Conservation status

The decline of the numbat, from its formerly wide distribution at the time of European settlement, is documented. Populations disappeared gradually in an east-west progression, with the expansion in range of introduced foxes. The rate of disappearance accelerated after 1920 when fox populations suddenly exploded. By the 1960s, numbats persisted in only two locations: the Gibson Desert and the southwest of Western Australia. The desert population disappeared first, leaving only two populations to the southwest of Perth by 1985.

An experimental fox control program, initiated in the early 1980s, demonstrated that numbat populations increased when fox populations were suppressed by monthly poison baiting. Fox predation was confirmed as the primary factor in the decline of numbats. Since 1985, there has been a successful recovery program involving translocation of wild individuals, supplemented with the reintroduction of captive-bred numbats to suitable habitat in nature reserves within their former southwestern range. This program, combined with regular fox baiting, has increased wild populations to nine localities. An additional two populations live within large, fenced reserves in South Australia and New South Wales. Rates of increase in translocated populations vary with the levels of predation by (native) raptors, residual levels of foxes and feral cats, dispersal opportunities, and habitat type that are related to food supply. Numbats probably never occurred in high density, even though they were widespread. Populations in which wide dispersal is limited by fencing or surrounding farmland increase more rapidly. In 1994, num-bats were upgraded from an Endangered listing to Vulnerable under IUCN Red List criteria.

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

Get My Free Ebook

Post a comment