Bird Research

Morgan Benowitz-Fredricks
Biologist, University of Washington

Recorded in August, 2003


This is a collaborative study, it's a 3-year, 3-colony study.

So we're on St. George Island here, we're on St. Paul Island, which is the other Pribilof Island, and we're on Buldir, at the end of the Aleutian chain.

It's a comparison of planktivorous and piscivorous, so planton-eating and fish-eating birds, so we're actually taking blood samples from both kinds of murres, both kinds of kittiwakes, and from a bunch of auklets.

So the kittiwakes and murres are pretty much fish eaters, and the auklets are pretty much plankton eaters.

And we're interested in tracing large-scale effects of climate change, and subtle shifts in ocean temperature, and how that trickles back up to the birds, because changes in timing of how the ocean warms can affect plankton, which then affects the fish, and so everything is linked in these cycles.

This hormone, corticosterone, is elevated in birds when food availability is low.
So they've done some studies where they quantified fish out in the ocean, and then they looked at how well the birds did in terms of reproduction and how their hormones levels were.

We try and do this really quickly because in order for us to know what their corticosterone levels are as a result of their environmental conditions, we have to get a blood sample in under three minutes because obviously, us catching them and doing this is stressful.

This guy is not too happy and I'm gonna let him go in a second.

And so his corticosterone levels are rising just as a result of what we're doing.

But, it takes the body about three minutes to start producing these hormones and so if we can get that blood sample in under three minutes, then we can see what the hormone levels were before we started catching them and that tells us, gives us some good information about how conditions are for this guy and how hard he's having to work to get his food.