Foraging behavior of a freshwater copepod: Frequency changes in looping behavior at high and low prey densities.


:The foraging behavior of Mesocyclops edax in artificial patches of high and low prey density was examined. In low density patches Mesocyclops swam in an irregular curvilinear path with little or no looping behavior. In high density patches Mesocyclops exhibited extensive horizontal and vertical looping behavior. Horizontal loops were performed in the normal hop and sink swimming mode, while vertical loops were associated with predator attacks on single prey items. Previous studies on terrestrial invertebrates revealed similar looping behaviors by predatiors and have suggested such looping behavior will increase the time a predator will spend in high versus low density prey patches. When food is patchily distributed and consumers are food-limited, the adaptive significance of remaining in a high density food patch may be substantial.






Williamson CE




Has Abstract


1981-09-01 00:00:00














  • Interaction between ungulates and bruchid beetles and its effect on Acacia trees: modeling the costs and benefits of seed dispersal to plant demography.

    abstract::Integrative studies of plant-animal interactions that incorporate the multiple effects of interactions are important for discerning the importance of each factor within the population dynamics of a plant species. The low regeneration capacity of many Acacia species in arid savannas is a consequence of a combination of...


    pub_type: 杂志文章


    authors: Rodríguez-Pérez J,Wiegand K,Ward D

    更新日期:2011-09-01 00:00:00

  • Are geckos useful bioindicators of air pollution?

    abstract::The response of an Australian arid-zone gecko community to sulphur dioxide and salt spray from a mine and industrial site was investigated from 1992 to 1995. Geckos were abundant and fecund at control sites in chenopod shrubland and annual capture rates were strongly influenced by minimum night temperatures. Capture r...


    pub_type: 杂志文章


    authors: Read JL

    更新日期:1998-04-01 00:00:00

  • Sin Nombre hantavirus decreases survival of male deer mice.

    abstract::How pathogens affect their hosts is a key question in infectious disease ecology, and it can have important influences on the spread and persistence of the pathogen. Sin Nombre virus (SNV) is the etiological agent of hantavirus pulmonary syndrome (HPS) in humans. A better understanding of SNV in its reservoir host, th...


    pub_type: 杂志文章


    authors: Luis AD,Douglass RJ,Hudson PJ,Mills JN,Bjørnstad ON

    更新日期:2012-06-01 00:00:00

  • Gut architecture, digestive constraints and feeding ecology of deposit-feeding and carnivorous polychaetes.

    abstract::We analyze gut architectures of 42 species of marine polychaetes in terms of their anatomically distinct compartments, and quantify differences among guts in terms of ratios of body volume to gut volume, relative compartmental volumes, total gut aspect ratios and compartmental aspect ratios. We use multivariate techni...


    pub_type: 杂志文章


    authors: Penry DL,Jumars PA

    更新日期:1990-01-01 00:00:00

  • Effects of temperature and CO2 enrichment on kinetic properties of NADP+-malate dehydrogenase in two ecotypes of Barnyard grass (Echinochloa crus-galli (L.) Beauv.) from contrasting climates.

    abstract::The apparent energy of activation (E a), Michaelis-Menten constant (K mfor oxaloacetate), V max/K mratios and specific activities of NADP+-malate dehydrogenase (NADP+-MDH; EC were analyzed in plants of Barnyard grass from Québec (QUE) and Mississippi (MISS) acclimated to two thermoperiods 28/22°C, 21/15°C, a...


    pub_type: 杂志文章


    authors: Simon JP,Potvin C,Strain BR

    更新日期:1989-10-01 00:00:00

  • Contrary choices: possible exploitation of enemy-free space by herbivorous insects in cultivated vs. wild crucifers.

    abstract::The pressure to escape natural enemies may shape how herbivorous insects use their plant resources. On wild crucifers, ovipositional preferences of the diamondback moth (Plutella xylostella; DBM) were similar to searching preferences of its main parasitoid, an ichneumonid wasp (Diadegma insulare). But on cultivated cr...


    pub_type: 杂志文章


    authors: Fox LR,Eisenbach J

    更新日期:1992-04-01 00:00:00

  • The recolonization potential of Metridium senile in an area previously depopulated by oxygen deficiency.

    abstract::Every summer the deepest parts of the inner Flensburg fjord are subject to O2-deficiency lasting from a few weeks to several months. In spring, however, populations of Metridium senile can be found in these areas, in spite of the fact that frequently the local anoxic period of the previous summer has been 2-3 times lo...


    pub_type: 杂志文章


    authors: Wahl M

    更新日期:1985-09-01 00:00:00

  • The persistence of ripe fleshy fruits in the presence and absence of frugivores.

    abstract::A trade-off between antimicrobial defences and palatability to dispersers may place limits on fruit persistence in nature. The retention times of ripe fruits on 34 wild plant species under natural conditions (unbagged persistence) and when fruits had been bagged with nylon mesh to exclude frugivores (bagged persistenc...


    pub_type: 杂志文章


    authors: Tang AM,Corlett RT,Hyde KD

    更新日期:2005-01-01 00:00:00

  • On the quantitative theory of reproductive effort in clonal plants: Refinements of theory, with evidence from goldenrods and mayapples.

    abstract::Recently I proposed a quantitative theory which predicts the partition of resources between vegetative growth and seed production in highly rhizomatous clonal plants (Armstrong 1982, 1983). My basic premise was that this partition should be controlled by basic geometric properties of clonal growth. My conclusions were...


    pub_type: 杂志文章


    authors: Armstrong RA

    更新日期:1984-08-01 00:00:00

  • Connectivity in riparian plants: influence of vegetation type and habitat fragmentation overrides water flow.

    abstract::Spatial genetic patterns can be influenced by a broad range of factors across a landscape. The hypothesis that heterogeneous vegetation and habitat fragmentation rather than water flow influence genetic patterns in two riparian plant species with different niches was tested. Genotyping by sequencing was used to assess...


    pub_type: 杂志文章


    authors: Hopley T,Byrne M

    更新日期:2018-10-01 00:00:00

  • Ecological aspects of thermoregulation at high altitudes: the case of andean Liolaemus lizards in northern Chile.

    abstract::We document activity field temperatures, daily activity patterns, and extent of thermoregulation in four species of Liolaemus lizards inhabiting at high altitude (above 3500 m) in the Andes of northern Chile. These four species have similar activity field temperature (Tb near 29°C) despite their being distributed at d...


    pub_type: 杂志文章


    authors: Marquet PA,Ortíz JC,Bozinovié F,Jaksié FM

    更新日期:1989-10-01 00:00:00

  • Proteolytic activity in the digestive tract of several species of fish with different feeding habits.

    abstract::Proteolytic activity in the gut contents of two cichlids and six cyprinids from an artificial basin in Sri Lanka was measured using a simple film strip method. This comparative study contributes to our general knowledge of digestion in herbivorous fish: 1) Specific proteolytic activity (per ml of gut content) is lower...


    pub_type: 杂志文章


    authors: Hofer R,Schiemer F

    更新日期:1981-03-01 00:00:00

  • Invasion by mobile aquatic consumers enhances secondary production and increases top-down control of lower trophic levels.

    abstract::Increased biological diversity due to invasion by non-indigenous species (NIS) is a global phenomenon with potential effects on trophic interactions and ecosystem processes in the invaded habitat. We assessed the effects of resource availability and invasion of three non-indigenous invertebrate grazers (two crustacean...


    pub_type: 杂志文章


    authors: Wikström SA,Hillebrand H

    更新日期:2012-01-01 00:00:00

  • Vector activity and propagule size affect dispersal potential by vertebrates.

    abstract::Many small organisms in various life stages can be transported in the digestive system of larger vertebrates, a process known as endozoochory. Potential dispersal distances of these "propagules" are generally calculated after monitoring retrieval in experiments with resting vector animals. We argue that vectors in nat...


    pub_type: 杂志文章


    authors: van Leeuwen CH,Tollenaar ML,Klaassen M

    更新日期:2012-09-01 00:00:00

  • Temporal records of δ(13)C and δ (15)N in North Pacific pinnipeds: inferences regarding environmental change and diet.

    abstract::Sea lion and seal populations in Alaskan waters underwent various degrees of decline during the latter half of the twentieth century and the cause(s) for the declines remain uncertain. The stable carbon ((13)C/(12)C) and nitrogen ((15)N/(14)N) isotope ratios in bone collagen from wild Steller sea lions (Eumetopias jub...


    pub_type: 杂志文章


    authors: Hirons AC,Schell DM,Finney BP

    更新日期:2001-12-01 00:00:00

  • The influence of ambient ultraviolet light on sperm quality and sexual ornamentation in three-spined sticklebacks (Gasterosteus aculeatus).

    abstract::Exposure to enhanced levels of ambient ultraviolet (UV) radiation (UVR) can have adverse effects on aquatic organisms including damage at the cellular and molecular level and impairment of development, fecundity and survival. Much research has been conducted on the role of the harmful UVB radiation. However, due to it...


    pub_type: 杂志文章


    authors: Rick IP,Mehlis M,Eßer E,Bakker TC

    更新日期:2014-02-01 00:00:00

  • Altered trophic pathway and parasitism in a native predator (Lepomis gibbosus) feeding on introduced prey (Dreissena polymorpha).

    abstract::Populations of invasive species tend to have fewer parasites in their introduced ranges than in their native ranges and are also thought to have fewer parasites than native prey. This 'release' from parasites has unstudied implications for native predators feeding on exotic prey. In particular, shifts from native to e...


    pub_type: 杂志文章


    authors: Locke SA,Bulté G,Marcogliese DJ,Forbes MR

    更新日期:2014-05-01 00:00:00

  • Spatial organization of a desert rodent community: food addition and species removal.

    abstract::From 1977 through 1983 we conducted experiments on a desert rodent community where supplemental seeds were added or certain rodent species and ants were removed from 0.25-ha fenced plots in a Chihuahuan Desert site in southeastern Arizona, USA. In this paper we examine the patterns of microhabitat use relative to vege...


    pub_type: 杂志文章


    authors: Bowers MA,Thompson DB,Brown JH

    更新日期:1987-04-01 00:00:00

  • Foraging and leaf-cutting of the desert gardening ant Acromyrmex versicolor versicolor (Pergande) (Hymenoptera: Formicidae).

    abstract::Four colonies of the desert leaf-cutter ant Acromyrmex versicolor versicolor (Pergande) located 30 miles N.E. of Tempe, Arizona were observed over a 7 month period. The ants utilized trails in foraging, a characteristic of higher attines, as well as foraging singly, a typical pattern among the more primitive gardeners...


    pub_type: 杂志文章


    authors: Gamboa GJ

    更新日期:1975-03-01 00:00:00

  • Environmental and genetic variation in the haematocrit of fledgling pied flycatchers Ficedula hypoleuca.

    abstract::We report a field study of the haematocrit of pied flycatcher (Ficedula hypoleuca) nestlings when close to fledging. First a descriptive study was conducted of both fledgling and adult haematocrit over 2 years to analyse correlates of variation in this trait. Then a swapping experiment was performed to see whether var...


    pub_type: 杂志文章


    authors: Potti J,Moreno J,Merino S,Frías O,Rodríguez R

    更新日期:1999-07-01 00:00:00

  • An empirical model for predicting microhabitat of 0+ juvenile fishes in a lowland river catchment.

    abstract::Species-habitat relationships are an important aspect of fish life history, particularly in early ontogeny. To address the lack of information on the microhabitat use/requirements of European coarse fishes, particularly 0-group fishes in riverine systems, an empirical model was generated from data collected in the Riv...


    pub_type: 杂志文章


    authors: Copp GH

    更新日期:1992-09-01 00:00:00

  • Dung beetles in an avian-dominated island ecosystem: feeding and trophic ecology.

    abstract::Globally, dung beetles (Scarabaeidae: Scarabaeinae) are linked to many critical ecosystem processes involving the consumption and breakdown of mammal dung. Endemic New Zealand dung beetles (Canthonini) are an anomaly, occurring at high abundance and low diversity on an island archipelago historically lacking terrestri...


    pub_type: 杂志文章


    authors: Stavert JR,Gaskett AC,Scott DJ,Beggs JR

    更新日期:2014-09-01 00:00:00

  • Does lipid-correction introduce biases into isotopic mixing models? Implications for diet reconstruction studies.

    abstract::Carbon isotopes are commonly used in trophic ecology to estimate consumer diet composition. This estimation is complicated by the fact that lipids exhibit a more depleted carbon signature (δ13C) than other macromolecules, and are often found at different concentrations among individual organisms. Some researchers argu...


    pub_type: 杂志文章,评审


    authors: Arostegui MC,Schindler DE,Holtgrieve GW

    更新日期:2019-12-01 00:00:00

  • The role of toxic nectar secondary compounds in driving differential bumble bee preferences for milkweed flowers.

    abstract::While morphological differences such as tongue length are often featured as drivers of pollinator floral preferences, differences in chemical detection and tolerance to secondary compounds may also play a role. We sought to better understand the role of secondary compounds in floral preference by examining visitation ...


    pub_type: 杂志文章


    authors: Villalona E,Ezray BD,Laveaga E,Agrawal AA,Ali JG,Hines HM

    更新日期:2020-07-01 00:00:00

  • Dynamics of dissolved oxygen isotopic ratios: a transient model to quantify primary production, community respiration, and air-water exchange in aquatic ecosystems.

    abstract::Dissolved O(2) is an important aquatic ecosystem health indicator. Metabolic and gas exchange (G) rates, which control O(2) concentration, are affected by nutrient loading and other environmental factors. Traditionally, aquatic metabolism has been reported as primary production:community respiration (P:R) ratios using...


    pub_type: 杂志文章


    authors: Venkiteswaran JJ,Wassenaar LI,Schiff SL

    更新日期:2007-08-01 00:00:00

  • An experimental demonstration of density-dependent reproduction in a natural population of Diamorpha smallii, a rare annual.

    abstract::In a North Carolina population of Diamorpha smallii, densities were artificially manipulated by thinning stands to predetermined densities. Individuals in areas of high density produce fewer seeds than individuals at low density in the same habitat. Three components of fecundity, the number of flowers per plant, the n...


    pub_type: 杂志文章


    authors: Clay K,Shaw R

    更新日期:1981-10-01 00:00:00

  • Adult-young interactions in island and mainland populations of the deermouse Peromyscus maniculatus.

    abstract::The demographic and ecological characteristics of island populations of small mammals have received increasing attention in recent years, but few studies have compared the behavioral characteristics of island populations with those of mainland populations. Behavior is considered an important variable because it is bel...


    pub_type: 杂志文章


    authors: Halpin ZT

    更新日期:1981-01-01 00:00:00

  • Unexpected patterns of sensitivity to drought in three semi-arid grasslands.

    abstract::Global climate models forecast an increase in the frequency and intensity of extreme weather events, including severe droughts. Based on multi-year relationships between precipitation amount and aboveground annual net primary production (ANPP), semi-arid grasslands are projected to be among the most sensitive ecosyste...


    pub_type: 杂志文章


    authors: Cherwin K,Knapp A

    更新日期:2012-07-01 00:00:00

  • Host-specific performance and host use in the kleptoparasitic marine snail Trichotropis cancellata.

    abstract::Generalist parasites may disproportionately use certain hosts because of different benefits associated with each host species. I measured the growth rate of the marine snail Trichotropis cancellata, a facultative kleptoparasite that can suspension feed and steal food, on different hosts to determine the relative nutri...


    pub_type: 杂志文章


    authors: Iyengar EV

    更新日期:2004-03-01 00:00:00

  • Efficiency of food utilization during fat deposition in the long-distance migratory garden warbler, Sylvia borin.

    abstract::1 Intake of food, fat, protein and carbohydrates and their fecal output were recorded during the annual body weight cycle of the garden warbler, and old-world longdistance migratory bird species, and the efficiencies of food and nutrient utilization, defined as the ratio (intake-fecal output)/intake, were calculated. ...


    pub_type: 杂志文章


    authors: Bairlein F

    更新日期:1985-12-01 00:00:00