Activity patterns and habitat preferences of translocated and resident tiger snakes (Notechis scutatus) in a suburban landscape

Abstract

Translocation of snakes is a common practice for managing human–snake conflict in many parts of Australia. The impact of this management on individual snakes is not known. Differences between translocated and non-translocated snakes in terms of their activity patterns and habitat use are likely to indicate an impact on individual snakes from this procedure. We investigated these issues in a suburban parkland close to Melbourne for one of the most familiar of these snakes, the tiger snake (Notechis scutatus). This parkland is frequently used by licenced snake controllers to release snakes that have been removed from nearby private properties at the owner’s request. We used two techniques to assess activity patterns and habitat preferences of resident and translocated snakes: direct observations of tiger snakes that were resident in the park, and radiotelemetry to compare a subset of resident snakes with translocated conspecifics. The size of our transmitters dictated that we only use telemetry for large snakes (≥750 mm snout–vent length), even though the resident population consisted mainly of intermediate-sized females (560–760 mm snout–vent length). Non-telemetred resident snakes were readily observed during spring, but rarely observed in summer and early autumn. Translocated snakes travelled greater distances than resident telemetred snakes, although there was no difference in the frequency of movements. For both groups the degree of cloud cover and maximum daily temperature had a significant influence on daily activity, with snakes being more likely to be active on relatively cool, sunny days. Relative humidity, wind speed and rainfall did not exert a significant influence on activity. Snakes exhibited bimodal peaks in daily activity, avoiding the hottest part of the day. Both resident and translocated snakes showed a preference for grassy woodlands associated with hills, but avoided escarpment woodlands and open plains. Floodplain riparian woodland was avoided by resident snakes, but used in proportion to its availability by translocated snakes. Because translocated snakes released at the study site moved larger distances and showed different habitat preferences to resident snakes we conclude that this practice influences individual snakes. Until the implications of translocation for both snakes and humans are fully understood, we recommend caution in the use of this management practice.