Sanford's Sea Eagle - Haliaeetus sanfordi

Family: Accipitridae
Genus: Haliaeetus
Species: H. sanfordi

Sanford's Sea Eagles are raptors that live in Papua New Guinea and the Solomon Islands. They form a clade with H. leucogaster (White-Bellied Sea Eagle), H. vocifer (African Fish Eagle), and H. vociferoides (Madagascar Fish Eagle). They also make up a superspecies with H. leucogaster.

Physical Description:

Sanford's Sea Eagles have a dark brown back and wings and a cream-colored head finely streaked with black. The underparts are rufous and the short, wedge-shaped tail is black with a pale tip. The wings are long and pointed. The eyes are brown, the beak and cere are gray, and the legs are white.

Juveniles are similar to adults but have more brown plumage and the head is darker. The tips of the feathers along the wing coverts and the back are white-tipped, and they have gray streaks along the crown, nape, and underside. They reach full adult plumage after 5-6 years.

Their call is a loud honking. Listen to a Sanford's Sea Eagle.

Size:

Length: 70-90 cm
Wingspan: 165-185 cm
Weight: Male: 1.1 kg. Female: 1.3-2.7 kg.

Habitat and Distribution:

They occur in a range of habitats, from inland montane forest to coasts and shorelines. Some coastal birds have been observed traveling inland to forage and a few pairs have completely inland territories. Sanford's Sea Eagles are found from 0-1,500 meters above sea level.

They live on two islands in Papua New Guinea (Bougainville and Buka) and on the Solomon Islands, from 5°S to 11°S. Less common on larger islands, their total range is 36,300 km². Adults are sedentary. There are an estimated 250-999 individuals.

Diet and Hunting:

They eat mammals, birds, and fish—mammalian prey includes flying foxes, fruit bats, rats, and Phalanger orientalis (Northern Common Cuscus). They have also been observed eating off of shark carcasses and carrying fish. As with several other species within the genus Haliaeetus they are kleptoparasites, meaning they steal food from other birds; in the case of Sanford’s Sea Eagles, they most often parasitize Pandion haliaetus (Osprey).

They hunt from a perch or forage above the coastline, tree canopy, or ground. Arboreal prey is snatched directly from the canopy.

Reproduction:

Breeding displays have been observed in June and August and consist of high-circling and calling. They most likely nest in trees, possibly including mangroves. Incubation and fledging periods are unknown.

Conservation:

The population is thought to be declining due to habitat loss from overfishing and logging pollution in addition to persecution in the form of shooting, both for sport and for food. They are currently listed as Vulnerable by BirdLife International.

Conservation measures undertaken include legal protection in some provinces in the Solomon Islands. Conservation measures proposed include surveys of inland areas on Guadalcanal, Malaita, and Makira to determine the impact humans have had on the eagles, establishing a database of known Sanford's Sea Eagle nests, researching the effects of degradation of marine and coastal environments, and conducting national education programs.

Taxonomy:

Molecular analyses have shown that genus Haliaeetus is closely related to the kite genera Milvus and Haliastur. There is also molecular evidence that Haliaeetus species H. sanfordi, H. leucogaster (White-Bellied Sea Eagle), H. vocifer (African Fish Eagle), and H. vociferoides (Madagascar Fish Eagle).

It is probable that H. sanfordi evolved from H. leucogaster in recent history, due to the fact there is only a 0.3% genetic difference between the two species. This is equivalent to the difference found between individuals of the same species of other eagles, but H. sanfordi and H. leucogaster have been classified separately due to differences in size, morphology, and behavior.

Other Names:

Brown Fish Eagle, Brown Sea Eagle, Forest Fish Eagle, Sanford’s Fish Eagle, Solomon Fish Eagle, Solomon Sea Eagle, Orel Sanforduv (Czech), Salomonhavørn (Danish), Sanford-zeearend (Dutch), Pruun-merikotkas (Estonian), Ruskomerikotka (Finnish), Pygargue de Sanford (French), Salomonenseeadler (German), Aquila di mare di Sanford (Italian), Soromon'umiwashi (Japanese), Bielik melanezyjski (Polish), Pigargo de Sanford (Spanish), Salomonhavsörn (Swedish).

Video of a Sanford's Sea Eagle:

References:

http://avibase.bsc-eoc.org/species.jsp?avibaseid=4CD1AF3EEDA9C809
BirdLife International (2012) Species factsheet: Haliaeetus sanfordi. Downloaded from http://www.birdlife.org on 16/02/2012.
Global Raptor Information Network. 2012. Species account: Sanford's Sea Eagle Haliaeetus sanfordi. Downloaded from http://www.globalraptors.org on 16 Feb. 2012
http://ibc.lynxeds.com/species/sanfords-sea-eagle-haliaeetus-sanfordi
BirdLife International 2008. Haliaeetus sanfordi. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. www.iucnredlist.org. Downloaded on 16 February 2012.
http://www.planetofbirds.com/accipitriformes-accipitridae-sanfords-sea-eagle-haliaeetus-sanfordi
Ferguson-Lees, James, and Christie, David A. Raptors of the World. Houghton Mifflin Company, 2001.