10.5061/DRYAD.HHMGQNKD3
Shutt, Jack
0000-0002-4146-8748
University of Edinburgh
Nicholls, James
University of Edinburgh
Trivedi, Urmi
Edinburgh Genomics
Burgess, Malcolm
Royal Society for the Protection of Birds
Stone, Graham
University of Edinburgh
Hadfield, Jarrod
University of Edinburgh
Phillimore, Albert
University of Edinburgh
Gradients in richness and turnover of a forest passerine’s diet prior to
breeding: a mixed model approach applied to faecal metabarcoding data
Dryad
dataset
2020
Foodwebs
Predator Prey Interactions
Diet Analysis
Natural Environment Research Council
https://ror.org/02b5d8509
NE/1338530,NE/I020598/1
Royal Society of Edinburgh
https://ror.org/03kx2pj14
2020-02-28T00:00:00Z
2020-02-28T00:00:00Z
en
https://doi.org/10.1111/mec.15394
86752584 bytes
5
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Little is known about the dietary richness and variation of generalist
insectivorous species, including birds, due primarily to difficulties in
prey identification. Using faecal metabarcoding we provide the most
comprehensive analysis of a passerine’s diet to date, identifying the
relative magnitudes of biogeographic, habitat and temporal trends in the
richness and turnover in diet of Cyanistes caeruleus (blue tit) along a
39-site, 2° latitudinal transect in Scotland. Faecal samples were
collected during 2014-15 from adult birds roosting in nestboxes prior to
nest building. DNA was extracted from 793 samples and we amplified COI and
16S minibarcodes. We identified 432 molecular operational taxonomic units
(MOTUs) that correspond to putative dietary items. Most dietary items were
rare, with Lepidoptera being the most abundant and taxon-rich prey order.
We present a novel statistical approach for estimation of gradients and
inter-sample variation in taxonomic richness and turnover using a
generalised linear mixed model. We discuss the merits of this approach
over existing tools and present new theory and methods for
model-based estimation of repeatability. We find that dietary richness
increases significantly as spring advances, but changes little with
elevation, latitude or local tree composition. In comparison, dietary
composition exhibits significant turnover along temporal and spatial
gradients and among sites. Our study shows the promise of faecal
metabarcoding for inferring the macroecology of food webs, but we also
highlight the challenge posed by contamination and make recommendations of
laboratory and statistical practices to minimise its impact on inference.