0000000000422213
AUTHOR
Derek A. Roff
Forceps size and immune function in the earwig Forficula auricularia L.
Females of many species select their mates on the basis of the size or intensity of sexual ornaments, and it has been suggested that these provide reliable signals of a male’s ability to resist parasites and pathogens. European earwigs, Forficula auricularia, are sexually dimorphic in forceps shape and length. Male forceps are used as weapons in male contests for access to females, but recent findings suggest that females also choose males on the basis of their forceps length. In the present study, we tested the hypotheses that in the European earwig, F. auricularia, the size of forceps is correlated with immune function and that immune function differs between the sexes. We found that enca…
An analysis of trade-offs in immune function, body size and development time in the Mediterranean Field Cricket, Gryllus bimaculatus
Summary 1Immune defence has recently been viewed as a life-history trait that shows trade-offs with other life-history traits. However, studies exploring correlations between different components of immune defence and other life-history traits are scarce. 2In this study, two measures of immune function, body size, and development time were studied in the Mediterranean Field Cricket, Gryllus bimaculatus. 3We found no differences between the sexes, but differences in the correlation between the measure of immune function, development time, and body size. In both sexes, encapsulation rate was negatively correlated with body size and development time, whereas lytic enzyme activity was positivel…
A comparison of three statistical methods for analysing extinction threat status
SUMMARYThe International Union for Conservation of Nature (IUCN) Red List provides a globally-recognized evaluation of the conservation status of species, with the aim of catalysing appropriate conservation action. However, in some parts of the world, species data may be lacking or insufficient to predict risk status. If species with shared ecological or life history characteristics also tend to share their risk of extinction, then ecological or life history characteristics may be used to predict which species may be at risk, although perhaps not yet classified as such by the IUCN. Statistical models may be a means to determine whether there are non-threatened or unclassified species that s…