A study of the biology of the wild rabbit in climatically different regions in eastern Australia. I. Patterns of distribution

Abstract

Patterns of distribution of warrens of the wild rabbit Oryctolagus cuniculus (L.) in subalpine, subtropical, and semi-arid areas are described.

At Snowy Plains, a subalpine valley in eastern New South Wales, 866 warrens occurred on an area of 9 square miles. There were 175 warrens per square mile on open country grazed by stock, but only 9 warrens per square mile on adjacent forested country.

At Mitchell, in subtropical southern Queensland, 871 warrens were mapped on 165 square miles. There were 44 warrens per square mile on alluvial deposits of sand along the margins of the Maranoa River and less than one warren per square mile in other habitats.

At Tero Creek in semi-arid north-western New South Wales, 4910 warrens were mapped on 250 square miles. Warren density per square mile was 38 on sand dunes, 19 on stony tablelands, eight on flat desert loams, six on stony pediments, and none on Mitchell grass plains. The preferred habitat was sand.

Mean warren size and distribution of warren sizes varied significantly between sites and habitats. The upper limit to warren size lay between 50 and 60 burrow entrances per warren.

The largest mean warren size occurred in the heavier soils. Mean warren size in sandy soils and in areas where rabbit control was practised was lower.

Patterns of use of warrens also showed significant differences from habitat to habitat. At Snowy Plains the smaller warrens were more inactive and at Mitchell and Tero Creek the larger warrens were more inactive. After a harsh, dry summer at Tero Creek a further significant decrease in activity in the larger warrens was measured.

Predation on nestling rabbits by foxes (Vulpes vulpes L.) was confined almost completely to warrens in sandy soils.

Traverse sight-counts of rabbits above ground at night showed good correlation between warren distribution and rabbit numbers.

Distribution of rabbit populations in relation to warren distribution is discussed.