ACCORDING to Marilyn Monroe, diamonds are a girl’s best friend - but for the female penguins at Edinburgh Zoo, a simple pebble will suffice.
As humans exchange cards and send presents to their loved ones on Valentine’s Day, the gentoo penguins at the capital’s zoo are engaging in their own romantic ritual. In a courtship display repeated every year, male birds present their prospective partners with a smooth, round pebble. If the female penguin accepts it, the couple will mate for life.
Alison MacLean, the head penguin keeper, supplies her charges with a mound of smooth, round pebbles, from which the male penguins will pick out their love offering. She said: "If the female accepts the pebble then she is effectively accepting the penguin as her mate.
"Pebbles are extremely important in the lives of this species of penguin.
"The females collect the stones from the males so that they can build secure nests for their chicks. It is crucial for them to build a high, round nest to ensure that the chicks are kept well away from the cold ground."
Edinburgh Zoo is world-famous for its breeding and care of gentoo penguins, which are known for their monogamy and dedication to their mates.
But while female penguins may be easily impressed, they are no pushover when it comes to pebbles.
Amanda Alabaster, of Edinburgh Zoo, said: "One year, I witnessed a female reject several rocks before the young male succeeded."
After the pebble ritual, the male and female will begin to build the nest - in exactly the same spot as the year before.