DOI: 10.5061/dryad.j91d66c
title: Data from: Previous exposure to myxomatosis reduces survival of European rabbits during outbreaks of rabbit haemorrhagic disease

description: 1. Exploiting disease and parasite synergies could increase the efficacy
 of biological control of invasive species. In Australia, two viruses were
 introduced to control European rabbits Oryctolagus cuniculus — myxoma
 virus in 1950, and rabbit haemorrhagic disease virus in 1995. While these
 biological controls caused initial declines of &gt; 95% in affected
 populations, today rabbits remain a problem in many areas, despite
 recurring outbreaks of both diseases. 2. We used eighteen years of
 capture-mark-recapture, dead recovery, and antibody assay data from a
 sentinel population in South Australia to test whether these two diseases
 interact to modify the survival of individual wild rabbits. We compared
 four joint, multi-state, dead-recovery models to test the hypotheses that
 rabbit haemorrhagic disease and myxoma viruses have synergistic (i.e.,
 previous exposure to one virus affects survival during outbreaks of the
 other virus) or additive effects (i.e., previous exposure to one virus
 does not affect survival during outbreaks of the other virus). 3. Rabbit
 haemorrhagic disease outbreaks reduced the survival of individuals with no
 immunity by more than half during the 58-day capture-trip intervals, i.e.,
 from 0.86–0.90 to 0.37–0.48. Myxomatosis outbreaks had a smaller effect,
 reducing survival to 0.74– 0.82; however, myxomatosis outbreaks were more
 prolonged, spanning more than twice as many trips. 4. There was
 considerable information-theoretic support (wAICc = 0.69) for the model in
 which exposure to myxomatosis affected survival during rabbit haemorrhagic
 disease outbreaks. Rabbits previously exposed to myxoma virus had lower
 survival during rabbit haemorrhagic disease outbreaks than rabbits never
 exposed to either virus. There was negligible support for the model in
 which previous exposure to rabbit haemorrhagic disease affected survival
 in myxomatosis outbreaks (wAICc &lt; 0.01). 5. Synthesis and
 applications — Our results indicate that biological control agents can
 have a greater impact than single-pathogen challenge studies might
 suggest. Introducing additional biological control agents might therefore
 increase mortality of rabbits beyond the additive effects of individual
 biological controls. Furthermore, our results show that by understanding
 and exploiting disease synergies, managers could increase the efficacy of
 biological controls for other invasive animals.
description: Rabbit capture
 historiesIndividual capture
 histories by immunity state. "0" = not captured. "N" =
 captured with no immunity. "M" = captured with myxoma virus
 immunity, "R" = captured with rabbit haemorrhagic disease virus
 immunity, "B" = captured with immunity to both rabbit
 haemorrhagic disease virus and myxoma virus. Data collected by
 Biosecurity, South Australia, Department of Primary Industries and
 RegionsCaptureHist.csvTrip CovariatesDetails of each trapping trip, including 'date'; whether the trip was classified as an outbreak of rabbit haemorrhagic disease virus ('RHDV') or myxoma virus ('MV'); intervals between trips ('Ints') = time between one trip and the next, expressed as a ratio of the mean interval between trips (58 days)—the last interval is the time between the last trapping trip and the last dead recovery; trapping effort ('SEffort'), the number of rabbits known to be alive ('KTBA'), estimated population size based on a POPAN model ('POPAN') and associated lower and upper confidence limits ('POPANlcl' and 'POPANucl'); and the number of days since the first trip. Data collected by Biosecurity, South Australia, Department of Primary Industries and Regions.TripCovariates.csvRabbit multi-state, dead recovery modelsMulti-state, dead-recovery models for 18 years of data from Turretfield rabbit population, South Australia. Code by Louise K. Barnett, November 2017 Before running the script you will need to install program MARK from http://www.phidot.org/software/mark/downloads/ Mac and Linux users might find this post helpful: http://www.phidot.org/forum/viewtopic.php?f=21&t=3233&p=10967&hilit=install+RMark#p10967Rabbit_Multistate_DeadRecovery.RPlotting output of multi-state, dead-recovery modelThis script is for plotting the output from the multi-state model script. Run the models and save the output first. Notes- Immunity state / previous exposure categories: N - Immunity to neither virus M - Immunity to myxoma virus only R - Immunity to rabbit haemorrhagic disease virus (RHDV) only B - Immunity to both viruses Age groups: Kittens ≤ 600 g (may have residual maternal immunity to RHD) Adults &gt; 600 g (unlikely to have residual maternal immunity)Rabbit_Multistate_Plotting_Output.R