Population density of the Northern Bettong 'Bettongia Tropica' in northeastern Queensland

Abstract

The population density of the northern bettong ('Bettongia tropica'), an endangered potoroid restricted to northeastern Australia, was estimated using minimum known-to-be-alive (MKTBA) and Jolly-Seber estimates derived from mark-recapture data. At Davies Creek in the north of the bettong's current range, bettong population densities were significantly lower in 'Allocasuarina' forest (1.5 bettongs km⁻²) that in 'Eucalyptus' woodland (3.7 - 7.5 bettongs km⁻²). At 'Eucalyptus' woodland sites south and west of Davies Creek, population density was up to twice as great as it was at Davies Creek, while at sites north of Davies Creek, population densities were very low. Capture success was variable, ranging between 5 and 21%. Our data support previous research that suggested 'B. tropica' density on the Lamb Range was correlated with latitude and moisture. Despite the restricted distribution of the northern bettong, our data indicate that populations on the Lamb Range, the species' stronghold, are generally healthy.