Galapagos hawk (Buteo galapagoensis)

Spanish: Busardo de Galápagos, Gavilán de Galapagos
KingdomAnimalia
PhylumChordata
ClassAves
OrderFalconiformes
FamilyAccipitridae
GenusButeo (1)
SizeLength: 55 cm (2)
Wingspan: 120 cm (3)

The Galapagos hawk is classified as Vulnerable (VU) by the IUCN Red List (1). Listed under Appendix II of CITES (4).

The Galapagos hawk is a large, dark coloured hawk with broad wings, and a broad tail (2) (5). Adults are sooty brownish-black in colour with a grey tail barred with darker stripes (2). The legs and skin at the base of the beak are yellow (3) and the bill is greyish black (5). Immature birds have blackish-brown upperparts, mottled with buff and white; the tail is off-white with wavy dark bars and their underparts are buff-coloured with a white throat flecked with blackish-brown spots. Males are noticeably smaller than females (5). The most typical call is a series of short screams that have been described as ‘keer, keeu’. Occasionally a rapid ‘cher, cher, cher’ is heard. When on the wing a scream is produced in bursts of three to five (5).

As the common name suggests, this hawk is endemic to the Galapagos Islands, Ecuador (2). It was once common throughout these islands, but there has been a worrying population decline and the species has become extinct on five islands (2). It is thought that there are around 150 breeding pairs at present (5).

The Galapagos hawk is found in all types of habitat on the Galapagos Islands, including lava-fields, shoreline, forest and mountains (2) (3).

The Galapagos hawk is an active and versatile predator, feeding on invertebrates, small lizards, snakes, rodents, hatchling tortoises and sea turtles as well as the marine iguanas found on the Galapagos Islands. It also takes carrion and is often associated with human camps, where it takes food scraps (5). There are no natural predators of this species on the Galapagos, and they show very little fear of humans (3).

Breeding may occur at any time of year (2). The Galapagos hawk tends to form long-term groups consisting of one female and several males. The female mates with all of the males, and they all assist in chick rearing. This type of social structure is known as ‘co-operative polyandry’, polyandry meaning ‘many males’ (6).

Nests are constructed in low branches, on an outcrop of larva or on the ground from sticks, and are lined with grass, bark, leaves and other available soft materials. They are used repeatedly for several years and become increasingly large, often up to 1.2 metres in diameter and three metres in height (3) (5). During courtship, pairs often rise to great heights and descend in criss-crossing flights (5). Mating occurs repeatedly during the day. Although up to two greenish-white eggs are laid, just one chick is usually reared (5). The incubation period lasts 37 to 38 days and the young are fully fledged at 50 to 60 days of age (3).

The most likely cause of the historical decline of the Galapagos hawk is persecution by humans, which continues today on a few islands (2). Competition for food with introduced predators such as cats is also a serious problem in some areas, particularly on the largest island, Isabella (2). The fact that this species is restricted to the Galapagos Islands, and has a small overall population, makes it inherently vulnerable. Although the population seems to be stable at present, if there be a further decline in numbers, the IUCN Red List status of the species should be upgraded to Endangered (1).

The Galapagos hawk is protected from international trade by its listing under Appendix II of the Convention on International Trade in Endangered Species (CITES) (4). It has been protected by Ecuadorian law since 1959. Much of the Galapagos Islands are classed as a national park and a marine reserve, and the archipelago was deemed a UNESCO World Heritage Site in 1979 (2). Ecological work into each population of the species is underway, which will enable effective conservation measures to be taken (2).

For more information on the Galapagos hawk see:

To find out more about conservation in the Galapagos Islands see:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

  1. IUCN Red List (April, 2008)
    http://www.iucnredlist.org
  2. BirdLife International (April, 2008)
    http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=3508&m=0
  3. Animal Diversity Web (March, 2004)
    http://animaldiversity.ummz.umich.edu/site/accounts/information/Buteo_galapagoensis.html
  4. CITES (April, 2008)
    http://www.cites.org
  5. Hawk Conservancy Trust (March, 2004)
    http://www.hawk-conservancy.org/
  6. Bollmer, J.L., Sanchez, T., Donaghy Cannon, M., Sanchez, D., Cannon, B., Bednarz, J.C., de Vries, T., Struve, M.S. and Parker, P.G. (2003) Variation in morphology and mating system among islands populations of Galapagos hawks. The Condor, 105(3): 428 - 438.