[Tweeters] Kestrels

[Bud Anderson via Tweeters]

At Sea-Tac Airport about six years ago, we had an unusual summer
concentration of kestrel family groups.

A normal family group is 7 birds, 2 adults and 5 young.

They congregated in mid-July through mid-August on the grassy areas between
runways, feeding on the late summer grasshopper bloom.

I caught, banded and relocated 35 birds during that short period and,
unfortunately, many others were struck by aircraft.

It was a remarkable storm of kestrels and I had never seen that number at
the airport before.

So, good productivity of young kestrels and good grasshopper numbers can
definitely create concentrations of these small falcons.

I have heard reports of a kestrel decline in the eastern US, but in my
experience and that of others, I don't know that there is hard evidence of
a decline here in WA.

Perhaps Sue Cottrell or Kent Woodruff could comment here. Both are banding
large numbers of kestrels in WA.

Finally, I hope that people understand that ageing kestrels in the field
can be very difficult. Females, even in hand, especially so.

Relatively recent studies have demonstrated that the old characteristics
for ageing females, used since the 1950s, were inaccurate.

Who would have guessed?

Bud Anderson
(360) 757-1911
falconresearch at gmail.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman11.u.washington.edu/pipermail/tweeters/attachments/20250812/f201c018/attachment.html>