Loads Of Housemartins This Morning

[rowanwitch]

I think they have all raised a second brood as there were a hundred plus adults and juveniles zipping around this morning they have dispersed to feed now but they are blooming noisy en masse. Count down til they all leave now although some years we get hundreds of swallows on the move through the area heading South using the balcony rails and anti pigeon nets on the block as resting spots. We are the highest point for miles and have parks, fields and a reservoir very close by. Perfect for a birdie pitstop.

[Khandro]

I have eight nests on the front of my house, a couple of days ago there were hundreds in the sky from all in the neighbourhood.

I think they are starting to rehearse for their exit.

What always puzzles me is how do they know when the moment to leave is? when do they know 'today's the day' & not a rehearsal?

[ToraToraTora]

Must be happy hour :)

[rowanwitch]

Combination of day length, temperature, and shift in prevailing winds, it's normally the first decent winds from the North West that seem to trigger them. Normally around 15th to 20th september, but last year we had a few stragglers into October. They were probably northern birds rather than the ones that had nested here.

[Khandro]

Huge flock again his evening. I'm sure it's practice & the newborn can get the hang of things before the astonishing departure for South Africa.
But my question remains; which one says "now!" ?
Is there such a thing as an alpha-house martin?

[seekeerz]

Must be Khandro, or maybe their lives are better organised than ours - still amazing though :)

[rowanwitch]

Average lifespan is just two years but a flock may have a few three year old birds who would know they had to leave, and if they take their brood , they could trigger a movement in the direction they need to travel but it's more likely they are following the food... As it gets colder further North they head down to where food is still more plentiful. It's likely flocks of migrating birds leapfrog one another so the birds you see one day are not necessarily the ones that were there last week