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Memmott Jane - - 2009
While food webs have provided a rich vein of research material over the last 50 years, they have largely been the subject matter of the pure ecologist working in natural habitats. While there are some notable exceptions to this trend, there are, as I explain in this paper, many applied ...
McCann Kevin Shear - - 2009
Here, we synthesize a number of recent empirical and theoretical papers to argue that food-web dynamics are characterized by high amounts of spatial and temporal variability and that organisms respond predictably, via behaviour, to these changing conditions. Such behavioural responses on the landscape drive a highly adaptive food-web structure in ...
Dunne Jennifer A - - 2009
Species loss in ecosystems can lead to secondary extinctions as a result of consumer-resource relationships and other species interactions. We compare levels of secondary extinctions in communities generated by four structural food-web models and a fifth null model in response to sequential primary species removals. We focus on various aspects ...
Bodini Antonio - - 2009
In ecosystems, a single extinction event can give rise to multiple 'secondary' extinctions. Conservation effort would benefit from tools that help forecast the consequences of species removal. One such tool is the dominator tree, a graph-theoretic algorithm that when applied to food webs unfolds their complex architecture, yielding a simpler ...
Allesina Stefano - - 2009
The robustness of ecosystems to species losses is a central question in ecology, given the current pace of extinctions and the many species threatened by human impacts, including habitat destruction and climate change. Robustness from the perspective of secondary extinctions has been addressed in the context of food webs to ...
Olff Han - - 2009
In ecosystems, species interact with other species directly and through abiotic factors in multiple ways, often forming complex networks of various types of ecological interaction. Out of this suite of interactions, predator-prey interactions have received most attention. The resulting food webs, however, will always operate simultaneously with networks based on ...
Romanuk Tamara N - - 2009
A central and perhaps insurmountable challenge of invasion ecology is to predict which combinations of species and habitats most effectively promote and prevent biological invasions. Here, we integrate models of network structure and nonlinear population dynamics to search for potential generalities among trophic factors that may drive invasion success and ...
Srinivasu P D N - - 2010
Use of additional food has been widely recognized by experimental scientists as one of the important tools for biological control such as species conservation and pest management. The quality and quantity of additional food supplied to the predators is known to play a vital role in the controllability of the ...
Millon Alexandre - - 2009
1. Changes in community composition are expected to entail cascading effects at different trophic levels within a food web. However, empirical evidence on the impact of changes in prey communities on the population dynamics of generalist predators, and on the extent of possible feedback processes, remains scarce. 2. We analysed ...
Takahashi T - - 2009
Divergent natural selection is thought to play a vital role in speciation, but clear, measurable examples from nature are still few. Among the many possible sources of divergent natural selection, predation pressure may be important because predators are ubiquitous in food webs. Here, we show evidence for divergent natural selection ...
Beauchamp Guy - - 2009
Despite its fundamental relevance to many ecological processes in predator-prey relationships, the functional response, which relates predator intake rate to prey density, remains difficult to document in the field. Here, I document the functional response of semipalmated sandpipers (Calidris pusilla) foraging on a burrowing amphipod Corophium volutator during three field ...
Chelini Marie-Claire - - 2009
Animals present an enormous variety of behavioural defensive mechanisms, which increase their survival, but often at a cost. Several animal taxa reduce their chances of being detected and/or recognized as prey items by freezing (remaining completely motionless) in the presence of a predator. We studied costs and benefits of freezing ...
Kondoh Michio - - 2009
Food-chain length, the number of feeding links from the basal species to the top predator, is a key characteristic of biological communities. However, the determinants of food-chain length still remain controversial. While classical theory predicts that food-chain length should increase with increasing resource availability, empirical supports of this prediction are ...
Pafilis Panayiotis - - 2009
Resource availability, competition, and predation commonly drive body size evolution. We assess the impact of high food availability and the consequent increased intraspecific competition, as expressed by tail injuries and cannibalism, on body size in Skyros wall lizards (Podarcis gaigeae). Lizard populations on islets surrounding Skyros (Aegean Sea) all have ...
Banasek-Richter Carolin - - 2009
Food webs depict who eats whom in communities. Ecologists have examined statistical metrics and other properties of food webs, but mainly due to the uneven quality of the data, the results have proved controversial. The qualitative data on which those efforts rested treat trophic interactions as present or absent and ...
Tan Eunice J - - 2009
Many species of the orb-web spider genus Cyclosa often adorn their webs with decorations of prey remains, egg sacs and/or plant detritus, termed ;detritus decorations'. These detritus decorations have been hypothesised to camouflage the spider from predators or prey and thus reduce predation risk or increase foraging success. In the ...
Tomy Gregg T - - 2009
The trophodynamics of per- and polyfluorinated compounds and bromine-based flame retardants were examined in components of a marine food web from the western Canadian Arctic. The animals studied and their relative trophic status in the food web, established using stable isotopes of nitrogen (delta15N), were beluga (Delphinapterus leucas) > ringed ...
Rezende Enrico L - - 2009
A long-standing question in community ecology is whether food webs are organized in compartments, where species within the same compartment interact frequently among themselves, but show fewer interactions with species from other compartments. Finding evidence for this community organization is important since compartmentalization may strongly affect food web robustness to ...
Rohwer Forest - - 2009
Marine viruses affect Bacteria, Archaea and eukaryotic organisms and are major components of the marine food web. Most studies have focused on their role as predators and parasites, but many of the interactions between marine viruses and their hosts are much more complicated. A series of recent studies has shown ...
Buitenhuis R - - 2010
The relationships between the predatory mites, Amblyseius swirskii (Athias-Henriot) and Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae), and their prey, western flower thrips (Frankliniella occidentalis Pergande) (Thysanoptera: Thripidae), were investigated to determine the effects of predation on intra-guild or extra-guild prey and predator preference. Life history characteristics of both predatory mites were ...
Beckerman Andrew P - - 2009
Food webs, descriptions of who is eating whom in an ecosystem, are one of the most enduring and influential concepts in ecology. An increasing number of studies are including parasite-host feeding interactions in food webs, each providing evidence that parasites alter our perception of food web structure. Amundsen et al. ...
Kishida Osamu - - 2009
Antagonistic phenotypic plasticity may strongly influence trait evolution in tightly interacting predator-prey pairs as well as the role that trait plasticity plays in community dynamics. Most work on trait plasticity has focused on single predator-prey pairs, but prey must often contend with multiple predators in natural environments. Hence, a better ...
Vannier J - - 2009
Exceptional fossil specimens with preserved soft parts from the Maotianshan Shale (ca 520 Myr ago) and the Burgess Shale (505 Myr ago) biotas indicate that the worldwide distributed bivalved arthropod Isoxys was probably a non-benthic visual predator. New lines of evidence come from the functional morphology of its powerful prehensile ...
Pawar Samraat - - 2009
To understand the dynamics of natural species communities, a major challenge is to quantify the relationship between their assembly, stability, and underlying food web structure. To this end, two complementary aspects of food web structure can be related to community stability: sign structure, which refers to the distributions of trophic ...
Rohner, Christoph
Great homed owls (Bubo virginianus) are among the most opportunistic avian predators. In the subarctic boreal forest, their diet consists mainly of snowshoe hares (Lepus americanus), which show extreme population cycles with a 8-11 year period. The aim of this thesis was to study the population ecology of great homed ...
Fyda Janusz - - 2009
Using laboratory microcosms, we studied direct and indirect interactions among different components of bi- and tritrophic communities. Filamentous cyanobacteria (Phormidium sp.) and autotrophic flagellates (Chlorogonium elongatum) were primary producers. The second trophic level was represented by ciliates Furgasonia blochmanni and Pseudomicrothorax dubius grazing on the filamentous cyanobacteria and two filter ...
Lewis Danny - - 2009
1. Entry of substantial numbers of natural enemies from outside a habitat can have profound impacts on food web structure in the recipient habitat, but underlying mechanisms are poorly understood, including the role of relative predator fitness in source and recipient habitats. We studied a naturally occurring annual movement of ...
Kimbro David L - - 2009
Although invasive species often resemble their native counterparts, differences in their foraging and anti-predator strategies may disrupt native food webs. In a California estuary, we showed that regions dominated by native crabs and native whelks have low mortality of native oysters (the basal prey), while regions dominated by invasive crabs ...
Sabo John L - - 2009
There are three hypothesized controls on food-chain length (FCL): energy supply (or "resource availability"), ecosystem size and disturbance (or "environmental variation"). In this article, the evidence for controls on FCL in freshwater ecosystems is evaluated. First, the various ways FCL can be measured are defined. Food-chain length typically is estimated ...
Srivastava Diane S - - 2009
The flow of energy and nutrients between trophic levels is affected by both the trophic structure of food webs and the diversity of species within trophic levels. However, the combined effects of trophic structure and diversity on trophic transfer remain largely unknown. Here we ask whether changes in consumer diversity ...
De Laender Frederik - - 2009
Bioaccumulation models predict internal concentrations of hydrophobic chemicals by incorporating key gain/loss processes reflecting the ecology of the exposed species and the characteristics of the chemical. Here, we propose a new methodology that uses ecological data and the principle of mass balance in food webs to estimate bioaccumulation in food ...
Petrites Anthony E - - 2009
Big brown bats (Eptesicus fuscus) use biosonar to find insect prey in open areas, but they also find prey near vegetation and even fly through vegetation when in transit from roosts to feeding sites. To evaluate their reactions to dense, distributed clutter, bats were tested in an obstacle array consisting ...
Macinnis, Maura Jan
Metazoan grazing of bacteria represents a potential pathway for the transfer of bacterial production to higher trophic levels. Freshwater cladocerans of the genus Daphnia are able to reduce bacterial abundance in lakes, but many experiments have been restricted to the summer months. It is therefore necessary to test the generality ...
Flynn Kevin J - - 2009
Animals with a gut, when confronted with food supplied ad libitum, can elevate their ingestion rates and inefficiently use the material they ingest. As a consequence, assimilation efficiency (AE) declines, resulting in food-density-dependent inefficiency (f-DDI). A model describing these processes shows that f-DDI can dampen the consequences of oscillations in ...
Baum Julia K - - 2009
1. Top-down control can be an important determinant of ecosystem structure and function, but in oceanic ecosystems, where cascading effects of predator depletions, recoveries, and invasions could be significant, such effects had rarely been demonstrated until recently. 2. Here we synthesize the evidence for oceanic top-down control that has emerged ...
Guillette Lauren M - - 2009
Pit-building antlions, the larvae of a winged adult insect, capture food by digging funnel-shaped pits in sand and then lying in wait, buried at the vertex, for prey to fall inside. The sedentary nature of this sit-and-wait predatory behaviour and, especially, antlions' innate ability to detect prey arrival, do not ...
O'Connor Mary I - - 2009
1. In many ecosystems, predator abundance, composition and diversity vary naturally among seasons and habitats. In addition, predator assemblages are changing due to overharvesting, habitat destruction and species invasions. 2. Predator species composition and richness can influence prey community structure and these effects can cascade to influence plant abundance and ...
Hebert Craig E - - 2009
Food web structure regulates the pathways and flow rates of energy, nutrients, and contaminants to top predators. Ecologically and physiologically meaningful biochemical tracers provide a means to characterize and quantify these transfers within food webs. In this study, changes in the ratios of stable N isotopes (e.g., delta(15)N), fatty acids ...
Michelutti Neal - - 2009
Migratory animals such as seabirds, salmon and whales can transport large quantities of nutrients across ecosystem boundaries, greatly enriching recipient food webs. As many of these animals biomagnify contaminants, they can also focus pollutants at toxic levels. Seabirds arguably represent the most significant biovectors of nutrients and contaminants from the ...
Bilu Einat - - 2009
Discussions of intraguild predation (IGP) have assumed that the nutritional quality of intraguild (IG) prey is similar to that of any other prey available to the IG predator. It has been suggested therefore that generalist predators do not distinguish between healthy and parasitized aphids and thus function as facultative predators ...
Frias-Lopez Jorge - - 2009
Prochlorococcus and Synechococcus are the two most abundant marine cyanobacteria. They represent a significant fraction of the total primary production of the world oceans and comprise a major fraction of the prey biomass available to phagotrophic protists. Despite relatively rapid growth rates, picocyanobacterial cell densities in open-ocean surface waters remain ...
Amundsen Per-Arne - - 2009
1. Parasites permeate trophic webs with their often complex life cycles, but few studies have included parasitism in food web analyses. Here we provide a highly resolved food web from the pelagic zone of a subarctic lake and explore how the incorporation of parasites alters the topology of the web. ...
Milligan, Heather
Freshwater and terrestrial ecosystems are tightly linked by food web interactions. Naturally occurring carbon and nitrogen stable isotopes provide a tool to quantify nutrient flows across ecological boundaries, however their application to freshwater-terrestrial systems has been limited. This thesis evaluated whether stable isotope analysis can be effective in differentiating freshwater ...
De Troch, Marleen
The re-use of faecal pellets in the water column before sinking to the seafloor is known as an important pathway in marine food webs. Especially planktonic copepods seems to be actively use their faecal pellets. Since benthic copepods (order Harpacticoida) live in the vicinity of their pellets, it remains unclear ...
Seymour J R - - 2009
Exploitation of microscale (microm-mm) resource patches by planktonic microorganisms may influence oceanic trophodynamics and nutrient cycling. However, examinations of microbial behavior within patchy microhabitats have been precluded by methodological limitations. We developed a microfluidic device to generate microscale resource patches at environmentally realistic spatiotemporal scales, and we examined the exploitation ...
Thelaus Johanna - - 2009
The natural reservoir of Francisella tularensis, the causative agent of tularaemia, is yet to be identified. We investigated the possibility that Francisella persists in natural aquatic ecosystems between outbreaks. It was hypothesized that nutrient-rich environments, with strong protozoan predation, favour the occurrence of the tularaemia bacterium. To investigate the differences ...
Lecomte Nicolas - - 2009
To what extent top predators - carnivores at the top of food chains - drive or just respond to ecosystem dynamics is a central, but partially unresolved, question in ecology. In this report, we highlight how different research approaches employed in aquatic and terrestrial ecology may have a bearing on ...
Vermaat Jan E - - 2009
The covariance among a range of 20 network structural properties of food webs plus net primary productivity was assessed for 14 published food webs using principal components analysis. Three primary components explained 84% of the variability in the data sets, suggesting substantial covariance among the properties employed in the literature. ...
Kr??ger Bj??rn - - 2009
BACKGROUND: During the Ordovician the global diversity increased dramatically at family, genus and species levels. Partially the diversification is explained by an increased nutrient, and phytoplankton availability in the open water. Cephalopods are among the top predators of today's open oceans. Their Ordovician occurrences, diversity evolution and abundance pattern potentially ...
Sirot Etienne - - 2009
Prey living in groups often partly rely on companions to detect predators. Accordingly, individuals having vigilant neighbors could decrease their own vigilance, engendering a certain level of vigilance coordination in the group. However, when a predator attacks, individuals that spot it react quicker than individuals that follow them and have ...
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