Long-term metapopulation dynamics of Bahamian ants

The ants of small islands in three Bahamian archipelagos were surveyed for periods ranging up to 18 years. Rates of species turnover were low in an absolute sense. Immigration rates exceeded extinction rates and the islands gained species in the previous decade (1990-1999), but the reverse was true for the current decade (2000-2007). Similar patterns were apparent for all three archipelagos. Excluding populations that went extinct, the two most common species experienced declines in relative abundance in the current decade. Increased hurricane activity in the current decade is one factor that may be responsible for the observed declines in the ant faunas, although a long-term decrease in precipitation in the region is likely to be the most important mechanism.