Survival estimation in a long-lived monitor lizard: radio-tracking of Varanus mertensi

The population dynamics of varanids (large monitor lizards) is poorly understood. We report on the most detailed study to date of a population of one of Australia’s largest semi-aquatic varanids, Varanus mertensi. Survival of V. mertensi was derived from known-fate modelling of radio-tracked individuals over two and a half years. We demonstrate empirically what intuition suggests; that apparent survival probability in long-lived lizards is high over short sampling periods, with body size and gender influencing these estimates. Survival estimation in long-lived species such as varanids clearly requires longterm studies.