Computer simulations are used to compare the ability of six analyses to detect differences in FA between stressed and unstressed populations and show that the optimal analysis depends upon the underlying form of the FA distributions.
A review of published and unpublished studies of passerines showed that natal philopatry was typically low, so maintaining a high level of inbreeding appears relatively unimportant for such birds.
Modelled development of character FA in relation to random developmental noise or perturbations, stress, developmental stability, and individual quality concluded that FA of sexually selected traits need not relate to stress or individual quality more than FA of other characters and unsigned FA could reliably relate to organism-wide developmental stability and quality.
This work has shown that adaptive changes in reproductive effort of parasitized hosts may account for both inverse and positive relationships between host reproductive output and incidence or degree of parasitism.
Results suggest that host races are indeed common in this group, and more likely to occur when hosts are long-lived, and the potential relevance of host race formation for the biodiversity of mites and ticks is discussed.
The results suggested that hormonally mediated sex differences in susceptibility to parasitism exist for mammals, even though the tests were extremely conservative, and indicate that differences in parasitism between the sexes are small, and that statistically significant male biases in Parasitism are not a general rule.
Using meta-analysis, it was found that FA-stress and FA-fitness relations were non-spurious, despite the large number of relations tested, and suggested that trait type was not predictive of the presence or strength of FA- stress or FA-Fitness relations and that relations were not stronger for poikilotherms, as one hypothesis suggested.
Female biases in parasitism by blood parasites could result from differential exposure of the sexes to vectors, or from oestrogen-based effects on immunity, which are unexpected.
It is hypothesised that when predation risk is high, the value of potential re-nesting exceeds the energetic risks of early breeding, and timing of arrival and breeding for shorebirds at four sites in the eastern Canadian arctic is affected.
Proceedings of the National Academy of Sciences…
15 August 1993
TLDR
It is predicted that the spatial abilities required to locate and return accurately to host nests may have produced a sex difference in the size of the hippocampal complex in cowbirds, in favor of females and found that use of space, rather than sex, breeding system, or foraging behavior per se, can influence the relativesize of the hippocampus.