Different patterns of behavioral variation across and within species of spiders with differing degrees of urbanization

Sex differences in the genetic architecture of aggressiveness in a sexually dimorphic spider

“…This is surprising as sex‐specific patterns of genetic variances and heritabilities are key to understanding sex‐specific selection, sexual dimorphism and the evolution and consequences of sexual conflict. Previous research has found that N. umbratica males are more aggressive than their female conspecifics but showed no sex differences in mean activity levels (Kralj‐Fišer et al, ). Kralj‐Fišer et al's () study also showed that individuals consistently vary in both behaviors, but found no correlation between aggressiveness and activity (Kralj‐Fišer et al, ).…”

“…We used a sexually dimorphic model species, the orb‐weaving spider Nuctenea umbratica , whose individuals exhibit consistent differences in aggressiveness (repeatability = r =0 .78 [95% CI: 0.63, 0.89]) and activity levels ( r = 0.48 [0.34, 0.63]) (Kralj‐Fišer, Hebets, & Kuntner, ), to estimate cross‐sex genetic correlations and narrow‐sense heritabilities of aggressiveness and initial activity in a novel environment. Males are more aggressive in intrasex combats than females (Kralj‐Fišer et al, ). However, the sexes show no differences in the mean levels of activity in novel environments (Kralj‐Fišer et al, ).…”

“…Males are more aggressive in intrasex combats than females (Kralj‐Fišer et al, ). However, the sexes show no differences in the mean levels of activity in novel environments (Kralj‐Fišer et al, ). As there is no evidence for a genetic association between aggression and activity levels (Kralj‐Fišer et al, ), we studied these two traits separately.…”

“…However, the sexes show no differences in the mean levels of activity in novel environments (Kralj‐Fišer et al, ). As there is no evidence for a genetic association between aggression and activity levels (Kralj‐Fišer et al, ), we studied these two traits separately. Based on the previously reported repeatabilities, we expected to find significant heritability of both traits (Lynch & Walsh, ).…”

“…In females, aggressiveness toward same‐sex conspecifics serves a female to defend her territory (web) and thereby foraging patch. Territorial disputes between females are rare (Kralj‐Fišer et al, ), probably because overt aggressiveness may have high fitness costs (Kralj‐Fišer & Schneider, ). In view of this, we predicted that there would be evidence of sex differences in the genetic underpinning for aggressiveness.…”