Landscape, koalas and people: A historical account of koala populations and their environment in South Gippsland

Abstract

We present an ecological history of the koala (Phascolarctos cinereus) population and its environment in South Gippsland, Victoria, both pre-and post-European settlement. We consider the role that the region's history may have had on the genetic structure of the current koala population in South Gippsland, which is the only known koala population in Victoria that does not originate from animals reintroduced as part of the Victorian translocation program. Following European colonisation of Australia, a range of anthropogenic factors, including hunting for the fur trade, resulted in widespread population declines for the koala. In Victoria, the situation was extreme. Currently, many koala populations in Victoria are derived from only a few individuals which existed less than 120 years ago. These populations therefore have comparatively low genetic diversity, a factor that plays a key role in long term population viability. In Victoria, the koala is not listed as a threatened species. Despite the low genetic diversity of most populations, the species is widely distributed across the state, and relatively common. Indeed, some populations are considered overabundant. However, many koala populations are not abundant, and population data are lacking for most. The South Gippsland koala population is of high conservation significance as it has greater genetic diversity compared to other Victorian populations, though there is little additional data to inform its conservation. An improved understanding of genetic diversity and gene flow between populations across the koala's range is required to guide the conservation of genetic diversity in this species. Monitoring population size, health and genetic relationships both within and between koala populations will enable better conservation outcomes.

Future‐proofing the koala: Synergising genomic and environmental data for effective species management

“…This strongly suggests that koala colonies endemic to northern Sydney were supplemented with captive‐source individuals, possibly in an attempt to reverse the rapid population declines of the mid‐late 20th century (Smith & Smith, 1990). The full range of koala translocations across eastern Australia is not well recorded, with evidence for undocumented translocations by organisations such as the Acclimatisation Society of Victoria (ASV) in the late 1800s and, more recently, by the government, wildlife carers, and other institutions (Fowler et al, 2000; Wedrowicz et al, 2017). This further complicates the identification of historic and contemporary biogeographic barriers for koalas, as undocumented translocations could have allowed certain genotypes to spread into areas where they would otherwise not be expected to occur.…”

Phylogenetic and geographical analysis of a retrovirus during the early stages of endogenous adaptation and exogenous spread in a new host

“…Koala samples were collected from animals across their natural range, including SEQLD, NENSW, southeast New South Wales (SENSW) and VIC. It is well documented that koalas in SA have been translocated to this state from VIC and QLD koala populations (Lindsay, 1950;Martin, 1989;Wedrowicz et al, 2017). As it would be difficult to deconvolute KoRV evolution and spread in SA koalas with this recent human intervention, koalas from this state were deliberately excluded from this study.…”

When an iconic native animal is overabundant: The koala in southern Australia

“…The relative abundance of southern koalas long hindered recognition of northern koalas as vulnerable under Commonwealth legislation (Shumway et al, ). Even within the southern states, there is little or no recognition of pervasive threats and declining populations in some areas; and limited resources are allocated to the monitoring or management of declining populations or to conserving the genetically diverse population in South Gippsland (Wedrowicz et al, ; Wedrowicz, Mosse, Wright, & Hogan, ).…”

“…Southern koalas have long been the subject of intensive management (Menkhorst, ). In Victoria, koalas from island populations established in the late 19th and early 20th century were used to reestablish populations on the mainland where hunting had brought about their near‐extinction, and to establish koalas in areas outside their historic range (e.g., Kangaroo Island, South Australia) (Menkhorst, ; Wedrowicz, Wright, Schlagloth, Santamaria, & Cahir, ). Between 1923 and 2006, over 12,000 koalas were translocated from French and Phillip Islands to the mainland (Menkhorst, ).…”