WEATHER INFLUENCES ON NEST SUCCESS OF THE ENDANGERED PUAIOHI (MYADESTES PALMERI)

摘要

The endangered Puaiohi (Myadestes palmeri) endemic to Kaua'i is the island's only remaining native thrush. Given its small population of ～500 birds, it is essential to understand conditions that affect the species' recruitment and survival. Previous observations of Puaiohi suggested that weather may influence nest success and productivity, but no studies investigated this relationship empirically. Our goal was to investigate potential links between weather conditions (precipitation and temperature) in the Puaiohi's range (～20 km~2) and several measures of reproductive success, using published data from 1996-1998 and new data collected by the Kaua'i Forest Bird Recovery Project from 2007-2009. Total rainfall in the previous wet season strongly and positively correlated with the majority of the nest success variables (three of four). Mean rainfall during the breeding season correlated positively with reproductive effort (attempts/season and length of breeding season) and with total reproductive output, but there was some evidence that too many rainy days during the peak breeding season associated with fewer young fledged per nesting attempt. Although there seem to be clear implications that weather affects reproductive output of Puaiohi, results from longer time series will be useful in refining this relationship. Given that prevailing weather conditions of the Puaiohi's range may shift with anthropogenic climate change, which in turn may alter the severity and frequency of El Nino Southern Oscillation events, our findings provide insight into future trends in reproductive output, and thus, population of this endangered species. Received 26 September 2014. Accepted 15 June 2015.