1,594 results match your criteria intraspecific competition

Modular Molecular Weaponry Plays a Key Role in Competition Within an Environmental Population.

Front Microbiol 2021 21;12:671092. Epub 2021 May 21.

Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.

The type VI secretion system (T6SS) operons of contain extraordinarily diverse arrays of toxic effector and cognate immunity genes, which are thought to play an important role in the environmental lifestyle and adaptation of this human pathogen. Through the T6SS, proteinaceous "spears" tipped with antibacterial effectors are injected into adjacent cells, killing those not possessing immunity proteins to these effectors. Here, we investigate the T6SS-mediated dynamics of bacterial competition within a single environmental population of . Read More

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Plasticity in Oviposition Site Selection Behavior in Drosophila suzukii (Diptera: Drosophilidae) in Relation to Adult Density and Host Distribution and Quality.

J Econ Entomol 2021 Jun 11. Epub 2021 Jun 11.

Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, USA.

Flexibility in oviposition site selection under temporally shifting environmental conditions is an important trait that allows many polyphagous insects to flourish. Population density has been shown to affect egg-laying and offspring fitness throughout the animal kingdom. The effects of population density in insects have been suggested to be mutualistic at low densities, whereas intraspecific competition is exhibited at high densities. Read More

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Seed encrusting with salicylic acid: A novel approach to improve establishment of grass species in ecological restoration.

PLoS One 2021 9;16(6):e0242035. Epub 2021 Jun 9.

ARC Centre for Mine Site Restoration, School of Molecular and Life Science, Curtin University, Bentley, Western Australia, Australia.

To achieve global ambitions in large scale ecological restoration, there is a need for approaches that improve the efficiency of seed-based interventions, particularly in overcoming the bottleneck in the transition from germination to seedling establishment. In this study, we tested a novel seed-based application of the plant stress modulator compound salicylic acid as a means to reduce seedling losses in the seed-to-seedling phase. Seed coating technology (encrusting) was developed as a precursor for optimising field sowing for three grass species commonly used in restoration programs, Austrostipa scabra, Microlaena stipoides, and Rytidosperma geniculatum. Read More

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Environmental drivers of sexual dimorphism in a lizard with alternative mating strategies.

J Evol Biol 2021 Jun 8. Epub 2021 Jun 8.

School of Natural Sciences, University of California, Merced, 5200 N. Lake Rd, Merced, CA, USA, 95343.

Understanding the relative importance of sexual and natural selection in shaping morphological traits is a long-standing goal of evolutionary ecology. Male-biased sexual size dimorphism (SSD) is typically associated with male-male competition. Similarly, male polymorphisms are considered a consequence of competitive social interactions. Read More

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Ecological causes of fluctuating natural selection on habitat choice in an amphibian.

Evolution 2021 Jun 6. Epub 2021 Jun 6.

Biology Department, Williams College, Williamstown, Massachusetts, 01267, USA.

We estimated natural selection targeting three traits related to habitat choice in a frog (Pseudacris maculata) breeding in pools on the rocky shores of Isle Royale, Michigan, over 16 years. Our aim was to identify the form and ecological causes of annual variation in directional and correlational selection as expressed in the survival and growth of tadpoles. We found directional selection favoring early breeding, but pool choice was under weak stabilizing selection. Read More

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Contrasting population manipulations reveal resource competition between two large marsupials: bare-nosed wombats and eastern grey kangaroos.

Oecologia 2021 Jun 6. Epub 2021 Jun 6.

School of Natural Sciences, University of Tasmania, Sandy Bay, TAS, Australia.

Resource competition is an important interaction that can structure ecological communities, but is difficult to demonstrate in nature, and rarely demonstrated for large mammals including marsupials. We analysed 10 years of population survey data to investigate resource competition between bare-nosed wombats (Vombatus ursinus) and eastern grey kangaroos (Macropus giganteus) at two sites to assess whether resource competition is occurring. At one site, wombat abundance was reduced by increased mortality from mange disease, whereas at the other site, kangaroo abundance was reduced primarily by culling. Read More

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Spatial segregation in a sexually-dimorphic central place forager: competitive exclusion or niche divergence?

J Anim Ecol 2021 Jun 5. Epub 2021 Jun 5.

Marine Apex Predator Research Unit (MAPRU), Department of Zoology, Institute for Coastal and Marine Research, Nelson Mandela University, Port Elizabeth, South Africa.

Sexual competition is increasingly recognized as an important selective pressure driving species distributions. However, few studies have investigated the relative importance of inter- vs. intrapopulation competition in relation to habitat availability and selection. Read More

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Basking and retreat site selection of Phymaturus palluma, a rock-dwelling lizard in the Highlands of Aconcagua.

An Acad Bras Cienc 2021 28;93(2):e20190662. Epub 2021 May 28.

Instituto Argentino de Investigaciones en Zonas Áridas, Consejo Nacional de Investigaciones Científicas y Técnicas (IADIZA-CONICET), Av. Ruiz Leal s/n, 5500 Ciudad de Mendoza, Argentina.

Basking and retreat sites constitute a key resource in the habitat of any ectotherm. Identifying the elements that are used and modelling the microhabitat selection of species is crucial for assessing the impact of anthropogenic disturbances at the population level and, therefore, focusing on conservation efforts. We investigated how structural attributes of the microhabitat and biotic factors influence the probability of basking and retreat sites use by Phymaturus palluma, a rock-dwelling and viviparous lizard endemic to the Central Andes of Argentina. Read More

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Bifurcations and hydra effects in Bazykin's predator-prey model.

Theor Popul Biol 2021 May 27. Epub 2021 May 27.

Department of Mathematics, Indian Institute of Technology Indore, Khandwa Road, Simrol, Indore 453552, Madhya Pradesh, India. Electronic address:

We consider Bazykin's model to address harvesting induced stability exchanges through bifurcation analysis. We examine the existence of hydra effects and analyze the stock pattern under predator harvesting. Prey harvesting cannot produce hydra effects in our model, whereas predator harvesting may cause multiple hydra effects. Read More

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Inter-sexual and inter-generation differences in dispersal of a bivoltine butterfly.

Sci Rep 2021 May 26;11(1):10950. Epub 2021 May 26.

Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland.

In organisms with discrete generations such as most insects, life-history traits including dispersal abilities often vary between generations. In particular, density-dependent differences in dispersal of bi- and multivoltine species may be expected because subsequent generations are usually characterized by a drastic increase in individual abundance. We investigated the inter-sexual and inter-generation differences in dispersal of a bivoltine butterfly, Lycaena helle, testing the following hypotheses: (1) male emigration is higher in spring generation, as males are prone to leave their natal habitat patches when the density of mating partners is low; (2) female emigration is higher in summer generation, when it helps to reduce intraspecific competition between offspring. Read More

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Interspecific and intraspecific foraging differentiation of neighbouring tropical seabirds.

Mov Ecol 2021 May 26;9(1):27. Epub 2021 May 26.

School of Environmental Sciences, University of Liverpool, Liverpool, L69 3GP, UK.

Background: Social interactions, reproductive demands and intrinsic constraints all influence foraging decisions in animals. Understanding the relative importance of these factors in shaping the way that coexisting species within communities use and partition resources is central to knowledge of ecological and evolutionary processes. However, in marine environments, our understanding of the mechanisms that lead to and allow coexistence is limited, particularly in the tropics. Read More

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Color vision and niche partitioning in a diverse neotropical primate community in lowland Amazonian Ecuador.

Ecol Evol 2021 May 30;11(10):5742-5758. Epub 2021 Mar 30.

Department of Neuroscience University of Texas at Austin Austin TX USA.

A recent focus in community ecology has been on how within-species variability shapes interspecific niche partitioning. Primate color vision offers a rich system in which to explore this issue. Most neotropical primates exhibit intraspecific variation in color vision due to allelic variation at the middle-to-long-wavelength opsin gene on the X chromosome. Read More

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Dynamic population stage structure due to juvenile-adult asymmetry stabilizes complex ecological communities.

André M de Roos

Proc Natl Acad Sci U S A 2021 May;118(21)

Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, 1090 GE Amsterdam, The Netherlands;

Natural ecological communities are diverse, complex, and often surprisingly stable, but the mechanisms underlying their stability remain a theoretical enigma. Interactions such as competition and predation presumably structure communities, yet theory predicts that complex communities are stable only when species growth rates are mostly limited by intraspecific self-regulation rather than by interactions with resources, competitors, and predators. Current theory, however, considers only the network topology of population-level interactions between species and ignores within-population differences, such as between juvenile and adult individuals. Read More

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Sublethal concentration of insecticide amplifies interference competition in a tortrix moth.

Ecotoxicol Environ Saf 2021 May 17;220:112324. Epub 2021 May 17.

Department of Biology, Queen's University, 116 Barrie Street, Kingston K7L 3N6, ON, Canada.

Insecticides are extensively used worldwide to kill insect pests, yet organisms are most often exposed to insecticides at sublethal concentrations. Our understanding of sublethal effects on life histories is needed to predict the impact of insecticides on population dynamics and improve insecticide use and pest control. Sublethal concentrations can impact life histories directly and indirectly through changes in the intraspecific competition. Read More

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No neighbour-induced increase in root growth of soybean and sunflower in mesh-divider experiments after controlling for nutrient concentration and soil volume.

AoB Plants 2021 Jun 14;13(3):plab020. Epub 2021 Apr 14.

Centre for Crop Systems Analysis, Wageningen University, P.O. Box 430, 6700AK Wageningen, The Netherlands.

Root competition is a key factor determining plant performance, community structure and ecosystem productivity. To adequately estimate the extent of root proliferation of plants in response to neighbours independently of nutrient availability, one should use a set-up that can simultaneously control for both nutrient concentration and soil volume at plant individual level. With a mesh-divider design, which was suggested as a promising solution for this problem, we conducted two intraspecific root competition experiments: one with soybean () and the other with sunflower (). Read More

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Potential use of Helianthus tuberosus to suppress the invasive alien plant Ageratina adenophora under different shade levels.

BMC Ecol Evol 2021 05 16;21(1):85. Epub 2021 May 16.

Key Laboratory of Green Prevention and Control of Agricultural Transboundary Pests of Yunnan Province, Agricultural Environment and Resource Research Institute, Yunnan Academy of Agricultural Sciences, Kunming, 650205, China.

Background: An ecological approach for managing biological invasions in agroecosystems is the selection of alternative crop species to manage the infestation of invasive alien plants through competition. In the current study, plant growth, photosynthesis, and competitive ability of the crop Helianthus tuberosus L. (Jerusalem artichoke) and the invasive alien plant Ageratina adenophora (Spreng. Read More

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Tail autotomy alters prey capture performance and kinematics, but not success, in banded geckos.

Integr Comp Biol 2021 May 14. Epub 2021 May 14.

Department of Evolution, Ecology, and Organismal Biology, 900 University Avenue, University of California, Riverside, California 92521.

Tails are versatile structures with diverse forms and functions across vertebrates. They are involved in almost all behaviors critical to survival including locomotion, feeding, and predator avoidance. Although the tail's role in locomotion and stability has been widely studied, its role in prey capture is relatively unknown. Read More

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Polar and neutral lipid composition of the copepod Lernaeocera lusci and its host Merluccius merluccius in relationship with the parasite intensity.

Parasitol Res 2021 Jun 14;120(6):1979-1991. Epub 2021 May 14.

Center of Urgent Medical Assistance of Tunis, Laboratory of Toxicology and Environment LR12SP07, University Tunis El Manar, Montfleury, 1008, Tunis, Tunisia.

Parasitic copepod Lernaeocera lusci is a common mesoparasite of the hake Merluccius merluccius. Although widely distributed throughout the Mediterranean, little is known about this pathogen. The current study was designed to assess the impact of different L. Read More

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Divide and conquer: Multicolonial structure, nestmate recognition, and antagonistic behaviors in dense populations of the invasive ant .

Ecol Evol 2021 May 18;11(9):4874-4886. Epub 2021 Mar 18.

Department of Entomology Texas A&M University College Station TX USA.

The ecological success of ants has made them abundant in most environments, yet inter- and intraspecific competition usually limit nest density for a given population. Most invasive ant populations circumvent this limitation through a supercolonial structure, eliminating intraspecific competition through a loss of nestmate recognition and lack of aggression toward non-nestmates. Native to South America, has recently invaded many locations worldwide, with invasive populations described as extremely large and dense. Read More

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Intertrip consistency in hunting behavior improves foraging success and efficiency in a marine top predator.

Ecol Evol 2021 May 13;11(9):4428-4441. Epub 2021 Mar 13.

School of Life and Environmental Sciences Deakin University Burwood Vic. Australia.

Substantial variation in foraging strategies can exist within populations, even those typically regarded as generalists. Specializations arise from the consistent exploitation of a narrow behavioral, spatial or dietary niche over time, which may reduce intraspecific competition and influence adaptability to environmental change. However, few studies have investigated whether behavioral consistency confers benefits at the individual and/or population level. Read More

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Population-specific sex and size variation in long-term foraging ecology of belugas and narwhals.

R Soc Open Sci 2021 Feb 3;8(2):202226. Epub 2021 Feb 3.

Globe Institute, University of Copenhagen, Denmark.

Intraspecific variation in resource use by individuals of different age, sex or size may reflect differing energetic requirements and physiological constraints. Males and females often show differences in diet owing to sexual size dimorphism, different life histories and/or habitat use. Here, we investigate how sex and size influence the long-term foraging ecology of belugas and narwhals in Greenland, using stable isotopes of carbon and nitrogen from bone collagen. Read More

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February 2021

Differential drivers of intraspecific and interspecific competition during malaria-helminth co-infection.

Parasitology 2021 May 11:1-10. Epub 2021 May 11.

Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.

Both initial infectious dose and the presence of co-infecting parasites can impact the within-host dynamics of infection. In mice infected with malaria, increasing initial infectious doses reduced the time it took for within-host malaria replication to peak, but also reduced the magnitude of this within-host replication. When mice were also co-infected with hookworms (helminths that reduce the availability of red blood cells (RBCs) to malaria parasites), peak within-host malaria replication was delayed. Read More

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Plant immunity: Good fences make good neighbors?

Curr Opin Plant Biol 2021 May 6;62:102045. Epub 2021 May 6.

PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, TA A-54 / K Campus International de Baillarguet, 34398, Montpellier Cedex 5, France. Electronic address:

Plant immunity is modulated by several abiotic factors, and microbiome has emerged as a major biotic driver of plant resistance. Recently, a few studies showed that plants also modify resistance to pests and pathogens in their neighborhood. Several types of neighborhood could be identified depending on the biological processes at play: intraspecific and interspecific competition, kin and stranger recognition, plant-soil feedbacks, and danger signaling. Read More

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Age and growth of from Penghu Channel, Taiwan: significance of their age distribution based on fossils.

PeerJ 2021 14;9:e11236. Epub 2021 Apr 14.

Department of Life Science, Tunghai University, Taichung City, Taiwan.

Dental material attributed to from the Middle to Late Pleistocene were recovered over decades from the Penghu Channel during commercial fisheries activities. The National Museum of Nature Science (NMNS) has a collection of such dental material, which differs in size and morphology and likely represents ontogenetic variation and growth trajectory of various age groups of . However, little is known regarding age determination. Read More

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Foraging conditions for breeding penguins improve with distance from colony and progression of the breeding season at the South Orkney Islands.

Mov Ecol 2021 May 4;9(1):22. Epub 2021 May 4.

British Antarctic Survey, High Cross, Madingley Rd, Cambridge, CB3 0ET, UK.

Background: According to central place foraging theory, animals will only increase the distance of their foraging trips if more distant prey patches offer better foraging opportunities. Thus, theory predicts that breeding seabirds in large colonies could create a zone of food depletion around the colony, known as "Ashmole's halo". However, seabirds' decisions to forage at a particular distance are likely also complicated by their breeding stage. Read More

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Planting Density Affects Growth and Ginsenoside Accumulation by Balancing Primary and Secondary Metabolism.

Front Plant Sci 2021 12;12:628294. Epub 2021 Apr 12.

State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, China.

Adjusting planting density is a common agricultural practice used to achieve maximum yields. However, whether the quality of medicinal herbs can be improved by implementing appropriate planting densities is still uncertain. The medicinal crop was used to analyze the effects of planting density on growth and ginsenoside accumulation, and the possible mechanisms of these effects were revealed through metabonomics. Read More

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Tree species rather than type of mycorrhizal association drives inorganic and organic nitrogen acquisition in tree-tree interactions.

Tree Physiol 2021 Apr 30. Epub 2021 Apr 30.

Plant Interactions Ecophysiology Group, Department of Biology, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany.

Mycorrhizal fungi play an important role for the nitrogen (N) supply of trees. The influence of different mycorrhizal types on N acquisition in tree-tree interactions is, however, not well understood, particularly with regard to the competition for growth-limiting N. We studied the effect of competition between temperate forest tree species on their inorganic and organic N acquisition in relation to their mycorrhizal type (i. Read More

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Risky Business: The Function of Play in a Venomous Mammal-The Javan Slow Loris ().

Toxins (Basel) 2021 04 28;13(5). Epub 2021 Apr 28.

Nocturnal Primate Research Group, School of Social Sciences, Oxford Brookes University, Oxford OX3 0BP, UK.

Immature mammals require opportunities to develop skills that will affect their competitive abilities and reproductive success as adults. One way these benefits may be achieved is through play behavior. While skills in developing use of tusks, antlers, and other weapons mammals have been linked to play, play in venomous animals has rarely been studied. Read More

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Hostile Interactions of Punjab Urial () towards Indian Gazelle () during Feeding Sessions in Captive Breeding Settings.

Animals (Basel) 2021 Apr 28;11(5). Epub 2021 Apr 28.

College of Wildlife and Protected Areas, Northeast Forestry University, Harbin 150040, China.

Natural wildlife habitats are regularly subjected to anthropogenic pressures for different purposes, which are heading the biodiversity towards drastic decline. Several endangered wild species are raised in captivity with the aim of re-introduction. In some instances, mixed herds' rearing approach in captivity is adopted for providing social enrichment to captive stocks; however, the impacts of species on each other are least documented. Read More

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Elevated CO2 causes different growth stimulation, water and nitrogen use efficiencies and leaf ultrastructure responses in two conifer species under intra- and interspecific competition.

Tree Physiol 2021 Apr 22. Epub 2021 Apr 22.

Department of Ecology, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China.

The continuously increasing atmospheric carbon dioxide concentration ([CO2]) has substantial effects on plant growth, and on the composition and structure of forests. However, how plants respond to elevated [CO2] (e[CO2]) under intra- and interspecific competition has been largely overlooked. In this study, we employed Abies faxoniana and Picea purpurea seedlings to explore the effects of e[CO2] (700 ppm) and plant-plant competition on plant growth, physiological and morphological traits, and leaf ultrastructure. Read More

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