One-year-old White-tailed Eagle chick cared for by parents

Unusual White-tailed Eagle behaviour has been observed on the Isle of Mull, with a pair choosing to tend to an injured one-year-old bird this summer rather than breed.

The adult pair continued to care for their injured offspring into its second year of life, going so far as to skip breeding this year to focus on tending to the youngster – rarely documented behaviour in the species.

The chick injured its left wing in July last year after its nest fell to the ground during unseasonably stormy weather. Despite its sibling surviving unscathed and fledging not long afterwards, the injured youngster's story has been a little less smooth.

The young White-tailed Eagle (left) with one of the adults (Martin Keivers).

 

Additional care

As the parents continued to support the chick its wing continued to heal and it finally took to the skies in the autumn, though with little hope from locals that it would survive the long, harsh winter ahead.

This spring RSPB Mull Officer Dave Sexton was aboard the Lady Jayne, run by Mull Charters, for an early0season White-tailed Eagle monitoring check, when he witnessed the adults feeding the immature bird.

Sexton said: "I looked at the skipper in astonishment and we both watched on, unable to quite believe what we'd just witnessed. I was astounded to see this behaviour which was new to me despite four decades of watching White-tailed Eagles in the field."

 

Unusual behaviour

Sexton continued: "Normally, in the autumn and certainly by the winter, all fledged young have naturally wandered away from their parents' territory and if they're still loitering when the next breeding season approaches, they aren't made very welcome. But here we were watching their chick, now over a year old, still in close company with its parents and still being fed!"

"For the adults to be tolerating the youngster and tending to it, well into a new breeding season, is unprecedented in my experience. Each day they share fish from Mull Charters with their disabled offspring and it seems to show a previously unseen type of White-tailed Eagle behaviour. 

"We normally think of eagles as 'hardwired' and unemotional but clearly there might be another side to their nature. It'll be fascinating to watch how long this might go on for. Could they tolerate it and feed it for another year … or two? What would happen as the immature starts to reach the subadult stage in three to four years' time? 

"It's hard to imagine this scenario continuing by then but who knows? We're in unchartered territory."