 |
| Isla Isabela |
 |
| Lago Crater |
 |
| Male Frigate-bird |
 |
| Female Frigate-bird |
 |
| Young Frigate-bird in Flight |
Isla Isabela is a birdwatcher’s paradise offering many species in addition
to the ever present population of boobies.
The island is literally covered with birds. One of the cruising guidebooks suggests looking for the flocks of circling birds to find this incorrectly charted Island. In addition to the variety of boobies, the island is also home to Great Frigate-birds, Magnificent
Frigate-birds, Sooty Terns, Brown Noddies, and Heermann’s Gulls.
It seemed eerie walking across the island
while so many birds stared down at us from every tree-top and frigate-birds flew about overhead
– it was as if we were in a scene from Jurassic Park.
The island is actually a result of
prehistoric volcanic activity, and the caldera of this extinct volcano is
located in the middle of the island.
The
caldera has since filled with water and is called Lago Crater.
Frigates, which are related to the Pelican, look rather prehistoric.
They are a
long-winged, fork-tailed bird with a hooked bill.
Interestingly, frigates can’t walk very well
and do not swim, so are essentially aerial creatures.
Having the largest wingspan (85 inches) to
body weight ratio of any bird, they are able to stay aloft for more than a week,
landing only to roost or breed.
The only
other bird known to spend days and nights on the wing is the Common Swift.
Male frigates are all-black and have a scarlet
throat pouch (gular pouch) that is inflated like a balloon during the breeding
season to attract a mate.
Females are black, but have a white breast and a blue eye-ring, while immature birds have a white head and white under-parts. Nests are
constructed in low trees and a single egg is laid each breeding season.
Both parents take turns feeding for the first
three months, after which the mother feeds the young for another eight
months.
Since it takes so long to rear a
chick, frigate-birds do not breed every year.
It is typical to see juveniles as big as their parents waiting to be
fed.
When youngsters sit waiting for
endless hours in the hot sun, they assume an energy-efficient posture - their
head hangs down and they sit so still that they appear to be dead.
When the parent returns, however, they wake
up and the hungry juvenile plunges its head down the parent’s throat and feeds.
Because frigates produce very little
oil, they are unable to land or take off from the water so their food source is
caught in flight, snatching prey from the beach or ocean surface with their
long, hooked bills.
Sometimes frigates rob
chicks from other seabirds, earning the nickname, Man of War birds.
We also saw Brown Pelicans and Heermann’s Gulls
strutting along the beach.
Adult
Heermann’s Gulls have a medium gray body and a red bill with a black tip.
In the breeding season the head is white and
in non-breeding season the plumage is a dusky gray.
After breeding, the bird colonies disperse to
central California and south as far as Guatemala, and less commonly north as
far as British Columbia.
Heermann’s Gulls
sometimes pirate prey from other seabirds, particularly Brown Pelicans with whom
they keep company.
We also enjoyed seeing
the numerous iguanas and lizards on the island, scurrying over rocks and hiding
in the underbrush. Visiting Isla Isabela is a wonderful stop for boaters, but the island is exposed to wind and ocean swell with a rocky irregular bottom that tends to "eat" anchors. It has been suggested that boaters secure a rope to the boat end of the anchor chain so it can quickly be cut loose in case of bad weather or in case the anchor becomes lodged in the rocks.
 |
| Male Frigate-bird looking for attention |
 |
| A Serious Male Contender with a Female and Younger Frigate-bird |
 |
| Juvenile Waiting to be Fed |
 |
| Baby Frigate-bird |
 |
| Heermann's Gulls |
 |
| The Cute Heermann's Gull |
 |
| A Camouflaged Iguana |
