Swallow feeding behaviour

[tmanson]

Fraser Valley Birders: Yesterday I reported on a mixed flock of Tree, and Violet-Green Swallows feeding just above/and, or. on Bristol Slough, just off the Hope Airport. Today, I had to drive to Mission, and I noticed exactly the same feeding patterns amongst a flock of Tree Swallows on Nicomen Slough. I know Tree Swallows, with their relatively short migrating patterns, are usually the first swallows back in the spring. I've always wondered they feed on this time of year. I don't notice a lot of flying insects around, which generate the usual swallow feeding patterns. I guess this partially answers the question, although I have no idea what insects are hatching on water surfaces this time of year.
Somewhat along the same lines, Jack Delair was telling me about his observations of one of the American Kestrels at the Hope Airport the other day. He said it was feeding on worms!! Bon appetit. Thor

Thor Manson
Hope, B.C.

[Gord]

Thor, Ive also noticed that 90% of the swallows Ive been seeing since they've arrived are ones feeding low over the Fraser River and other water bodies. There is at least 3 violet-green swallows to every 1 tree swallow feeding on the Fraser the last week. There is obviously some sort of hatch taking place as they feed very low to the water and seem to often concentrate their efforts in certain areas. Later in the month a larger species of insect starts to hatch which attracts hundreds of mew gulls picking them off the water as they emerge.

Ive never heard of worm-eating kestrels! A good observation to document!!

[Gord]

Here's a shot of the swallows over the Fraser River.

[mac]

Gord

A Google on Kestrels eating worms came up with one reference -

Cade, T. J. 1982. The falcons of the world. Comstock-Cornell Univ. Press, Ithaca, NewYork.

The article this ref. was in is at

el.erdc.usace.army.mil/tes/pdfs/serdp97-4.pdf.



Mac

[Gord]

Good investigating Mac!

I looked around and didnt find anything myself. Ill be sure to make note of this observation as it doesnt sound like a common occurrence.