Blackfooted Penguins, Spheniscus demersus (Breeding, climatic adaptation, threats and conservation measures) – Video

This video was taken at Monterey Bay Aquarium, California, USA in June 2012

Breeding: The African Penguin reaches breeding maturity in about four years.  They form nesting colonies, with pairs returning to the breeding site year after year. The breeding nests are usually found on coastal islands, where pairs construct their nests from their hardened excrements (guano) in a form of dug burrows in the guano or scrapes in the sand under boulders or bushes whereas some protection from the sun is provided. Black-footed penguins are monogamous as the breeding takes place with the same mate.

Two or three greenish eggs are laid each time in the breeding nest whereas egg incubation provided by both parents in shifts. The bare batch of skin on the lower abdomen allows the transfer the heat to the eggs as required during the incubation that lasts 40 days. The parents continue to guard their chicks that stay in the nest until they reach about 30 days old. Also, the adults -that continue to carry out foraging trips- feed their chicks with food which is brought up from their stomachs. This continues until the chicks fledge which occurs when they reach 70-80 days old. Afterwards, the immature penguins leave the land and go to the sea on their own where they remain for 12-24 months. Then they usually return to the land site where they hatched and molt into the familiar penguin adults.

Climatic adaptations: In cool climates, penguins have evolved behavioral and morphological features that help them retain heat. This includes the thick layer of fat under the skin and the densely packed feathers compared to other birds. In warmer climates, the pink glands above their eyes of the birds are believed to have a thermoregulation role to aid the bird in losing heat especially when the bird is out of the water for prolonged periods. Limiting their time at the nesting site to dusk and dawn is a behavioral pattern to protect themselves from solar radiation.

Threats and conservation measures

Threats: As a result of the collapse of Black-footed Penguin populations, the species is classified as Vulnerable (VU) on the IUCN Red List 2007.

Several threat sources contribute to the collapse of the black-footed penguins. These include human activities as represented in the previous practice of egg collection for human consumption, overfishing of penguins’ food of sardines and anchovies; oil pollution; removal and use of guano as organic fertilizer. The use of Penguin skins in leather goods has contributed to the over hunting of the bird.

The black-footed penguin’s predators contribute to the collapse of the penguin’s populations. Ocean predators include sharks and fur seals while land-based predators include mongooses, genets, and feral cats.

Conservation measures: The mediation measures include the establishment of nature reserves on locations or islands on which the species breeds. The egg collection and bird slaughtering are widely prohibited. Similarly, the collection of guano is no longer allowed.

The positive mitigation measures include the recovery of rescued oiled birds, hand-rearing and releasing abandoned chicks, and setting up artificial nests.

References: The Encyclopedia of Earth, Wikipedia, Mac Como Zoo

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