Due to people overfishing the worlds seas, not only have fish populations fallen dramatically, also bird species that normally rely on fish for their diet are strongly affected. On some islands off the coast of South Africa, its impact is expressed in the bizarre behaviour of pelicans swallowing gobblets in one go!
Each day, hoards of pelicans fly across to one of the only places Cape gannets still breed. Wandering through the gannet colony, the pelicans target chicks up to 2kg in weight that will fit inside their massive bills. Because of the decreasing fish numbers, both gannet parents need to leave their chicks to forage at sea. This leaves their offspring vulnerable to the large hungry pelican mouth.
This unusual behaviour shows how adaptable and opportunistic pelicans need to be because of the changing food supplies. It is again a sad example how we humans affect entire food chains with our increasing need for resources.