The eVects of plant defenses on herbivory can diVer among spatial scales. This may be particularly common with indirect defenses, such as extraXoral nectaries (EFNs), that attract predatory arthropods and are dependent on predator distribution, abundance, and behavior. We tested the defensive eVects of EFNs in quaking aspen (Populus tremuloides Michx.) against damage by a specialist herbivore, ...

Globally, elevated extinction risk in mammals is strongly associated with large body size. However, in regions where introduced predators exert strong top-down pressure on mammal populations, the selectivity of extinctions may be skewed towards species of intermediate body size, leading to a hump-shaped relationship between size and extinction risk. The existence of this kind of extinction patt...

Globally, elevated extinction risk in mammals is strongly associated with large body size. However, in regions where introduced predators exert strong topdown pressure on mammal populations, the selectivity of extinctions may be skewed towards species of intermediate body size, leading to a humpshaped relationship between size and extinction risk. The existence of this kind of extinction patter...

The present paper aims at evaluating the distribution pattern of Culicidae immature stages and relationship with their potential insect predators in Taksebt Dam, Algeria. surveys temporary permanent habitats this dam using dipping technique allowed us to identify 13 mosquito species belonging four genera a clear dominance Cx. pipiens perexiguus. Predators larvae were abundant 11 families three ...

The hypothesis of the selfish herd has been highly influential to our understanding of animal aggregation. Various movement strategies have been proposed by which individuals might aggregate to form a selfish herd as a defence against predation, but although the spatial benefits of these strategies have been extensively studied, little attention has been paid to the importance of predator attac...

© 2012 Allen et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Top-Predators as Biodiversity Regulators: Contemporary Issues Affecting Knowledge and ...

Some biological parameters of the sprat, Sprattus sprattus phalericus, collected from Turkish Black Sea coast between 2008 and 2009 were investigated. Sprat is an important food resource for many top predators. In present work, length frequency distribution, relationship between length and weight, sex ratio and condition factor of sprat have been studied.

We study the growth of a directed transportation network, such as a food web, in which links carry resources. We propose a growth process in which new nodes (or species) preferentially attach to existing nodes with high indegree (in food-web language, number of prey) and low outdegree (or number of predators). This scheme, which we call inverse preferential attachment , is intended to maximize ...