The osprey1 (Pandion haliaetus, from the Greek for 'sea eagle') is a large fish-eating bird famous for its dramatic method of hunting which involves plunging into water to seize its prey in its feet. This dive can follow a period of hovering tens of metres above the surface or may be made from atop a convenient waterside tree or pole. The bird is quite capable of lifting fish weighing over 3kg out of the water although there are reports of some unlucky birds drowning after tackling prey that was too big for them. For an experienced bird, about one in every four fishing attempts is successful.
In flight, this bird resembles a very large gull at first glance. The angled wings and the largely white underparts coupled with the dark plumage above add to this overall impression. Seen at closer range, the striking dark eye bar and a white face give the osprey quite a dashing piratical appearance. The rather heavy flapping during hovering contrasts with the unhurried grace of the osprey's normal flight pattern, and the dives into the water can be very spectacular indeed.
Although the osprey hunts only fish, it is interesting to note that the classic raptor profile of a passing osprey will often alarm other birds which will then begin mobbing; this is a bird defence technique in which prey birds will swarm around a predator to drive it off.
Breeding and Migration
Since the late 1950s, after an absence of about 40 years which was brought about largely by shooting and egg collecting, the osprey has staged a very satisfactory comeback in Scotland.
At the turn of this century, there were about 100 breeding pairs of these migratory birds visiting Scotland and roughly 100 chicks could be successfully fledged in a single breeding season. To put that in perspective, there are over 70,000 pairs of kestrels and 400-500 pairs of golden eagles in the UK.
With the aid of a controversial re-introduction programme, the birds are now also breeding in England. The first English osprey chick was successfully fledged in 2001 after more than 150 years. Some purist birders still would prefer that there was no intervention by man and argue that a natural spread to England would be have been inevitable following the rapid growth rate of the osprey population in Scotland.
Typically, the birds lay three eggs in a clutch, and they like to nest near water in trees or ruined buildings with good panoramic views. They may even nest on electricity pylons, which has the added benefit of deterring egg thieves. The nest is a huge construction, which can be visible from a considerable distance. Ringing (banding) studies have shown that breeding pairs are quite loyal to the same nest sites year after year.
Ospreys arrive in late March or April after having spent the winter months in West Africa and they will stay in the UK until late September or even October. There can be snow on the ground while these 'summer visitors' are still in the country, but for obvious reasons the birds are wise to leave before the lochs freeze over. The web-site at Osprey Project details the movements of some radio-tracked individual birds.
Where to See Ospreys
An excellent place to observe ospreys fishing is at Spey Bay on the Moray Firth coast where several birds may be seen in the air at the same time from July to the end of summer. The sudden flight and noisy alarm calls of the roosting terns is often a sign that an osprey is approaching.
The Tugnet Icehouse is another fine vantage point as is the disused railway bridge about half a mile upriver.
Findhorn Bay, just a few miles along the coast is also popular with the ospreys as a fishing area.
Visitors to the fish farm on the outskirts of Aviemore are sometimes treated to very close up views of ospreys fishing.
The famous RSPB Reserve at Loch Garten is a great place to learn about ospreys and to view them at the nest site. Remote cameras and microphones at the nest site add real immediacy to the experience there.
Visit RSPB Webcams.
In England, osprey viewing can be done at Rutland Water Nature Reserve during the summer or, with a bit of luck, at any lake or reservoir during the migration periods.
Philip Brown's book The Scottish Ospreys is regarded as a classic, and is recommended reading for anyone who wishes to learn about this graceful hunter and the early years of its recolonisation of the UK.
A more modern book with excellent photos to accompany the informative text is Ospreys, by Roy Dennis, Colin Baxter Photography LTD, 1991.