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Individual variation of isotopic niches in grazing and browsing desert ungulates.
Oecologia 2015; 179(1):75-88O

Abstract

Ungulates often adjust their diet when food availability varies over time. However, it is poorly understood when and to what extent individuals change their diet and, if they do so, if all individuals of a population occupy distinct or similar dietary niches. In the arid Namibian Kunene Region, we studied temporal variations of individual niches in grazing gemsbok (Oryx gazella gazella) and predominantly browsing springbok (Antidorcas marsupialis). We used variation in stable C and N isotope ratios of tail hair increments as proxies to estimate individual isotopic dietary niches and their temporal plasticity. Isotopic dietary niches of populations of the two species were mutually exclusive, but similar in breadth. Isotopic niche breadth of gemsbok was better explained by within-individual variation than by between-individual variation of stable isotope ratios, indicating that gemsbok individuals were facultative specialists in using isotopically distinct local food resources. In contrast, inter- and intra-individual variations contributed similarly to the isotopic niche breadth of the springbok population, suggesting a higher degree of individual isotopic segregation in a more generalist ungulate. In both species, between-individual variation was neither explained by changes in plant primary productivity, sex, geographical position nor by group size. Within species, individual dietary niches overlapped partially, suggesting that both populations included individuals with distinct isotopic dietary niches. Our study provides the first evidence for isotopic dietary niche segregation in individuals of two distinct desert ungulates. Similar, yet isotopically distinct dietary niches of individuals may facilitate partitioning of food resources and thus individual survival in desert ecosystems.

Authors+Show Affiliations

Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research, 10315, Berlin, Germany, lehmann@izw-berlin.de.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

25953117

Citation

Lehmann, D, et al. "Individual Variation of Isotopic Niches in Grazing and Browsing Desert Ungulates." Oecologia, vol. 179, no. 1, 2015, pp. 75-88.
Lehmann D, Mfune JK, Gewers E, et al. Individual variation of isotopic niches in grazing and browsing desert ungulates. Oecologia. 2015;179(1):75-88.
Lehmann, D., Mfune, J. K., Gewers, E., Brain, C., & Voigt, C. C. (2015). Individual variation of isotopic niches in grazing and browsing desert ungulates. Oecologia, 179(1), pp. 75-88. doi:10.1007/s00442-015-3335-1.
Lehmann D, et al. Individual Variation of Isotopic Niches in Grazing and Browsing Desert Ungulates. Oecologia. 2015;179(1):75-88. PubMed PMID: 25953117.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Individual variation of isotopic niches in grazing and browsing desert ungulates. AU - Lehmann,D, AU - Mfune,J K E, AU - Gewers,E, AU - Brain,C, AU - Voigt,C C, Y1 - 2015/05/09/ PY - 2014/06/13/received PY - 2015/04/28/accepted PY - 2015/5/9/entrez PY - 2015/5/9/pubmed PY - 2016/4/8/medline SP - 75 EP - 88 JF - Oecologia JO - Oecologia VL - 179 IS - 1 N2 - Ungulates often adjust their diet when food availability varies over time. However, it is poorly understood when and to what extent individuals change their diet and, if they do so, if all individuals of a population occupy distinct or similar dietary niches. In the arid Namibian Kunene Region, we studied temporal variations of individual niches in grazing gemsbok (Oryx gazella gazella) and predominantly browsing springbok (Antidorcas marsupialis). We used variation in stable C and N isotope ratios of tail hair increments as proxies to estimate individual isotopic dietary niches and their temporal plasticity. Isotopic dietary niches of populations of the two species were mutually exclusive, but similar in breadth. Isotopic niche breadth of gemsbok was better explained by within-individual variation than by between-individual variation of stable isotope ratios, indicating that gemsbok individuals were facultative specialists in using isotopically distinct local food resources. In contrast, inter- and intra-individual variations contributed similarly to the isotopic niche breadth of the springbok population, suggesting a higher degree of individual isotopic segregation in a more generalist ungulate. In both species, between-individual variation was neither explained by changes in plant primary productivity, sex, geographical position nor by group size. Within species, individual dietary niches overlapped partially, suggesting that both populations included individuals with distinct isotopic dietary niches. Our study provides the first evidence for isotopic dietary niche segregation in individuals of two distinct desert ungulates. Similar, yet isotopically distinct dietary niches of individuals may facilitate partitioning of food resources and thus individual survival in desert ecosystems. SN - 1432-1939 UR - https://www.unboundmedicine.com/medline/citation/25953117/Individual_variation_of_isotopic_niches_in_grazing_and_browsing_desert_ungulates_ L2 - https://dx.doi.org/10.1007/s00442-015-3335-1 DB - PRIME DP - Unbound Medicine ER -