Survivorship in two populations of long-tailed bats (Chalinolobus tuberculatus) in New Zealand

The survival of New Zealand long-tailed bats (Chalinolobus tuberculatus) was assessed in two populations, one at Hanging Rock, South Canterbury, South Island, the other at Grand Canyon, central west North Island. Apparent survival of adult females over winter was calculated using mark-recapture analysis over 5 years. Annual survival varied from 0.75 (95% CI = 0.54-0.88) to 0.89 (0.48-0.99) at Hanging Rock and 0.55 (0.39-0.71) to 0.91 (0.44-0.99) at Grand Canyon. Estimates of apparent survival were consistent with those from a longer-term study of long-tailed bats in the Eglinton Valley, Fiordland, South Island. The intrinsic rate of increase (lambda) at Hanging Rock was 0.90 (95% CI = 0.4-0.99), indicating that this population may be declining more rapidly than that in the Eglinton Valley. At Grand Canyon, population estimates fluctuated annually, with no clear trend. Predation by introduced mammals and loss of habitat likely caused declines at Hanging Rock. Management of these factors is essential to avoid the local extinction of the species. Long-term monitoring (greater than 5 years) is required to determine more robust population trends for these long-tailed bat populations.