Treecreeper

Treecreepers are beautifully adapted to hunting for small insects in the bark of trees. Those long, needle shape claws give them the grip they need to climb and hang on the underside of branches and their beak is like a long, curved pair of fine forceps. You can often see them in the Botanic Garden (where this one was photographed on an alder tree on Monday lunchtime) or along the woodland nature trail at the bottom of the garden.

In winter they are most often seen in small flocks of blue tits, great tits and long-tailed tits but from spring onwards they're more solitary. Treecreepers have a characteristic foraging strategy, starting at the bottom of the tree, working their way upwards and exploring every crevice until they're maybe 5 -10 metres above the ground then flying to the base of another trunk and starting all over again. Nuthatches tend to use the reverse strategy, often climbing down trees head-first.

Treecreepers nest behind loose bark on dead trees.

Bulrushes

When the pond behind Mountjoy 2 was formed, at the end of the 1990s, it was delibaterately plants with a wide selection of native plant species, to create a teaching resource and a habitat for the wide variety of animals that would soon colonised it. The northern and eastern edges of the pond are planted with bullrushes (or, to be botanically correct, reedmace).

Bulrushes are unusual plants inasmuch as they flower in autumn and produce their ripe seeds in spring - the exact reverse of the reproductive sequence of most of our native plants - so in March the 'maces' burst open and release drifting clusters of these cottony seeds.

Seven-spot ladybird

This little huddle of native 7-spot ladybirds on the Science Site, still hibernating amongst a cluster of wild cherry flower buds that were just beginning to loosen their bud scales in today's sunshine, make a useful comparison with the superficially similar alien harlequin ladybird, which arrived in Durham last year and which you can find out more about here. The red and black-spotted form of the harlequin has more spots, a more domed body and is noticeably larger.... and we'd like to hear from anyone who thinks they've found one.  

Frogs and Toads

The various ponds throughout the university, in college grounds and in the area behind Mountjoy 2, provide excellent breeding sites for frogs (above) and toads (below). Frogs lay large blogs of spawn in shallow water in spring, while toads deposit long strings of eggs around waterweeds. A very large toad population has developed in the large pond behind Mountjoy 2, which hosts hundreds of toads that emerge from their hibernation sites in Hollingside and Little High Woods in March and migrate to the pond, producing their distinctive barking mating calls when they arrive. By Congregation Day in late June the young toadlets are ready to leave the pond and leave the water to hunt for small insects and slugs in the grasslands and woodlands nearby.

Long-horn moth

This little day-flying moths with disproportionately long antennae breeds at several locations on the university estate, including beside the footpath that runs along the east side of John Snow House towards Hollingside Wood and in the Botanic Garden. Its caterpillars feed on dead birch leaves. Only the males have these long antennae, which they use to detect pheromones emitted by females; often, females have a small swarm of eager males fluttering around them.

Tawny Mining Bee

In spring, from mid-April until mid-May, you'll find what appear to be one centimetre-high 'volcanoes' of sandy soil at many locations throughout the university - including the area around the trees outside the library. They are the entrance holes to the nests of this mining bee, which excavates a chamber underground where it lays its egg and provisions it with pollen collected from spring-flowering plants like dandelion.  The larva develops underground on its subterranean food store, pupates and then emerges in the following spring, to begin the cycle again. This species is an important pollinator of fruit trees and also has a fondness for gooseberry blossom.

Himalayan Balsam

Himalayan balsam was introduced into Britain's gardens in 1839 and has since spread throughout the length and breadth of the United Kingdom, along the banks of rivers. The walls of its seed pods develop internal tensions as they dry out, so when they are ripe they explode at the slightest touch and scatter seeds in all directions. The flowers provide a rich source of pollen and nectar for bees in late summer and early autumn. Until recently it was assumed that the spread of this plant might have a devastating effect on native riverbank wild flowers but recent studies indicate that it has a relatively minor impact, and that removing it could create open habitat for more aggressive and damaging weeds. The plant grows along the bank of the River Wear, especially between Millburngate and Prebends bridges, and there are small colonies on university land - at the top and bottom of 'Cardiac Hill' on the Science Site, for example.

Cowslips

Cowslips have been deliberated planted under the trees on the north side of John Snow House on the Science Site and the dense population that has now developed produces a good crop of seeds, so these attractive grassland wild flowers are steadily spreading outwards from their original site of introduction.

Banded Agrion Damselfly

Several species of damselfly breed in ponds on the university estate but banded agrion damselflies have so far only been recorded from the small stream that runs from Van mildert college pond and through the southern edge of the Botanic Garden. They are most often seen in late June and July. Only the male has these blue-spotted wings - the female's wings are transparent and her body is a duller shade of green. Both can sometimes be seen resting on the beech tree leaves beside the stream at the point where it runs along the edge of the haymeadow in the Botanic Garden. The males defend a short stretch of territory along the stream and perform a courtship dance in front of the females - an aerial ballet that leads her to the site for egg laying.

Common Darter Dragonfly

On sunny days in July, August and early October you are likely to find common darter dragonflies basking on sun-warmed surfaces around the large pond behind Mountjoy 2, between the science site and the Botanic Garden. Dragonflies' large eyes provide almost wrap-around 360 degree vision and the hundreds of separate lenses in each eye makes they very senisitive to anything moving across their field of vision, but if you approach slowly you can usually get a close look at them. During egg laying the male grips the female behind her head with the tip of his tail and they fly in tandem low over the pond edge, with the female dipping her tail in the water to deposit eggs on waterweeds.