For each of these three habitat types, three replicates were selected, totaling nine sampling locations; the mean riparian length in each cell of type 2 was 2122 m (sd ¼ 465 m), respectively representing 4.3%, 3% and 3% of each sampling unit, and the mean patch area of type 3 was 0.03 km2 (sd ¼ 0.02 km2), composing 1%, 2.5% and 4% of the respective sampling squares.
To account for seasonal variation in population dynamics, two sampling periods were defined: dry season (May to July 2006: high temperatures – 20 C – and low precipitation – < 40 mm) and wet season (November 2006 to February 2007: low temperatures – 13 C – and high precipitation – > 100 mm).