The striated caracara (''Phalcoboenus australis'') is a

bird of prey Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predat ...

of the family

Falconidae The falcons and caracaras are around 60 species of diurnal birds of prey that make up the family Falconidae (representing all extant species in the order Falconiformes). The family is divided into three subfamilies, Herpetotherinae, which inclu ...

. In the

Falkland Islands The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubouze ...

, it is known as the Johnny rook, probably named after the Johnny penguin ( gentoo penguin).

Description

The adults'

plumage Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...

is almost black in color, while the legs and lores are orange and the neck has silver striations. Chicks have chestnut down, which they lose after their first molt. Juveniles (i.e., after fledging until entering fourth year) have brown plumage with chestnut striations on nape and breast that deepen as they age. Full adult plumage is acquired after the fifth molt (i.e., entering fourth year), though the beak does not reach full adult coloration until the fifth year.

Distribution and habitat

The species breeds on coastal islands off

Tierra del Fuego Tierra del Fuego (, ; Spanish for "Land of the Fire", rarely also Fireland in English) is an archipelago off the southernmost tip of the South American mainland, across the Strait of Magellan. The archipelago consists of the main island, Isla ...

, through the Chilean fjords, and the outer islands of the Falklands archipelago. Although logistical challenges prohibit a comprehensive survey of the mainland population, the Falklands is thought to be the species stronghold. Historical records indicate the species range may have included East Falkland, however striated caracaras now breed only in the outer islands in association with

penguin Penguins (order Sphenisciformes , family Spheniscidae ) are a group of aquatic flightless birds. They live almost exclusively in the Southern Hemisphere: only one species, the Galápagos penguin, is found north of the Equator. Highly adap ...

and

albatross Albatrosses, of the biological family Diomedeidae, are large seabirds related to the procellariids, storm petrels, and diving petrels in the order Procellariiformes (the tubenoses). They range widely in the Southern Ocean and the North Pac ...

colonies.

Behaviour

Feeding

The striated caracara is primarily a

scavenger Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feedin ...

, feeding on

carrion Carrion () is the decaying flesh of dead animals, including human flesh. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...

, mainly dead

seabird Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same envir ...

s and dead

sheep Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to domesticate ...

, offal and food scraps. Invertebrates also comprise a large part of their diet, including kelp fly larvae dug from intertidal kelp wrack, beetles, and earthworms dug from invasive grasses in hillside drainages. However, striated caracaras will opportunistically prey on weak or injured animals, such as young seabirds and newborn lambs, the latter which has led it to be persecuted by sheep farmers.

Breeding

The nest is built on the ground, tussac stands, or cliff ledges, where the female will lay up to 4 eggs. Their hatching is timed to coincide with the

nesting season The nesting season is the time of year during which birds and some other animals, particularly some reptiles, build nests, lay eggs in them, and in most cases bring up their young. It is usually in the spring. Bird conservation Bird conservat ...

s, providing a constant food supply for the chicks. Once chicks have fledged, they disperse and gather into flocks.

Status and conservation

The population in the Falklands is estimated at 500 breeding pairs. Juveniles and adults are almost entirely fearless of humans and treat their approach with indifference. Over time, conflict with the sheep farmers has led to a great reduction in their numbers. This is now being corrected by the

Falkland Islanders Falkland Islanders, also called FalklandersChater, Tony. ''The Falklands''. St. Albans: The Penna Press, 1996. p. 137. and nicknamed Kelpers, are the people of the British Overseas Territory of the Falkland Islands. Identity The Island ...

Gallery

File:Striated Caracara with a dead Gentoo Penguin chick (5557011581).jpg, Subadult striated caracara feeding on a dead gentoo penguin chick File:Striatedcaracara2.jpg, Juvenile (2 year old) striated caracara File:Striatedcaracara5.jpg File:Striatedcaracara1.jpg File:Phalcoboenus australis -Amazona Zoo, Cromer, Norfolk, England-8a.jpg, Subadult striated caracara at Amazona Zoo, Norfolk, England File:Striated Caracara on Sealion Island.jpg, Adult striated caracaras on Sea Lion Island, Falkland Islands

References

External links

Falkland Islands Johnny Rooks
Facebook research page
Carancho austral en Tierra del Fuego
Facebook research page

issued for

* {{Taxonbar, from=Q916843 striated caracara striated caracara Birds of the Falkland Islands Birds of Tierra del Fuego striated caracara striated caracara