Friday 24 August 2012

Penquins on the Equator

Galapagos Penguins
One of the most fascinating marine creatures on the archipelago is the Galapagos Penguin. Aren’t penguins those cold-weather tuxedoed outdoorsmen who shield each other from the cold by forming tight groupings so only those on the outside of the circle are hit by the violent elements in Antarctica? Aren’t they the animals that get trapped below the ice?  Don't they waver on the edges of ice flows waiting for the moment to jump into the frigid water to search for food? Yes, some penguins are – but not all.

Penguins SwimmingOur islands are blessed to be the indigenous home of the Galapagos Penguin.  This is the only species of penguin that lives above the Equator. They are able to do so because of the cool water temperatures that result from the Cromwell Currents. There are “warm water” Humboldt penguins along the coasts of continental Ecuador, Chile and Peru, but they do not go north of the Equator.

Called a banded penguin, the Galapagos Penguin would never be physically mistaken for the more familiar Antarctic penguins.  First, our penguins are much smaller, just about 19 inches tall and about 5 ½ pounds; females are even smaller.  The Galapagos Penguin has a black head with a white border behind the eye, around the black ears and chin, to join on the throat.  They are blackish-grey on top and white on their bellies, and have two black bands across their breast and extending down to their thigh.  The Galapagos Penguin is the third smallest species of penguin.

Maps of Isabela Island, Galapagos
While our penguins can be seen throughout the archipelago, 90-95% are found on Fernandina and Isabela Islands to the West.  It’s on Isabela that they visit the northern hemisphere.  Fortunately for me and my guests, as I guide, I’ve seen the penguins all over the archipelago. On two recent trips I saw penguins on Bartolome, one time a pair and the other about six standing in formation on the rocks near the water. (Some of the pictures on this blog are from Bartolome and provided courtesy of Aqua Surround.) We were especially lucky because there are believed to be only about 800 breeding pairs of Galapagos Penguins in the world so the population density outside of Fernandina and Isabela makes it very unique and even lucky to find them.

A Pair of Galapagos Penquins Which Mate for Life
A Pair of Galapagos Penquins Which Mate for Life
Penguins pair for life and breed with just one other penguin. Usually eggs are laid in rock-face crevices and caves, outside of direct sunshine, between May and January; when food is most abundant. Only two eggs are laid at a time and, because of food restrictions, even if both eggs hatch, only one chick will be nurtured. It takes only 38-40 days to incubate before the chicks are born. Both the male and female take care of newborn chicks; one is always left behind to care for the new babies when the other goes for nourishment. The chick is guarded for about 30 days after hatching. Then, it molts, gets adult feathers, and is on its own in about 60 to 65 days.

Galapagos Penquin Chick
Galapagos Penguin Chick
The chicks, like their parents, blend with the hard rock surfaces on which they are born.  But, instead of featuring black and white markings, they are brown above and white below with no black banded markings.  The coloration, we believe, not only provides protection from hawks – their primary natural predator – but also from the hot sun.  Other predators are crabs, snakes, owls and even the sea lions.

Our Galapagos Penguins tend to stay in the cool Pacific Water, fed by the Cromwell Current, during the day and return to the land at night. They feed on the multitude of small fish readily available near the shoreline, often sardines and mullet fish. Though they are clearly adapted to the hot sunshine, they do have to adjust their behavior to this equatorial environment. That explains why they stay in the water and close to the shore – so they can jump right in for a quick swim and cool down. On land, they also self-regulate their body temperature by keeping their feet out of the sun to prevent sunburned feet and by stretching out their flippers so that heat can escape through tiny arteries. They sometimes look comical in their movements when what they are actually doing is panting, using evaporation to cool the throat and airways.

Galapagos Penguins
We are always fearful for the future of the Galapagos Penguin as the population is so reduced.  It is the rarest of all penguin species. The weather, a reduction in the number of small fish and human interference in the nature of fishing and boating have severely impacted the penguin numbers. By reducing the fish on which the Galapagos Penguins rely as their primary food source, El Nino severely drained the Galapagos Penguin population by about 70% in the last two decades. The fact that we now have less than 1000 breeding pairs is particularly striking since as recently as 1970, the population was estimated to be between 6,000 and 15,000 birds in the area we call the Galapagos Marine Reserve. In October 1997, the Charles Darwin Research Station conducted a census on all of the islands and recorded a total population of 883 adults, with 184 juveniles and 217 birds of indeterminate age. While that statistic is striking, it indicated a 27% increase in the population from that recorded in a 1996 census.

The Galapagos Penquin is a valuable and extremely precious member of the Galapagos eco-system.  As a naturalist guide, it always brings joy when we see these special creatures on our adventures throughout the archipelago.

No comments:

Post a Comment