Chinstrap penguins are easily recognizable by the black bands under their heads that give them the appearance of wearing helmets. They’re found in Antarctica, the Sandwich Islands and other southern island chains, where they live on barren islands and congregate on icebergs during winter. Experts consider these birds to be the most aggressive species of penguin.
In 2004, two male chinstrap penguins at the Central Park Zoo formed a pair-bond and took turns trying to “hatch” a rock. A zookeeper later substituted the rock with a fertilized egg, and Roy and Silo hatched and raised the chick. A children’s book titled “And Tango Makes Three” was written about the penguins.