The influence of male age on reproductive success after a single mating has been explored widely; however, few studies have investigated whether quantitative or qualitative differences in male sperm are responsible for the observed patterns. Moreover, the role of male age on sperm competitive...

In polyandrous species, paternity may be influenced by the timing and frequency of mating. Female spiders possess 2 genital openings that lead to separate sperm-storage structures. Thus, even when mating with a previously mated female, a male may reduce direct sperm competition by inseminating...

Various orb-weaving spiders add extra silk structures--"web decorations"--to their webs. The adaptive value of these web decorations is still unclear, and the suite of functional hypotheses remains controversial. Spiders in the genus Argiope decorate their webs with densely woven zigzag ribbons...

Large mammalian herbivores must balance foraging efficiency with multiple constraints, including the risk of gastrointestinal parasitism. The costs imposed by gastrointestinal parasites are likely to exert selective pressure on hosts to develop aversion behaviors. Fecal aversion, or the...