Speaker: Abi Mustard
Reporter: Sue Gale
Abi is the leader of this project, which aims to firmly re-establish the Osprey as a breeding bird in central England. The Osprey is our third largest bird of prey with a wingspan of 1.4 to 1.8 meters. The females are largest, and it is possible to distinguish chicks in the nest on the basis of size only. In the UK 2 or 3, occasionally even 4, eggs are laid, the current pair at Rutland being exceptionally
efficient in rearing 4 chicks each year. Ospreys are exclusively fish eaters and are adapted to do so. They can rotate an outer talon to give a better grip on the slippery prey. They also have excellent eye-sight, and especially strong wing muscles so that they can rise from the water while holding their prey.
Ospreys are migratory birds, wintering for the most part in West Africa, although some do linger in Southern Spain. They don’t migrate as a family – the female leaving first, then the chicks and lastly the male. The juvenile birds therefore have to find their own way, and only about 30% of them will return. Satellite trackers have allowed researchers to plot the routes used as well as speed and altitude. Birds cross the Sahara as quickly as possible, but they may roost there when necessary.
They seem to recognise general features of the landscape, and individuals will use the same stop- over each time they migrate.
Although they are widespread throughout the world, Ospreys became extinct as a breeding bird in the UK in 1837, a result of egg collection and shooting. They returned to Scotland in 1954 , when a pair raised a chick at Loch Garten, but the rate of increase and spread was very slow. By 1994 there were 95 pairs but it was forecast that at that rate it would take 100-150 years to colonise central England. A re-introduction scheme was devised to speed things up, and Rutland Water was
selected. As the birds are site-faithful and will return to the place where they fledged, it was necessary to translocate chicks. Between 1996 and 2001 64 chicks from Scottish sites were brought to Rutland. Initially only the youngest chick from a brood of at least 3 was taken, but survival was very poor. From 1997 onwards the oldest of 2 or 3 was moved, and this was much more successful.
In 2005 a further 11 chicks were moved in to balance the gender distribution, but otherwise the population has been self-sustaining.
As a rule birds do not return to breed until 2 years after fledging, and the first pair returned in 1997. However it was 2001 before the first successful breeding was recorded. The happy pair were a male from Rutland and a female originally from Scotland, and this male has not raised a total of 32 chicks.
In 2007 a Rutland born Osprey bred and he is still with us, the oldest bird in the population. Birds fledged at Rutland have been found at Glaslyn in Wales - – male from 2004-14 and several females at Dyfi. Currently all of the females in Wales were fledged at Rutland. After 10 years of the Rutland project there are 10 breeding pairs in the area, but only one of the nests is on the reserve. 188 chicks have been fledged, and Abi is hoping to see the 200th this year.
Surprisingly the females are more likely to disperse to other sites than the male birds. , although there has been a Rutland male breeding in Norfolk since 2015. It raised 3 chicks that year with a German female. The success of the several reintroductions means that there are 300-400 breeding pairs currently in the UK. Excitingly a new project is to take place in Suffolk, at the Blythe Estuary – and details are in literature from Suffolk Wildlife Trust.
For the future, Abi and the Project will continue to work with landowners to provide perches for nests, and keep up the support for the self-sustaining Rutland Ospreys. Many thanks to Abi for an interesting and informative evening.
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