The Intelligence Of Crows

Mike Fairgrieve

Rail police were flapping when they found small pebbles and gravel on stretches of North-east railway sleepers.

But you could have knocked them down with a feather when they discovered the bird-brained culprits were crows!

Sgt Mike Burnett of British Transport Police said: "The problem was spotted by an engineer doing maintenance work.

"It was first reported as people putting stones on the line.

"But something did not make sense. It was out at Kennethmont and Huntly and that's not an area where we would expect trouble.

"Our first thought was kids, but it's in the middle of nowhere."

Then an eagle-eyed signal operator solved the mystery.

Mike said: "He spotted the birds putting them on the lines so the trains would go over them."

It turns out the crows know exactly what they're doing.

They place the stones on the tracks, wait for trains to run over them, then swallow the debris, which helps them digest their food.

At first Mike thought it was a wind-up.

"I checked the date to see it wasn't April 1.

"I've been in this job for 20 years and never known anything like it."

It was also news to Julia Harris, of the Royal Society for the Protection of Birds.

She said: "I've never heard of that before, but crows are definitely known as being among the most inventive birds, like others from the same family such as jackdaws."

She says crows and other birds have no teeth so they need to swallow grit to help them grind up their food.

A ScotRail spokesman said: "I think that's absolutely amazing. It sounds like something out of Alfred Hitchcock's The Birds."

But he didn't think the rail company would be taking any measures to clip the culprits' wings.

He said: "We have enough problems already with people putting washing machines and allsorts on railway lines.

"At least these birds are doing something for a proper purpose. This is a serious part of their life," he said.

The tale of the brainy birds coincides with a major conference in Aberdeen today.

The 8th International Seabird Group Conference, being held in the city today and tomorrow, was being told that Aberdeen is believed to have the world's biggest population of roof-nesting herring gulls.

It had been hoped that Aberdeen's refuse switch from black bags to wheelie bins would put an end to the gull menace.

But the large birds, with the characteristic blood-red mark on their beaks, have not been completely run out of town.

Conference organiser Martin Heubeck said: "I'm not surprised. Wheelie bins alone won't solve the problem.

"Walk down Union Street at 3am on Sunday and you will see the leftovers from takeaways scattered all over the place.

"So there's still a food source readily available."

During another recent visit to the Granite City he could see that there were still plenty of nesting spots.

He said: "I was staying at the Travel Lodge on Union Street a week ago and I could see a flat roof on Bridge Street which was heaving with herring gulls.

"But they could easily have been prevented from nesting there by putting up wires."

Herring gulls and other seabirds, like black-headed gulls, have moved to coastal areas and inland in larger numbers since the 1980s and the 1990s.

And, like foxes, they have taken root in many of our towns and cities, feasting on leftovers.

Ironically Seabird 2000, the largest survey of UK seabirds in 15 years, shows that UK numbers of herring gulls have declined in the past 30 years.

Mr Heubeck says that's taking the total over all. The numbers in coastal areas have fallen as the gulls move into the towns.

Herring gulls have taken a dive along with Arctic skuas, shags, kittiwakes and some species of tern.

But the good news is that there have been big rises in the populations of gannets guillemots and - everyone's favourite - puffins.

Britain has 8 million seabirds and 5.2 million are in Scotland.

Nobody has yet counted how many are perched on Aberdeen's rooftops.