High niche overlap between two successfully coexisting pairs of Lake Malawi cichlid fishes

2009 ◽  
Vol 66 (4) ◽  
pp. 579-588 ◽  
Author(s):  
Christopher H. Martin ◽  
Martin J. Genner
Keyword(s):  
Resource Availability ◽  
Niche Overlap ◽  
Lake Malawi ◽  
Resource Scarcity ◽  
Ecological Niches ◽  
Similar Species ◽  
Dietary Overlap ◽  
Resource Abundance ◽  
Species Pairs ◽  
Foraging Rate

Many species in high-diversity assemblages appear to coexist in similar ecological niches. It has been proposed that interspecific resource partitioning in these assemblages may only occur during periods of resource scarcity. We tested this hypothesis by measuring resource abundance, dietary overlap, foraging rate, and territoriality in a Lake Malawi rock cichlid assemblage over a period of 1 year. Our study examined two pairs of morphologically similar species, with each pair comprising one native species and one invader species that has successfully established after being translocated from another region of the lake. All four species changed their diet and foraging rate in response to seasonal variation in resource abundance. However, dietary overlap within both species pairs remained high in all seasons and was not influenced by resource availability. Similarly, territoriality did not decline during periods of low resource availability, suggesting no decrease in the strength of interspecific competition. These data suggest that these species pairs are successfully coexisting despite substantial niche overlap during resource scarcity. Thus, the coexistence of species within this radiation may not depend on the evolution of divergent resource use patterns.

scholarly journals Simulated evolution assembles more realistic food webs with more functionally similar species than invasion

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tamara N. Romanuk ◽  
Amrei Binzer ◽  
Nicolas Loeuille ◽  
W. Mather A. Carscallen ◽  
Neo D. Martinez
Keyword(s):  
Food Webs ◽  
Native Species ◽  
Niche Overlap ◽  
Ecological Niches ◽  
Similar Species ◽  
Ecosystem Structure ◽  
Competition Theory ◽  
Parapatric Speciation ◽  
And Function ◽  
Ecosystem Structure And Function

AbstractWhile natural communities are assembled by both ecological and evolutionary processes, ecological assembly processes have been studied much more and are rarely compared with evolutionary assembly processes. We address these disparities here by comparing community food webs assembled by simulating introductions of species from regional pools of species and from speciation events. Compared to introductions of trophically dissimilar species assumed to be more typical of invasions, introducing species trophically similar to native species assumed to be more typical of sympatric or parapatric speciation events caused fewer extinctions and assembled more empirically realistic networks by introducing more persistent species with higher trophic generality, vulnerability, and enduring similarity to native species. Such events also increased niche overlap and the persistence of both native and introduced species. Contrary to much competition theory, these findings suggest that evolutionary and other processes that more tightly pack ecological niches contribute more to ecosystem structure and function than previously thought.

Dietary overlap and food resource partitioning among fish species of a tropical estuary in Northeastern Brazil

Gaia Scientia ◽  
2016 ◽  
Vol 10 (4) ◽  
pp. 86-95 ◽  
Author(s):  
Adna Ferreira da Silva Garcia ◽  
Ana Lúcia Vendel
Keyword(s):  
Resource Partitioning ◽  
Species Coexistence ◽  
Food Resource ◽  
River Estuary ◽  
Niche Overlap ◽  
Northeastern Brazil ◽  
Dietary Overlap ◽  
Feeding Niche ◽  
Tropical Environments ◽  
Food Resource Partitioning

The current work investigates dietary overlap and food partitioning among nine abundant carnivorous fishes caught in the shallow waters of the Paraíba do Norte river estuary, Paraíba State, Brazil. Fishes were sampled with a beach seine net between January and December 2008 and a total of 958 specimens had their stomach content analyzed. Crustacea was the dominant food resource for Lutjanus alexandrei, L. jocu and Bathygobius soporator, whereas Telostei were consumed mainly by Centropomus undecimalis and C. parallelus. In contrast, Polychaeta were preyed upon mainly by Diapterus rhombeus, Eucinostomus argenteus, Sciades herzbergii and S. parkeri. Although most species consumed similar food items, they did that in varying proportions and amounts. Overall, the niche overlap among species was low (< 0.60), but there were several cases where pair of species had their feeding niche highly overlapped (between 0.72 and 0.97). These findings corroborate the hypothesis that food resource partitioning determines species coexistence in estuarine tropical environments.

scholarly journals Unravelling the Potamonautes lirrangensis (Rathbun, 1904) species complex (Potamoidea: Potamonautidae), with the description of two new species

2021 ◽  
Vol 744 ◽  
Author(s):  
Neil Cumberlidge ◽  
Emily Johnson ◽  
Paul F. Clark ◽  
Martin J. Genner
Keyword(s):  
Species Complex ◽  
Central Africa ◽  
Taxonomic Status ◽  
Lake Malawi ◽  
Molecular Evidence ◽  
Similar Species ◽  
Freshwater Crab ◽  
Distribution Maps ◽  
Congo River ◽  
Two New Species

The taxonomic status of the widely distributed freshwater crab Potamonautes lirrangensis (Rathbun, 1904) sensu lato is revised because morphological and molecular evidence indicates that this taxon is a complex comprising more than one species. Four taxa are now recognized: Potamonautes lirrangensis (Rathbun, 1904) s. str. and P. kisangani sp. nov. from the Middle Congo River in Central Africa, P. amosae sp. nov. from the drainages of Lakes Kivu and Tanganyika, and P. orbitospinus (Cunnington, 1907) from Lake Malawi which had been previously synonymised with P. lirrangensis s. lat. Diagnoses, illustrations and distribution maps are provided for each of these taxa and they are compared to similar species from Central and Southern Africa.

Size overlap in intertidal decapod communities along the chilean coast

2020 ◽  
Vol 84 (2) ◽  
Author(s):  
Patricio De los Ríos-Escalante ◽  
Guillermo Figueroa-Muñoz ◽  
Marco A. Retamal ◽  
Rolando Vega-Aguayo ◽  
Carlos Esse
Keyword(s):  
Body Size ◽  
Null Model ◽  
Local Scale ◽  
Ecological Niches ◽  
Similar Species ◽  
Chilean Coast ◽  
Niche Specialization ◽  
High Diversity

The intertidal crustaceans on the Chilean coast are characterized by high diversity and niche specialization. The present study applied a size overlap null model for intertidal decapod communities at four different sites on the Chilean coast. The results revealed that there is a size overlap for the four sites, though body size is significantly different for each location. This means that the reported species would share their ecological niches. The results agree with the first classic environmental descriptions for Chilean intertidal decapods at a local scale and support the observations for similar species on the southern Pacific and southern Atlantic coasts.

Does resource availability govern vertical stratification of small mammals in an Australian lowland tropical rainforest?

2006 ◽  
Vol 33 (7) ◽  
pp. 571 ◽  
Author(s):  
R. Rader ◽  
A. Krockenberger
Keyword(s):  
Resource Availability ◽  
Tropical Rainforest ◽  
Vertical Stratification ◽  
Resource Abundance ◽  
Canopy Trees ◽  
Small Mammal Community ◽  
Castanospermum Australe ◽  
Mammal Community ◽  
Mammal Assemblages ◽  
Access To Food

Mammal assemblages of rainforest communities are commonly vertically stratified. This can be associated with competition for, or access to, resources in the upper canopy layers of the forest. This study investigated the extent of vertical stratification in a small mammal community of a tropical rainforest and whether any structure was related to resource abundance. The mammal community was vertically stratified, with Pogonomys mollipilosus and Cercartetus caudatus found only in the upper canopy layers and Rattus sp., Isoodon macrourus and Antechinus flavipes rubeculus on the ground and in the understorey layer. Melomys cervinipes and Uromys caudimaculatus were found at all four height layers. Total rodent captures were not significantly correlated with the abundance of fruit and flower resources, but arboreal captures of M. cervinipes and P. mollipilosus were correlated with the number of individual canopy trees of four prominent flower- and fruit-yielding species: Syzigium sayeri, Acmena graveolens, Argyrodendron perelatum and Castanospermum australe. We suggest that arboreal behaviour in these rodents serves to provide the advantages of first access to food resources, the availability of abundant resources in the canopy, and, ultimately, reduced competition in the upper strata.

scholarly journals Ecological niche overlap among species of the genus Zaluzania (Asteraceae) from the dry regions of Mexico

2020 ◽  
Vol 153 (3) ◽  
pp. 337-347
Author(s):  
Mario Ernesto Suárez-Mota ◽  
José Luis Villaseñor
Keyword(s):  
Ecological Niche ◽  
Potential Distribution ◽  
Area Under The Curve ◽  
Niche Overlap ◽  
Ecological Niches ◽  
Niche Conservatism ◽  
Distribution Models ◽  
Closely Related Species ◽  
Environmental Pressures ◽  
Fundamental Niche

Background and aims – The hypothesis of ecological niche conservatism postulates that closely related species share ecologically similar environments; that is, they tend to maintain the characteristics of their fundamental niche over time. The objective of this study is to evaluate the similarity and equivalence of the ecological niches among species of the genus Zaluzania (Asteraceae), characteristic of the Mexican arid and semi-arid regions, to infer their potential niche conservatism. Methods – Based on critically reviewed herbarium occurrence data, potential distribution models for eight species of Zaluzania were generated using the Maxent algorithm. The overlap between potential distribution areas was then evaluated using equivalence and ecological niche parameters implemented in the ENMTools software; for this we quantified the degree of overlap and similarity between the niches using the equivalence (D) and similarity (I) parameters.Key results – The resulting models show that species display areas of high suitability along the Mexican dry regions, as well as overlapping heterogeneous values. All models showed high AUC (Area Under the Curve) values (> 0.8). The D and I values between each pair of species showed low values of overlap.Conclusions – Each species of the genus shows a fundamental niche distinct from their sister species. The genus thus offers an example of niche divergence among species, with each one adapting to different environmental pressures. Our results do not support the hypothesis of niche conservatism in the genus, suggesting that the species evolved in divergent environments.

scholarly journals High-throughput sequencing reveals dietary segregation in Malaysian babblers

2021 ◽  
Author(s):  
Mohammad Saiful Mansor ◽  
Fasihah Zarifah Rozali ◽  
Sian Davies ◽  
Shukor Md Nor ◽  
Rosli Ramli
Keyword(s):  
High Throughput ◽  
High Throughput Sequencing ◽  
Prey Selection ◽  
Niche Partitioning ◽  
Peninsular Malaysia ◽  
Similar Species ◽  
Insectivorous Birds ◽  
Dietary Overlap ◽  
Dietary Flexibility ◽  
Wide Range

Abstract The coexistence of numerous species within a community results from how those species use available resources. Babblers are one of the major groups of Malaysian insectivorous birds, which frequently forage in dense vegetation cover and have a high level of sympatry. Therefore, examining the diet, prey selection and niche segregation of babblers can be challenging. In this study, we used high-throughput sequencing to investigate potential dietary overlap or segregation among 10 babbler species of the four genera of the family Pellorneidae and Timaliidae: Pellorneum, Malacopteron, Stachyris and Cyanoderma in central peninsular Malaysia. We tested the hypothesis that trophically similar species may differ in resource use to avoid competitive exclusion. We identified 81 distinct arthropod taxa from fecal samples, belonging to 71 families representing 13 orders, which were predominantly from 16 dipteran, 13 lepidopteran and 10 coleopteran families. Of all the prey taxa consumed, 45% were found to be distinct across the 10 babbler species, and less than 35% were shared simultaneously by three or more babbler species, indicating minimal dietary overlap. The black-throated babbler Stachyris nigricollis and moustached babbler Malacopteron magnirostre had the most generalist tendencies because they consumed a greater variety of prey taxa. Small dietary overlap values (Ojk) and a relatively wide range of food resources suggest that dietary segregation occurred among the studied babblers. The great diversity of prey consumed revealed the presence of dietary flexibility among the sympatric insectivorous birds, thus reducing any active dietary competition and facilitating the coexistence through niche partitioning.

scholarly journals Extensive sympatry and frequent hybridization of ecologically divergent aquatic plants on the Qinghai-Tibetan Plateau

2021 ◽  
Author(s):  
Zhigang Wu ◽  
Zhong Wang ◽  
Dong Xie ◽  
Juan Zhang ◽  
Pengsen Cai ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Aquatic Plants ◽  
Related Species ◽  
Environmental Gradients ◽  
Niche Overlap ◽  
Hybrid Zones ◽  
Limited Information ◽  
Freshwater Biodiversity ◽  
Genetic Incompatibility ◽  
Species Pairs

Hybridization has fascinated biologists in recent centuries for its evolutionary importance, especially in plants. Hybrid zones are commonly located in regions across environmental gradients due to more opportunities to contact and ecological heterogeneity. For aquatic taxa, intrazonal character makes broad overlapping regions in intermediate environments between related species. However, we have limited information on the hybridization pattern of aquatic taxa across an altitudinal gradient. In this study, we aimed to test the hypotheses that niche overlap and hybridization might be extensive in related aquatic plants in alpines. We evaluated the niche overlap in three related species pairs on the Qinghai-Tibetan Plateau and assessed the spatial pattern of hybrid populations. Obvious niche overlap and common hybridization were revealed in all three pairs of related aquatic plants. The plateau edge and river basins were broad areas for the sympatry of divergent taxa, where a large proportion of hybrid populations occurred. Hybrids are also discretely distributed in diverse habitats on the plateau. Differences in the extent of niche overlap, genetic incompatibility and phylogeographic history might lead to inconsistences in hybridization patterns among the three species pairs. Our results suggested that plateau areas are a hotspot for ecologically divergent aquatic species to contact and mate and implied that hybridization may be important for the freshwater biodiversity of highlands.

scholarly journals Relationships between taxonomic and functional diversity: insights into assembly processes

2016 ◽  
Author(s):  
Doriane Stagnol ◽  
Lise Bacouillard ◽  
Dominique Davoult
Keyword(s):  
Functional Diversity ◽  
Community Assembly ◽  
Rocky Shore ◽  
Taxonomic Diversity ◽  
Distinct Species ◽  
Ecological Niches ◽  
Similar Species ◽  
Marine Habitats ◽  
Ecological Redundancy ◽  
And Function

Among the potential indicators of biodiversity, those based on the functional traits of species are interesting because they measure the aspects of diversity that potentially affect community assembly and function. However, trait-based approaches are still rarely considered and little is known about the degree to which taxonomic diversity (TD) and functional diversity (FD) are correlated. Yet, this relationship is thought to depend on the extent of ecological redundancy within the assemblage, i.e. the number of taxonomically distinct species that exhibit similar ecological functions. In this study, we characterized taxonomic and functional diversity within and between two marine habitats (rocky shore vs mudflats) under human-induced disturbances. Models were also used to test whether the relationship between TD and FD differed according to the indices used to characterize them. We found little effect of human disturbance on the shape of the TD-FD relationship, whereas communities of the mudflat appeared to be less redundant than those of rocky shore. This could be explained by the assembly rules of ecosystems: biotic filtering (competition and resource partitioning) reduces redundancy by selecting for functionally dissimilar species, whereas abiotic filtering increases redundancy by selecting for similar species sharing adaptations to a particular environment. The rocky shore environment is characterized by heterogeneity that allows the formation of distinct ecological niches that can be colonized by similar species: the abiotic filtering does not limit the redundancy permitted by habitat. Conversely, in the more homogeneous environment of mudflat, the biotic filter mitigates redundancy. Trait-mediated abiotic filtering appears to play an important role in community assembly in complex habitats, whereas the relative importance of competitive exclusion appears to be greater in homogeneous habitats.

Niche differentiation of tallgrass prairie plants species along soil hydrological gradients

Botany ◽  
2019 ◽  
Vol 97 (9) ◽  
pp. 487-494
Author(s):  
John Markham
Keyword(s):  
Tallgrass Prairie ◽  
Niche Overlap ◽  
Niche Differentiation ◽  
Vegetation Survey ◽  
Soil Hydrology ◽  
Hydrological Conditions ◽  
Species Analysis ◽  
Species Pairs ◽  
Tallgrass Prairies ◽  
Study Sites

This study addressed whether the distribution of species in frequently burned lowland tallgrass prairies is driven by gradients in soil hydrology. On three study sites, the hydrological conditions in 1 m2 vegetation survey plots where quantified as the number of days the soil was anaerobic less than 15 cm below the surface, and the surface of the soil was drier than 0.4 m3·m−3. On each site, the centroid of each species hydrological niche was defined as the hydrological conditions in plots where it occurred, weighted by its abundance. Species found on all sites maintained a consistent ranking between sites along the soil drying gradient, but not the anaerobic gradient. The levels of niche overlap between species pairs along both hydrological gradients were significantly less than the overlap from randomly assigning species to the hydrological gradients. Indicator species analysis suggested that on each site the communities were best described as consisting of two subgroups. The hydrological niches of the species in these subgroups were significantly different from one another, suggesting that these subgroups are associated with wet or dry habitats. Overall, these analyses suggest that hydrology plays a major role in determining the structure of these frequently disturbed communities.

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