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Investigating individual‐based habitat settlement decisions is a central theme in ecology, yet studies that quantify density‐dependent habitat selection or tie fitness to resource selection decisions remain rare. We quantified habitat selection in golden‐mantled ground squirrels (Callospermophilus lateralis) across two spatial scales (home‐range placement, and occurrence within the home range) by using 11 consecutive years of data on individual space use, and we used resource selection functions and multilevel modeling to address how habitat preferences may be influenced by density or linked to fitness outcomes. Squirrels preferred dry meadow over other habitat types (wet meadow, aspen, spruce, and willow) at both spatial scales. Squirrels were more likely to use dry meadow that contained shorter vegetation and vision‐enhancing prominences such as rocks (“perches”). The use of dry meadow at each scale was not influenced by changes in density. The use of dry meadow did not lead to increased litter size, pre‐hibernation mass, or survival. However, squirrels that experienced a greater number of perches or lower local densities had higher survival rates. Our results suggest that a lack of visual obstruction, probably facilitating detection of predators, drives habitat selection in this system. Surprisingly, squirrels maintained their preference for dry meadow as density increased, and they experienced reduced survival as a result. This work furthers our understanding about the causes and consequences of changes in habitat use, informing wildlife management and conservation.

30 31 32 3 | P a g e ABSTRACT (268 WORDS) 33 Understanding the nature of faunal assembly and community structure remains central to 34 ecology. Research in North American deserts and some tropical forests provides evidence of 35 energetic compensation and zero-sum dynamics, suggesting that species in some natural 36 assemblages may be replaced with limited impact on ecosystem function. Experimental removal 37 of a dominant small mammal (degu, Octodon degus) from replicate plots in semi-arid coastal 38 thorn-scrub habitat in north-central Chile revealed no evidence for energetic or functional 39 compensation; energetic consumption remained significantly lower on degu exclusions relative 40 to control plots after 17 years of exclusion. This occurs in spite of the fact that the geographic 41 species pools for South American sites generally are similar in size to those of most North 42 American sites (mean and mediannumber of species, 16.3 and 21.5 vs 21.0 and 20, respectively). 43 A macroecological assessment of energetically equivalent species at 394 arid sites in North 44 America, the Gobi Desert, and South America indicates that the number of potentially equivalent 45 species is lower (Gobi) or similar to (South America) than that found in North America, but 46 when segregated by trophic groups these faunas differ markedly. North American sites include 47 large numbers of granivorous species whereas South American sites are dominated by 48 omnivores. The more general trophic strategy in the latter sites would be expected to facilitate 49 compensatory responses within local faunas, suggesting either that our site is anomalous or that 50 other factors are governing local dynamics. Further research is needed to understand the 51 generality of compensatory dynamics within natural systems, as this mechanism has direct 52 relevance to discussions on ecological resilience in the face of ongoing environmental change.53 54 4 | P a g e