Banding Semipalmated Plovers

Semipalmated Plover

One of the best things about working out of the Churchill Northern Studies Centre (CNSC) is the opportunity to share with and learn from other biologists working on a broad range of topics, from bay ice and zooplankton in tundra ponds, to trees, seals and foxes. Today, Shawn, Brad and I took a break from our Godwits and followed Anne Corkery and Jen, from Trent University, to their site to help band Semipalmated Plovers.

We arrived at Bird Cove and began walking along the broad, gravelly beach. It was windy, and quite cold, at least compared to yesterday's heat. We started to see Semipalmated Plovers running along the beach almost immediately; they would pause to give their two-syllabled call, raising their entire bodies with effort, and would then resume running in short sprints from one spot to another, legs a blur. Some were already banded here, with a combination of two color bands on the right leg, and a color band and flag over a metal band on the left leg, but we soon found some territorial birds without bands, indicating new nests to be found.

We sat on the sand to watch an unbanded male, in hopes of him leading us to his nest. As Anne and I watched, the male stood quite still for a while, and it took me a while to notice the head of his female poking up from the ground just at his feet. She was incubating on the nest, and the male had led us straight to it-- how kind! We walked over to the nest in order to set up a walk-in trap. This is a metal-mesh cylinder with a screened over top that is placed over the nest; there is a door on one side where the bird can enter, but when you run towards the trap to retrieve the bird, it tries to get out the opposite side and ignores the door.

While we approached the nest, and as Anne measured the eggs and placed the trap over the nest, the birds constantly called and gave broken-wing displays, walking away from the nest as they did. When they were about 20 meters away, and noticed that we had not followed them away from the nest, they would run back and try again, starting their display from just a few feet away.

When the trap was set and the eggs measured, we would sit back a few dozen meters and watch as the adult bird would slowly approach its nest and investigate the mesh cage. It would often take several minutes, but eventually the bird would find the door and determine the trap to be inanimate enough for its liking, and it would sit down to incubate. Anne would then run towards the door side of the trap and grab the bird from underneath. Then we went to work, putting a unique combination of color bands on its tiny, yellow legs. In the hand, their 48 grams feel almost non-existent, especially compared to the 400-gram Whimbrels we have been banding recently, but their large, dark, inquisitive eyes make the handful of feathers feel infinitely more significant than their weight suggests.

Photo Op!

Parasitic Jaeger

This morning, with my Sunday off, I did something I thought I would never do: I put on my hip boots (voluntarily) and trudged out to one of our study sites. But this time I was on my own, and working my own schedule-- I was out to photograph a pair of Parasitic Jaegers and a pair of Golden-plovers at their nests. These are both species that were surprisingly difficult to approach and photograph early in the season (i.e. before they were on nests), and since I haven't been carrying a camera while we work (when they are cooperative), this was my first real chance to capture some cool images. Luckily for me, they were cooperative enough to get some good shots today, but uncooperative enough still to merit more attempts in the coming weeks.

I parked behind the rifle range, before a large expanse of wet, sub-arctic tundra, and rammed open the stiff door of our old Suburban. I immediately regretted not putting on a bug net before getting out, because now I had to struggle to put it on without trapping dozens of mosquitos between the net and my face. I pushed the shells into the shotgun, pulled up my hip boots and headed into...the big, open, wet area in front of the car--I don't think it's actually called anything in particular by anyone, now that I think about it.

I made my way to the Golden-plover nest first, and watched the bird calling loudly from a lichen mound as I approached. It repeatedly uttered a clear ascending whistle, jumping up to a higher pitch seamlessly, as if sliding into a falsetto. When I came closer, the bird depressed and spread its tail, and shuffled away, feigning a broken wing to draw me away from its nest.

American Golden-plover

I spotted the Jaeger incubating from quite a ways off, and saw it flush to a different mound to watch me approach before I was even within half a kilometer. The bird's mate came flying in from much farther away, and the two of them watched from separate mounds. As I got closer, they circled around me, calling sporadically.

When I got within 100 meters of the nest (which held two, surprisingly small eggs), the birds began to take turns dive-bombing me. One would fly away from me and upwards, then suddenly bank and dive towards my head with stiff, outstretched wings; with a sudden "whoosh," it would pass and begin another climb while its mate swooped down.

As I got even closer, the birds abandoned their efforts to scare me away and instead tried to draw me away with broken wing displays. They would sit near me and spread the wings on the ground, and slowly flap and squawk, sometimes even rolling on their backs and sides. It was strange to see this formidable nest predator desperately defending its own, precious eggs.

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...