Biol. Lett. 10.1098/rsbl.2009.0710 (2009)

Credit: ISTOCKPHOTO / R. KHALIL

Several endangered primate species could be adversely affected by climate change, finds a new study.

Ruscena Wiederholt and Eric Post of Pennsylvania State University looked at whether El Niño events, in which abnormally warm surface waters in the Pacific Ocean affect the climate, could influence primate populations in the tropics. They focused their attention on four species of New World primates: the muriqui of Brazil (Brachyteles arachnoids), the woolly monkey (Lagothrix lagotricha) in Colombia, Geoffroy's spider monkey (Ateles geoffroyi) on Barro Colorado Island in Panama, and the red howler monkey (Alouatta seniculus) in Venezuela. They found that after every event, all four of the species suffered either an immediate or a lagged decline in population. Populations of spider, woolly and muriqui monkeys, species that mostly eat fruit, were affected in the year directly following El Niño events, and suffered the largest declines. Howler monkeys, who mostly eat leaves, suffered population declines during El Niño years.

Climate change is expected to increase the frequency of El Niño events. The effects could be devastating for several species of New World monkey that are already threatened with extinction, warn the researchers.