Gentoo penguins have earned their place among the romantic birds. They give pebbles to their potential mates before mating as a symbol to help build their nest more nicely and to deliver the message that they are interested in breeding. Also they choose the same mate every year for breeding.
https://medium.com/illumination/climate-change-is-increasing-the-numbers-of-an-endangered-species-of-penguins-14da3182483d
















