BEHAVIOUR never seen before in a rare bird of prey has been recorded by cameras in a Scottish conservation project.

The “exceptional” footage shows male hen harriers standing guard over nests and a hen harrier brood being hunted by two species of owl.

Conservationists say the pictures tell an amazing story that shows the kind of hurdles hen harrier chicks – the species nests on the ground – have to overcome to survive.

The discoveries were made as part of Heads Up for Harriers, a Partnership for Action Against Wildlife Crime Scotland (PAW) project, led by Scottish Natural Heritage (SNH).

Figures released today also show 30 young birds have successfully fledged on participating estates.

On two occasions, a male harrier was recorded spending up to 35 minutes standing over or beside a nest, guarding the chicks when the female harrier was away.

This is believed to be highly unusual harrier behaviour as the only time a mother usually leaves a nest for the first six weeks is to briefly catch a food drop from the father to feed the chicks.

The footage has also captured a hectic night of activity involving a fox and a short-eared owl which ended with five chicks being killed by another owl.

According to the pictures from the nest camera, the mother spent eight days taking care of her five newly-hatched chicks, until she was scared off the nest by a fox. The unattended chicks were then surveyed first by a short-eared owl before being killed by a long-eared owl.

The long-eared owl ate three of the chicks. The mother returned to remove the remaining dead chicks just before dawn. The attack happened this spring in the Langholm area of southern Scotland.

Professor Des Thompson, chairman of the PAW Scotland Heads up for Harriers group and SNH’s principal scientific adviser, said the pictures of the incidents were “exceptional”.

“It’s the first time we’ve observed such behaviour by a male hen harrier and the first time we’ve seen a hen harrier nest under attack by two other raptors, one after the other,” he said. “As ground-nesting birds, hen harriers already face extra obstacles in order to protect their chicks. That’s why it’s so important that we crack down on persecution against these vulnerable birds, which already face so many challenges to survive.”

Field worker Brian Etheridge said the project was uncovering what seemed to be new behaviour.

“We’re surprised the long-eared owl didn’t take its prey away but instead stayed at the nest for almost an hour. We haven’t seen an owl behave in this way before and can’t explain it at this point. We also don’t know why the fox and the short-eared owl didn’t eat the chicks when they had the chance.”

Heads Up for Harriers project field worker Scott Smith added: “These pictures tell an amazing story that helps us understand the kind of hurdles which hen harrier chicks must overcome if they are to survive. Nests can fail for many reasons and the Heads Up for Harriers project is keen to learn everything we can to help hen harriers flourish.”

A total of 27 Scottish upland estates took part in the project this year, with 17 nests monitored and 30 young birds successfully fledging from eight nests. Four nests failed at egg stage and five nests failed with chicks. The primary reason for failure at chick stage was fox predation although owl predation and starvation due to adult birds not being able to provide enough food also played a part.