Inbreeding results from matings between relatives and can cause a reduction in offspring fitness, known as inbreeding depression. Previous work has shown that a wide range of environmental stresses, such as extreme temperatures, starvation and parasitism, can exacerbate inbreeding depression. It has recently been argued that stresses due to intraspecific competition should have a stronger effec...

To understand the evolution of parental care, one needs to estimate the payoffs from providing care for the offspring and the payoffs from terminating care and deserting them. These payoffs are rarely known. In this study we experimentally estimated the rewards from brood desertion in a species that has a variable pattern of parental care. In particular, either the female or the male parent may...

The effects of male and female body size, and correlated characteristics, on male mating behaviour were investigated in the western mosquitofish Gambusia affinis. Because larger females typically have larger broods in Gambusia sp., it was predicted that males would attempt more copulations with larger females. Two-way ANOVA showed that female body size was a significant predictor of male mating...

Sex ratio theory predicts that, under local mate competition, a more female-biased offspring sex will be produced by females when their relatedness to mates is closer. We assess how the sexual composition of broods responds mother–mate using Goniozus legneri Gordh (Hymenoptera: Bethylidae), parasitoid wasp that has biased ratios due competition. Relatedness was varied providing virgin with eith...

Trade-offs between brood size and offspring size, offspring survival, parental condition or parental survival are classic assumptions in life history biology. A reduction in brood size may lessen these costs of care, but offspring mortality can also result in an energetic gain, if parents are able to utilize the nutrients from the demised young. Males of the broad-nosed pipefish (Syngnathus typ...

are secreted by queen brood at half the rate found for worker brood. Methyl oleate, repellent to the mite, is secreted in large amounts compared with the attractive esters. Quantitative and qualitative differences in the esters present on worker, drone, and queen broods could partially explain the weaker attraction exerted by queen brood on the mite, compared with the attractive effects of work...

Reproductive strategy is a central feature of the ecology of invasive species as it determines the potential for population increase and range expansion. The red swamp crayfish, Procambarus clarkii, has invaded many countries and caused serious problems in freshwater ecosystems. However, little is known about the effects of environmental conditions on crayfish paternity and offspring traits in ...

Anopheles crucians Wiedemann (sensu lato) was investigated for the presence of cryptic species using rDNA ITS2 sequences. This complex of species presently contains the named species An. crucians, An. bradleyi King, and An. georgianus King. Adult female mosquitoes were collected at 28 sites in Alabama, Florida, Georgia, North Carolina, Mississippi, and Louisiana, resulting in 245 progeny broods...

Recently, gaining knowledge about thermal refuges for vulnerable species has been a major focal point of ecological studies, and this focus has been heightened by predicted temperature increases associated with global climate change. To better understand how organisms respond to thermal landscapes and extremes, we investigated the thermal ecology of a gallinaceous bird species (northern bobwhit...

Rates of multiple paternities were investigated in the sailfin molly (Poecilia latipinna), using eight microsatellite loci. Genotyping was performed for offspring and mothers in 40 broods from four allopatric populations from the south-eastern U.S.A. along a geographic stretch of 1200 km in west-east direction and approximately 200 km from north to south. No significant differences regarding ra...