Understanding the foraging ecology of animals gives insights into their trophic relationships and habitat use. We used stable isotope analysis to understand the foraging ecology of a critically endangered marine predator, the Māui dolphin. We analysed carbon and nitrogen isotope ratios of skin samples ( n = 101) collected from 1993 to 2021 to investigate temporal changes in diet and niche space. Genetic monitoring associated each sample with a DNA profile which allowed us to assess individual and population level changes in diet. Potential prey and trophic level indicator samples were also collected ( n = 166; 15 species) and incorporated in Bayesian mixing models to estimate importance of prey types to Māui dolphin diet. We found isotopic niche space had decreased over time, particularly since the 2008 implementation of a Marine Mammal Sanctuary. We observed a decreasing trend in ∂ 13 C and ∂ 15 N values, but this was not linear and several fluctuations in isotope values occurred over time. The largest variation in isotope values occurred during an El Niño event, suggesting that prey is influenced by climate-driven oceanographic variables. Mixing models indicated relative importance of prey remained constant since 2008. The isotopic variability observed here is not consistent with individual specialization, rather it occurs at the population level.
Variation In Isotope Values Changes In Diet Population Level Changes 15N Values Population Level Individual Specialization Niche Space Stable Isotope Analysis Trophic Relationships Potential Prey
AI-powered Research feed
Introducing Weekly Round-ups!Beta
Round-ups are the summaries of handpicked papers around trending topics published every week. These would enable you to scan through a collection of papers and decide if the paper is relevant to you before actually investing time into reading it.
Climate change Research Articles published between Nov 21, 2022 to Nov 27, 2022
Nov 28, 2022
Articles Included: 2
No potential conflict of interest was reported by the authors. The conception and design of the study, acquisition of data, analysis and interpretatio...Read More
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on “as is” basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The Copyright Law.