scholarly journals Structure of mandibles in relation to trophic niche differentiation in a tropical millipede community

2011 ◽  
Vol 6 ◽  
pp. 37-49 ◽  
Author(s):  
Irina Semenyuk ◽  
A.V. Tiunov ◽  
Sergei Golovatch
Keyword(s):  
Niche Differentiation ◽  
Trophic Niche

Coexistence of morphologically similar bats (Vespertilionidae) on Madagascar: stable isotopes reveal fine-grained niche differentiation among cryptic species

2014 ◽  
Vol 31 (2) ◽  
pp. 153-164 ◽  
Author(s):  
Melanie Dammhahn ◽  
Claude Fabienne Rakotondramanana ◽  
Steven M. Goodman
Keyword(s):  
Stable Isotopes ◽  
Deciduous Forest ◽  
Niche Differentiation ◽  
Sympatric Species ◽  
Trophic Niche ◽  
Trophic Levels ◽  
Seasonal Migration ◽  
Similar Species ◽  
Fine Grained ◽  
Hair Samples

Abstract:Based on niche theory, closely related and morphologically similar species are not predicted to coexist due to overlap in resource and habitat use. Local assemblages of bats often contain cryptic taxa, which co-occur despite notable similarities in morphology and ecology. We measured in two different habitat types on Madagascar levels of stable carbon and nitrogen isotopes in hair (n = 103) and faeces (n = 57) of cryptic Vespertilionidae taxa to indirectly examine whether fine-grained trophic niche differentiation explains their coexistence. In the dry deciduous forest (Kirindy), six sympatric species ranged over 6.0‰ in δ15N, i.e. two trophic levels, and 4.2‰ in δ13C with a community mean of 11.3‰ in δ15N and −21.0‰ in δ13C. In the mesic forest (Antsahabe), three sympatric species ranged over one trophic level (δ15N: 2.4‰, δ13C: 1.0‰) with a community mean of 8.0‰ δ15N and −21.7‰ in δ13C. Multivariate analyses and residual permutation of Euclidian distances in δ13C–δ15N bi-plots revealed in both communities distinct stable isotope signatures and species separation for the hair samples among coexisting Vespertilionidae. Intraspecific variation in faecal and hair stable isotopes did not indicate that seasonal migration might relax competition and thereby facilitate the local co-occurrence of sympatric taxa.

Identification of trophic niches of subterranean diving beetles in a calcrete aquifer by DNA and stable isotope analyses

2014 ◽  
Vol 65 (2) ◽  
pp. 95 ◽  
Author(s):  
Tessa M. Bradford ◽  
William F. Humphreys ◽  
Andrew D. Austin ◽  
Steven J. B. Cooper
Keyword(s):  
Stable Isotope ◽  
Trophic Ecology ◽  
Niche Partitioning ◽  
Niche Differentiation ◽  
Trophic Niche ◽  
Coi Gene ◽  
Stable Isotope Analyses ◽  
Prey Preferences ◽  
Diving Beetles ◽  
Isotope Analyses

The Yilgarn calcrete aquifers in Western Australia are an interesting system for investigating the process of speciation within subterranean habitats, because of the limited opportunities for dispersal between isolated calcretes. The presence of different-sized diving beetles (Dytiscidae) in separate calcretes, including sympatric sister-species pairs, suggests that species may have evolved within calcretes by an adaptive shift as a result of ecological-niche differentiation. We have studied the potential for trophic niche partitioning in a sister triplet of diving beetles, of distinctly different sizes, from a single aquifer. Fragments of the mitochondrial COI gene, specific to known species of amphipods and copepods, were polymerase chain reaction-amplified from each of the three beetle species, indicating that there is an overlap in their prey items. Significant differences were found in the detected diets of the three species, and results showed a propensity for prey preferences of amphipods by the large beetles and one species of copepod for the small beetles. A terrestrial source of carbon to the calcrete was suggested by stable isotope analyses. The combined approach of molecular, stable isotope and behavioural studies have provided insight into the trophic ecology of this difficult-to-access environment, providing a framework for more fine-scale analyses of the diet of different-sized species to examine speciation underground.

scholarly journals Trophic niche differentiation and microhabitat utilization revealed by stable isotope analyses in a dry-forest bat assemblage at Ankarana, northern Madagascar

2013 ◽  
Vol 30 (2) ◽  
pp. 97-109 ◽  
Author(s):  
Melanie Dammhahn ◽  
Steven M. Goodman
Keyword(s):  
Nitrogen Isotopes ◽  
Niche Differentiation ◽  
Trophic Niche ◽  
Trophic Levels ◽  
Dry Forest ◽  
Carbon And Nitrogen ◽  
Hair Samples ◽  
Primary Consumers ◽  
Secondary Consumers ◽  
Mammal Assemblages

Abstract:Bats are important components in tropical mammal assemblages. Unravelling the mechanisms allowing multiple syntopic bat species to coexist can provide insights into community ecology. However, dietary information on component species of these assemblages is often difficult to obtain. Here we measured stable carbon and nitrogen isotopes in hair samples clipped from the backs of 94 specimens to indirectly examine whether trophic niche differentiation and microhabitat segregation explain the coexistence of 16 bat species at Ankarana, northern Madagascar. The assemblage ranged over 4.4‰ in δ15N and was structured into two trophic levels with phytophagous Pteropodidae as primary consumers (c. 3‰ enriched over plants) and different insectivorous bats as secondary consumers (c. 4‰ enriched over primary consumers). Bat species utilizing different microhabitats formed distinct isotopic clusters (metric analyses of δ13C–δ15N bi-plots), but taxa foraging in the same microhabitat did not show more pronounced trophic differentiation than those occupying different microhabitats. As revealed by multivariate analyses, no discernible feeding competition was found in the local assemblage amongst congeneric species as compared with non-congeners. In contrast to ecological niche theory, but in accordance with studies on New and Old World bat assemblages, competitive interactions appear to be relaxed at Ankarana and not a prevailing structuring force.

scholarly journals Competition and feeding ecology in two sympatric Xenopus species (Anura: Pipidae)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3130 ◽  
Author(s):  
Solveig Vogt ◽  
F. André de Villiers ◽  
Flora Ihlow ◽  
Dennis Rödder ◽  
John Measey
Keyword(s):  
Food Preferences ◽  
Stomach Contents ◽  
Niche Overlap ◽  
Niche Differentiation ◽  
Shannon Index ◽  
Trophic Niche ◽  
Western Cape ◽  
The South ◽  
Amphibian Species ◽  
Study Sites

The widespread African clawed frog (Xenopus laevis) occurs in sympatry with the IUCN Endangered Cape platanna (Xenopus gilli) throughout its entire range in the south-western Cape, South Africa. In order to investigate aspects of the interspecific competition between populations of X. laevis and X. gilli, an assessment of their niche differentiation was conducted through a comprehensive study on food composition and trophic niche structure at two study sites: the Cape of Good Hope (CoGH) and Kleinmond. A total of 399 stomach contents of X. laevis (n = 183) and X. gilli (n = 216) were obtained together with samples of available prey to determine food preferences using the Electivity index (E*), the Simpson’s index of diversity (1 − D), the Shannon index (H′), and the Pianka index (Ojk). Xenopus gilli diet was more diverse than X. laevis, particularly in Kleimond where the Shannon index was nearly double. Both species were found to consume large amounts of tadpoles belonging to different amphibian species, including congeners, with an overall higher incidence of anurophagy than previously recorded. However, X. laevis also feeds on adult X. gilli, thus representing a direct threat for the latter. While trophic niche overlap was 0.5 for the CoGH, it was almost 1 in Kleinmond, suggesting both species utilise highly congruent trophic niches. Further, subdividing the dataset into three size classes revealed overlap to be higher in small frogs in both study sites. Our study underlines the importance of actively controlling X. laevis at sites with X. gilli in order to limit competition and predation, which is vital for conservation of the south-western Cape endemic.

A historical perspective of niche differentiation between two top predators in the Uruguayan coastal area

2019 ◽  
Vol 46 (2) ◽  
pp. 136 ◽  
Author(s):  
Florencia Artecona ◽  
Maite De María ◽  
Leandro Bergamino ◽  
Diana Szteren
Keyword(s):  
Marine Mammals ◽  
Species Abundance ◽  
Niche Differentiation ◽  
Trophic Niche ◽  
Trophic Levels ◽  
Isotopic Niche ◽  
Recent Period ◽  
The South ◽  
Coastal Habitat ◽  
Top Predators

Context As top predators, marine mammals play a key role consuming in different trophic levels and the trophic niche characterization may help to understand how species utilize and share resources . On the coast of the Río de la Plata and the South-west Atlantic, the South American sea lion (Otaria flavescens) and the franciscana dolphin (Pontoporia blainvillei) are two important predators. Aims The present study investigated potential trophic overlap of both species by measuring stable carbon (δ13C) and nitrogen (δ15N) isotopes over two periods: historical (1959–79) and recent (2002–15) on the Uruguayan coast. Methods Bone samples of P. blainvillei and O. flavescens were used to determine the isotopic niche using the Stable Isotope Bayesian Ellipses in R (SIBER) analysis. Key results The isotopic niche did not overlap between species in any period. δ15N was higher in O. flavescens in both periods (20.29‰±0.73 in the historical and 19.95‰±1.0 in the recent period), indicating that it feeds at a higher trophic level than P. blainvillei. The δ13C was also significantly higher in O. flavescens than in P. blainvillei during the two periods (O. flavescens: –11.43±0.6‰ historic, –12.72±0.4‰ recent, and P. blainvillei: –12.69±1.1‰ historic, –13.84±1.3‰ recent). The isotopic niche areas of P. blainvillei in recent and historic periods confirmed they forage in 2 distinct environments, marine and estuarine, with low isotopic overlap. This overlap was higher in the recent period. Conclusions and Implications O. flavescens and both P. blainvillei groups were segregated in both periods, with a higher overlap in the recent. These species appear to reduce competition by using different resources in the same coastal habitat. O. flavescens preferentially feeds on benthic fish and showed wider trophic amplitude in both periods, whereas P. blainvillei has a more coastal–pelagic diet and included a greater variability of resources in its diet. The differences between species trophic niches can still be detected after both marine mammals species abundance has declined and after the development of fisheries.

scholarly journals The role of echolocation strategies for niche differentiation in bats

2018 ◽  
Vol 96 (3) ◽  
pp. 171-181 ◽  
Author(s):  
Annette Denzinger ◽  
Marco Tschapka ◽  
Hans-Ulrich Schnitzler
Keyword(s):  
Pattern Recognition ◽  
Open Space ◽  
Recognition Task ◽  
Positional Information ◽  
Niche Differentiation ◽  
Trophic Niche ◽  
Barro Colorado Island ◽  
Narrow Space ◽  
Pulse Echo

Guilds subdivide bat assemblages into basic structural units of species with similar patterns of habitat use and foraging modes, but do not explain mechanisms of niche differentiation. Bats have evolved four different echolocation strategies allowing the access to four different trophic niche spaces differing in niche dimensions. Bats foraging in open and edge spaces use the “aerial hawking or trawling strategy” and detect and localize prey by evaluating pulse–echo trains in which the prey echo is unmasked. The pulse–echo pairs deliver mainly positional information on the prey and only little information on its nature. Signals are highly variable and are adapted for detection and localization in open space and (or) edge space. In narrow space, bats identify prey by solving a pattern recognition task. Bats using the “flutter detecting strategy” evaluate glint pattern in prey echoes; bats using the “active gleaning strategy” evaluate the spectral–temporal pattern of the prey–clutter echo complex; and bats using the “passive gleaning strategy” evaluate the pattern of prey-generated cues to find food and use echolocation only for spatial orientation. The less variable signals of narrow space bats are adapted for pattern recognition. The diverse and species-rich tropical bat assemblage at Barro Colorado Island, Panama, is here used as an exemplar for assigning bats to guilds, and we discuss the role of echolocation and other adaptations for niche differentiation within guilds.

Resource abundance and frugivory in two manakin species (Aves: Pipridae) inhabiting a reforested area in Colombia

2012 ◽  
Vol 28 (5) ◽  
pp. 511-514 ◽  
Author(s):  
Juan A. Morales-Betancourt ◽  
Gabriel J. Castaño-Villa ◽  
Francisco E. Fontúrbel
Keyword(s):  
Community Ecology ◽  
Related Species ◽  
Species Coexistence ◽  
Niche Differentiation ◽  
Trophic Niche ◽  
Central Issue ◽  
Frugivorous Birds ◽  
Closely Related Species ◽  
Resource Abundance ◽  
Resource Dynamics

Coexistence of closely related species is a central issue in community ecology, and those species are expected to present niche differentiation, particularly when resources become scarce (García & Arroyo 2005). Hence, resource abundance and diet differences might be playing a key role in determining species coexistence (Chapman & Rosenberg 1991, Stevenson et al. 2000). Trophic niche differentiation in frugivorous birds could be driven by fruit selection, morphology, behaviour (Moermond & Denslow 1983, 1985) and the spatiotemporal resource dynamics (Blake & Loiselle 1991, Saracco et al. 2005, Solórzano et al. 2000).

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