WatchList Species Account for Least Storm-Petrel (Oceanodroma microsoma)

Qualifies for the list as a Red List Species

The world's smallest storm-petrel, only the size of a sparrow, the Least Storm-Petrel breeds only on islands off Baja California and in the northern islands in the Gulf of California but moves irregularly north to waters off California in late summer, particularly in years when water temperature is higher, sometimes in considerable numbers. It breeds colonially on rocky islands off northwestern Baja California and is active at the nest only at night. Nest sites are often crevices in a cliffs but unlike other storm-petrels it does not nest in burrows. In mid-autumn it moves south along the coast of Central America as far as Panama and occasionally farther south. It occurs closer to shore than other storm-petrels and may often be seen from shore. It forages for zooplankton on the surface.

Numbers may be stable but overfishing and pollution in the Gulf of California could negatively affect its populations. Introduced predators (cats and rats) are a problem on some nesting islands.