The number of blue-footed boobies, one of the most iconic Galapagos bird species, has declined by 50% in the last 20 years, according to a recent study published by biologists from Wake Forest University in the journal Avian Conservation and Ecology.
“It is alarming,” according to lead Professor Dave Anderson. “ There has been a drastic change from the 1980s and 1990s, when young blue-foots were common throughout the archipelago. Until 1997 there were literally thousands of boobies at breeding colonies and hundreds of nests full of hatching chicks. Then, suddenly, the boobies weren’t there.”
The researchers suspect that the disappearance of sardines from the birds’ diet may be to blame, though they don’t know exactly why the fish are disappearing from Galapagos waters. Overfishing is one possibility. Or it could be the result of a natural cycle, which has caused sardine numbers to plummet across the eastern Pacific in the last 15 years.
During the course of the study, sardines dropped to less than half of the boobies’ diet. Past research on booby populations in the islands has shown that the birds successfully reproduce only when their diet consists almost entirely of sardines.
In spite of the decrease in their numbers, blue-footed boobies are currently listed as a Species of Least Concern by the International Union for the Conservation of Nature. Unfortunately, the designation could quickly change if boobies don’t start reproducing in greater numbers soon