A white-tailed eagle chick found dead on the Isle of Mull had bird flu, prompting fresh fears for the species in Scotland.
Chicks in at least four white-tailed eagle nests on Mull have died shortly before or after fledging in recent weeks.
One of the dead chicks tested positive for bird flu, but the other three bodies were too decomposed to give accurate results.
At 19, the number of chicks on the island was already one lower than last year’s record number – that was before adult bird behaviour suggested some of the chicks had died.
RSPB Scotland‘s Mull Officer Dave Sexton said adult birds would usually be alarmed if humans approached a nest with a chick in it, but they had stopped doing this.
Worried about the chicks given the current bird flu outbreak, NatureScot and RSPB Scotland arranged for expert climbers to scale Sitka spruce trees to swab the bodies for testing.
‘Heartbreaking’ chick deaths
Climbers scaled almost 40ft to swab the chicks, the most recently deceased testing positive for bird flu.
Another chick tested negative, but these results could have been affected by the level of decomposition.
Mr Sexton said: “Late summer is usually an incredible time of year for Mull’s white-tailed eagles as the youngsters fledge and learn to fend for themselves; a happy time for those of us involved in monitoring them during their first few months.
“These past few weeks though have instead been heartbreaking with so many chicks dying. Visiting nest after nest where, instead of hearing young birds calling, there’s silence, and where adult birds are ignoring my presence rather than alarming, is awful.”
Fear for the future
Chick numbers on Mull are being affected by a number of factors this year alongside bird flu, including bad weather and trees collapsing.
With earlier deaths combined with more recent ones, just half as many chicks are expected to survive as in 2021.
Breeding numbers have been “significantly” impacted as a result, and while one year with this level of deaths shouldn’t affect the future white-tailed eagle population, a prolonged outbreak would.
The dead chicks on Mull join thousands of wild birds that have died across the UK as a result of the bird flu outbreak.
NatureScot is currently leading a task force aiming to tackle the current outbreak, plan ahead for future outbreaks and take action to help protect and restore bird populations.
Conversation