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. 2011 Dec 20;6(12):e28939. doi: 10.1371/journal.pone.0028939

Table 1. Definitions and labels for covariates tested in resource selection models.

Covariate Label Definition
Park park discrete variable; sample found inside Emas National Park
Distance to park parkDist distance, in meters, to the National Park
Natural water spring spring discrete variable; site is within 500 m of a natural water spring
Rivers river distance, in meters, to the nearest permanent river-like waterway
Any road road within 30 meters of any road, paved or unpaved
Distance to road roadDist distance, in kilometers, to any road, paved or unpaved
Distance to main road MainroadDist distance, in kilometers, to any paved or busy road
Riverine forest forest discrete variable; high, tall-canopy forest habitat determined by year-round high soil moisture.
Woodland cerrado cerrado discrete variable; closed woodland with crown cover of 50% to 90%, made up of trees, often 8–12 m or even taller, casting a considerable shade so that the ground layer is much reduced
Open cerrado open cerrado discrete variable; vegetation is dominated (at least visually) by trees and shrubs often 3–8 m tall and giving more than 30% crown cover but with still a fair amount of herbaceous vegetation
Open grassland grassland discrete variable; dry grassland without shrubs or trees or with a scattering of shrubs and small trees
Inundated marshland marsh discrete variable; seasonally waterlogged grasslands
Cattle pasture pasture discrete variable; pasture area used for grazing livestock, predominantly cattle
Agriculture agriculture discrete variable; agricultural land used for growing soy, corn, millet, cotton, or sugar cane
Unknown unknown habitat of unknown type; classification could not be determined due to cloud cover over satellite image
Distance to agriculture agDist distance, in kilometers, to any agricultural field
Distance to closed closedDist distance, in kilometers, to either forest or cerrado
Distance to edge edgeDist distance, in kilometers, to any habitat edge
Closed-canopy closed proportion of closed-canopy habitat (cerrado, forest) within 1.4 km2 of a sample
Open-canopy open proportion of non-agriculture, open-canopy habitat (grassland, open cerrado, ranchland) within 1.4 km2 of a sample
Natural habitat natural proportion of natural habitat (forest, cerrado, open cerrado, grassland, marsh) within 1.4 km2 of sample
Non-cropland nocrop proportion of non-cropland habitat within 1 km2 of a sample
Elevation elevation elevation, in meters, as analyzed from a Digital Elevation Model
Habitat heterogeneity heterogeneous number of different vegetation types within small, medium, and large window around sample