Secondary sexual traits are expected to reflect a balance between sexual selection and natural selection. We test the hypothesis that plasticity in sexual advertisement behaviors can influence this trade-off, allowing showier traits than expected for a given level of predation risk. Specifically, we tested whether the degree of behavioral plasticity exhibited in response to chemical cues of a c...

The evolution of life history traits is regulated by energy expenditure, which is, in turn, governed by temperature. The forecasted increase in temperature variability is expected to impose greater stress to organisms, in turn influencing the balance of energy expenditure and consequently life history responses. Here we examine how increased temperature variability affects life history response...

Predator-prey interactions involving an aquatic insect and zooplanktonic prey of different sizes were investigated to quantify prey mortality exposed to predators. Laboratory experiments were undertaken with the young and adult gerrid Rheumatobates crassifemur to test predation and size selectivity on the cladocerans Daphnia gessneri, Ceriodaphnia richardi, and Bosmina tubicen. Population fluct...

1. Predators impose costs on their prey but may also provide benefits such as protection against other (e.g. nest) predators. The optimal breeding location in relation to the distance from a nesting raptor varies so as to minimize the sum of costs of adult and nest predation. We provide a conceptual model to account for variation in the relative predation risks and derive qualitative prediction...

BACKGROUND An understanding of the evolution of potential signals from plants to the predators of their herbivores may provide exciting examples of co-evolution among multiple trophic levels. Understanding the mechanism behind the attraction of predators to plants is crucial to conclusions about co-evolution. For example, insectivorous birds are attracted to herbivore-damaged trees without seei...

two 60 day experiments on predation behavior of leeches were conducted concurrently. in the first, medicinal leeches, hirudo orientalis (utevsky and trontelj, 2005) were fed to satiation on bovine blood and subsequently transferred into two large opaque plastic containers of equal size but with differing temperatures, 6-7?c and 23-24?c, containing starved erpobdella octoculata (l.). at the high...

1. Predation rate (PR) and kill rate are both fundamental statistics for understanding predation. However, relatively little is known about how these statistics relate to one another and how they relate to prey population dynamics. We assess these relationships across three systems where wolf-prey dynamics have been observed for 41 years (Isle Royale), 19 years (Banff) and 12 years (Yellowstone...

anthocoris nemoralis (f.) (hemiptera: anthocoridae) is one of the most prominent predators of the pear psylla, cacopsylla pyricola (forster) (hemiptera: psyllidae) and is considered as a biological control agent against this pest. in order to investigate the effects of plant varieties on predation of c. pyricola by a. nemoralis, the functional response of both the sexes of a. nemoralis to pear ...