Coronavirus lockdown: still more birds

In a normal year, spring would be the time that I would have visited many of the best wildlife locations here in northern England - the Lake District, Teesdale, Weardale, the Tyne valley, the Yorkshire Dales and the Northumberland and Yorkshire coasts. Instead, the coronavirus lockdown has confined me close to home, but it has been a real eye-opener. By following the same route around my local patch every morning, I've been able to watch spring unfold leaf by leaf, and have come to appreciate a the wealth of wildlife within one mile of home, here in the North Pennine foothills.

So, here are some birds seen within the last couple of weeks.

Blue tit, just at the moment when oak buds begin to burst

Singing male chaffinch. With so little traffic on the roads, hearing bird song so clearly every morning has been pure delight.

The calls of curlews in the pastures have been a constant accompaniment to early morning walks

I see magpies feeding on the ground in one of the smallholdings along my route

Cock pheasant

Perhaps the greatest, most uplifting joy has been the song of skylarks. Fine weather on most days has meant that they have been singing, high in a clear blue sky, I must pass at least a dozen pairs every morning.

Song thrush

I always knew there were yellowhammers here, but never realised there were so many.

There is a large pond hidden amongst the trees, which is where this pair of Canada geese will be nesting. Sometimes they graze in the pastures.

Partridges, like yellowhammers, are a red list species but they seem to be doing fairly well here. As the grass in the pastures grows taller they are becoming more difficult to spot. They spend quite a lot of time in an oilseed rape crop, where you can sometimes see them along the tractor wheelings.

A large muck heap, on the edge of one of the pastures, is a favourite place for pied wagtails to hunt flies.

I saw the first swallow in the third week of April but, nearly three weeks later they haven't arrived in large numbers yet.

A tree full of wood pigeons

I hear this blackbird singing every morning, but he rarely shows himself this clearly

Golden plovers in a sheep pasture. Surprise visitors, staying just one day on their way to breeding sites on the fells of Weardale.

Lapwings in the pastures now have eggs, so they become vociferous if anyone comes too close.

Whitethroat, nesting in brambles on the edge of an oilseed rape field.

One morning, I watched jackdaws plucking hairs from the winter coast of a horse, for use as nest lining

I'm seeing goldfinches more frequently, now that colt'sfoot and dandelion seeds are ripening -  favourite food items

One morning, I saw these linnets on the road ahead of me, collecting scraps of sheep wool for nest lining.

By early May many birds had nestlings to feed. This starling was collecting earthworms in a smallholding sheep pasture.


Some that got away:
Great spotted woodpecker - just a flypast, too quick for me
Goldcrest - early morning on a dull day, so no light and constantly moving
Oystercatcher - away in the distance in a field, probably on their way to breeding sites in Weardale
Sparrowhawk - too high, too fast

Nomad bee and apple blossom

This little nomad bee Nomada sp. has a real liking for crab apple blossom in our garden.

These bees are cleptoparasites, laying their eggs in the nest holes of a mining bee while their host is still provisioning it with pollen, intended to sustain its own larva when its egg hatches.

The nomad bee larva hatches first, eating the host egg and then feeding on its stored pollen.

The light, sandy soil in our garden seems to suit mining bees well, but  parasitic nomad bees and bee-flies must surely limit their breeding success.

There are over 30 species of nomad bee in Britain, many rather similar in appearance, but I would hazard a guess that this might be Panzer's nomad bee Nomada panzeri which is one of the commonest, most widely distributed species.

Bee-flies, tawny mining bees and blackcurrant bushes

There seemed to be dark-edged bee-flies Bombylius major all over the garden during most of April, either sunning themselves on stones or collecting nectar from lesser celandines, aubretia and primroses. 

These parasites drop their eggs near the nest holes of mining bees, where their larvae take over the unfortunate host's pollen store and complete their development at the expense of the bee's own offspring. The season for this activity in spring is quite short so the parasite and host's flight periods need to synchronise and the parasite needs to be able to find those egg-laying sites, which can be quite inconspicuous.

Bee-flies are restless, highly active insects that hover while the feed, and this makes them fairly easy to photograph, but they also spend a lot of time simply hovering in one spot, high above the ground, without feeding.

In our garden they almost always choose the area around the blackcurrant bushes to hang motionless in the air, sometimes for many minutes, and I've often wondered why they indulge in this energetically expensive behaviour, where they burn fuel in much the same way as a helicopter, simply to stay in one place. And what it is about the blackcurrant bushes that attracts them? It could be that  they congregate here to find mates, but they can easily do that at the floral feeding sites. 

I think the answer to why they congregate in the air above the blackcurrants is that one of the common pollinators of blackcurrant flowers is the tawny mining bee Andrena fulva, whose nest holes they parasitize. 

So could it be that this is where the bee-flies loiter to  identify their hosts, and then follow their pollen-laden victims back to their nest holes? If so, do they identify the mining bees visually - that orange fur does make them conspicuous - or is there something more subtle that gives away the host bees' presence - scent, maybe?

No easy way to answer that last question, but next spring I'll be watching again, to see if the hovering bee-flies do follow the mining bees when they leave the blackcurrant flowers and head for their burrows.