Thursday, December 17, 2020

Handsome heron

 

This very handsome heron has taken to perching on a rock just downstream of the bridge over the river Wear at Wolsingham, offering excellent views of his preening activities. The heron breeding season begins in February, so I imagine this is a prelude to February courtship.









Wednesday, December 9, 2020

Roe deer

 I often see roe deer in the distance when I'm walking in Weardale, but it's usually just bobbing white tails in the distance as they bound away amongst the trees. But these two - a mature doe and her almost full-grown fawn - were unusually cooperative and hung around long enough for me to take some pictures.


The fawn has a darker, rougher coat and smaller ears.






Wednesday, December 2, 2020

Gorse seed weevils

 Gorse can be found in bloom in every month of the year, even in the depths of winter. I don't know how many of these flowers produce seed without bumblebees and honeybees to pollinate them but I do know, from experiments I did years ago, that their pollen is viable and capable of germinating at low temperatures, close to freezing. So it may be that, with some violent buffeting from winter winds, some pollen is shaken onto stigmas and they do produce some seed.








If they do, then they may avoid seed predation by the gorse weevil Exapion ulicis, which hibernates through winter. This little beetle emerges from hibernation in spring and lays eggs on the ovary, where its grubs feed on the developing seed through the summer. They pupate as the pod ripens and adults often hatch in the pods, only to be thrown out along with any remaining seeds when the pods burst open on warm summer days.


When the autumn weather is wet some of the seed pods do not develop walls that are brittle enough to split open, so the weevils die, trapped inside. I took some old, undehisced pods home and opened a few to see if there were any dead weevils inside, and found a few live ones. 

















When they fell out of the pods I thought they were dead, because they were lying on their backs with their legs curled up, but this was just thanatosis - feigning death, a predator avoidance strategy which weevils often use when danger threatens. Soon their were waving their legs in the air and rolling over onto their feet, to scuttle away across the kitchen table.















Gorse seed weevils are very effective seed predators and have been used in New Zealand and California, where gorse has been introduced and has become a noxious weed, in attempts to limit its invasive tendencies.





Sunday, November 29, 2020

Sphagnum (bog moss) spore capsules

I don't often find spore capsules on bog moss Sphagnum species but they are well worth looking out for because they have a remarkable way of discharging their spores. 



















They look like chestnut brown spheres, that swell and darken as they age.

When they mature you can see the lid. At this stage they remind me of tiny ginger jars. Gas pressure builds up inside as they age, and when the wall begins to dry out it shrinks. Eventually the pressure within  becomes so great that the capsule explodes, blowing the lid off and sending a column of spores into the air.


You can watch a video of this explosive 'air gun' mechanism  by clicking here

Sunday, November 15, 2020

Salmon and sea trout

The salmon and sea trout spawning season is over for another year, but while it lasted there were some spectacular opportunities to view of these fish trying (unsuccessfully) to leap Spurleswood beck waterfall at Blackling Hole in Hamsterley forest. After prolonged heavy rainfall, when the beck is in spate, the water falling into the deep pool creates upwelling conditions that the fish exploit when they try to make the jump.










Buzzards and Kestrels

 When I first came to Durham 45 years ago, it would have been a rare pleasure to watch a buzzard soaring overhead. I could only be sure of seeing them if I crossed the Pennines into Cumbria or travelled into Wales. Now, I see them here almost every day. No less that eight circling overhead at once when I was walking near Wolsingham in Weardale last week. Maybe easy access to road kill, and the plentiful rabbit supply locally, are factors that have led to an increase in numbers?














While buzzards bred successfully and became established here, kestrels seemed to go into decline over the last couple of decades, although they seem to have done much better lately. 















I photographed this young bird hunting along the sea cliffs at Dawdon near Seaham, on the Durham coast. It must have hovered a dozen times without stooping on prey and it didn't make a successful kill while I watched. Perhaps still perfecting its hunting kills. They seem to expend a lot of energy for small, infrequent rewards.




Wednesday, August 26, 2020

Goldfinches

Goldfinches must be the most colourful of all the native finches. I have seen then on most walks this year, first as single pairs in spring and, once their breeding season was over, in flocks, often in the company of linnets.


Immaculate breeding plumage, in spring.
This side view shows the beak well - longer and more pointed that most finches, perfect for wheedling seeds out of teasel heads in autumn

In late spring, dandelion seeds are a favourite meal

That pointed beak is also perfect for extracting seeds from ripe larch cones

And later in the year their diet sometimes switches to oilseed rape seeds


Late summer and the breeding season is over. Often in mixed flocks, with linnets on the Durham coast



Late in the summer, knapweed seeds are favourite food

I often see flocks on up to 200 goldfinches on the Durham coast between Hawthorn Dene and Dawdon,  in early autumn

Saturday, August 22, 2020

heather moorland in August

 The moorlands of Weardale are a sea of purple heather at the moment, often stretching all the way to the horizon. Billions of tiny, nectar-rich flowers are in bloom, feeding vast numbers of insects, from minute thrips to butterflies.



The flowering of the heather coincides with the breeding season of these heather Colletes bees (Colletes succinctus), below. They lay their eggs in tunnels excavated in the sandy moorland soil, usually on a south facing patch of bare ground, then provision the egg with heather pollen before sealing the chamber. They're solitary bees, unlike the highly organised, social nests of honeybees and bumblebees, but do aggregate their nests in huge colonies. Yesterday we must have walked past many thousands of them, congregating at the entrance to their tunnels and shuttling backwards and forwards to the heather flowers.



The vast expanse of flowers also attracts butterflies. Yesterday we saw red admirals, small coppers, small tortoiseshells and small heaths. The small coppers breed on dense, transient patches of sorrel that grows quickly on the bare soil after a heather burn.



This 'woolly bear' caterpillar (below) is the larva of the northern race of the oak eggar moth Lasiocampa quercus. It spends two years in the larval stage, overwintering as a larva before emerging to feed again, then pupating over a second winter before it finally emerges as a spectacular moth.



And finally, a rove beetle Platydracus stercorarius, with wings tightly folded under those red wing cases