Galapagos Penguin
Written By: TK, Biology 487, Winter 2009
Photo by Scott Ableman
Spheniscus mendiculus
Status (IUCN v3.1)
Endangered
Severe El Niño cycles and introduced predators have caused catastrophic declines in Galapagos penguin populations. Experts fear that a particularly severe El Niño could result in extinction.
Conservation Concerns
The most serious threat to the Galapagos penguins is the increasing severity of El Niño cycles believed to be caused by global warming. While the penguins live in a very warm climate typically unsuitable for penguins, they rely on cold upwellings to bring nutrient rich water from depths. During El Niño cycles this nutrient delivery is disrupted, resulting in dramatic shortages in food supply and devastating mortality rates in penguin population. During each of the severe El Niño events of 1982-1983 and 1998-1999 the populations of the Galapagos penguin was reduced by over 50%.
While the penguins have been threatened by introduced species and predation, experts believe that climate change has the potential to drive them to extinction. The relatively small population size and high degree of isolation dramatically increase the probability that a serious El Niño event will wipe-out the entire species.
Distribution
Descriptive Characteristics
Plumage
Adult: Like many penguins, Galapagos penguins are black with a white frontside. Semi-circular white swoops extend from behind the eyes and extend around to meet under the chin. Plumage of males and females is identical.
Juvenile: Juvenile plumage is gray and white rather than black and white. Juveniles also display white cheek-patches which fade as the penguin matures.
Chick: Chicks have light gray down.
Measurements
Males are generally slightly larger than females.
Males
Weight: 2 kg
Height: 53.0 cm
Beak: 5.82 cm
Flipper: 11.87 cm
Foot: 10.2 cm
Females
Weight: 1.87 kg
Height: 50.0 cm
Beak: 5.39 cm
Flipper: 11.41 cm
Foot: 9.5 cm
Breeding Biology
Incubation Period: 38-42 days
Second Clutch: Breeding takes place as frequently as possible for the penguins and is limited by food supply and/or molting requirements.Chick Rearing Period: 60 days
Nest: Nests are produced from any found materials such as pebbles and twigs.
Age at First Breeding: 4 years
Maximum Lifespan: 20 years
Average Lifespan: 10 years
Molt: Molting occurs when a penguin has gained enough weight to support the 10-15 days ashore required for the process. Penguins accumulate roughly 400g additional weight to support the molting process. Molting takes place every 6-12 months.
Prey
Galapagos penguins feed on fish less than 15mm in length.
Predators
On land these penguins have been vulnerable to crabs and snakes (mostly young penguins) as well as cats, dogs, rats, hawks, and owls. Many of the penguins’ greatest land threats are human introductions to the islands. Like other penguins, the dark/light coloration of their plumage camouflage the penguins while underwater. Still, the penguins are vulnerable to large marine predators, such as sharks, while feeding.
