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Psychologists, economists, and advertising moguls have long known that human decision-making is strongly influenced by the behavior of others. A rapidly accumulating body of evidence suggests that the same is true in animals. Individuals can use information arising from cues inadvertently produced by the behavior of other individuals with similar(More)
Empirical work in arid shrubland systems has documented a distinct spatial pattern of soil nutrient distribution, with higher concentrations of nutrients under shrub canopies compared to bare ground interspaces between shrubs. This “fertile island” pattern is considered characteristic of arid ecosystems. However, recent work at a desertified shrubland site(More)
An important stabilizing mechanism in most diversity stability models is the insurance hypothesis, which involves correlation/covariance relationships among species. These models require that species do not fluctuate synchronously over time: that is, the correlation between pairs of species does not equal 1.0. However, the strength of this stabilizing(More)
Analyses of long-term experimental data from the Chihuahuan desert revealed that species diversity of other rodents was higher on plots from which kangaroo rats (Dipodomys spp.) had been removed. The difference was due to consistently higher colonization and lower extinction probabilities of small granivorous rodents in the absence of competitively dominant(More)
Animals often settle near competitors, a behavior known as social attraction, which belies standard habitat selection theory. Two hypotheses account for these observations: individuals obtain Allee benefits mediated by the physical presence of a competitor, or they use successfully settled individual as a source of information indicating the location of(More)
We provide experimental evidence that predators are a major factor organizing a community of granivorous grassland birds (mostly emberizid finches). Our focus is not on the lethal effects of predators, but on the simple idea that (i) birds will not settle where they perceive a high risk of predation, and (ii) species differ in their perception of the safety(More)
In earlier work (Lima et al. 1985; Lima 1985), we found that gray squirrels (Sciurus carolinensis) and black-capped chickadees (Parus atricapillus) when exploiting a patch of food in the open often carried individual food items to protective cover for consumption. Their tendency to carry (i) decreased as distance of the patch from cover increased, and (ii)(More)
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