To effectively balance investment in predator defenses versus other traits, organisms must accurately assess predation risk. Chemical cues caused by predation events are indicators of risk for prey in a wide variety of systems, but the relationship between how prey perceive risk in relation to the amount of prey consumed by predators is poorly understood. While per capita predation rate is ofte...

Abstract Mathematical models of population growth have been constructed to provide an abstract of some significant aspect of true ecological situation. In this paper, we put some models where the parameters of the biological growth model systematically change over time. The growth rate of the predator depends upon predation on the modeled and alternate prey. Two stable equilibrium separated by ...

In the diet of raptors the presence of prey-species is influenced by their abundance and the ground-level vegetation in territories, this situation being analysed for the Bonelli s eagle (Hieraaetus fasciatus) in south-eastern Spain. First, the minimum number of prey-items for the reliability of results was tested, obtaining between 15 and 30 prey-items depending of pair. Second, differences in...

The endangered snow leopard is a large felid that is distributed over 1.83 million km(2) globally. Throughout its range it relies on a limited number of prey species in some of the most inhospitable landscapes on the planet where high rates of human persecution exist for both predator and prey. We reviewed 14 published and 11 unpublished studies pertaining to snow leopard diet throughout its ra...

Spiders have became more and more important as model organisms of foraging ecology (Uetz 1992 ; Wise 1993). Their foraging intake, especially that of orb-weaving spiders, can be easily estimated . These are sit-and-wait predators whose prey intake can be measured by examining insects trapped on webs . Furthermore, all spiders exhibit external digestion by injecting into the prey digestive juice...

Generalist predators are widely acknowledged to contribute valuable levels of biological control in agroecosystems throughout the world. Although their feeding habits can result in the rejection of target pests in favor of preferred and often more nutritious non-pest prey, these natural enemies are capable of colonizing habitats prior to the arrival of pests by subsisting on alternative sources...

The Mexican Garter Snake (Thamnophis eques) is a terrestrial-aquatic generalist that feeds on both aquatic and terrestrial prey. We describe size-related variation and sexual variation in the diet of T. eques through analysis of 262 samples of identifiable stomach contents in snakes from 23 locations on the Mexican Plateau. The snake T. eques we studied consumed mostly fish, followed in lesser ...

Amphipod abundance and biomass were determined in soft-bottom substrates (SBS), monospecific Thalassia testudinum patches and T. testudinum with attached macroalgae (SAV) from Términos Lagoon. Amphipods were absent in SBS, and their density and biomass were higher in SAV (3351 individualsm(-2), 1718 mg AFDWm(-2)) than in T. testudinum (1220 indm(-2), 625 mg AFDWm(-2)). Although macroalgae and s...

A prey-predator model with a sexual reproduction in prey population and nonlocal consumption of resources by two spatial dimensions is considered. Patterns produced the without terms periodic boundary conditions are studied first. Then, Turing patterns induced interaction (see Banerjee et al. (2018) [1]) dimensional space explored along effects range on resulting under proper parametric restric...