scholarly journals Nutritional ecology provides insights into competitive interactions between closely-related marten species

2019 ◽  
Author(s):  
Andrea Gazzola ◽  
Alessandro Balestrieri
Keyword(s):  
Interspecific Competition ◽  
Food Item ◽  
Resource Competition ◽  
Feeding Habits ◽  
Nutritional Ecology ◽  
Metabolizable Energy ◽  
Competitive Interactions ◽  
Stone Marten ◽  
Pine Marten ◽  
Nutrient Profiles

AbstractFor generalist, closely-related predators as those belonging to the genusMartes, it is a hard task to differentiate the effects on feeding habits of variation in food availability from those of resource competition. To overcome this obstacle, we reviewed dietary studies that assessed the relative bulk of each food item, as either percent biomass or percent mean volume, in the diet of both the pine-(M. martes) and stone-(M. foina) marten, and calculated the nutrient profiles (intakes of protein, lipids and carbohydrates, expressed as percentages of total metabolizable energy) of each diet. Both martens’ diets tightly clustered (average values: 47% protein-, 39% lipid- and 14% carbohydrate energy), but, most interestingly, in allopatry the nutritional niches of the two species did not differ, while the stone marten ate more carbohydrates and less protein when sympatric with the pine marten. Our data suggest that stone marten frugivory is the result of interspecific competition.

Pine marten vs. stone marten in agricultural lowlands: a landscape-scale, genetic survey

2016 ◽  
Vol 61 (4) ◽  
pp. 327-335 ◽  
Author(s):  
Alessandro Balestrieri ◽  
Aritz Ruiz-González ◽  
Enrica Capelli ◽  
Maria Vergara ◽  
Claudio Prigioni ◽  
...  
Keyword(s):  
Landscape Scale ◽  
Stone Marten ◽  
Pine Marten ◽  
Genetic Survey

scholarly journals Feeding habits of Stellifer rastrifer (Perciformes, Sciaenidae) at Guaratuba mangrove, Parana, Brazil

1998 ◽  
Vol 41 (4) ◽  
pp. 423-428 ◽  
Author(s):  
Paulo de Tarso C. Chaves ◽  
Ana Lúcia Vendel
Keyword(s):  
Feeding Behaviour ◽  
Food Item ◽  
Feeding Habits ◽  
Fish Populations ◽  
The Individual ◽  
High Level ◽  
Individual Size

Feeding habits of Stellifer rastrifer (Perciformes, Sciaenidae) at Guaratuba mangrove, Parana, Brazil, were studied from February 1996 to February 1997. It was observed that its diet was based on invertebrates, mainly Decapoda non-Brachyura and Polychaeta. In a smaller proportion there were plants, Copepoda, Gammaridea and Mollusca. The level of contribution of each food item changed according to the season and the individual size. Such plasticity in feeding behaviour was similar to that described to some fish populations from other estuaries, and could be an indicator of the high level of instability presented by this kind of ecosystem.

scholarly journals Trophic niche breadth of pond zooplankton species using stable isotope analysis and the relationship with the abiotic and biotic factors

2019 ◽  
Vol 6 (1) ◽  
pp. 180917 ◽  
Author(s):  
Hideyuki Doi ◽  
Kwang-Hyeon Chang ◽  
Shin-ichi Nakano
Keyword(s):  
Stable Isotope ◽  
Niche Breadth ◽  
Resource Competition ◽  
Feeding Habits ◽  
Zooplankton Biomass ◽  
Trophic Niche ◽  
Zooplankton Species ◽  
Carbon And Nitrogen ◽  
Ecosystem Size ◽  
The Relationship

Zooplankton species have different feeding habits, but the diversity of their food resources and the factors governing them are still largely unknown. We here estimated the differences in the trophic niche breadths of dominant zooplankton species in ponds, using stable isotopes. To understand the differences in trophic niches of different zooplankton species, we measured the carbon and nitrogen stable isotope ratios and calculated the nearest-neighbour distance (NND), and standard deviation of NND (SDNND) of the bi-plot space of stable carbon and nitrogen isotopes in pond zooplankton. We tested the relationship between the NND/SDNND and environmental factors, as well as the zooplankton biomass, using generalized linear models (GLMs). For cladocerans, including Bosmina, Ceriodaphnia and Daphnia, the NNDs were significantly correlated with the biomass, pond morphology (volume and depth), total phosphorous (TP) and fish presence. For copepod species, including Eodiaptomus and cyclopoids, NNDs were significantly correlated with pond morphology, TP and fish presence, but not with biomass. In GLMs of SDNND, significant correlated factors were less than those for NND, and for some species, pond morphology and TP were significantly correlated with SDNND. Here, we found that the NND and SDNND of zooplankton species were related to various factors, including their biomass, predator presence, pond size and water quality. For cladocerans, biomass may be supported by trophic niche breadth, probably because of the consequences of resource competition. Also, predation and ecosystem size may influence trophic niche breadth due to changes in zooplankton behaviours.

Interspecific Competition and Population Control in Freshwater Fish

1956 ◽  
Vol 13 (3) ◽  
pp. 327-342 ◽  
Author(s):  
P. A. Larkin
Keyword(s):  
Interspecific Competition ◽  
Freshwater Fish ◽  
Quantitative Data ◽  
Population Control ◽  
Feeding Habits ◽  
Reproductive Potential ◽  
Habitat Type ◽  
Fish Populations ◽  
Population Interaction

Interspecific competition is defined as the demand of more than one organism for the same resource of the environment in excess of immediate supply. When two species are "competing for a niche" the term competition has been used to include phenomena such as predation of the two species on each other, competition to avoid a parasite, etc. Making this distinction in natural situations is unrealistic. In the limited sense in which interspecific competition is defined above, it is a discrete phenomenon, which with other phenomena such as predation, can be measured as a factor involved in interaction between species.Freshwater environments offer comparatively few opportunities for specialization in fishes. In consequence many species have a relatively wide tolerance of habitat type, a flexibility of feeding habits and in general share many resources of their environment with several other species of fish. Cannibalism and mutual predation are common complications of competitive relationships between species. The organization of freshwater fish communities is thus characterized by breadth at each level of the food chain rather than by a height of a pyramid of numbers. Flexible growth rate and high reproductive potential permit fish populations to tide over unfavorable periods of competition. In these circumstances it is difficult to separate the role of interspecific competition from other phenomena as a factor of population control. As a subordinate factor, predisposing fish to loss from other causes, interspecific competition may act to influence population levels. There is need for quantitative data and mathematical models for study of the types of population interaction typical in freshwater fish associations.

scholarly journals Local Victory: Assessing Interspecific Competition in Seagrass From a Trait-Based Perspective

2021 ◽  
Vol 12 ◽  
Author(s):  
Agustín Moreira-Saporiti ◽  
Sonia Bejarano ◽  
Inés G. Viana ◽  
Elizabeth Fay Belshe ◽  
Matern S. P. Mtolera ◽  
...  
Keyword(s):  
Resource Competition ◽  
Plant Size ◽  
Maximum Length ◽  
Competitive Interactions ◽  
Size Difference ◽  
Seagrass Species ◽  
Thalassia Hemprichii ◽  
Functional Strategy ◽  
Seagrass Meadows ◽  
Halophila Ovalis

Tropical seagrass meadows are formed by an array of seagrass species that share the same space. Species sharing the same plot are competing for resources, namely light and inorganic nutrients, which results in the capacity of some species to preempt space from others. However, the drivers behind seagrass species competition are not completely understood. In this work, we studied the competitive interactions among tropical seagrass species of Unguja Island (Zanzibar, Tanzania) using a trait-based approach. We quantified the abundance of eight seagrass species under different trophic states, and selected nine traits related to light and inorganic nutrient preemption to characterize the functional strategy of the species (leaf maximum length and width, leaves per shoot, leaf mass area, vertical rhizome length, shoots per meter of ramet, rhizome diameter, roots per meter of ramet, and root maximum length). From the seagrass abundance we calculated the probability of space preemption between pairs of seagrass species and for each individual seagrass species under the different trophic states. Species had different probabilities of space preemption, with the climax species Thalassodendron ciliatum, Enhalus acoroides, Thalassia hemprichii, and the opportunistic Cymodocea serrulata having the highest probability of preemption, while the pioneer and opportunistic species Halophila ovalis, Syringodium isoetifolium, Halodule uninervis, and Cymodocea rotundata had the lowest. Traits determining the functional strategy showed that there was a size gradient across species. For two co-occurring seagrass species, probability of preemption was the highest for the larger species, it increased as the size difference between species increased and was unaffected by the trophic state. Competitive interactions among seagrass species were asymmetrical, i.e., negative effects were not reciprocal, and the driver behind space preemption was determined by plant size. Seagrass space preemption is a consequence of resource competition, and the probability of a species to exert preemption can be calculated using a trait-based approach.

scholarly journals Spring diet of the pine marten in Sardinia, Italy

2015 ◽  
Vol 38 (2) ◽  
pp. 183-190 ◽  
Author(s):  
M. Lombardini ◽  
◽  
M. Murru ◽  
A. Repossi ◽  
C. E. Cinerari ◽  
...  
Keyword(s):  
Small Mammals ◽  
Feeding Habits ◽  
Central Italy ◽  
Trophic Niche ◽  
Generalist Predator ◽  
Large Mammals ◽  
Pine Marten ◽  
Insect Larvae ◽  
Eliomys Quercinus ◽  
Index Value

Knowledge of a carnivore’s foraging behaviour is essential to understand its ecology. The pine marten Martes martes is commonly defined as an opportunistic generalist predator since its diet in Europe includes mammals, fruits, birds and invertebrates. Based on faecal analyses, we evaluated spring feeding habits and trophic niche breadth of the pine marten in a Mediterranean landscape on the island of Sardinia (Central Italy). The most important source of food for the pine marten was small mammals (mainly Apodemus sylvaticus, Mus musculus and Eliomys quercinus), accounting for 52% of the percent mean volume. Important secondary foods were invertebrates (mainly beetles and insect larvae) and birds (almost exclusively passerines), whereas large mammals, lagomorphs, reptiles and fruits made little contribution to the diet. The diet composition and the Levins’ index value suggest that the pine marten in Sardinia behaves as a facultative specialist predator, with a specialization towards small mammals.

scholarly journals Effect of food types on competitive interaction between Aedes aegypti (LINNAEUS, 1762) and Ae. albopictus (SKUSE, 1894) (Diptera, Culicidae): a proximate level appraisal

2017 ◽  
Vol 86 (2) ◽  
pp. 99-118 ◽  
Author(s):  
Sampa Banerjee ◽  
Sushree Mohan ◽  
Soujita Pramanik ◽  
Soumyajit Banerjee ◽  
Goutam K. Saha ◽  
...  
Keyword(s):  
Life History ◽  
Aedes Aegypti ◽  
Interspecific Competition ◽  
Food Quality ◽  
Population Characteristics ◽  
Competitive Interactions ◽  
Food Type ◽  
Pupal Weight ◽  
Fish Food ◽  
Larval Habitats

AbstractCompetitive interactions between coexisting Aedes aegypti and Ae. albopictus have been implied as a crucial factor shaping life history traits and population characteristics. The overlap in resource requirements and similarities in the life history strategies of the two Aedes mosquitoes form a basis for competitive interactions. In the present study, the role of the food quality of the larval habitats in influencing the outcome of competition between Ae. aegypti and Ae. albopictus is evaluated to highlight food quality as a basis for asymmetric competitive outcomes. Instar I larvae of the two mosquitoes were reared using conspecifics or heterospecifics of constant size and equal ratio with four different food types: boiled rice, boiled pulses, a mixture of boiled rice and pulses, and fish food. Competitive interactions were evaluated using age at pupation (AP), pupal weight (PW), dry adult weight (AW) and wing length (WL) with respect to intra- and interspecific competition for the two sexes of each mosquito species. The results show that Ae. albopictus developed faster but achieved a smaller size compared to Ae. aegypti under interspecific competition conditions, the extent of the difference varying significantly with the food type. Given the variety of food resources available in the small container larval habitats, the results of the study imply that food quality may act differentially with respect to larval development and adult body size, depending on the conspecifics or heterospecifics and on the sex of the species concerned. The dominance of one species over the other may also be a consequence of the resource utilization pattern that varies in the larval habitats.

scholarly journals Biomass explains the intensity of facilitative – not competitive – interactions: three intraspecific tests with annuals

Web Ecology ◽  
2012 ◽  
Vol 12 (1) ◽  
pp. 49-55 ◽  
Author(s):  
C. Ariza ◽  
K. Tielbörger
Keyword(s):  
Size Dependence ◽  
Resource Competition ◽  
Theoretical Models ◽  
Plant Size ◽  
Competitive Interactions ◽  
Positive Interactions ◽  
Plant Interactions ◽  
Belowground Competition ◽  
Size Dependent ◽  
Negative Effect

Abstract. Despite efforts to discern the role of plant size in resource competition, the circumstances under which size-dependent plant-plant interactions occur are still unclear. The traditional assumption is that competition intensifies with increasing neighbour size. However, recent studies suggest that the size (biomass) dependence of competitive interactions is strongest at very low biomass levels and becomes negligible after a certain threshold neighbour biomass has been reached. We searched for the generality of such patterns for three common annual plant species in Israel. We monitored target and neighbour biomass along their entire lifecycle using an even-aged, intraspecific and intrapopulation competition screenhouse experiment under water-limited conditions. For all focal species, neighbour presence had a net negative effect on vegetative biomass at harvest. However, this was not explained by increasing neighbour biomass over time, as a consistent pattern of size-dependent facilitative, rather than competitive, interactions was observed at all life stages. We explain these observations in terms of co-occurring aboveground facilitation and dominant belowground competition for water. Since our findings are the first of their kind and contradict theoretical predictions of biomass dependence of net negative interactions, we advocate further experiments addressing size dependence in interactions among plants. In particular, theoretical models addressing size dependence of positive interactions must be developed.

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