Intraspecific variation in thermoregulation, movements and habitat use by Australian blacksnakes, Pseudechis porphyriacus (Elapidae)

Radiotelemetric studies of snake behavior often have been based on few animals, monitored in single study areas for short periods of time. A four-year study involving three widely separated study areas, in which 44 blacksnakes (Pseudechis porphyriacus) were radio-tracked for an average of 90 days each, revealed unexpectedly high variability in habitat use, activity levels, daily movements and activity ranges. Significant variation was documented among individual snakes, between sexes, among seasons, among years, and among study areas. 

The only characteristic that showed little variation was activity temperature range: active blacksnakes maintained body temperatures of 28 to 31°C over a variety of seasons, study areas, and ambient temperatures. This constancy was apparently achieved by varying behavioral characteristics, especially activity levels and times. 

Activity ranges varied from 0.02 ha to over 40 ha in different snakes, and were larger in males during the mating season. Reproductive activity declined or ceased in two populations during a severe drought. The behavioral flexibility exhibited by P. porphyriacus makes it difficult to describe "typical" behavior for this species, and suggests that many previous radiotelemetric field studies of snakes should be interpreted with caution.