White-tailed Eagle

Scientific name: Haliaeetus albicilla

Identification

Photo by Laurie Campbell

The white-tailed eagle or sea eagle is the UK’s largest bird of prey, with a huge wing span of up to 2.5 metres.  The wings are very broad and appear more rectangular than those of a golden eagle.  They have fingered tips.  As the name suggests, they have a white tail, ridged with black in juveniles.  The short tail has a distinctive wedge shape.  The head and neck are pale, almost white in mature birds, although juveniles are dark brown, and do not attain full adult plumage until 4-5 years of age.  They have a hooked yellow beak, much more prominent than that of a golden eagle, and piercing golden eyes.  The legs and talons are yellow.

Habitat and Distribution

White-tailed eagles are found along rocky coastlines, estuaries and lochs near the sea, although they will also range inland, especially juveniles.  The species is very widely distributed, with strongholds in Russia and Norway.  It has been reintroduced to the UK, after being driven to extinction, and is now found in Scotland and Ireland.  In Scotland the best places to see whte-tailed eagles are Mull, Skye and parts of the northwest Highlands.

Global distribution of the white-tailed eagle (IUCN 2011)

Diet

White-tailed eagles eat a variety of prey.  As their other common name, sea eagle, suggests, they take fish, but also birds, mammals and carrion.  They are opportunistic hunters and often steal food from other birds. Their method of fishing is very different to that of the osprey; flying low over the water before briefly hovering and snatching the fish, whereas ospreys will hover from a great height and then drop quickly down to the water.  White-tailed eagles will also sometimes plunge right into the water.

Reproduction

White-tailed eagles reach sexual maturity at 5-6 years of age.  Eyries are built in the top of mature trees, made from sticks.  They are often added to each year and so can become huge structures, more than 2 metres wide and deep.  1-3 eggs are laid in late March-early April and incubated for 38-40 days, predominantly by the female.  For the first three weeks after hatching the male does all of the hunting, and after that time the female will take turns to hunt.  The young fledge after 70 days and remain reliant on their parents for a further 5-6 weeks.  Young sea eagles often roam widely in their first few years of life, before finding a breeding territory and mate.  They can live to over 20 years of age.

Status and Threats

White-tailed eagles are classified by the IUCN as ‘Least Concern’.  The species suffered huge declines in Europe during the 19th and 20th centuries and was driven to extinction in the UK, mainly through persecution.  It has since been reintroduced to the west coast of Scotland and more recently to the east coast, and a reintroduction programme is currently underway in Ireland.  As with many birds of prey, the species suffered huge losses in the 1950s and 1960s due to organochlorine pesticides such as DDT, which caused egg shell thinning.  The main current threat in the UK is persecution, predominantly through poisoning, something which has overshadowed the otherwise successful reintroduction programmes.  Illegal egg collection remains an additional threat.

Within the UK white tailed eagles are strictly protected under Schedules 1, 1A and A1 of the Wildlife and Countryside Act 1981 and The Nature Conservation (Scotland) Act 2004.  They are included on the Red List of UK birds of conservation concern.  It is an offence to intentionally take, injure or kill a white-tailed eagle or to take, damage or destroy its nest, eggs or young. It is also an offence to intentionally or recklessly disturb the birds close to their nest during the breeding season.  Violation can result in a fine of up to £5000 and/or a prison sentence of up to 6 months.

Internationally, they are listed on CITES Appendix I and II and CMS Appendix I and II.