“…In other cases the reproductive activity is spread out over weeks or months, but nonetheless is clearly seasonal rather than continuous (e.g., most temperate-zone species ;Fitch 1970, Abts 1988, Aichinger 1992, Bauer 1992b, Alkins-Koo 2000. Proximate factors generally have proved more amenable to study, with robust evidence that seasonal reproduction can be initiated by stimuli such as variations in day length (Murton and Westwood 1977, Burns 1985, Kumar and Kumar 1991, Chandola-Saklani et al 2004, temperature (Obbard andBrooks 1987, Hart 2004), rainfall (Patterson Manuscript Lampo and Medialdea 1996, Madsen and Shine 1999b, Christian et al 2003, and food supply (Tinney et al 2001, Clouet 2003, Rubenstein and Wikelski 2003, or interactions between these factors (Janzen 1967, Johannes 1978, Kramer 1978, Garrido et al 2000, Hau 2001, Pankhurst and Porter 2003. Because the time of year at which reproduction occurs is a major axis of life-history variation, extensive research has sought to clarify both the proximate and ultimate reasons for the observed diversity in patterns of reproductive timing.…”