sharp-eyed to pick it out from among the surrounding grasses once its few flowers have dropped off.

Another non-native species that is very rare in County Durham but which occurs around Van Mildert college pond is the Skunk Cabbage. Despite its name, it isn’t related to cabbages at all. In fact it is a type of Arum lily. As its name suggest, it is rather smelly and not remotely edible. The skunk-like odour it's flowers give off is designed to attract flies and beetles to pollinate the flowers.

Bats about St Cuthbert's

'Can you come and get this bat out of our lightshade please?'  A strange but true start to a working day last week because this fully grown adult female pipistrelle bat did indeed manage to get itself trapped inside a light shade in one of St Cuthbert's College accommodation blocks.  

The most likely theory is that the bat got into the loft space above the light fitting, crawled through the small gap that the electricity cables pass through and ended up inside the shade unable to find its way out again.  The fully enclosed shade contained two light bulbs, permanently on, and so the bat was very hot, very dehydrated and emaciated.  Luckily, the University's energy saving policy meant that lower power energy efficient bulbs were fitted.  Had they been traditional light bulbs the bat would have been unlikely to survive the extra heat generated. So, our energy saving policy is good for bats as well as for the environment and the University bank balance.   After a few days in captivity, fed on a luxury diet of mealworms, the bat had recovered sufficiently to be released successfully.

Given that St Cuthbert is credited with introducing the first ever bird protection laws in the world when living the hermit's life on the Farne Islands in the late 600s, the great man would surely have been delighted to have a bat in his college.

Durham University estate and its buildings provide roost sites and feeding habitat for at least 6 of the 11 species of bat recorded in County Durham and as such we make a very significant contribution to the conservation and well-being of this declining and misunderstood group of animals.

Confusing woodland warblers

Photo by Phil Gates

A willow warbler, a migrant that spends the winter in Sub-Saharan Africa, was also noted for the first time this year on Saturday, singing by the car park of the Botanical Gardens. The willow warbler’s close relative the chiff-chaff has been heard singing around Durham for the last few weeks now. The two species, which are difficult to separate by eye, can be easily told apart by their very different songs. Click on the links below to listen to their song (click the play buttons):

http://www.rspb.org.uk/wildlife/birdguide/name/w/willowwarbler/

http://www.rspb.org.uk/wildlife/birdguide/name/c/chiffchaff/

Don’t forget to record sightings of these or any other species on the Greenspace Biodiversity link:

http://www.dur.ac.uk/greenspace/internalpartners/biodiversity/records/

Spring has sprung



photo by Phil Gates

 One swallow does not a summer make – or so the saying goes. But if two swallows do, then we’re in luck as the first two swallows were sighted around the Mountjoy Site on Saturday morning.

The two birds, one male and one female were seen flying around the top of the site. Males can easily be told from females by their much longer tails. These two birds could have spent last winter as far south as Cape Town in South Africa before travelling back to Durham.

Spring Woodland Wildflowers

Any of the University's extensive mature woodland areas are a pleasure to visit in Spring. Not only does birdsong fill the air but the common spring flowers are showing their heads and brightening up the lengthening days.  Earliest out is the wood anemone.

Then the bluebells follow.

Perhaps the best bluebell show of all is in Great High Wood, which has a good footpath network readily accessible from the Mountjoy site (follow the track that angles off the main site road just past the smaller of the car parks adjacent to Engineering) or cut into the woods from Hollingside Lane just past the entrance to the Botanic Garden.

It is also well worth stopping to take a close look at the beautiful smaller white flowers of the wood sorrel.

Swifts

A pilot study of Swift nesting boxes has begun at two University colleges, Grey and Josephine Butler, this month. This joint project between Durham University, Durham Biodiversity Action Partnership and Durham Bird Club will monitor the boxes in the hope that migrating birds will breed this summer. Swifts arrive from Africa and look for nesting sites. Most make their home in roof spaces, entering through gaps in tiles or under the eaves. Others nest in the gaps in crumbling brickwork. However, they are struggling to find suitable homes in towns and cities due to the British public's obsession with home improvement.

Swifts are one of the most graceful and speedy summer visitors to Britain. They are such good fliers, they even sleep on the wing. Their wings are scythe-shaped, while their tails are forked.  They eat flying insects and airborne spiders. Unlike swallows, they never perch on wires.

We are very grateful to construction company Laing O'Rourke for assistance in erecting the boxes.

Long-Tailed Tits

These beautiful little birds can be seen all around the estate, including college grounds. They nest in woods and hedgerows where they build a luxury home for themselves and their offspring. They line the nest with up to 2,000 feathers and will fly between 600 - 700 miles searching for the best materials to camouflage it.

When the breeding season is over, they form small, sociable flocks of about ten birds, consisting of adults and their offspring. They search for food together and roost communally, huddling together for warmth.