The impact of disease on the survival and population growth rate of the Tasmanian devil
Shelly Lachish, School of Integrative Biology, University of Queensland, St Lucia, Brisbane 4072, Australia. Tel.: +617 3365 2769. Fax: +617 3365 1655. E-mail: email@example.com
- 1We investigated the impact of a recently emerged disease, Devil Facial Tumour Disease (DFTD), on the survival and population growth rate of a population of Tasmanian devils, Sarcophilus harrisii, on the Freycinet Peninsula in eastern Tasmania.
- 2Cormack–Jolly–Seber and multistate mark–recapture models were employed to investigate the impact of DFTD on age- and sex-specific apparent survival and transition rates. Disease impact on population growth rate was investigated using reverse-time mark–recapture models.
- 3The arrival of DFTD triggered an immediate and steady decline in apparent survival rates of adults and subadults, the rate of which was predicted well by the increase in disease prevalence in the population over time.
- 4Transitions from healthy to diseased state increased with disease prevalence suggesting that the force of infection in the population is increasing and that the epidemic is not subsiding.
- 5The arrival of DFTD coincided with a marked, ongoing decline in the population growth rate of the previously stable population, which to date has not been offset by population compensatory responses.