title: Highly overlapping winter diet in two sympatric lemming species revealed by DNA metabarcoding.
abstract: Sympatric species are expected to minimize competition by partitioning resources, especially when these are limited. Herbivores inhabiting the High Arctic in winter are a prime example of a situation where food availability is anticipated to be low, and thus reduced diet overlap is expected. We present here the first assessment of diet overlap of high arctic lemmings during winter based on DNA metabarcoding of feces. In contrast to previous analyses based on microhistology, we found that the diets of both collared (Dicrostonyx groenlandicus) and brown lemmings (Lemmus trimucronatus) on Bylot Island were dominated by Salix while mosses, which were significantly consumed only by the brown lemming, were a relatively minor food item. The most abundant plant taxon, Cassiope tetragona, which alone composes more than 50% of the available plant biomass, was not detected in feces and can thus be considered to be non-food. Most plant taxa that were identified as food items were consumed in proportion to their availability and none were clearly selected for. The resulting high diet overlap, together with a lack of habitat segregation, indicates a high potential for resource competition between the two lemming species. However, Salix is abundant in the winter habitats of lemmings on Bylot Island and the non-Salix portion of the diets differed between the two species. Also, lemming grazing impact on vegetation during winter in the study area is negligible. Hence, it seems likely that the high potential for resource competition predicted between these two species did not translate into actual competition. This illustrates that even in environments with low primary productivity food resources do not necessarily generate strong competition among herbivores.
authors: Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway.
authors: Eeva M
authors: EM
authors: Soininen
authors: Département de Biologie & Centre d'Études Nordiques, Université Laval, Québec, Canada.
authors: Gilles
authors: G
authors: Gauthier
authors: Département de Biologie & Centre d'Études Nordiques, Université Laval, Québec, Canada.
authors: Frédéric
authors: F
authors: Bilodeau
authors: Chaire de Recherche du Canada en Biodiversité Nordique & Centre d'Études Nordiques, Université du Québec à Rimouski, Québec, Canada.
authors: Dominique
authors: D
authors: Berteaux
authors: Université Grenoble Alpes/CNRS, Laboratoire d'Écologie Alpine (LECA), Grenoble, France.
authors: Ludovic
authors: L
authors: Gielly
authors: Université Grenoble Alpes/CNRS, Laboratoire d'Écologie Alpine (LECA), Grenoble, France.
authors: Pierre
authors: P
authors: Taberlet
authors: Natural History Museum, University of Oslo, Oslo, Norway; Department of Botany, St Petersburg State University, St Petersburg, Russia.
authors: Galina
authors: G
authors: Gussarova
authors: Natural History Museum, University of Oslo, Oslo, Norway; SPYGEN, Savoie Technolac, Le Bourget du Lac, France.
authors: Eva
authors: E
authors: Bellemain
authors: NTNU University Museum, Norwegian University of Science and Technology, Trondheim, Norway.
authors: Kristian
authors: K
authors: Hassel
authors: NTNU University Museum, Norwegian University of Science and Technology, Trondheim, Norway.
authors: Hans K
authors: HK
authors: Stenøien
authors: Natural History Museum, University of Oslo, Oslo, Norway.
authors: Laura
authors: L
authors: Epp
authors: Natural History Museum, University of Oslo, Oslo, Norway.
authors: Audun
authors: A
authors: Schrøder-Nielsen
authors: Natural History Museum, University of Oslo, Oslo, Norway.
authors: Christian
authors: C
authors: Brochmann
authors: Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway.
authors: Nigel G
authors: NG
authors: Yoccoz
mesh_terms: D000818:Animals; D001110:Arctic Regions; D003411:Arvicolinae / Q000235:genetics* / Q000502:physiology; D058893:DNA Barcoding, Taxonomic; D011157:Population Dynamics; D012621:Seasons; D061350:Sympatry / Q000235:genetics* / Q000502:physiology
references: Oecologia. 1985 Jun;66(3):430-436
references: 28310875
references: Proc Natl Acad Sci U S A. 2011 Feb 1;108(5):1970-4
references: 21245340
references: Oecologia. 2013 Aug;172(4):1007-16
references: 23232938
references: Front Zool. 2009 Aug 20;6:16
references: 19695081
references: Oecologia. 2000 Jul;124(1):130-137
references: 28308406
references: PLoS One. 2012;7(8):e42427
references: 22900021
references: Mol Ecol Resour. 2011 Mar;11(2):404-8
references: 21429154
references: Oecologia. 1994 May;97(4):439-450
references: 28313731
references: Proc Biol Sci. 2003 Feb 7;270(1512):313-21
references: 12614582
references: PLoS One. 2013 Jun 27;8(6):e68128
references: 23826371
references: Philos Trans R Soc Lond B Biol Sci. 2013 Aug 19;368(1624):20120482
references: 23836788
references: Oecologia. 2007 Oct;153(4):931-41
references: 17618466
references: PLoS One. 2012;7(4):e35643
references: 22558187
references: Nature. 2014 Feb 6;506(7486):47-51
references: 24499916
references: Mol Ecol. 2012 Apr;21(8):1931-50
references: 22171763
references: Trends Ecol Evol. 2009 Feb;24(2):110-7
references: 19100655
references: Oecologia. 2011 Dec;167(4):967-80
references: 21701915
references: Ecology. 2012 Jul;93(7):1707-16
references: 22919916
references: Plant Mol Biol. 1991 Nov;17(5):1105-9
references: 1932684
references: Mol Ecol Resour. 2010 Nov;10(6):1009-18
references: 21565110
references: Oecologia. 2012 Apr;168(4):935-46
references: 22042523
references: Isotopes Environ Health Stud. 2014;50(3):361-81
references: 24830842
references: Mol Ecol Resour. 2009 Jan;9(1):51-60
references: 21564566
references: Proc Biol Sci. 2011 Feb 22;278(1705):481-9
references: 20980307
references: BMC Genomics. 2010 Jul 16;11:434
references: 20637073
references: J Anim Ecol. 2012 Jul;81(4):747-55
references: 22325037
references: Mol Ecol. 2012 Apr;21(8):1789-93
references: 22486819
references: Nucleic Acids Res. 2007;35(3):e14
references: 17169982