Notes on the spatial ecology and habitat use of three sympatric Nerodia (Serpentes: Colubridae)

The spatial ecology and habitat use of three sympatric water snakes (colubridae: Nerodia) were studied in a large, man made reservoir, in central Texas, USA. Nerodia harteri paucimaculata appeared to be more sedentary and specialized in its habitat requirements than N. erythrogaster transversa  or N. rhombifer rhombifer, and the only long movements undertaken were due to habitat loss (five snakes morved 0.8km). Nerodia r. rhombifer were most vagile; one individual moved 5.8km over 12 days, while the longest recorded movement for a N. e. transversa was 0.97km over an 11 month recapture interval. There was no overall significant difference in the mean distance moved per day: Nerodia r. rhombifer moved 86.21m N. e. transversa moved 64.35 m/day, while N. h. paucimaculata moved 30.9 m/day. Preliminary data (habitat, body size and unpublished dietary differences) hint at resource partitioning, which may be a carry over from the river system in which they are thought to have evolved.