On Tuesday, Brendan, Phil, Tricia (“Tree”) and I went over to White and Seavey islands to help the Haywards and the Tern Interns to conduct an island-wide census of tern nests. And by island-wide I mean an area about the size of a football field, though, of course, rockier. I was amazed to find that, after tallying up the numbers at the end of the survey, we found that there are 2044 nests on the island this year! And apparently this is a decrease – there were over 2400 last year. Just by eyeballing it, it looked like around 3 to 5 terns could nest within one Herring Gull territory!
The censusing process itself was quite an experience. Preparations involved duct-taping socks to our hats, for the terns dive-bomb but their beaks are too fragile and can break on bike-helmets, and filling our pockets with popsicle sticks, which we used to mark the nests as we counted them.
All eleven of us lined up on one side of the island and then walked across it, shouting out the egg number for every nest we encountered as the birds rose up in a cloud and dived at us, their sharp beaks poking holes in the duct tape and their machine-gun calls filling our ears. And then suddenly, for about the space of a breath, they went dead silent. I looked up from the nest I was shoving a popsicle stick under and saw the whole colony of terns rise up and fly away from us, towards the water... and then turn right around and come rushing back at us, machine gun noises louder than ever before! It was the most unreal experience, as if someone had pressed the mute button by accident and then, apologizing and fumbling, accidentally turned the volume way up high in an attempt to unmute; a common enough incident, I suppose, except not in the natural world. And of course, there is a term for this behavior –“dread flight”. Apparently, gulls do it to and I dearly wish a Bald Eagle would fly over the island so I could film a gull “dread flight”.
|Terns in the air during the tern census|
Wednesday dawned cold and rainy. But of course, nests need to be checked in all weather short of a hurricane. The wet chicks looked pitiful with their wet down plastered down (hehe) over their puny little bodies and the pink knobbly skin over their spines poking out on their backs. I could easily tell the “good” parents from the “bad” ones from the degree of wetness of their chicks, and, as I found out today, some of the chicks unlucky enough to have very “bad” parents who didn't do a good job of sheltering them, didn't make it. Interestingly enough, all of the dead chicks I found today were either B or C chicks (as opposed to A chicks) further corroborating the prevalent idea that hatching early gives gull chicks a distinct advantage.
Thankfully today was, is, bright and sunny and I was able to take a zodiac out here to Smuttynose island and find some more Herring Gulls to conduct playbacks on. I scoured the trail leading to the east end of the island but the area was covered with Great Black-backed Gulls, and after two hours of searching, I had only found two Herring nests. It was hot and my backpack was heavy so I headed back to the “center”, dropped off everything but my speakers, notebook and binoculars near where Island Archaeology students were digging for artifacts and bones, and decided to stroll out towards the west of the island which I had never seen before. There were more Black-backed Gulls, yeowing their low, almost cow-like yeows and diving low over me. A few rock hops into walking along the coast, however, the monotony of Black-backed yeows was broken by a sharper, shriller yeow that made me reach into my backpack to check if I'd left my iPod on. Nope, I hadn't, it was a live Herring Gull and, what's more, I realized as it flew out of the bushes lining the coast, it had a bright green field-readable band on its leg! E87. Huzzah for the second banded gull I've spotted on Smuttynose this summer! I looked up its history in the Gull Database when I got back to Appledore and apparently it was banded on Sandpiper Beach as a chick in 2006 and had only ever been re-sighted once, off the Isles of Shoals. So it's exciting to know that it has returned to the isles and is nesting on Smuttynose!
|A video grab of E87 returning to his nest|
The more I think about it, and the more questions I get asked at the dinner table (like, what exactly are you doing with all this data?), I realize that even though these gulls that I'm studying are so common, so (relatively) easy to observe, we yet know so little about them – for example, we still can't explain why E87 ended up on Smuttynose instead of Appledore – because they are just so complex and just so... alive! It's hard to classify them, to set up a cause and effect model for their behavior, to take into account all of the factors that determine what they do. I mean, how many of can explain our own actions? I can't really explain why I love working with birds that try to kill me everyday; I just know that I do!