April 10, 2020

Penguins & Pebbles

Eggs Aren’t Just for the Easter Bunny!


It’s that time of year when love is in the air for many species of animals. You may have heard that a penguin courts his would-be mate by presenting a shiny pebble. If she accepts, the pair will most likely become life-long mates. This story may seem too cute to be true, but it actually is true!


The two species we have at the Pittsburgh Zoo & PPG Aquarium are gentoo penguins and macaroni penguins. They are both native to the rocky shores of the Antarctic peninsula and the numerous islands surrounding the continent. They build their nests out of pebbles that both the male and female help to collect. When a potential mate presents his pebble to the female, he is demonstrating that he will be an attentive mate and parent!

In the wild, these species often gather together in large colonies and are accustomed to being surrounded by thousands of other birds. At the Zoo, we provide them with platforms for their nests, but some may opt to build their nests out on exhibit. They choose their own spot. Established couples, however, will typically nest in the same spot every year.

Throughout the breeding season, nest-building never quite ends. The penguins continue to collect pebbles to build up their nests and they often steal from other nests to do so. It is a constant game of pebble musical-chairs!

For those penguins not yet in a mated pair, they still enjoy playing with the pebbles and will stay close to the nests. The younger penguins often practice courting behaviors for when they are old enough to participate. Gentoo penguins reach sexual maturity around 3 years of age, and the macaroni penguins around 5 years of age.

The macaroni penguins typically lay their eggs in mid-April, and the gentoo penguins lay in early May. Each female will lay 1-2 eggs, and both parents take turns sitting on the eggs to keep them warm and safe. The chicks hatch in late-May or early-June and are fully grown by September!

You can watch our penguins building their nests LIVE on our Penguin Cam!