How strong is selection for cheating in mutualisms? The answer depends on the type and magnitude of the costs of the mutualism. Here we investigated the direct and ecological costs of plant defense by ants in the association between Cordia nodosa, a myrmecophytic plant, and Allomerus octoarticulatus, a phytoecious ant. Cordia nodosa trees produce food and housing to reward ants that protect the...

Inconspicuous prey pay a cost of reduced feeding opportunities. Flowers are highly nutritious but are positioned where prey would be apparent to predators and often contain toxins to reduce consumption. However, many herbivores are specialized to subvert these defenses by retaining toxins for their own use. Here, we present a model of the growth and life history of a small herbivore that can fe...

Induced plant responses to herbivory appear to be universal, yet the degree to which they are specific to sets of herbivores is poorly understood. The generalist/specialist hypothesis predicts that generalist herbivores are more often negatively affected by host plant defenses, wheras specialists may be either unaffected by or attracted to these same ‘‘plant defenses’’. Therefore, specialists s...

Positive effects of competitor species richness on competitor productivity can be more pronounced at a scale that includes heterogeneity in 'bottom-up' environmental factors, such as the supply of limiting nutrients. The effect of species richness is not well understood in landscapes where variation in 'top-down' factors, such as the abundance of predators or herbivores, has a strong influence ...

Regular, self-organized spatial patterns in primary producers have been described in a wide range of ecosystems and are predicted to affect community production and resilience. Although consumers are abundant in most systems, the effect of trophic interactions on pattern formation in primary producers remains unstudied. We studied the effects of top-down control by herbivores on a self-organize...

Three hundred commensal Escherichia coli recovered from healthy herbivorous, carnivorous, and omnivorous mammals from one zoo were characterized for their phylogenetic origin, intestinal virulence gene (VG) prevalence, and genomic diversity. The phylogenetic structure of the E. coli (groups A, B1, B2, and D) from the herbivores was homogenous, with a prevailing representation of group B1. In th...

Numerous studies have highlighted the roles of nutrient availability and fluctuations therein for invasion success alien plants. Many others also role herbivores in success. However, how herbivory level interact driving plant into native communities remains largely unexplored. We grew eight invasive species as target pot-mesocosms with five different synthetic a three-factorial design two level...

Mammalian herbivores can be divided into two groups on the basis of the principal site of microbial fermentation. Fore-gut fermenters have an expanded and differentiated fore-stomach. Eutherian fore-gut fermenters include sloths, colobid monkeys, hippos, peccaries, camelids and ruminants. Marsupial fore-gut fermenters include the kangaroos, wallabies and rat-kangaroos. Hind-gut fermenters have ...

Mammalian herbivores can be divided into two groups on the basis of the principal site of microbial fermentation. Fore-gut fermenters have an expanded and differentiated fore-stomach. Eutherian fore-gut fermenters include sloths, colobid monkeys, hippos, peccaries, camelids and ruminants. Marsupial fore-gut fermenters include the kangaroos, wallabies and rat-kangaroos. Hind-gut fermenters have ...

Hooklike trichomes of Passiflora adenopoda provide a specific, effectively absolute defense against heliconiine butterfly larvae, a major class of Passiflora herbivores. It is suggested that since mechanical defenses are usually more selective in their action against herbivores, they usually are evolved by a plant only after it has accumulated a series of chemical defenses.