This study links spatial and seasonal patterns of mortality of the hard clam, Mercenaria mercenaria (L.), in marine soft bottoms with the predation rates and habitat use of its main predator, the blue crab, Callinectes sapidus Rathbun. Patterns of predation on tethered juvenile clams exposed to the natural assemblage of predators were compared among different habitat types in fall and summer. B...

Predators can affect individual fitness and population and community processes through lethal effects (direct consumption or ‘density’ effects), where prey is consumed, or through non-lethal effects (trait-mediated effects or interactions), where behavioural compensation to predation risk occurs, such as animals avoiding areas of high predation risk. Studies of invertebrates, fish and amphibian...

one of the most important predator-prey interactions is functional response which its type and parameters are affected by different factors including host plant characteristics. in this research, the influence of leaf surface on functional response and prey consumption rate of third instar larvae of the episyrphus balteatus (de geer, 1776) (diptera: syrphidae) to third instar nymphs of aphis go...

functional response of the female ladybeetle, hippodamia variegata (goeze) (col., coccinellidae) to varying densities (5, 10, 20, 40, 60 and 80) of third instar nymphs of aphis gossypii glover was assessed in a growth chamber (25˚c, 65± ­5% rh and a photoperiod of 16l: 8d h), on the black eyed bean, vigna unguiculata (l.), in an open patch design. the logistic regression showed a type ii functi...

INTRODUCTION One of the most important trade-offs for many animals is that between survival and reproduction. This is particularly apparent when mating increases the risk of predation, either by increasing conspicuousness, reducing mobility or inhibiting an individual's ability to detect predators. Individuals may mitigate the risk of predation by altering their reproductive behavior (e.g. incr...

Predation is a fundamental ecological and evolutionary process that varies in space, and the avoidance of predation risk is of central importance in foraging theory. While there has been a recent growth of approaches to spatially model predation risk, these approaches lack an adequate mechanistic framework that can be applied to real landscapes. In this paper we show how predation risk can be d...

Predation directly triggers behavioural decisions designed to increase immediate survival. However, these behavioural modifications can have long term costs. There is therefore a trade-off between antipredator behaviours and other activities. This trade-off is generally considered between vigilance and only one other behaviour, thus neglecting potential compensations. In this study, we consider...

It is widely believed that aposematic signals should be conspicuous, but in nature, they vary from highly conspicuous to near cryptic. Current theory, including the honest signal or trade-off hypotheses of the toxicity-conspicuousness relationship, cannot explain why adequately toxic species vary substantially in their conspicuousness. Through a study of similarly toxic Danainae (Nymphalidae) b...