Data from: The potential importance of unburned islands as refugia for the persistence of wildlife species in fire-prone ecosystems

The persistence of wildlife species in fire-prone ecosystems is under
increasing pressure from global change, including alterations in fire
regimes caused by climate change. However, unburned islands might act to
mitigate negative effects of fire on wildlife populations by providing
habitat in which species can survive and recolonize burned areas.
Nevertheless, the characteristics of unburned islands and their role as
potential refugia for the post-fire population dynamics of wildlife
species remain poorly understood. We used a newly developed unburned
island database of the north-western United States from 1984–2014 to
assess the post-fire response of the greater sage-grouse (Centrocercus
urophasianus), a large gallinaceous bird inhabiting the sagebrush
ecosystems of North America, in which wildfires are common. Specifically,
we tested whether pre- and post-fire male attendance trends at mating
locations (leks) differed between burned and unburned areas, and to what
extent post-fire habitat composition at multiple scales could explain such
trends. Using time-series of male counts at leks together with
spatially-explicit fire history information, we modelled whether male
attendance was negatively affected by fire events. Results revealed that
burned leks often exhibit sustained decline in male attendance, whereas
leks within unburned islands or >1.5 km away from fire perimeters
tend to show stable or increasing trends. Analyses of post-fire habitat
composition further revealed that sagebrush vegetation height within 0.8
km around leks, as well elevation within 0.8km, 6.4km, and 18 km around
leks, had a positive effect on male attendance trends. Moreover, the
proportion of the landscape with cheatgrass (Bromus tectorum) cover
>8% had negative effects on male attendance trends within 0.8 km,
6.4 km, and 18 km of leks, respectively. Our results indicate that
maintaining areas of unburned vegetation within and outside fire
perimeters may be crucial for sustaining sage-grouse populations following
wildfire, and requires more attention in wildlife management.