Don’t be deceived by the innocent look this newborn Nazca Booby, less than a month old, is sharing. It’s quite likely that she aided in the untimely demise of her younger sibling.
Nazca Boobies, like these that I observed last May on Isla de la Plata off the shore of Puerto Lopez, Ecuador, practice obligatory siblicide, an act wiki describes as such:
Mothers lay two eggs, several days apart. If both eggs hatch, the elder chick pushes its sibling out of the nest area, leaving it to die of thirst or cold. The parent booby cannot intervene and the younger chick inevitably dies.
..Nazca Booby dominant A-chicks always begin pecking their younger sibling(s) as soon as they hatch; moreover, assuming it is healthy, the A-chick usually pecks its younger sibling to death or pushes it out of the nest scrape within the first two days that the junior chick is alive.
Adults that have failed to breed frequently seek out nestlings in their colony, and during those visits they often bite, preen and even try to copulate with chicks. The causes of this behavior are not fully understood.
This Oedipal-like variation does rub some of the varnish from the cuteness factor of these birds, but it doesn’t make them any less amazing.
Most common in the Galapagos Islands, they are plentiful enough on Isla de la Plata to ensure that most visitors will see a few during their day hike across the island. The one below, according to my guide, had recently arrived from the Galapagos, some 1,100 kilometers, or almost 700 miles, away.
More on Isla de la Plata, part of Machalilla National Park and dubbed the Poor Man’s Galapagos, soon.