ield methods for rodent studies in Asia and the Indo-Pacifi c Ken P. Aplin, Peter R. Brown, Jens Jacob, Charles J. Krebs & Grant R. Singleton Australian Centre for International Agricultural Research Canberra, Austalia e Australian Centre for International Agricultural Research (ACIAR) was established in June by an Act of the Australian Parliament. Its mandate is to help identify agricultural problems in developing countries and to commission collaborative research between Australian and developing country researchers in fields where Australia has a special research competence. Where trade names are used, this constitutes neither endorsement of nor discrimination against any product by the Centre. ACIAR MONOGRAPH SERIES is peer-reviewed series contains results of original research supported by ACIAR, or deemed relevant to ACIAR’s research objectives. e series is distributed internationally, with an emphasis on developing countries. © Australian Centre for International Agricultural Research Aplin, K.P., Brown, P.R., Jacob, J., Krebs, C.J. and Singleton, G.R. Field methods for rodent studies in Asia and the Indo-Pacific. ACIAR Monograph No. , p. ISBN 1 86320 393 1 (print) ISBN 1 86320 394 X (electronic) Technical editing, design and production by Clarus Design, Canberra Printed by BPA Print Group, Melbourne Contents Acknowledgments . Randomisation and interspersion . Randomisation . Chapter : Why study rodent populations? . .9 Interspersion . Introduction . Summary . Rodents as pest species . Further reading . Rodents as benefi cial species . Ecologically based rodent management . Chapter : Capture and handling of rodents . Phase : problem defi nition . Introduction . Phase : ecological and historical studies . Capture methods . Phase : designing and testing management options . Major types of trap . Purpose and scope of this book . Checking and cleaning traps . Further reading . Comparing trap and bait effi cacy . Habitat surveys . Chapter : Design of fi eld studies . Trapping eff ort and frequency . Introduction . Handling a captive rodent . General principles of experimental design . Methods of euthanasia . Identifi cation of hypotheses and key factors . Asphyxiation . Size of experimental units . Cervical dislocation . Duration of an experiment . Safety issues . Inclusion of controls . Diseases transmitted to humans by rats and mice . Replication . Further reading . C C Chapter : Rodent taxonomy and identification . Chapter : Reproduction and growth in rodents . Introduction . Introduction . Basic taxonomic concepts . Basic reproductive anatomy . e meaning of scientific and common names . Male reproductive tract . Units of classification . Female reproductive tract . Morphological and genetic approaches to Pregnancy and embryonic development . distinguishing species . Trimester . Collecting voucher specimens . Trimester . Wet specimens . Trimester . Dry specimens . Growth and maturation after birth . Major groups of Asian rodents . Attainment of sexual maturity . Identifying murid rodents . Lifespan and menopause . Determining the age and sex of a rodent . Assessing reproductive activity from external Taking measurements . characteristics . Diagnostic characteristics . Assessing reproductive activity from internal Further reading . characteristics . Key reproductive parameters . Chapter : Population studies . Commencement and cessation of the breeding season . Introduction . Percentage of adult females in breeding condition . Relative estimates of abundance . Percentage of adult females that produce multiple Trap success . litters within one season . Tracking tiles . Average litter size . Census cards . Pre-weaning mortality rate . Burrow counts . Recording reproductive data . Visual surveys . Further reading . Calibrating relative estimates of abundance . Estimates of population size . Equipment . Marking techniques . Calculating population size from capture–mark–release data . Further reading . C C Chapter : Studies of movement . Chapter : Assessing crop damage and yield losses . Introduction . Introduction . Some basic concepts . Methods for estimating damage . Techniques for studying movement . Timing of damage . Capture–mark–release trapping . Spatial distribution of damage . Spool-and-line methods . Estimating damage at sowing/transplanting . ..