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Fitness implications of seasonal climate variation in Columbian ground squirrels

Dobson, F. Stephen and Lane, Jeffrey E. and Low, Matthew and Murie, Jan O. (2016). Fitness implications of seasonal climate variation in Columbian ground squirrels. Ecology and evolution. 6 :16 , 5614-5622
[Research article]

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Available under License Creative Commons Attribution.


Official URL: http://dx.doi.org/10.1002/ece3.2279


The influence of climate change on the fitness of wild populations is often studied in the context of the spring onset of the reproductive season. This focus is relevant for climate influences on reproductive success, but neglects other fitness- relevant periods (e.g., autumn preparation for overwintering). We examined variation in climate variables (temperature, rainfall, snowfall, and snowpack) across the full annual cycle of Columbian ground squirrels (Urocitellus columbianus) for 21 years. We investigated seasonal climate variables that were associated with fitness variables, climate variables that exhibited directional changes across the study period, and finally observed declines in fitness (-0.03 units/year; total decline = 37%) that were associated with directional changes in climate variables. Annual fitness of adult female ground squirrels was positively associated with spring temperature (r = 0.69) and early summer rainfall (r = 0.56) and negatively associated with spring snow conditions (r = -0.44 to -0.66). Across the 21 years, spring snowmelt has become significantly delayed (r = 0.48) and summer rainfall became significantly reduced (r = -0.53). Using a standardized partial regression model, we found that directional changes in the timing of spring snowmelt and early summer rainfall (i.e., progressively drier summers) had moderate influences on annual fitness, with the latter statistically significant (rho = -0.314 and 0.437, respectively). The summer period corresponds to prehibernation fattening of young and adult ground squirrels. Had we focused on a single point in time (viz. the onset of the breeding season), we would have underestimated the influences of climate change on our population. Rather, we obtained a comprehensive understanding of the influences of climate change on individual fitness by investigating the full lifecycle.

Authors/Creators:Dobson, F. Stephen and Lane, Jeffrey E. and Low, Matthew and Murie, Jan O.
Title:Fitness implications of seasonal climate variation in Columbian ground squirrels
Series Name/Journal:Ecology and evolution
Year of publishing :2016
Page range:5614-5622
Number of Pages:9
Publisher:John Wiley & Sons Ltd.
Publication Type:Research article
Article category:Scientific peer reviewed
Version:Published version
Copyright:Creative Commons: Attribution 4.0
Full Text Status:Public
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Ecology
Keywords:climate, fitness, ground squirrels, seasons, sliding windows
Permanent URL:
Additional ID:
Type of IDID
Web of Science (WoS)000381578400005
ID Code:13975
Faculty:NJ - Fakulteten för naturresurser och jordbruksvetenskap
Department:(NL, NJ) > Dept. of Ecology
(S) > Dept. of Ecology
Deposited By: SLUpub Connector
Deposited On:19 Jan 2017 12:26
Metadata Last Modified:09 Sep 2020 14:17

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