In February of 2011, I spent roughly three weeks on the
island of Abaco, in the Bahamas. Having never before been to the Caribbean,
everything was new. From the first time I was spoken to – in a language that
was vaguely intelligible but clearly not the one I spoke – I knew this was
going to be interesting. My job was to set up nest boxes for the endangered
Bahama Swallow and to that end, I headed to the southern half of Abaco island,
probably the best spot in the world for these swallows. Abaco is a really thin
island, never more than a few miles wide, but well over 60 miles long. Most
fortunately Abaco has not yet succumbed to the sprawling resorts and still has
loads of “virgin” pine forests remaining – which are commonly said to be the only breeding
sites for the swallow.
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Bahama Swallow box, Abaco Neem farm |
But no one told the swallows that, apparently. I found them
breeding in two places: cell phone towers and roofs. This presented the paradox of the species: why are they restricted to two relatively undeveloped islands,
yet utilizing human settlements almost exclusively? Personally, my thought is
that House Sparrows abound in areas of high human development, but exist in low
enough densities on these islands that the swallows still have some breeding
sites available to them. House Sparrows (English Sparrows, Passer domesticus)
we introduced to North America by some well-meaning, but tragically misguided
Victorians about the turn of the century in New York and Boston. They wanted
the New World to have the wonderful fauna of the old world and thus they
brought a myriad of species from Europe (including, it is said because of its
mention in a Shakespeare play, starlings).
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Bahama Swallow, Abaco Neem Farm |
I do not know whether the House Sparrows on the Bahamas were
a separate introduction or part of the rapid expansion of House Sparrows after
the initial release in the northeast, but they are certainly in great numbers there now.
Additionally, I should note that besides some circumstantial evidence, I have
nothing to back up my hypothesis that House Sparrows are outcompeting the
Bahama Swallows. Many other hypotheses about the decline can be posited:
perhaps they need pine forests to feed, not breed, or maybe they adapt well to
small amounts of human disturbance, but not extensive development. But they are
certainly competing on some level – a local guide took me to known nesting
sites from previous years and in each one we found a sparrow nest, not a
swallow.
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Wilson's Plover, Abaco |
But the island was not all doom and gloom – it was hard to
dwell on the decline of a species when confronted with a comfortable hammock
and beautiful blue water after work every day. And the birds and butterflies
were simply fantastic: northern warblers migrate yearly to the Caribbean and
mesh with local birds whose names I had to find in James Bond's bird guide.
James Bond? The story goes that Ian Fleming often visited the Caribbean and
birdwatched – remember that much of it was British holdings at the time – and
when looking for title character's name, he found the author of the local bird
guide possessed a fine-sounding British name and the rest is history. Whether
apocryphal, I do not know, but the bird guide is still in use and allowed me to
identify several bird that I would have been stymied by otherwise.
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This bird does not show up in US bird guides: Black-faced Grassquit |
Abaco also holds one of the last populations of the Cuban
Parrot – a big beautiful bird with some odd habits. Not only does it not nest
in trees, like any sane parrot would do, it also does not just nest on the
ground – no, it nests in limestone crevasses, mostly in or near extensive cave
networks. This puts it in jeopardy of being eaten by voracious predators: house
cats and raccoons. Neither species is native to the island and both, despite
their cute appearances are serious problems for island birds. Baby parrots in
holes present an easy target for these predators and, especially as raccoons
move southward on the island, the small population of parrots seems in jeopardy.
I was lucky enough to see the parrots on a few occasions and hear them on many
more occasions (almost all parrots are loud and obnoxious).
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Cuban Parrot, Abaco, in a flock of 8-10 or so |
And I managed to find a pretty rare bird for the island: a Swainson's Warbler - one of the harder warblers to find in the US, as well.
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Not a good picture - but a good bird! Swainson's Warbler |
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Western Spindalis, male. The females are completely nondescript tanagers. |
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A weatherbird - Magnificent Frigatebird - named for their tendency to come inshore before storms (or so they say). |
I would like to learn more about the success of artificial nests for the Bahama swallow. Can you help? Sole
ReplyDeleteUnfortunately, I have had no success with the boxes I erected. All that has utilized them is House Sparrows, I believe.
ReplyDelete