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Galapagos Gulls |
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Lava Gull and
Swallow-tailed Gull on Galapagos, November 2012 |
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Lava Gull is the rarest gull in the world.
It is endemic to Galapagos, where its population is
probably fewer than 300 pairs. San Cristobal Island on Galapagos on
11 November 2012. Low population numbers are the reason it is listed
as Vulnerable by
International
Union for Conservation of Nature
(IUCN). |
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Possible first or second year Lava Gull
at the fish market in Puerto Ayoro, Santa Cruz Island. This
individual is paler than usual and has pale edges to the primaries,
Its plumage may be bleached by the sun and salt water or is leucistic - lacking pigment. It was scavenging at the fish market in Puerto Ayoro
on 13 November 2012. |
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Swallow-tailed Gull is a near-endemic of
the Galapagos Islands, where most of the population breeds, but
about 50 pairs also breed on an island off Colombia, South America.
Swallow-tailed Gulls feed exclusively at night, the only gull in the
world to do so. Their diet consists mainly of squid and fish, which come to the
surface at night to feed on plankton. During the day we saw many
resting. At night though, they flew
alongside our boat as we sailed from island to island. This adult in
breeding plumage was on South Plaza Island, Galapagos on 10 November
2012. |
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Adult Swallow-tailed Gull in breeding
plumage in flight has a dramatic upperwing pattern similar to
Sabine's Gull. All adults we saw were in breeding plumage. |
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A pair of adult Swallow-tailed Gulls
copulating on South Plaza Island. They breed on a 9 month cycle,
rather than a year cycle like most other gulls. If nesting fails
they will breed more often. South Plaza 10 November 2012 |
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This juvenile Swallow-tailed Gull was
being cared for by adults. Adults continue to feed young until the
chick is three months old. Genovesa Island on 15 November 2012 |
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Juvenile
Swallow-tailed Gull with unmistakable pattern on the upper
parts. South Plaza on
10 November 2012. |
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Only on Galapagos -
Adult Swallow-tailed Gull landing near Galapagos Sea Lion. South
Plaza Island on 10 November 2012 |
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Interesting article |
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Breeding Ecology of the Swallow-tailed Gull, Creagrus furcatus
by Michael P. Harris. The Auk, Vol. 87, No. 2 (Apr.,
1970), pp. 215-243 |
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