ABSTRACT
Understanding the factors that cause variation in offspring size is fundamental to resolving important theoretical and conceptual issues in studies of life-history evolution. Models of selection of offspring size usually consider how (or if) offspring size correlates with offspring survival or performance (e.g., Jayne and Bennett 1990; Congdon et al. 1999; Janzen and Warner 2009) and/or how reproductive resources are partitioned by females into either larger offspring size or larger numbers of offspring (Smith and Fretwell 1974; Stearns 1992; Bernardo 1996; Charnov 1997; Marshall and Uller 2007; Brown and Shine 2009; Janzen and Warner 2009).
