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.
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| The headgear, on Brendan |
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”.
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| 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!
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| 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!
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