نتایج جستجو برای: predation
تعداد نتایج: 12312 فیلتر نتایج به سال:
The mechanisms underlying responses of invertebrates to forest edges remain poorly understood. Here, we use an experimental approach to investigate the predation rates on butterflies in two neotropical forest fragments. Neither distance from forest edge nor degree of forest openness affected predation rates on artificial caterpillars. The mean predation rate of artificial caterpillars on Barro ...
Trade-offs between predation risk and forage fundamentally drive resource selection by animals. Among migratory ungulates, trade-offs can occur at large spatial scales through migration, which allows an "escape" from predation, but trade-offs can also occur at finer spatial scales. Previous authors suggest that ungulates will avoid predation risk at the largest scale, although few studies have ...
In agroecosystems, local and landscape features, as well as natural enemy abundance and richness, are significant predictors of predation services that may result in biological control of pests. Despite the increasing importance of urban gardening for provisioning of food to urban populations, most urban gardeners suffer from high pest problems, and have little knowledge about how to manage the...
We used the introduction of a generalist nest predator, the red squirrel Tamiasciurus hudsonicus, and of a large herbivore, the Sitka black-tailed deer Odocoileus hemionus sitkensis, to the islands of Haida Gwaii (Queen Charlotte Islands, British Columbia, Canada) to study how predator assemblage and habitat quality and structure influenced nest predation in forest birds. We compared losses of ...
The idea that copulation might increase predation risk is a classic suggestion, but empirical evidence to support it is surprisingly scarce. While some early work found decreased vulnerability to predation during mating, two lab and one very recent field study documented increased predation during mating in freshwater amphipods, water striders and locusts. Decreased vigilance, less efficient es...
Behavioural responses to reduce predation risk might cause demographic 'costs of fear'. Costs differ among species, but a conceptual framework to understand this variation is lacking. We use a life-history framework to tie together diverse traits and life stages to better understand interspecific variation in responses and costs. We used natural and experimental variation in predation risk to t...
Journal Club Every so often, a hypothesis comes along that contains an idea that makes you wonder why no one has thought of it before. A recent paper by T.E. Martin et al. 1 contains such a conceptual leap. In 1949, A.F. Skutch provided an original hypothesis regarding the evolution of parental care behaviour in birds. The hypothesis was that nest predation should increase with increasing paren...
To better understand the predator-prey relationship and to compare predation rates, we studied the life table and predation rate of the predator Eocanthecona furcellata Wolff (Hemiptera: Pentatomidae) when reared on two major crucifer pests, Spodoptera litura (F.) (Lepidoptera: Noctuidae) and Plutella xylostella L. (Lepidoptera: Plutellidae). The net reproductive rate, intrinsic rate of increas...
Supplementary feeding of ungulates, being widely used in game management, may have unwanted consequences. Its role in agricultural damage is well-studied, but few studies have considered the potential for the practice to attract ground nest predators. Our goal was to identify the factors influencing ground nest predation in the vicinity of year-round supplementary feeding sites for wild boar an...
Predation is an important factor in the dynamics of gypsy moth (Lymantria dispar L.) populations, yet predation rates can be difÞcult to estimate accurately in the Þeld. Biased estimates can result from spatial heterogeneity in risk or from artifacts associated with deploying prey. Here we compare predation rates on freeze-dried gypsy moth pupae afÞxed with beeswax to pieces of burlap withpreda...
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