Once prolific throughout Europe, the Osprey – a medium-large bird of prey which is a specialist fish-eater – was so heavily persecuted in the nineteenth and early twentieth centuries that it became extinct in Scotland in 1916. However, it was re-colonised in the 1950s, and a pair have nested successfully almost every year at Loch Garten near Aviemore since 1959.
In 2010, the breeding population in Aberdeenshire was 23, with at least 35 young fledged. There is an Osprey eyrie at a confidential location on Haddo Estate which has been occupied successfully for a number of years. Unfortunately, gale force winds which struck in May 2011 blew the nest out of its tree, though it is hoped that they will re-build for 2012. A large quantity of brash has been left near the site to encourage them to return. Thankfully, there have been sightings of young birds at a former nesting site on the Estate, so we remain hopeful for their continued survival at Haddo.
Habitat, Feeding & Breeding
The Osprey is a specialist feeder of both fresh and saltwater medium-sized fish. The bird will fly above the surface of the water to locate fish and then execute a near vertical dive with its wings half-folded and feet thrown forward at the last minute. The fish are caught in the talons after a maximum 1m dive underwater. Osprey talons are long and curved and there are short spines covering the underside of their toes to assist with the holding of fish. The bird is also able to close its nostrils to stop water getting up its nose during a dive.
Ospreys are monogamous and are strongly faithful to their nest and their mate. They tend to build their eyries on top of large conifers. The nest is large and made of branches and twigs and lined with small twigs, moss, bark and grass. It takes both birds 2-3 weeks to build is usually around 1.2 – 1.5m high and 0.5m deep, but with the addition of extra material over the years this can increase. The female will lay 2 or 3 eggs at the middle to end of April which she will incubate for 37 days. As with other raptors, the chicks usually hatch a few days apart. Nesting duties are clearly divided: the female carries out incubating, brooding and direct feeding of the young and guards them throughout nesting; the male is the major provider of fish for the female and their young. The chicks will fledge at 53 days and both parents will feed them. They stay close to the nest for another 2 months. Many juvenile birds die before they are 3, while the average life span of an Osprey is around 8 years – the oldest known Osprey, however, lived for over 30 years.
How to spot an Osprey
- The Osprey has mainly white underparts and a white head and brown upper parts.
- Its short tail and long narrow wings with four long ‘finger’ feathers give it a very distinctive appearance.
- In flight Ospreys have arched wings and drooping ‘hands’ which makes them look like a very large gull with a wing span of 5-6 feet.
- Their call is a series of sharp whistles and when they are near the nest they are very noisy, calling out ‘chereek’ quite frantically.