Fears about the fate of the young female osprey - known simply as Blue YZ - were first raised last November when experts at the Scottish Wildlife Trust lost radar contact with the record-breaking raptor.
But staff at the trust’s Loch of the Lowes reserve in Perthshire have now confirmed that her bones and the satellite tag have now been recovered in Guinea-Bissau. And it likely the young chick had died of starvation or exhaustion.
Blue YZ had left the trust’s Loch of the Lowes Reserve last September to follow her mother - the legendary “Lady” - on the 3000 mile migration to Africa.
Blue YZ had been the centre of worldwide media coverage last summer when her mother, now 28 years old, defied all the odds by fledging her 50th chick at the reserve. Lady had staggered wildlife watchers earlier in the year when she returned to her nest at the end of March for a record 23rd year. She laid four eggs, but only one chick, Blue YZ, successfully fledged.
The trust announced today: “We can now confirm the sad news that Blue YZ, the osprey chick born at Loch of the Lowes in summer 2013, has died in Guinea-Bissau as her bones and the satellite tag have now been recovered. We have suspected this was her fate, but this is the first concrete proof we have been able to ascertain.”
Ranger Emma Rawling said: “Blue YZ made a successful first migration to Guinea-Bissau last autumn, and her journey held us all enthralled and produced some fascinating insights. In November, her satellite tracking data showed a very worrying trend with the bird slowing down and eventually stopping in a rice field. We strongly suspected that the bird had died and the transmitter then stopped sending any new data. Unfortunately we were unable at the time get anyone to the area to investigate.
“A couple of weeks ago, the satellite tag started sending data again - but still from exactly the same place. We discussed this with experts like Roy Dennis, and came to the conclusion that it was most likely that the tag had recently been turned over and was now facing the sun and getting charge from its solar panel.”
She explained that the “exact up-to-date location information” had enabled the trust to enlist the help of a local anthropology fieldworker and a national park warden to finally locate the remains of Blue YZ in an area of salt pan and rice paddies.
Said Ms Rawling: “The osprey was only bones. It therefore looks most likely that our bird died of exhaustion, injury, or starvation in this field, and that her body lay amongst the vegetation and was scavenged by local predators. The tag only worked when the body was rolled over, either by an animal or by water washing over it, and its solar panel again faced the sun.
She added: “What a great story this bird has told- in her short but eventful life she has taught us all so much and is now the reason to build wonderful links between two distant countries.”