Galápagos Islands | Our Research

Galapagos Adult_wm

Common Name: Galápagos penguin
Species Name: Spheniscus mendiculus

IUCN Status: Endangered
The Galápagos penguin population has declined since the 1970s because of severe El Niños and introduced predators. Humans brought rats, cats, dogs, and goats to the islands, and climate change is linked to increases in greenhouse gases associated with human use of fossil fuels. Although it is hard to undo the damage humans have done to the islands, there are steps that we can take to mitigate our negative impact and help increase the population of Galápagos penguins. Creating safe, high-quality nest sites may be one way to help build the population.

 

Conservation Concerns
The most serious threat to the Galápagos penguins is climate change. The increasing frequency and severity of El Niños reduces upwelling and food availability for penguins and other seabirds. Galápagos penguins live on the equator, an unusual place for a penguin. This is made possible by the deep, cold upwellings of the Cromwell current that bring nutrient-rich water to the surface. During El Niños, this nutrient delivery is disrupted, resulting in severe shortages of food. The most severe events can cause penguins to starve. During each of the severe El Niños of 1972, 1982-1983 and 1998-1999, the population of the Galápagos penguins declined and adult penguins died.
The relatively small population size and high degree of isolation of the Galapágos penguins make them vulnerable to extinction. A long El Niño that causes upwelling to fail for 3 to 6 months could devastate this already endangered population.

Descriptive Characteristics
Chicks:

▪ Chicks have light gray down that covers their back, head, and flippers.
▪ White or light gray down covers the chest, abdomen, and chin.
▪ There are no distinctive spots on chest and abdomen.
▪ Feet are whitish, light gray, or pinkish.

Juveniles:
fledgling just with down sm islet_wm red
▪   A fledgling is a bird that has recently left its nest. For the purposes of this description fledglings will be grouped with juveniles.
▪   Fledgling plumage turns from blue-gray to grayish and from grayish to brown before the first molt.
▪   Most fledglings have white cheeks that become grayer.
▪   Individual-specific spots on chest become visible.
▪   If food is available the juvenile will undergo its first molt at about 6 months.
▪   They lack the dark band around their chest and the white band that outlines their cheeks.
▪   Their very white feet become mottled as they age.

 

 

 

Adults:
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▪ Adults have black-brown feathers on their back and head and a white front-side.
▪ They have bare skin around eyes and bill during breeding.
▪ Individual-specific spots on chest and abdomen stay throughout their lifetime.
▪ Semi-circular white bands extend from behind eyes, outline cheeks, and meet under chin.
▪ A black inverted u-band forms across chest, may run down to legs, and varies among individuals.
▪ Flippers are dark on the back but have individual black and white pattern on underside (aka ventral surface).
▪ The coloration of their bill is pronounced. The upper bill is dark and the lower is whitish-pink with a black tip base. The lower mandible is sometimes yellowish.
▪ They do not have the white tail spot that other Spheniscus penguins have.
▪ Plumage similar between males and females.
▪ Males have deeper and thicker bills than females.

Measurements

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males are generally slightly larger than females
Galapagos Male Female_wm
males have thicker deeper and thicker bills than females

Breeding Biology

Galápagos penguins living on the Equator must find shaded areas in which to breed. They can overheat standing on the hot lava in direct sunlight, but can jump into the water to keep cool. To breed and molt, they seek lava tubes, caves, and crevices. They collect feathers, bones, leaves, and sticks to add to their nests and have high nest-site fidelity, often returning the same nest year after year. This high fidelity is likely due to a lack of quality nest sites Nests we have built had eggs or chicks 6 months after construction. Unlike other penguins, the timing of Galápagos penguin breeding is variable and based on upwelling. In seasons with strong upwelling, penguins may breed up to 3 times in a year. In an El Niño year penguins may skip breeding. Like other penguin species, both parents take turns incubating the eggs and feeding the chicks.
Galapagos Life Cycle - FINAL Fig.12_wm
Number of eggs laid: 2, generally 3-4 days apart
Incubation Period: 38-42 days
Second and Third Clutch: Breeding takes place as frequently as conditions allow. They molt first and then, if they are in good condition and upwelling continues, they breed.
Chick Rearing Period: 60 days
Average Lifespan: unknown
Maximum Lifespan: unknown, ≥ 10 years

Molt

Molting is a process of shedding old feathers and growing new ones. They first molt at approximately 6 months. It occurs weeks to months before reproduction and requires a large storage of energy. It may take penguins several weeks to gain enough weight, nearly a third (approximately 400g) to molt. The timing is based on body condition and condition of feathers. Penguins usually stay on land for 10-15 days—fasting; often in the shade; and are reluctant to enter the water. A molt usually occurs twice a year but is based on food availability.

Foraging
Galápagos penguins primarily consume nearshore schooling fish, often feeding within 5 meters of shore. They eat small fish, crustaceans, and cephalopods, and have trouble swallowing big prey. Penguins forage during the day, alone or in small groups but often feed in multi-species feeding groups with pelicans, boobies, noddies and predatory fish like tuna. Dives for food are short (less than 1 minute) and often shallow (less than 6 meters).

Distribution

dist map
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Breeding sites are found on Isabela (Villamill, Caleta iguana, Playa de Los Perros, Isla Marielas, Tagus Cove, Roca Vicente, Northern Isabela), Fernandina (Cabo Douglas, Punta Espinosa, Punta Mangle, Cabo Hammond), Bartolomé, Santiago, Sombrero Chino, and Floreana Islands (Post Office Bay). Most are found on the northern and eastern coast of Fernandina and southwestern Isabela. In the 1970s Marielas Island was an important breeding area but the number of penguins was reduced by the early 2000s, possibly due to the introduction of rats. During the migration period penguins travel around the islands in search of food. In April of 2014 a juvenile penguin was photographed on Genovesa, the first time a penguin has been seen on the island. To see pictures and videos of sightings of penguins visit www.igalapagos.org/recent-sightings.

Peng_NH&CFor more information on the penguins, threats, and conservation pick up a copy of
Penguins: Natural History and Conservation by Dr. Pablo Garcia Borboroglu and Dr. P. Dee Boersma (University of Washington Press).