for analysis. We did not include births of unknown sex in our estimates of BSR, which is equivalent to assuming that there were no biases in assignment to the unknown category. The species in which both males and females disperse are expected to have intermediate BSRs, as long as both sexes disperse over equal distances and impose similar competitive costs on mothers and their resident offspring. We compiled information about BSRs from a variety of sources (see electronic supplementary material). As branch lengths were not available for all parts of this tree, we allowed the phylogenetic regression programme to set branch lengths using the default method. Faust Thompson (2000) compiled captive birth records for 14 species of primates with known dispersal patterns. Here we examine the effects of LRC, LRE and the extent of sexual dimorphism on BSRs. Studies of sex ratio adjustment in a variety of invertebrate taxa provide strong support for quantitative predictions derived from theoretical models (. This hypothesis was subsequently amended to take into account the effects of local resource competition on maternal investment strategies of primate females. Marmota marmota ) and wild dogs lycaon pictus BSRs are biased in favour of males, and males are more effective helpers than females (. 2005 The Royal Society, view Full Text, sign in for Fellows of the Royal Society.
Here, we examine the role of LRC and LRE on BSRs within the primate order. abstract "Local resource competition and male dispersal may generally lead to: 1) intense competition among females for resources and reproductive opportunities, 2) limiting the recruitment of females, 3) extensive maternal investment in vulnerable female offspring, and 4) facultative adjustment of the sex ratio of progeny. In cooperatively breeding species of birds, the extent of the bias in BSRs is associated with differences in the benefits derived from male and female helpers. Only species with samples of births which exceed 100 were no cc adult dating used to construct this graph. An analysis of data from wild populations also failed to find a significant relationship between BSR and sexual size dimorphism ( F 1,340.792,.380).
Maternal rank and local resource competition do not
Local resource competition and local resource enhancement
Local resource competition and facultative adjustment