Meeting Abstract

80.5  Tuesday, Jan. 6  Delayed implantation in carnivores, causes and consequences and reproductive effort. ORR, Teri J*; LINDENFLORS, Patrick ; DALEN, Love ; ANGERBJOERN, Anders ; GARLAND, Theodore Jr.; Univ. of California, Riverside; Stockholm University; Stockholm University; Stockholm University; Univ. of California, Riverside teri.orr@email.ucr.edu

The diversity of mammalian reproduction includes delayed implantation (DI), a period of diapause during which blastocysts formed after fertilization remain unattached to the female tract instead of immediately implanting. This unusual mode of reproduction seems limited to 9 of the 21 mammalian orders, and has been studied most thoroughly in the Carnivora, where 67 of 269 species are known to possess DI. The adaptive significance of DI is still unclear, and phylogenetic analyses have been limited to treating gestation length as a proxy for the presence or absence of DI. However, DI is appropriately treated as a binary dependant variable. Recently, A. R. Ives and Garland developed a method for performing phylogenetic logistic regression. We use this new method to evaluate two general questions. 1-Is DI associated with body mass, latitude, seasonality or mating system? 2-Do quantitative life history traits predict the occurrence of DI? For question 2, we examine several life history attributes, including age at first reproduction, litter size, litters per year, reproductive lifespan, weaning mass, and a newly developed emergent calculation of lifetime reproductive effort (LRE, Charnov et al. 2007), which approximates the energy females devote to reproduction in a lifetime and incorporates all of the aforementioned life history traits. Supported in part by NSF DEB-0416085.