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White-Tailed Eagles on the Isle of
Mull
King of British Raptors
Imposing
Standing (from head to talon) at a metre tall and weighing-in at
around 7 kg, the White-tailed Eagle is the largest and heaviest
bird of prey in the British Isles. Its huge bulk and long, broad
wingspan of 2.5 metres make this King of British raptors a truly
majestic and awe-inspiring sight when seen perched or in flight.
Adult birds possess a strikingly white tail, from which the bird
derives its name, although immature birds have to endure several
moults before their dark brown (almost black) tail feathers
whiten.
 The plumage of adult birds is mainly brown with a noticeably paler
head and neck, the colour of which has a tendency to lighten
further with age. The head colour of older birds can look
conspicuously white.
White-tailed Eagles have large heads with adults sporting a huge,
thick yellow beak, the colour of which can match its eyes, legs
and feet. Immature birds take up to five years to reach maturity,
during which time the bird’s eyes, tail and beak colour will
progressively take on the appearance of adult plumage.
Adult's White Tail
Reversed Sexual Dimorphism
As with most birds of
prey, the female White-tailed Eagle is considerably larger (up to
36” in length, compared to 27”) and heavier than the male (up to 7
kg, compared to 5.4 kg) and tends to be the dominant partner in
the relationship. This size difference allows a mated pair to hunt
a wider variety of food items within their territory, females
being capable of catching and killing larger and heavier prey.
Wing Shape
The flight patterns of a
White-tailed Eagle are determined by it's wing shape. White-tailed
Eagles have long, broad, vulture-like wings that are ideal for
gliding and soaring on up-draughts. It is not unusual to witness
one of Mull's White-tailed Eagles spiralling effortlessly on
'lazy' wings high above a hillside or sea cliff on the island.
This is a great way for the bird to save energy while keeping an
'eagle eye' on potential hunting opportunities.
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