Serological data from wild rabbits support the hypothesis that a second RHDV-like virus was already present in Australia before rabbit haemorrhagic disease virus (RHDV) was introduced as a biological control agent. This putative virus apparently persists in most wild rabbit populations in the presence of RHDV, and antibodies raised against it appear to protect some rabbits from fatal rabbit haemorrhagic disease (RHD). High titres of these antibodies are most commonly found in rabbits from high rainfall areas; this may explain why the initial mortality from RHD declined as the disease spread from dry areas into wetter regions and why it remains less effective as a biological control in wetter regions today. The implications for further advances in rabbit control are discussed, including the need to isolate this putative RHDV-like virus and develop specific ELISA tests to facilitate its detection in the field.

Context. Scat genotyping has not been routinely used to measure fox (Vulpes vulpes) abundance and our study sought to provide a benchmark for further technique development and assessment of field methods.Aims. This study sought to provide a comparative assessment of some common methods used to determine fox density and contrast their success with scat DNA genotyping.Methods. DNA recovered from fox scats was used to genotype individual red foxes and determine their abundance at four transects. Population indices were also developed from bait take, scat counts and sand plot tracks using index-manipulationindex (IMI) procedures on the same transects. Known samples of foxes were taken from two treatment transects using cyanide delivered in the M-44 ejector to manipulate the population and to recover foxes at the end of the trial.Key results. Replicated counts on a 41-km-spotlight transect at the field site before and after the population manipulation had low variance and good correlation (r 2 = 0.79, P < 0.01). Scat genotypes revealed 54 foxes in eight days and, when combined with biopsy DNA from recovered foxes, a minimum known to be alive (KTBA) density of between 1.6 and 5 foxes km -1 was calculated for the transects. Overall, 15/30 (50%) of all recovered foxes had not been detected by scat genotyping, 23/53 (49%) of KTBA genotypes were detected only once and 5/54 (9.5%) of foxes were found to have moved between two transects.Conclusions. At transects where population manipulation occurred, surviving individuals contributed significantly more scats than at the control transects and some individuals were detected at bait stations at a much greater frequency. This strongly suggested that they had contributed disproportionately to some IMI density estimates that were probably influenced by a change in the activity of some individuals rather than changes in population density alone. At one transect, eight foxes were confirmed to be present by spotlight surveys and were detected by scat and KTBA genotypes, yet were undetected by scat, bait station and sand plot indices.Implications. Scat and other DNA-based survey techniques provide a great deal of information about the identification and movement of individuals and if DNA sampling methods can be made more efficient they have the potential to provide accurate abundance estimates that are independent of the control technique.

Context. It is important to examine the long-term effectiveness of rabbit management programmes based on warren destruction using modern warren ripping machinery, at a time when the continuing impacts of both myxomatosis and rabbit haemorrhagic disease (RHD) may have reduced the capacity of rabbit populations to recover. Aims. To determine the long-term effectiveness of coordinated warren ripping programmes in reducing rabbit densities and maintaining these low densities. Methods. Commencing in 1998, 14 sites with coordinated warren ripping programmes and three sites without rabbit control were monitored within Victoria. Spotlight counts of rabbit numbers recorded before the spread of RHD and warren ripping were compared with numbers recorded from 2005 to 2008. The efficacy of coordinated warren ripping programmes was assessed in relation to the machinery used, the manner in which the warrens were ripped, the characteristics of the ripped areas and the impact of follow-up control. Key results. Warren ripping programmes were very successful in reducing rabbit numbers for up to 10 years, whereas rabbit populations that were not managed returned to pre-RHD densities. The most effective warren ripping programmes, which reduced populations to 97% of the pre-RHD densities and maintained them at this level, used heavy, powerful ripping machinery to rip all warrens within 12 months. There was no evidence that the relationship between rabbit population decline and warren ripping was affected by the characteristics of the ripped areas or the follow-up control effort. Conclusions. Following the spread of RHD in areas where warren ripping is practicable, well-managed ripping programmes provide an immediate solution for achieving and sustaining low rabbit populations. Implications. The efficacy of RHD in regulating rabbit populations has diminished. The improvement of existing or the development of new biological control agents could take decades. In contrast, coordinated warren ripping programmes provide more predictable long-term reductions in rabbit populations.

Summary1. The effect of rabbit population density on transmission of rabbit haemorrhagic disease virus (RHDV) is a critical aspect of disease ecology for rabbit control and rabbit conservation. We examined the interaction between rabbit control and spread of RHDV and a non-pathogenic calicivirus (bCV) in Australian wild rabbit populations, and reviewed existing recommendations for control in this context. 2. Rabbits were sampled at eight pairs of sites; from rabbit populations where densities had been reduced by conventional control and from matching uncontrolled populations. Sites chosen ranged from hot, arid areas where RHDV had greatly reduced rabbit numbers to cooler, higher-rainfall areas where rabbits remained more abundant. Virus activity was implied from antibody profiles in sera of surviving rabbits. 3. Reducing population density by conventional control had a similar effect on disease transmission despite a seven-fold difference in initial density. Populations reduced by 70% or more had lower RHDV antibody prevalence in juvenile rabbits but not in adult rabbits, indicating that reducing rabbit density slowed but did not stop RHDV transmission. We found no interactions between rabbit control, RHDV and bCV that could be exploited to improve rabbit management. 4. Synthesis and applications. Delayed RHDV infection in rabbit control sites is likely to be offset by higher mortality in older rabbits, so that conventional rabbit control does not reduce the impact of RHDV on rabbit populations. Only minor changes to delay the timing of summer rabbit control programmes in cooler areas of Australia are necessary to take best advantage of RHDV-induced reduction in rabbit numbers. For conservation management of rabbits in Europe, these findings indicate that RHDV may continue to have a severe impact on rabbit populations that have been reduced to low population density, but also raise the possibility that bCVs might be introduced to rabbit populations to aid their recovery.

With ongoing introductions into Australia since the 1700s, the European rabbit (Oryctolagus cuniculus) has become one of the most widely distributed and abundant vertebrate pests, adversely impacting Australia's biodiversity and agroeconomy. To understand the population and range dynamics of the species and its impacts better, occurrence and abundance data have been collected by researchers and citizens from sites covering a broad spectrum of climatic and environmental conditions in Australia. The lack of a common and accessible repository for these data has, however, limited their use in determining important spatiotemporal drivers of the structure and dynamics of the geographical range of rabbits in Australia. To meet this need, we created the Australian National Rabbit Database, which combines more than 50 yr of historical and contemporary survey data collected from throughout the range of the species in Australia. The survey data, obtained from a suite of complementary monitoring methods, were combined with high‐resolution weather, climate, and environmental information, and an assessment of data quality. The database provides records of rabbit occurrence (689,265 records) and abundance (51,241 records, >120 distinct sites) suitable for identifying the spatiotemporal drivers of the rabbit's distribution and for determining spatial patterns of variation in its key life‐history traits, including maximum rates of population growth. Because all data are georeferenced and date stamped, they can be coupled with information from other databases and spatial layers to explore the potential effects of rabbit occurrence and abundance on Australia's native wildlife and agricultural production. The Australian National Rabbit Database is an important tool for understanding and managing the European rabbit in its invasive range and its effects on native biodiversity and agricultural production. It also provides a valuable resource for addressing questions related to the biology, success, and impacts of invasive species more generally. No copyright or proprietary restrictions are associated with the use of this data set other than citation of this Data Paper.