Saturday, June 19

Whimbrels are Stupid



Our team spent the better half of Friday catching, banding, and flagging Whimbrels. We are focusing some of our efforts on this species this year as part of a project by the Arctic Shorebird Demography Network (ASDN). ASDN aims to census breeding populations, determine the relative significance of migratory stopover sites, monitor population trends, and inform regional management about how to help meet conservation goals for North American shorebirds.

The best thing about Whimbrels is that they are far stupider than Godwits. To find a Godwit nest--a grass cup hidden under the low tangle of branches of a Dwarf Birch--you must first wander by chance into a territory to find one of the birds calling at you in irritation. The second step is to slowly and meticulously cover about a quarter of a square kilometer by walking tight lines back and forth, as if mowing a lawn. The incubating bird will only flush if you are within about 1 meter of the nest, and it is almost impossible to detect before that point. Whimbrels, on the other hand, lay their eggs in open scrapings on much drier ground, often on elevated mounds of lichen; and since they chase any bird that flies by their nest, a territory can be detected from kilometers away when a raven or jaeger flies over (we've even seen them waste their time and energy chasing Lesser Yellowlegs away from their nests). Once you are in a Whimbrel territory and have the pair in sight, you can simply walk back about 100 meters, sit down, and watch them. They almost immediately go to sit on their nest, at which point you walk over, hold out the GPS, press "mark," and you have yourself a nest.


When it comes time to catch the incubating bird, we use a "bow net." This is essentially a spring-loaded, dome shaped net, that is folded into a crescent and staked down around the nest. It is held open by a screw, which is attached to a spool of fishing line, so that when you sit back and relax about 100 meters away, all you have to do is pull the line to dislodge the screw and catch the bird under the net.


While preparing for one such capture, as we were standing at the nest staking in the bow net, the bird that we had flushed off the nest walked right back and watched the whole process from less than a meter away, all the while giving a broken wing display and jumping up and down. Brad beckoned it like you would a timid cat, and it would walk towards him inquisitively, only to walk away again feigning a broken wing and pretending to eat (i.e. picking up goose poop in its bill and discarding it repeatedly) to try to distract us from its nest.

After we had left, and after watching us place a large foreign object next to its nest, the Whimbrel investigated the net for a few seconds before settling right back down on its four, large eggs. We watched as it huddled back and forth, nestling its breast feathers over the eggs; Nathan gave a signal, and Shawn pulled the line. As soon as the bird was caught, Nathan (who had been lying much closer to the nest than the rest of us) sprinted over to get the bird as quickly as possible, lest it stomp on its own eggs while trying to get out of the net.

We ended up catching and banding five Whimbrel in just a few short hours. If only Godwits were stupid...

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