London penguins conduct 'thefts' to impress mates

"Criminal" penguins have been conducting a series of thefts at the London Aquarium.

As the mating season begins, gentoo penguins have been pinching pebbles from rival nests.

With a stealthy glance over their shoulders, the fiendish birds quickly waddle to their neighbours' nests, steal a stone and run back to their own breeding ground.

But as the number of break-ins increase, the gentoos have become suspicious of their fellow colony members.

If they notice a rival moving in to plunder their pebbles they quickly run back to defend their nests.

The colony of 10, which arrived at the attraction last year, are in the middle of their first mating season at the aquarium.

Males declare their interest in a female by selecting and presenting a "love token" in the form of a pebble to their chosen female.

If it is accepted, the couple then begin collecting more pebbles to line their doughnut-shaped nest.

The birds build their stone nests to elevate and protect their eggs.

Smooth pebbles are "like gold dust" because they are easy to pick up and comfortable to lie on, according to those who tend to the birds.

Hayley Clark, aquarist at the Sea Life London Aquarium, said extra pebbles had to be put into the enclosure after burglar Vladimir has conducted daily robberies on surrounding nests.

She said:

Ms Clark added that there has been "a few tiffs" over pebble thefts.

"They will run over pretty sharpish and tell them where to go," she said. "It can get a little bit aggressive but they generally back away very quickly."

No eggs have been seen yet but breeders are hoping that a few will turn up in the next few weeks.

The pilfering activities of pesky penguins were also featured in the BBC's Frozen Planet when crews captured Adelie penguins performing a similar thefts while filming in Antarctica.