Experimental removals reveal dietary niche partitioning facilitates coexistence between native and introduced species
AffiliationUniv Arizona, Sch Nat Resources & Environm
MetadataShow full item record
CitationDerbridge, J. J., & Koprowski, J. L. (2019). Experimental removals reveal dietary niche partitioning facilitates coexistence between native and introduced species. Ecology and evolution, 9(7), 4065-4077.
JournalECOLOGY AND EVOLUTION
RightsCopyright © 2019 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractNiche overlap between native species and ecologically similar invaders can lead to competitive exclusion of threatened native species, but if two such species also co-occur naturally elsewhere, interactions between native and introduced populations may mirror coevolved niche partitioning that reduces competition and promotes coexistence.A single, insular population of Fremont's squirrel (Tamiasciurus fremonti) the Mount Graham red squirrel (MGRS; T. f. grahamensis) in the Pinaleño Mountains, Arizona, USA, is critically endangered and resource competition with introduced Abert's squirrels (Sciurus aberti) may threaten its long-term persistence. The species are naturally synoptic in other mountain sites, and both consume diets comprised primarily of conifer seeds and fungi.We conducted experimental removals of introduced Abert's squirrels and used stable isotope analysis of diets before and after removals, and of diets in naturally syntopic populations to test the hypothesis that dietary niche partitioning can facilitate coexistence between native and introduced species. We also developed a novel approach to determine the influence of fluctuating food availability on carbon enrichment in consumers.Mount Graham red squirrels and introduced Abert's squirrels partitioned the dietary niche similarly to naturally syntopic populations. Removals had no apparent effect. Diet of MGRS was more closely linked to availability of resources than to presence of Abert's squirrels.Flexible dietary niche of introduced Abert's squirrels may have allowed them to exploit a resource opportunity in syntopy with MGRS. Variable food production of MGRS habitat may intensify competition in poor years, and territorial defense against non-native Abert's squirrels likely imposes fitness costs on individual MGRS. Similarity in our model species' diets may make MGRS more vulnerable to competition if climate change eliminates the advantages of larder-hoarding. Where introduced populations of ecologically similar species are better adapted to changing conditions, they may ultimately replace southern peripheral populations of native species.
NoteOpen access journal
VersionFinal published version
SponsorsUSDA Forest Service; American Society of Mammalogists Grant in Aid of Research; T&E Inc. Grants for Conservation Biology; University of Arizona; Arizona Game and Fish Department
- Seed Removal Increased by Scramble Competition with an Invasive Species.
- Authors: Minor RL, Koprowski JL
- Issue date: 2015
- Differential Effects of Roads and Traffic on Space Use and Movements of Native Forest-Dependent and Introduced Edge-Tolerant Species.
- Authors: Chen HL, Koprowski JL
- Issue date: 2016
- Genome-wide markers reveal a complex evolutionary history involving divergence and introgression in the Abert's squirrel (Sciurus aberti) species group.
- Authors: Bono JM, Pigage HK, Wettstein PJ, Prosser SA, Pigage JC
- Issue date: 2018 Sep 12
- Parasites of the Abert's squirrel (Sciurus aberti) and red squirrel (Tamiasciurus hudsonicus) of New Mexico.
- Authors: Patrick MJ, Wilson WD
- Issue date: 1995 Apr
- Comparative analysis of microbiota along the length of the gastrointestinal tract of two tree squirrel species (<i>Sciurus aberti</i> and <i>S. niger</i>) living in sympatry.
- Authors: Reed A, Pigage JC, Pigage HK, Glickman C, Bono JM
- Issue date: 2019 Dec