The Peruvian diving petrel (local name in Peru: Potoyunco) belongs to the family
Pelecanoides (Diving Petrels) represented worldwide by only four species.

Historically the species was ranking from the islands of Lobos de Tierra (6° south) in Peru
to Corral, Chile (37° south). It is estimated that the species original population some 80
years back was counted in several millions, with the main colonies at the islands of Chincha, San Gallan, La Vieja, Ballestas, Mazorca, Lobos de Tierra, Macabí, Guañape, Pescadores, Lobos de Afuera, Ancón, Callao and Arica in Peru, as well as Iquique, Taltal and Valparaíso in Chile.

However as the bird digs nesting caves in the ground the extraction of guano (bird-droppings used as fertilizer) was the main factor destroying the birds’ breeding grounds. Direct hunting for human consumption by guano-workers and local fishermen was an additional factor as well as the introduction of species. On the island of Cañaral in Chile for example the original population was estimated in 1938 at about 200.000 breeding pairs. Introduced foxes killed the entire population in only a few years.

Today Birdlife International and the International Union for Nature Conservation (IUCN) defined the Peruvian diving petrel to be a species in danger of extinction (IUCN: EN B2ab(iii,v) = in danger of extinction because the area of distribution is smaller than 500 km2, the species does not exist in more than five places and the reduction of the population continues or further habitat degradation can be observed)   

The Peruvian diving petrel is protected by Peruvian law as being an endangered species (Ministerial Resolution Nº. 01062-90-AG-DGFF). Hunting, extraction, transport or export for commercial purposes is prohibited by Supreme Decree Nº 013-99-AG

In Chile the species was declared a vulnerable population and was legally protected since 1955 by Supreme Decree 268, prohibiting the hunting of the species during the nesting period as well as the collection of eggs and the capture of chicks. Sale and export is prohibited and to keep them captive a special permit is required.

Actual population estimates:

In Peru:          
12,200 – 13,200 breeding pairs in the Islands La Vieja and San Gallan in the Paracas National Reserve (last count: 1996). On the island Corcovado, located 20 kms northwest of Chimbote a colony of three breeding pairs and a second one of seven breeding pairs have been registered in 2005.

In Chile:         
220 nests have been counted on the Island Pan de Azúcar in the late eighties, but 1995 none was found. Island of Choros, Coquimbo: an estimated 2000 breeding pairs.

Behavior:    

Even though diving petrels are relatives of the Albatrosses and Petrels, they have separated very early and evolved different. They are not very good flyers but much better swimmers using their wings just like penguins in order to swim under water. They fed during the day offshore and return only at night to their breeding grounds. Their main food is plankton organisms (85.3 - 91.1%) The remaining percentage of their food is fish, mainly anchovies.

Diving petrels can dive up to 83 meters deep but the average depth of the deepest dives was recorded at around 30 meters.

They nest in underground nests caved about 70 centimeters deep into the guano layers and nearly a meter deep into sand. If there is no good ground for digging they may also use holes between rocks. They reproduce all year around but have two peaks of reproduction (one in November/December).

They lay only one egg. Reproductive success was estimated at only 33.4%.

For information on marine birding tours with a good probability for the observation of Peruvian diving petrels click here.