New Zealand Journal of Zoology 22: 291-304. 1995.
Abstract
We radio-tracked five male and four female rats for 6 nights in
primary forest at Rotoehu, North Island, New Zealand. From trapping we
estimated rat density at the study site to be 6.2 rats/ha. Radio-tracking
revealed mean (±SE) restricted polygon home ranges to be three times
greater in males (1.1 ± 0.29 ha) than females (0.3 ± 0.04 ha). Male ranges
overlapped considerably, whereas those of females were largely exclusive.
The ranges of males encompassed several female ranges. Four radio-collared
rats were retrapped and administered a lethal dose of the anticoagulent
poison brodifacoum. During the 3-5 nights after poisoning but before
death, we detected no significant change in home range area or
utilisation, arboreality, or movements. Further research is required to
determine if rats prey on other fauna while fatally intoxicated or
cause secondary poisoning after being eaten by other predator species.