effort: the density from this study was compared, therefore, with the number of birds per square kilometer given by Robson
et al. (1991).
3.3. Investigating habitat use and effect of human activity
We measured habitat variables both at a small scale, directly along each transect, as well as at large scale, using Google
Earth 7.1.2. The small scale variables recorded were: (1) ground vegetation coverage (absent, low and high) every 100 m
along each transect; and (2) presence of domesticated cattle (present or absent) at every 100 m on transect. Large scale
variables recorded were: (3) distance to permanent running or standing water, determined using Google Earth direct
observation, discussion with rangers and consulting maps; and (4) distance to permanent human settlement, which was
determined by observation, discussion with rangers and map consultation. All habitat variables and presence of human
activities were treated as predictor variables.