Applications of stable isotope techniques to the ecology of mammals

Abstract

ABSTRACT1. Stable isotope analysis (SIA) has the potential to become a widespread tool in mammalian ecology, because of its power in resolving the ecological and behavioural characteristics of animals. Although applications of the technique have enhanced our understanding of mammalian biology, it remains underused. Here we provide a review of previous applications to the study of extant mammals, drawing when appropriate on examples from the wider ecological literature, to identify the potential for future development of the approach. 2. Stable isotope analysis has been applied successfully to understanding the basic foraging decisions of mammals. However, SIA generates quantitative data on a continuous scale meaning that the approach can be particularly powerful in the characterization of community metrics, such as dimensions of resource partitioning within species assemblages or nutrient dynamics in food chains. Resolving spatial and temporal patterns of individual, intraspecific and interspecific resource use is of fundamental importance in animal ecology and evolutionary biology and SIA will emerge as a critical tool in these fields. 3. Geographical differences in naturally occurring stable isotopes have allowed ecologists to describe large-scale mammal migrations. Several isotopic gradients exist at smaller spatial scales, which can provide finer resolution of spatial ecology. 4. A combination of foraging and movement decisions is of prime importance in the study of ecotoxicology, since this discipline requires quantitative understanding of exposure risk.

Reconstruction of breastfeeding and weaning practices using stable isotope and trace element analyses: A review

“…In other words, researchers need to know when the studied tissue was synthesized in the individual's life and how large was the lag time between the actual dietary change and the incorporation of isotopic and trace elemental signals into the tissue. Problems related to the incorporation of elements into body tissues have been intensively discussed in isotope ecology (reviewed by Crawford et al, 2008;Martı nez del Rio et al 2009;Wolf et al, 2009;Boecklen et al, 2011). The assessment of biological age is relatively straightforward in soft tissues because the potential time lags between actual weaning ages and elemental signals are relatively small.…”

“…The quantitative evaluation of contributions from breast milk, weaning foods, and adult foods in subadult diet requires knowledge of these elemental routings. Problems related to the routing of elements from dietary components to body tissues have been extensively discussed in isotope ecology (reviewed by Crawford et al, 2008;Martı nez del Rio et al 2009;Wolf et al, 2009;Boecklen et al, 2011). While carbon, nitrogen, and sulfur atoms in tissue protein mainly reflect those in dietary proteins, carbon atoms in tissue apatite reflect those from the entire diet (Krueger and Sullivan, 1984;Ambrose and Norr, 1993;Tieszen and Fagre, 1993;Podlesak and McWilliams, 2006;Kellner and Schoeninger, 2010;Froehle et al, 2012).…”

“…Stable nitrogen isotope analysis, as well as carbon, has been used in the dietary reconstruction in ecology and bioarchaeology (reviewed by Schwarcz and Schoeninger, 1991;Schoeninger and Moore, 1992;Pate, 1994;Katzenberg and Harrison, 1997;Crawford et al, 2008;Lee-Thorp, 2008;Crowley, 2012;Sandberg et al, 2012). The d 15 N value increases with an elevated trophic level (bioenrichment: DeNiro and Epstein, 1981;Minagawa and Wada, 1984;Schoeninger and DeNiro, 1984;Bocherens and Drucker, 2003), and, in general, is higher in marine organisms than in terrestrial organisms (Schoeninger et al, 1983;Schoeninger and DeNiro, 1984).…”

Expansion of great cormorant colony immediately increased isotopic enrichment in small mammals

“…We used hair of the rodents as metabolically inert samples, preserving the isotopic record of the animal's diet (Crawford et al, 2008;Bauduin et al, 2013). Hair samples were cut off with scissors from between the shoulders of all trapped specimens of A. flavicollis and M. glareolus (88 and 29 individuals, see Table 1).…”

Isotopic signatures (δ 13C and δ15N) of muscle, carapace and claw in Phrynops geoffroanus (Testudines: Chelidae)

“…In addition, in the case of ␦ 15 N there was a significant difference for there is a relation for chelonians muscle and carapace samples when analysing ␦ 13 C and ␦ 13 N composition. The tissues of consumers are synthesised by nutrients present in the diet, so they usually reflect the isotopic composition of their food (DENIRO & EPSTEIN 1978, HOBSON & CLARK 1992a, CRAWFORD et al 2008). The differences found in the isotopic signatures of the tissues can result from different metabolic processes involved in the formation of different tissues.…”