Sunday, August 21, 2011

Endemic Means What?

Waved Albatros Pair
"Demic" is a Greek root meaning people or populace, so pandemic means something affecting a wide scope of the populace, and endemic means a population restricted to a locality or region. An endemic species is behind the evolutionary eightball, so to speak, since it only lives in one location, such as the Galapagos, and if something happens to that habitat, they are closer to extinction than other more widespread species. The Galapagos, needless to say, is famous for its high number of endemic species. Not only are they endemic to the Galapagos, but often to only one island in the archipelago.

Waved Albatross Wings Spread
Consider the Waved Albatross which breeds only on the island of Espanola, then takes to the air and spends the rest of its time at sea until it's time to return to Espanola and breed again. It is a long-lived bird with a low reproduction rate, breeding in one location, making it a vulnerable species.
Waved Albatross Courtship
They mate for life, greeting each other with beak clacking, raised beaks and a formalized dance. A single egg is laid on bare ground, sometimes right in the middle of the path taken by visitors, between mid-April and late June, and incubation takes 60 days...

Waved Albatross Chick
...resulting in a baby only a mother would love.  The are fed with pre-digested oil manufactured by the parents from fish and squid. Young birds don't start breeding until their sixth year!

The Waved Albatross has a wingspan of up to 8.2 feet, but can't take off from land unassisted. Albatross Airport is an open field atop a cliff on Espanola Island. The Albatross waddles towards the precipice, wings outstretched, until the wind gives enough lift for takeoff.
Galapagos Penguin

Who expects to see Penguins at the equator? Don't they belong in snowy Antarctica? Well, usually, except for the Galapagos Penguin, of course, the smallest Penguin in the world, and the only one which breeds entirely in the tropics. The current population is estimated to be about 1,400 individuals, found mainly on Fernandina, parts of Isabela, and in small numbers on Bartolome, where we found this little guy. They were seriously affected by El Nino in 1982-3 and 1997-8. The warm waters of El Nino affected its food supply and reduced the population by 75% and 65%, respectively. Numbers are recovering, but its a slow breeder, and faces further trouble with cats, rats and dogs on the main islands.

Lava Gull
The Lava Gull is possibly the rarest or least numerous gull in the world, according to my field guide. They are scavengers and nest robbers, nesting on the ground, often near ports such as Puerto Ayora in Santa Cruz, where we saw our first one. The total population is thought to be only about 400 pairs, so they are definitely vulnerable.

Swallow-tail Gull
The Swallow-tailed Gull is the second of only two gull species in the Galapagos. It is the only nocturnal gull in the world, leaving the nest at dusk and fishing well out to sea. Unsurprisingly, little is known about its feeding habits, but it may have special visual and sonar facilities, making use of the bioluminescence of light-emitting animals in the water. They have a distinctive red eye ring.

Swallow-tail Gull Chick
This persistent chick chased his mother around, tapping on a white spot on her beak until she finally gave in and regurgitated a lump of fish and I-don't-know-what-else, which seemed to satisfy him.

Swallow-tail Gull in Flight
The field guide estimates their numbers at 2-3,000 pairs, breeding throughout the year on beaches, rocky ledges and cliffs producing a single egg every nine or ten months. In the non-breeding season they fly off to the coastal waters of Ecuador and Peru. Due to the isolation of the islands, none of these birds apply the old adage about not putting all your eggs in one basket, or one island, and they are at risk. You can understand why the Park Service is so particular about visitors.


Mary Howell Cromer said...

Oh the gulls are splendid, but those Albatross...what gems, and that young one, such wonderful images you are sharing, just don't want them to stop~

Jen said...

Wow, so many awesome birds, and great info to go along with them... I only just learned that there are tropical penguin species and was quite surprised. Love the Lava Gull, and the Swallow-tailed Gull chick!

Kathiesbirds said...

What a beautiful gull that swallow-tail is! Wow, so much information. You sure are having the trip of a lifetime!