Rabbits have a number of parasites that are specific to them and that can impact rabbit survival through direct mortality, or by impacting on physical condition or potentially exacerbating the impacts of other rabbit diseases such as myxomatosis or rabbit haemorrhagic disease.
This project investigated the potential to use Eimeria as a new rabbit biocontrol agent. Eimeria are intestinal parasites and the two most pathogenic species were previously only recorded in a few isolated populations of rabbits. Eimeria have been shown to reduce the health of rabbits and in some cases to kill them.
This project was part of a national rabbit biocontrol pipeline strategy and a concomitant national program to detect new biocontrols.
The national program used an expert panel and a discussion paper to review recommendations from researchers, literature and a global watch network. Potential biocontrols, including Eimeria, were prioritised for further research based on their specificity for European rabbits, potential impact, ease of importation and humaneness.
This project aimed to determine the distribution and prevalence of Eimeria species across Australia to inform decisions about whether they may show potential as a rabbit biocontrol if not widely distributed.
The project sampled the intestines and faeces of wild rabbits from 26 locations across Australia. The most pathogenic Eimeria species, E. flavescens and E. intestinalis, were more widely distributed than had been recorded previously, being found at 90 and 50 per cent of locations, respectively.
The fact that E. intestinalis was not recorded at half of the locations raises the potential that it could impact the health and survival of naïve rabbits.
However, before more detailed work on E. intestinalis is undertaken, the apparent lack of E. intestinalis at some sites should be confirmed by sampling some of these sites repeatedly, across several different seasons . This additional sampling would determine whether apparent gaps in the distribution of E. intestinalis are a result of the sampling approach employed at most sites (most sites were sampled at a single time of the year) or an accurate reflection of its distribution.
This project is funded through an external research grant separate to the Centre for Invasive Species Solutions current innovation portfolio