Tsunami impact on the population development of a critically endangered hummingbird species of a Pacific island

It is a long-standing question how tsunamis can influence wild populations of animals and plants. Here, we assessed short-term changes in the population of the critically endangered Juan Fernández Firecrown (Sephanoides fernandensis) by using abundance data recorded 1 year before and 1 year after the 2010 Chilean tsunami. We tested that the abundance of Firecrowns declined in the areas where the tsunami caused the massive loss of Cabbage Trees, an important seasonal nectar source for Firecrowns. The abundance of Juan Fernández Firecrowns decreased after the tsunami, but also was affected by the habitat type, altitude, and the abundance of Cabbage Trees. Firecrowns tended to be more abundant in settlement areas than in native forest whereas the reduction in Firecrown abundance after the tsunami was more intense in settlement areas than in native forest. As expected, this habitat effect was dependent on the massive loss of Cabbage Trees in settlement areas following the tsunami. In spite of the short-term nature of our data, our results are conclusive in showing that the loss of an important food source causes short-term changes in the distribution and abundance of Firecrowns, which, in turn, could contribute to population decline.