Reintroduction of the greater stick-nest rat (Leporillus conditor) to Heirisson Prong, Shark Bay: an unsuccessful attempt to establish a mainland population

Abstract

Greater stick-nest rats were reintroduced to Heirisson Prong from Salutation Island at Shark Bay to establish the first mainland population in Western Australia in over 60 years. Forty-eight animals were transferred over two years from August 1999 to a 17-ha enclosure of natural vegetation that excluded foxes and feral cats. This refuge from introduced predators was located within a larger 1200-ha area where these predators were controlled. Stick-nest rats were able to disperse from the refuge to the wider area. The reintroduction was unsuccessful, with the last record in August 2007. Rats were reproducing in most years, yet only 28 recruits were detected over the reintroduction. Mean condition of rats was better at the reintroduction site relative to the source site. Survivorship of successive translocation cohorts was poorer than that of their predecessors, and survivorship of recruits was poorer than that of translocated animals. The most likely explanations for the decline are predation from monitors and small birds of prey within the refuge, and from monitors, small birds of prey and feral cats outside the refuge. An irruption of other rodents immediately before and coinciding with the reintroduction and building rabbit numbers likely contributed to elevated levels of predation from predators.

Morphological variation in skull shape and size across extinct and extant populations of the greater stick-nest rat (

“…Leporillus conditor has been used in several translocation programs in recent decades, with the Franklin Islands population acting as the primary source (Pedler and Copley 1993;Short et al 2018Short et al , 2019White et al 2018). Our analyses show that these individuals are likely larger than their extinct counterparts in most mainland locations, with the exception of central Australia.…”

Threatened stick-nest rats preferentially eat invasive boxthorn rather than native vegetation on Australia’s Reevesby Island

“…However, L. conditor may favour L. ferocissimum bushes because the large thorns provide more protection from predators than the plants that are native to the animal's offshore island refuges. A preference for thorns and spines by L. conditor is supported by Short et al (2018) who found that very prickly Acacia tetragonophylla bushes were the primary nesting shrubs used by L. conditor at Heirisson Prong (Introduced in 1999, last sighting in 2007), in Shark Bay, Western Australia.…”

“…Successful translocations occurred in novel ecosystems on St Peter Island and Reevesby Island in South Australia, and Salutation Island in Western Australia, which are free from feral predators such as cats and foxes (Copley 1999a). The success of this recovery plan resulted in the down-listing of this species' conservation status from 'Endangered' in 1996to 'Vulnerable' in 2008to 'Near Threatened' in 2016 the IUCN Red List of Threatened Species (Short et al 2018).…”

Envisioning the future with ‘compassionate conservation’: An ominous projection for native wildlife and biodiversity

“…Despite numerous attempts, none of these species have been successfully established into their former ranges without the protection of predator-free fenced areas or islands (Bannister et al 2016;Moseby et al 2018). While there might be hope for some (West et al 2018), it seems that most of these vulnerable species do not have the life histories or behavioural strategies that will allow them to ever coexist with introduced predators (Short et al 2018). For these animals, conservation fences coupled with the eradication of introduced predators are often the only thing standing between them and extinction in the wild (Fig.…”