Community Involvement in Bank Swallows?

[Stephen Stephen]

http://i153.photobucket.com/albums/s219/Squidcan/Birds2/IMG_9326.jpg

Two summers ago, while vacationing on Prince Edward Island, I had my first opportunity to create images of Bank Swallows. I was fortunate enough to be there over several days when the young birds were getting ready for their first flights.

I noticed that often more that two birds (e.g. 3-5) at a time would hover near the mouth of individual burrows. They seemed to be encouraging the young ones to fly. While I expected the two parents to be doing this I wasn't sure if this was a behaviour of colonial birds or, perhaps the other birds might have been earlier fledglings from the same burrow. (Although you can see them all in this poor image there were three young ones in this burrow and, one of the adults I believe has just landed outside.)

[Axel Hildebrandt]

Great topic! I think you are right. I saw something similar with barn swallows. There was one fledgling sitting on the ground and there were many birds around him chattering until the little one finally flew back to the nesting area.

[John Chardine]

Here's one possible interpretation Stephen- selfish behaviour. A fledgling indicates that a burrow might be free for use by another pair. Young pairs, which tend to breed late in the season, may usurp a burrow from the resident pair preparing to produce a second brood. In this way they get a head start and the fledgling indicates that the burrow is a good one. Therefore, the birds you saw may simply be trying to gain ownership of a ready-made burrow.

Further thoughts??

[Stephen Stephen]

Thanks for your suggestions and comments Axel and John. John, you certainly could be right. It was difficult to to clearly identify most individual birds as they left and returned to the colony. The parents were more obvious since they brought food and took away fecal sacs.

Perhaps I'll have another opportunity to observe this behaviour in the future.

[John Chardine]

Stephen- One thing I forgot to add is that I have observed young breeding pairs of Brown Noddies actually attacking the fledgling at the nest and in a couple of cases killing it. We interpreted that as a method of gaining access to the nest site with a view to breeding that year or the next. However, if this sort of thing happens in swallows and noddies, where are the real parents when they are needed most?!