Meeting Abstract

82.2  Friday, Jan. 6  Change in Avian Pox prevalence varies by species and land use type in Galápagos finches ZYLBERBERG, M*; LEE, KA; KLASING, KC; HAHN, TP; WIKELSKI, M; UC Davis; UC Davis; UC Davis; UC Davis; Max Planck Institute for Ornithology

Introduced disease has been implicated as an important factor in recent extinctions and population declines. Avian pox (AP), a pathogen implicated as a major factor in avian declines and extinctions in Hawaii was introduced to the Galápagos in the last century. While AP is thought to have increased in prevalence in recent years, no study has carefully evaluated the threat this disease poses to the Galápagos avifauna. In this paper, we examine the course of the AP epidemic in seven species of Galápagos finch on Santa Cruz Island, Galápagos. We describe temporal change in infection and recovery rates from 2000-2009. Then, we test two hypotheses regarding geographic variation and temporal patterns in disease prevalence: specifically, that AP prevalence and recovery trends vary 1) by altitude, or 2) according to human land use patterns. We show that AP prevalence has increased dramatically from 2000-2009. However, we find that this increase in prevalence varies by species and by geographic location. Specifically, while small ground finches, small tree finches, warbler finches, and cactus finches appear to suffer high mortality rates from the disease, medium ground finches appear much less susceptible. In addition, populations in agricultural areas appear to be much harder hit than those in either urban or undeveloped areas. In both cases, variation in innate immune function at least partially explains apparent variation in susceptibility to AP. We conclude that AP poses a threat to the integrity of the Galápagos avifauna, and that more work is needed to understand why certain species and populations appear to be particularly affected by this disease.