This evening, a pair of them were feeding their young on the power-line outside my house, so I took a few photos. Here is a slideshow of the best ones (original photos here):

Swallows rock.

We were just sitting out in the garden, enjoying the lovely sunny evening, and drinking tea (Yorkshire Tea, obviously).

“The swallows are late this year,” I said. “I’ve seen them elsewhere, but they haven’t made it into the hills yet.”

Ten seconds later: “Swallow!”

Not quite enough to make a summer, but we’re getting there.

Swallow feeding its young on the gutter of my house (More photos »)

Not that it’s been much of a summer.

• Swallows preparing for migration
• Crane fly season
• Swallows’ feeding habits

Over the years, I have noticed other ways in which the weather influences swallows’ feeding habits. Last weekend, the weather was so cold and miserable that the insects stayed very near the ground, meaning that the swallows were flying at knee-height as they broke either side of me while I watched them from by back lawn. Earlier this week, during an uncharacteristically seasonal warm spell, they flew either side of my car chasing the insects in the shade of a local wood. One evening the summer before last, I watched them flying about the eaves of my house in pursuit of the craneflies that were basking in the residual heat radiating from my west-facing wall. On windy days, I look for them flying low on the leeward side of drystone walls, chasing the insects sheltering there. And on very, very wet days like today, they congregate underneath one of the sycamore trees in my garden, feasting on the insects sheltering from the rain.

Swallows feeding beneath the sycamore in my garden this morning

• Swallows preparing for migration
• Crane fly season

It looks as if summer has officially arrived in the Pennines.

What are the odds we have snow next week?

• Swallows preparing for migration
• Stone the crows (which, despite appearances, is about lapwings)

It’s crane fly season here in West Yorkshire. Last week, we were suddenly inundated with them. One week there wasn’t any sign of them, the next they were all over the place—particularly in the evenings.

I didn’t know, until I looked it up, that crane flies spend most of their lives underground in their larval forms, which are known a leatherjackets. I knew that leatherjackets were very common round here, and are a favourite food of the local crows (particularly the rooks), but I did not know that leatherjackets transform into crane flies. You learn something every day.

I naturally supposed that crane flies emerge en masse to increase their chances of encountering a mate—which I still guess is right. But then I had another thought: emerging en masse will also give the individual crane flies a better chance of avoiding being eaten by predators: plenty more fish in the sea, so to speak. And then it occurred to me that they emerge in early September, which is about the time that swallows traditionally start heading south for the winter. Could the timing of the crane flies’ emergence in September be an adaptation to avoid being eaten by swallows?

If so, it isn’t a 100% reliable strategy. One evening last week, a family of swallows spent a good half-hour hunting around the west-facing eaves of my house. I initially mistook them for local bats—I had not seen swallows that close to the house before. I wonder if they were hunting crane flies, which appear to be attracted to the residual warmth of the building after sunset.

See also: Swallows preparing for migration

Postscript: Telegraph: Hot weather breeding boom brings invasion of the daddy long-legs

It’s getting to be what the locals around here refer to as a little back-endish—by which they mean summer is on its way out, and autumn approaches.

Returning to my house today, I spotted several swallows congregating on the nearby telephone wires. At this time of year, this is a clear sign that they are preparing to migrate south for the winter. As they appeared to be fairly settled, I grabbed my camera and walked back down the hill to fire off a few photographs. It turned out that the swallows on the telephone wires were recently fledged juveniles, who were waiting to be fed. I watched for ten minutes or so as their parents gathered flies over the adjacent fields and returned to feed their young.

By coincidence, I am currently reading Richard Mabey’s biography of the famous Eighteenth Century naturalist, Gilbert White (Amazon UK), who was an early influence on Darwin. White was fascinated by swallows. Their annual appearance in spring and disappearance again in late summer was still a mystery during his lifetime. In February, 1769, he wrote to his friend, Thomas Pennant:

When I used to rise in the morning last autumn, and see the swallows and martins clustering on the chimnies and thatch of the neighbouring cottages, I could not help being touched by a secret delight, mixed with some degree of mortification: with delight to observe with how much ardour and punctuality those poor little birds obeyed the strong impulse to migration, or hiding, imprinted on their minds by their great Creator; and with some degree of mortification, when I reflected that, after all our pains and inquiries, we are yet not quite certain to what regions they do migrate; and are still farther embarrassed to find that some do not actually migrate at all.

To his dying day, White never did find out for certain whether swallows migrated or hid (by which he meant hibernated). We now know that swallows migrate from Britain to South Africa during our winter: a phenomenal journey for such a small bird. And we now know that this impulse to migration is not imprinted on their minds by a creator, but by evolution.

Darwin was right: there is grandeur in his view of life.