22-05-2025
- General
- The Herald Scotland
Birdwatchers baffled as Tweed Valley ospreys caught in ménage à trois
Forestry and land Scotland (FLS) cameras are capturing in real time the unorthodox behavior of the three birds, which appear to be indulging in a form of polygamy known as polygyny.
Cameras set up as part of The Tweed Valley Osprey Project are providing a rare insight into the natural behaviour between the adult birds – Mrs O, a female who has previously nested at the site, a new female dubbed 'F2' and young male being called Newboy – as the three-way partnership develops during the season.
Despite their ferocious nature, neither female has objected to a rival getting her claws into their mate, and have been sharing food as well as living space and quality time with the young male.
The three ospreys have laid four eggs together (Image: FLS) Both have hatched four eggs between them, which are expected to open in the coming weeks, with the female birds have been taking turns to incubate them.
It is not yet known what impact four demanding chicks will have on the scene of unorthodox domestic bliss playing out in the tree tops.
Tweed Valley Osprey Project Co-ordinator, Diane Bennett said: 'So far things are looking good. The females seem amicable and tolerant with both having mated with the male bird and laying four eggs between them.
'The only tension witnessed so far has been on the arrival of a fish delivery from the male as the two females both make a grab it.
'Mrs O usually wins the fish and flies off to feed but has been seen to return with a portion remaining and letting the other female have it.'
Ms Bennet said the trio's nesting arrangements was 'very rare', and the first time it had ever been on a livestream camera.
Similar mating set-ups have been observed, but only though distant observation.
The three ospreys appear to be living in domestic bliss (Image: FLS) Ms Bennet added: 'Getting to watch this saga close up as the season unfolds is exciting both for the drama but also for the important research insights it will allow.'
The background and identity of the new arrivals is unclear as while they both have British Trust for Ornithology (BTO) rings to generate information on the survival, productivity and movements of bird, they are not fitted with coloured, alphanumeric Darvic rings that allows researchers to identify individual birds.
Mrs O is also only fitted with a BTO ring but because she has been returning to the site for several years, she can be identified from her head markings.
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The Tweed Valley Osprey viewing centre at Glentress is accessible to all users. Ospreys have been coming to breed here since the 1990s and the project – funded and managed by FLS and supported by a team of volunteers – aims to protect and provide safe places for them to settle and nest.
The Tweed Valley polygyny saga can be viewed at the Wildlife Hub at Glentress Forest in Peebles between 10am- 4pm each day, where the camera is streaming live onto the big screen, with volunteers on duty most of the time, to interpret what is happening with the osprey family.
