Today is a mixed feeling day as I'm suffering from empty nest syndrome. As I mentioned in my last post, my house is home to a house martin nest, sadly just the one, but being colonial nesters, all the houses around me with suitable eves also have a nest. It was quite sad this spring because in the middle of that very dry spell between March and May they arrived back and attempted to build another nest on my house but there just wasn't enough mud about to build one. The solitary dawbs of mud now splattering my wall are all that is left of their gargantuan attempt to beat the unpredictable British weather.
Most mornings (and evenings) I'm serenaded by the squabbling and activity of my martins. This morning though it was especially noisy. From the bedroom window, constant sleek bird shaped shadows darted hither and yon to the nest. Sounds of increasing activity drove me outside to have a look at what was happening, or at least what I thought was happening. And I was right.
The fledgelings were leaving the nest, with encouragement from the adults and already emerged young birds. House martins when fledging strictly speaking don't permanently leave the nest, they vacate it and can come back at night to roost, or in bad weather can seek shelter there. But this morning, I think was the second brood's first foray into the wide open skies of Somerset. And a good morning too, blue skies after a night of deluging rain of Biblical proportions.
It's always difficult knowing how many house martins are fledging. Normal brood size is 4-5 eggs and generally mortality of chicks is quite low. Today I think 5 fledged as at one time there were 7 birds around the nest, both flying and clinging to the wall. It was absolutely fantastic watching them as individual birds flew to the nest, around the nest, went into the nest and emerged out of the nest in very rapid succession. Occasionally a head would be seen at the nest entrance and another bird would fly up to it, chattering away, before both birds flew off in a wide downward arc and away, only for the whole process to be repeated again.
Last year my pair managed to raise 3 broods, they finally left in early October. I don't think this year is suitable for three broods, and in a way I hope they don't lay again because if the weather deteriorates they'll just abandon the chicks and head south to Africa. I will have a think over the winter whether there's a way of providing ledges of something on the house to help more nest be built next year, as I'd love to have half a dozen on the house, no matter how messy they make the windows.
It's a worrying time for lovers of house martins. Although there are about 3-400,000 pairs in the UK at the moment, this is actually a 60% or more drop in population from the 1980's and why the bird has been amber listed in the IUCN system since 2002. No one really knows why they are declining so fast, but as they are intricately linked to human habitation (even their scientific name urbica and colloquial name refer to dwellings) there may be a link to modern houses being less suitable, having fewer eves and overhangs. Certainly fledging data suggests pairs of adults are raising chicks with no change in mortality. But then again, insect numbers are fluctuating, and with climate change the Sahara is expanding. Is it just too far now to fly south to their wintering grounds. However on the plus side if winters continue to warm in Europe, which after the last 2 winters seems astonishing, potentially martins may follow a small percentage of their swallow cousins who increasingly seem to be able to overwinter in north Africa rather than fly across the Sahara.
Originally martins were cliff dwellers much like their cousins the sand martin, although the latter make nest holes in soft sediment and not nests. At some point now lost in the depths of history, they took to nesting on buildings, attaching their mud nest cup under eaves, presumably when houses began to be stable enough to replace the rigidity of rock. If you think about it the first solid houses built were castles and they were built often on rocky outcrops. So did the martins just make an obvious leap, when natural nest sites were exhausted. The nest is just fabulous and takes up to 10 days to build, and over 1000 beak sized pellets of mud. So that is 2000 flights from and to a nest in 10 days. An enormous effort. And that's possibly why this year other birds failed to make new nests on my walls. My theory is as everywhere nearby was parched earth, the nearest mud is the river, a quarter of a mile away, just too far to be worth while. But it is worth it as if a new nest successfully fledges chicks, the adults will return each year to re use it with just a light renovation each spring.
The other interesting thing with the martins around me is there are a lot of nests around my house but few elsewhere in the estate. The house and a few others around me were built in 1997 and half a dozen used to be the show houses. Show houses tend to be built literally in a building site. My theory is then that the martins again spotted an opportunity and built on these new show house cliffs surrounded by the mud of a building site. A perfect habitat and they have kept coming back ever since. Whereas in other parts of the estate they never got established and as the mud was built over, they could not colonise beyond this initial colony. I don't know either why martins never seem to build nests on dark eves, always one painted white. Most of the houses here have dark eves.
References to house martins in literature and folklaw are surprisingly few and far between. Which I find odd given that the swallow has been a writers muse for generations. but I think we should change that because they are such beautiful birds. Christians think the bird is lucky, possibly as it has connections as a servant of god, and in olden days it was thought lucky to live in a house with a martins nest if the young fledged successfully.
I'd agree with that, I'm a very lucky man to share a house with such wonderful birds of the air.