title: Advancing the match-mismatch framework for large herbivores in the Arctic: Evaluating the evidence for a trophic mismatch in caribou.
abstract: Climate-induced shifts in plant phenology may adversely affect animals that cannot or do not shift the timing of their reproductive cycle. The realized effect of potential trophic "mismatches" between a consumer and its food varies with the degree to which species rely on dietary income and stored capital. Large Arctic herbivores rely heavily on maternal capital to reproduce and give birth near the onset of the growing season but are they vulnerable to trophic mismatch? We evaluated the long-term changes in the temperatures and characteristics of the growing seasons (1970-2013), and compared growing conditions and dynamics of forage quality for caribou at peak parturition, peak lactation, and peak forage biomass, and plant senescence between two distinct time periods over 36 years (1977 and 2011-13). Despite advanced thaw dates (7-12 days earlier), increased growing season lengths (15-21 days longer), and consistent parturition dates, we found no decline in forage quality and therefore no evidence within this dataset for a trophic mismatch at peak parturition or peak lactation from 1977 to 2011-13. In Arctic ungulates that use stored capital for reproduction, reproductive demands are largely met by body stores deposited in the previous summer and autumn, which reduces potential adverse effects of any mismatch between food availability and timing of parturition. Climate-induced effects on forages growing in the summer and autumn ranges, however, do correspond with the demands of female caribou and their offspring to gain mass for the next reproductive cycle and winter. Therefore, we suggest the window of time to examine the match-mismatch framework in Arctic ungulates is not at parturition but in late summer-autumn, where the multiplier effects of small changes in forage quality are amplified by forage abundance, peak forage intake, and resultant mass gains in mother-offspring pairs.
authors.affiliation: U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, United States of America.
authors.forename: David
authors.identifier: http://orcid.org/0000-0003-1087-1937
authors.initials: D
authors.lastname: Gustine
authors.affiliation: Wildlife and Fisheries Science, Texas A&M University, College Station, Texas, United States of America.
authors.forename: Perry
authors.initials: P
authors.lastname: Barboza
authors.affiliation: U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, United States of America.
authors.forename: Layne
authors.initials: L
authors.lastname: Adams
authors.affiliation: U.S. Geological Survey, Alaska Cooperative Fish and Wildlife Research Unit, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America.
authors.forename: Brad
authors.initials: B
authors.lastname: Griffith
authors.affiliation: Alaska Department of Fish and Game, Fairbanks, Alaska, United States of America.
authors.forename: Raymond
authors.initials: R
authors.lastname: Cameron
authors.affiliation: Alaska Department of Fish and Game, Fairbanks, Alaska, United States of America.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Whitten
mesh_terms: D000818:Animals; D001070:Appetitive Behavior; D001110:Arctic Regions; D018533:Biomass; D057231:Climate Change; D005260:Female; D060434:Herbivory; D007774:Lactation; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism; D036801:Parturition; D063245:Plant Development; D012053:Reindeer / Q000502:physiology*; D012621:Seasons; D013696:Temperature
chemical_list: D009584:Nitrogen