Swifts (1 Viewer)

I don't know if it's the good weather, but I don't think I have ever seen as many swifts as I have this year. Anyone else noticed a change this year?

JTweedie said:

I don't know if it's the good weather, but I don't think I have ever seen as many swifts as I have this year. Anyone else noticed a change this year?

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In most parts of the temperate distribution, there are four waves* of swifts, normally following a predictable schedule (within one or two days each way), the last wave being those that breed in the far north of their distribution. It's possible that the delayed spring and the delayed arrival of our local breeders coincided with the fourth wave's arrival; the fourth wave may have found themselves affected by the courting behaviour of our local residents; this courting period appeared noticeably shorter than usual, and so perhaps passage birds were influenced into nest-site finding and selection. It's but speculation on my part, but I had thought of it as a possible answer to seeing a second build-up in local numbers beyond that of previous years.
MJB

*1st wave: non-breeding birds, possibly last year's broods.
2nd wave: a small but significant number of 'opportunistic' early arrivals (assumed to be mostly males) that risk starvation if insects are late, but have first pick of nest sites when the bulk of females arrive.
3rd wave: the main movement of birds that breed at temperate latitudes.
4th wave: birds that breed in the smallest window of opportunity in the northernmost breeding distribution, but don't succeed annually.

I have definitely noticed more swifts this year than compared to last. Still no swifts nesting in my swift boxes though the house sparrows who nested in one of them are on their second brood now.

Regards Gerard.

Thanks for the input. I don't know of any nesting sites, and in normal years I see very few of them where I live. I normally have to travel outside Glasgow to see them, but this year I don't think I've gone one day without seeing them outside my window - sometimes just one, but at other times tens of them. I've even seen hundreds of them in a mixed flock of swallows, and house and sand martins.

I did wonder if the late arrival had been a factor too.

Now you mention it JT there are heaps around here as well.

Rich

I have also recorded swifts in places where I haven't seen them in previous years, including sometimes through my window (a small group seems to nest somewhere close to the House Martin colony further down the street, and I also saw HM through my window a lot of times this spring although they are usually absent). I don't see them everywhere all the time; yesterday I went to one riverside place and saw only Barn Swallows, no House Martins or Swifts, although I have seen all three species few days earlier. I guess they all choose their own height and locality of where they will feed each day.
(Barn Swallows seem to be doing especially well at their boat colonies, plenty of juveniles. I was afraid for them because we had long winter)

Based on counts from a single east coast location, the 2013 Swift passage has been above normal. Almost all other summer migrants have been far down on expectations. This includes Hirundines. House Martin is looking like a potential future Red List candidate.

It is only a hypothesis but I am wondering if Swifts are better able to cope with the north-easterly winds which have prevailed this year, than many other migrants. I also sense that Swifts have been feeding closer to ground level more often than in the past. Could this be a consequence of less competition from hirundines. There is no scientific study to support this. Just a thought.

Dave