As the end of August approaches, so does the
conclusion of the Farallon seabird season.
After about 6 months of being inhabited by several hundred thousand
birds, the island environment is dramatically changing. While the seabirds may be leaving, large numbers
of elephant seals and several species of migrating land-birds are arriving;
marking the beginning of the land-bird and white shark season.
As the late-season seabird intern, I am fortunate
to be currently witnessing these changes.
By the time I arrived on the island in early July, the Common Murre
chicks were already fledging, and most of the auklet, oystercatcher, gull, and
guillemot chicks were well on their way towards being mostly feathered. Days were spent vigorously banding chicks,
conducting diet surveys, and doing our best to protect ourselves from the angry
gulls and their grenade-like guano.
Nights were spent mist-netting storm-petrels and Rhinoceros
Auklets (see previous blog post).
 |
| The seabird crew conducting a Cassin's and Rhinoceros Auklet survey. Chicks are weighed and banded. |
When we weren’t netting, we
were spending our evenings either baking pies or cramming ourselves into the
murre blind to watch the chicks fledge. While
this was for fun, it became quite the sporting event. Common Murres nest on cliffs and rocky
out-croppings; therefore, when a chick is ready to fledge, it usually has to
make quite the leap of faith to reach the water. It is crucial for chicks to reach the water
as quickly as possible because of the high probability of a gull snatching them
up. The male adult will guide the chick
to the edge of the cliff and either gently nudge it over the edge, or fly down
to the water to wait for it to dive in.
In the spirit of this summer’s Olympics, we decided to judge each fledge
similarly to professional divers. Each fledgling
was rated on a scale from 1-10 based on two categories: accuracy (how skillfully
did the chick reach the water?) and creativity (we liked to give those that
made things exciting a little credit). Some fledglings would gracefully glide all
the way to the water despite their nubbin-like wings providing minimal control
(a great accuracy score). Others would
do a series of somersaults and tumbles down the cliff that theoretically,
should have resulted in death. However,
these courageous little guys would bounce up and somehow make it into the water
(definite high creativity score). Each
dive a chick made was often accompanied with “ooo’s” and “ahh’s” or “oh
noooooo’s” from the crowd gathered in the blind. I am happy to report that the majority of fledglings
were successful and received scores well over five.
 |
| Pigeon Guillemot chicks are rather feisty. This particular chick fledged yesterday. |
However, due to chicks fledging and most of the
breeding birds leaving the island, field work over the past few weeks has
dramatically slowed down. So what
exactly have we done in that time?
The last two weeks were spent not only packing and
preparing for the seasonal crew switch, but also conducting the late season
census of Tufted Puffins. The purpose of
this census was not only to obtain an estimate of the island population, but to
determine the number of breeding adults and their nest site locations. Several areas around the island in which
puffins had been observed earlier in the seabird season, were surveyed and
active nesting sites were determined.
Tufted Puffins live on rocky hillsides and cliffs and build their nests in
deep crevices. Because of crevice depth
and location, puffin nests are inaccessible to the biologists. Therefore, we designate active sites based on
consistent adult presence and chick feedings (a bird is seen entering a crevice
with fish in its beak). Over 120 active sites and 240 breeding pairs
were observed this year!
 |
| The last of the seabird interns: (left to right) Alexandra Gulick, Jen Aragon, and Erica Lander |
This past weekend, the last of this summer’s
seabird crew (minus me) departed the island.
Meaning, my current duties are to finish all late season surveys. These include weighing and banding the last
few Pigeon Guillemot and Rhinoceros Auklet chicks before they fledge, and
continuing the breeding surveys for Ashy Storm Petrels and the Cassin’s Auklets
that have relayed. Cassin’s relays are quite
unusual and the Farallones are one of the few locations that this species attempts
to have a second brood.
 | |
| A downy-feathered Cassin's Auklet chick. This chick is one of many second brood attempts. |
 |
| A fully-feathered Cassin's Auklet chick. It should be fledging soon! |
Although seabird surveys will be concluded soon,
the fall crew is hard at work surveying and mist-netting migrating land-birds. Shorebirds such as Wandering Tattlers, Ruddy
and Black Turnstones, Pacific Golden-Plover, Whimbrels, and several species of sandpipers have been
seen. Brown-headed cowbirds, Wilson’s
Warblers, Northern Rough-winged Swallows, and two Blue Grosbeaks are also among
the several migrant species that have arrived on the island in the past few
days. Most notably, a Ruff was seen a
few days ago. This is only the second
island record for this Eurasian species!
With the continuous fog we have been having, we have not seen quite the
wave of birds we are hoping for…yet. The
weather has cleared up today though, and the fall biologists are out conducting
surveys at this very moment.
I have two weeks left on the island and I’m quite
anxious to see what will happen next.
Just when you think you’ve seen everything, something new ALWAYS
happens. The Farallon Islands are a very
wild and unique place where life is simple and is governed by the nature around
it. I am not quite sure whether I will
be re-entering the real world of the
mainland, or leaving it behind on the Farallones.
Written by: Alexandra Gulick
No comments:
Post a Comment