Conventional and molecular analysis of the diet of gentoo penguins: contributions to assess scats for non-invasive penguin diet monitoring

Xavier, Jose ORCID: https://orcid.org/0000-0002-9621-6660; Cherel, Yves; Medeiros, Renata; Velez, Nadja; Dewar, Meagan; Ratcliffe, Norman ORCID: https://orcid.org/0000-0002-3375-2431; Carreiro, Ana R; Trathan, Phil N. ORCID: https://orcid.org/0000-0001-6673-9930. 2018 Conventional and molecular analysis of the diet of gentoo penguins: contributions to assess scats for non-invasive penguin diet monitoring. Polar Biology, 41 (11). 2275-2287. https://doi.org/10.1007/s00300-018-2364-8

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Text This is a post-peer-review, pre-copyedit version of an article published in Polar Biology. The final authenticated version is available online at: https://doi.org/10.1007/s00300-018-2364-8 Paper penguins diet methods_REVISED.docx - Accepted Version Download (149kB)

Abstract/Summary

There is a growing search for less invasive methods while studying the diet of Antarctic animals in the wild. Therefore, we compared the diet of gentoo penguins from stomach contents (i.e. through visual identification of prey remains) and scats (i.e. faeces), and further compared prey DNA assay in fresh and old scats. Prey remains identified visually in stomach contents and scats were broadly comparable: the crustaceans and fish were the most important components, with Themisto gaudichaudii clearly being the most frequent and numerous prey species in both sampling methods. By mass, differences in species frequency were observed in stomach contents (Parachaenichthys georgianus) and scats (Champsocephalus gunnari), with the former fish species absent in scats. Differences were detected in the most frequent prey (T. gaudichaudii and Euphausia superba) and in various fish species, most with bigger sizes in scats. Allometric equations to estimate most crustacean’s sizes (i.e. relationships between carapace and mass/total length) are needed. For DNA studies, when comparing DNA from fresh and old scats, both provided similar results that, in general, were also similar to the visual analysis. In order to use penguin scats (along with the use of DNA analyses) for monitoring purposes, allometric equations to estimate mass and size of prey (most crustaceans) and better designed species-specific primers are needed for targeting key prey species (e.g. Euphausia superba, T. gaudichaudii). These DNA methodologies can complement other methods (i.e. visual analyses and stomach contents analyses) in monitoring programs of penguins.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1007/s00300-018-2364-8
ISSN:	0722-4060
Additional Keywords:	Pygoscelis papua, Southern Ocean, prey genetics, Feeding ecology, Conservation
Date made live:	02 Jul 2018 11:26 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/520420

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