Evidence map›Paper›PMID 42237227›Full record

ArticleBMC ecology and evolution2026

Within-population isotopic niche variation of mammalian herbivores over a body mass and habitat gradient.

Runè van der Merwe, Chanel Lewis, Daryl Codron

Abstract read
In one paragraph

Article in BMC ecology and evolution, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

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5 · Who and what money

Authors and funding

3 authors.

Runè van der MerweDepartment of Zoology and Entomology, University of the Free State, PO Box 339, Bloemfontein, 9301, South Africa. runevandmerwe@gmail.com.
Chanel LewisDepartment of Zoology and Entomology, University of the Free State, PO Box 339, Bloemfontein, 9301, South Africa.
Daryl CodronDepartment of Zoology and Entomology, University of the Free State, PO Box 339, Bloemfontein, 9301, South Africa.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundIndividuals within populations may have distinct ecological niches, leading to a partitioned population niche structure. Such structure occurs because of both extrinsic and intrinsic factors. Body mass is suggested to limit between-individual diet niche variation within large-bodied mammalian herbivore populations, as their high intake requirements and associated search costs restricts opportunity for individuals to specialise. This study used stable isotope analysis to investigate niche structure within populations of mammalian herbivores to determine if (1) body mass correlates with the degree of niche structure and if (2) environmental conditions mediate this relationship. Stable carbon and nitrogen isotope compositions of faecal material of 16 herbivore species ranging in body mass (~ 10 to ~ 1420 kg) and geographical location were analysed. For each population, isotopic niche width (ellipse areas) and dispersion patterns (variance in geometric distance between individuals) in isotopic bi-space were quantified as proxies for population niche structure. Linear mixed models were used to test the effect of body mass, and local rainfall and reserve area (proxy for ecological conditions) on these indices of structure.

resultsIsotopic niche widths and dispersion metrics varied between species both within and between reserves, but the directionality of differences was not consistent, with some populations having broader niche widths and/or higher levels of dispersion than others, even within the same species. Although species differed in the degree of niche structuring within their respective populations, there was no effect of interspecific differences in body mass. The degree of dispersion (and thus between individual isotopic niche differences) is also not a function of ecological opportunity, but increased area might allow populations to expand their isotopic niche widths.

conclusionsThese findings suggest that niche variation and dispersion patterns in herbivore populations is limited by factors other than body size and intake requirement, despite the well-established role of body mass in shaping diet, as well as many other behavioural, ecological, and life history traits.

Indexed as

Body WeightEcosystemHerbivoryMammalsAnimalsCarbon IsotopesFecesNitrogen IsotopesCarbon IsotopesNitrogen IsotopesDispersion metricsFaecesIsotopic niche widthNiche structureStable isotope analysis

Identifiers

PMID42237227
PMCPMC13474679

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.