Osprey - Pandion haliaetus

Osprey are primarily found in the Scottish Highlands as they prefer the pine forests and the freshwater rivers and lochs, yet they can be seen on their spring and winter migration routes as they will stop at suitable rivers and lakes for days with a plentiful supply of fish to feed before moving on. They start to arrive back from Africa in late March and leave again in August/September time. It was during the winter migration that an Osprey was spotted at the Wiltshire Wildlife Trust Reserve Langford Lakes in 2006.

Habitat

The Osprey’s main habitat requirement is it needs a large supply of medium sized fish (it is a very specialist feeder taking only medium sized fish) that it can catch from the surface of clear unpolluted water.

Description

Adult Osprey’s have a slightly crested white head with a speckled crown and a black eye stripe. It has dark brown upperparts and mottled underparts. It is most likely to be seen in flight from below and can be identified by the long white wings which are angled at the ends where there is a large black patch. The young are similar in appearance to the adults but they are lighter brown above and less mottled below.

Biology

Being a specialist feeder, the Osprey has a particular hunting technique. It will locate its prey by gliding high above the surface of the water at about 30m, once located it will go into a near vertical dive by folding its wings close to its body and at the last moment bringing its feet forward to catch the fish. Its feet have long curved talons and spiny-scaled toes that help the Osprey to catch and keep hold of its prey. Adult Osprey can carry fish weighing up to 2kg.

Nests are built at the top of large trees and are called eyries; they are made up of branches, twigs, moss and bark. Ospreys do not breed until they are 5 years old and stay with the same mate and nest site year after year.

Threats

The Osprey went through a massive population decline in the 1800s and 1900s due to Victorian egg and skin collectors. It became extinct as a breeding bird in England in the early 1840s but continued to breed in Scotland until the early 1900s. In the mid 1900s it had naturally recolonised in Scotland, but the recovery has been slow due to the continuation of egg collection and pollution of its food from pesticides. In 2001 there were a number of breeding sites in Scotland and there was the first successful breeding in England. They can be easily disturbed when nesting; and even abandon a nest if there is unusual activity in the nesting area.

Conservation

The Osprey is protected under Schedule 1 of the Wildlife and Countryside Act 1981 with the highest level of protection making it illegal to intentionally take, injure or kill an Osprey or damage, destroy or move its nest, eggs and young. It also protects the birds from disturbance close to their nest during the nesting season.