Published online by Cambridge University Press: 30 July 2010
Despite the aseasonality of temperature and day length of many tropical regions, especially when compared with temperate latitudes, most tropical animals show fairly pronounced seasonal shifts in foraging, movement patterns and reproduction (Flecker & Feifarek 1994, Saul 1975, Wolda & Fisk 1981). Understanding reproductive seasonality in tropical avian communities involves distinguishing among complex interactions between weather, resource abundance, hormones, behaviour and other life-history traits (Wikelski et al. 2003). While there is a great deal of evidence that many tropical bird species breed seasonally (Hau 2001, Marchant 1959, Miller 1963, Snow & Snow 1964), we still understand little of the causes which drive observed patterns (Wikelski et al. 2003). Most studies which address the seasonality of reproduction in tropical birds have focused on locations with fairly extreme temporal changes in rainfall (Cruz & Andrews 1989, Lack 1950, Marchant 1959, Poulin et al. 1992, Voous 1950), and comparatively few have looked at relatively aseasonal low-latitude locations (Miller 1963, Moreau 1950). Similarly, though a few studies have pointed out slight variation in the within-species initiation of breeding based on microhabitat (Wikelski et al. 2003), we know very little about how micro-habitat choice for nesting may affect (or be affected by) breeding seasonality. In this study I describe the nesting cycle of the spotted barbtail (Premnoplex brunnescens), from the Ecuadorian Andes to better understand how reproduction may be seasonal when climatic cues are subtle or absent.