An improved technique for indexing abundance of Himalayan thar

Current monitoring of Himalayan thar (Hemitragus jemlahicus) populations in New Zealand involves a technique based on repeated observations by different, experienced observers. The method gives no measure of error and hence does nor allow for statistical comparison of repeated surveys. We outline a faster and cheaper technique that enables statistical comparison between surveys based on mark-recapture theory.

Predator indices from artificial nests and tracking tunnels: do they tell the same story?

Artificial nests and tracking tunnels are alternative predator encounter devices that can be used to predict predation risk to native species. Tracking tunnels are used ubiquitously in New Zealand, whereas artificial nests are used extensively overseas. To assess whether these devices give similar information about predation risk, we compared tracking tunnel and artificial nest data from 16 native forest fragments in the central North Island over two summers.

Sampling skinks and geckos in artificial cover objects in a dry mixed grassland-shrubland with mammalian predator control

Introduced mammalian predators threaten populations of endemic New Zealand lizards but their effects on lizard populations have not been quantified on the mainland. We trialled the use of artificial cover objects (ACOs) for sampling small terrestrial lizards (the skinks Oligosoma maccanni, O. nigriplantare polychroma and O. inconspicuum, and gecko Hoplodactylus maculatus) in three experimental mammal-management treatments: a mammal-proof fence, two sites in an intensive mammal-removal area, and an experimental control site with no mammal removal.