Study plots
Out of the 49 independent grassland locations with active prairie dog
colonies, three locations were selected for each grassland type,
resulting in a total of 12 grassland locations. Locations were selected
based on accessibility and spatial distance. We selected locations with
at least 5 km separation, due to prairie dogs average dispersal distance
(Garret and Franklin, 1988). Preference was also given to locations
where community-based conservation projects had already been implemented
or are currently implemented by local organizations to ensure
feasibility of the study results for future conservation efforts within
GPCA El Tokio. Cattle activity was observed at all selected locations
and has been documented by Estrada-Castillón et al. (2010), but no
detailed information was available on the number of cattle or stocking
densities. In each of the 12 grassland locations, we selected two sites
differing in prairie dog disturbance (WP = with active prairie dogs
burrow section, WOP = without active prairie dog burrows section) and
marked a randomly selected 30x30 m quadrat for each condition,
considered as site (n=24). All sites were representative of the
vegetation and placed congruent to the cardinal directions. WP and WOP
sites within the same location had a minimum distance of 1 km, except
for sites in one of the mountain locations, where WP and WOP sites were
only 300 m apart due to lack of availability of alternative study areas.
Within each site, six random 5x5 m plots, aligned along their edges
following the cardinal directions, were delimited as well. Randomization
was performed by blindly throwing six 60 cm diameter rings to fall at
random. The burrow closest to the rings was selected as the center of
the WP plots. Whenever the selected site had less than 6 burrows within
it, all burrows were selected for plots and the leftover plots were
randomly selected and assigned as non-burrow plots. To account for
seasonal effects, the 5x5 m plots were further halved to create two
5x2.5 m subplots, which from here on are considered as seasonal
subplots. Seasonal subplots were assigned as eastern (rainy season) and
western (dry season; Figure 1b) halves. Data collection took place
during August-September 2019 (rainy season) and during December
2019-January 2020 (dry season).