Sources of intraspecific variation in the isotopic niche of a semi-aquatic predator in a human-modified landscape
Intraspecific variation modulates patterns of resource use by species, potentially affecting the structure and stability of food webs. In human-modified landscapes, habitat disturbance modifies trophic interactions and intraspecific niche variation, impacting population persistence. Here, we investi...
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| Format: | Article |
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PeerJ Inc.
2023-08-01
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| Online Access: | https://peerj.com/articles/15915.pdf |
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| author | André Costa Pereira Gabriela Bielefeld Nardoto Guarino Rinaldi Colli |
| author_facet | André Costa Pereira Gabriela Bielefeld Nardoto Guarino Rinaldi Colli |
| author_sort | André Costa Pereira |
| collection | DOAJ |
| description | Intraspecific variation modulates patterns of resource use by species, potentially affecting the structure and stability of food webs. In human-modified landscapes, habitat disturbance modifies trophic interactions and intraspecific niche variation, impacting population persistence. Here, we investigated the relationship of sex, ontogeny, and habitat factors with the trophic niche of Caiman crocodilus in an agricultural landscape. We evaluated temporal variation in the trophic niche parameters using carbon and nitrogen stable isotope analysis from different body tissues. We found that caimans exploit the same carbon and nitrogen pools through time, with low isotopic variability between seasons, partly due to the slow isotope turnover rates of tissues in crocodilians. Conversely, the trophic niche of caimans varied across habitats, but with no evidence of a difference between natural and anthropogenic habitats. It apparently results from the influence of habitat suitability, connectivity, and caiman movements during the foraging. Our findings highlight the broader niches of juvenile caimans relative to adults, possibly in response of territorialism and opportunistic foraging strategy. Although using similar resources, females had a larger niche than males, probably associated with foraging strategies during nesting. Considering the sex and body size categories, caimans occupied distinct isotopic regions in some habitats, indicating apparent niche segregation. Ontogenetic trophic shifts in the isotopes (δ13C and δ15N) depended on sex, leading to resource partitioning that can potentially reduce intraspecific competition. Decision-makers and stakeholders should consider the trophic dynamics of sex and body size groups for the sustainable management and conservation of caiman populations, which implies in the maintenance of wetland habitats and landscape heterogeneity in the Formoso River floodplain. |
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| id | doaj.art-9d2e2700678f4fecb7b875984dfcde6c |
| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T07:24:14Z |
| publishDate | 2023-08-01 |
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| spelling | doaj.art-9d2e2700678f4fecb7b875984dfcde6c2023-12-03T07:09:42ZengPeerJ Inc.PeerJ2167-83592023-08-0111e1591510.7717/peerj.15915Sources of intraspecific variation in the isotopic niche of a semi-aquatic predator in a human-modified landscapeAndré Costa Pereira0Gabriela Bielefeld Nardoto1Guarino Rinaldi Colli2Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade de Brasília, Brasilia, Distrito Federal, BrazilDepartamento de Ecologia, Instituto de Ciências Biológicas, Universidade de Brasília, Brasilia, Distrito Federal, BrazilDepartamento de Zoologia, Instituto de Ciências Biológicas, Universidade de Brasília, Brasilia, Distrito Federal, BrazilIntraspecific variation modulates patterns of resource use by species, potentially affecting the structure and stability of food webs. In human-modified landscapes, habitat disturbance modifies trophic interactions and intraspecific niche variation, impacting population persistence. Here, we investigated the relationship of sex, ontogeny, and habitat factors with the trophic niche of Caiman crocodilus in an agricultural landscape. We evaluated temporal variation in the trophic niche parameters using carbon and nitrogen stable isotope analysis from different body tissues. We found that caimans exploit the same carbon and nitrogen pools through time, with low isotopic variability between seasons, partly due to the slow isotope turnover rates of tissues in crocodilians. Conversely, the trophic niche of caimans varied across habitats, but with no evidence of a difference between natural and anthropogenic habitats. It apparently results from the influence of habitat suitability, connectivity, and caiman movements during the foraging. Our findings highlight the broader niches of juvenile caimans relative to adults, possibly in response of territorialism and opportunistic foraging strategy. Although using similar resources, females had a larger niche than males, probably associated with foraging strategies during nesting. Considering the sex and body size categories, caimans occupied distinct isotopic regions in some habitats, indicating apparent niche segregation. Ontogenetic trophic shifts in the isotopes (δ13C and δ15N) depended on sex, leading to resource partitioning that can potentially reduce intraspecific competition. Decision-makers and stakeholders should consider the trophic dynamics of sex and body size groups for the sustainable management and conservation of caiman populations, which implies in the maintenance of wetland habitats and landscape heterogeneity in the Formoso River floodplain.https://peerj.com/articles/15915.pdfAnthropogenic habitatsCaiman crocodilusOntogenetic shiftsSexual niche variationNiche temporal variability |
| spellingShingle | André Costa Pereira Gabriela Bielefeld Nardoto Guarino Rinaldi Colli Sources of intraspecific variation in the isotopic niche of a semi-aquatic predator in a human-modified landscape PeerJ Anthropogenic habitats Caiman crocodilus Ontogenetic shifts Sexual niche variation Niche temporal variability |
| title | Sources of intraspecific variation in the isotopic niche of a semi-aquatic predator in a human-modified landscape |
| title_full | Sources of intraspecific variation in the isotopic niche of a semi-aquatic predator in a human-modified landscape |
| title_fullStr | Sources of intraspecific variation in the isotopic niche of a semi-aquatic predator in a human-modified landscape |
| title_full_unstemmed | Sources of intraspecific variation in the isotopic niche of a semi-aquatic predator in a human-modified landscape |
| title_short | Sources of intraspecific variation in the isotopic niche of a semi-aquatic predator in a human-modified landscape |
| title_sort | sources of intraspecific variation in the isotopic niche of a semi aquatic predator in a human modified landscape |
| topic | Anthropogenic habitats Caiman crocodilus Ontogenetic shifts Sexual niche variation Niche temporal variability |
| url | https://peerj.com/articles/15915.pdf |
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