THE POPULATION ECOLOGY OF SOME WOODLAND CARABID BEETLES, WITH PARTICULAR REFERENCE TO THEIR DISPERSIVE BEHAVIOUR. by Keith N.A. Alexander, B.Sc, Royal Holloway College A Thesis submitted for the degree of Doctor of Philosophy of the University of London May ,1986 . ProQuest Number: 10097579 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest. ProQuest 10097579 Published by ProQuest LLC(2016). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. Microform Edition © ProQuest LLC. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 "We went to all the places which a beetle might be near, And we made the sort of noises which a beetle likes to hear. And I saw a kind of something, and I gave a sort of shout: "A beetle-house and Alexander Beetle coming out!" " A.A. Milne. 11 ABSTRACT The Population Ecology of some woodland carabid beetles, with particular reference to their dispersive behaviour. The mobility of carabid beetles in the field has been studied by a number of researchers in recent years, but the small scale movements are still poorly understood. The populations of five species of carabid beetles living in a Surrey oakwood were therefore investigated using pitfall trapping and individual marking techniques over a period of three years. Five aspects of the complications associated with the interpretation of pitfall trapping and mark-release-recapture studies were investigated: (i) baiting of the traps by the catch itself, (ii) escape ability of captured beetles, (iii) changes in behaviour following overlong pro­ cedures between capture and release, (iv) density effects produced in trapping, and (v) effects of marking procedures on behaviour and survival, No effects could be demonstrated for (i), (iv) and (v). However, the escape rate in Nebria brevicollis was shown to be very high, and the behaviour of the same species affected by the length of time between capture and subsequent release. More than 3000 recaptures of marked beetles were made. Survival into a second breeding season was found to be commonplace in all five species; a few even entered a fourth. The distributions of the beetles within the study area were aggregated, particularly so in Nebria, where it was also shown that the beetles tend to remain in the areas where they are in the highest densities. Distributions changed little with season. Peak displacement rates were associated with the breeding season Ill in Nebria but, whereas this fell off with the onset of winter in first season beetles, the level remained high in second season individuals. Pterostichus madidus exhibited a significant lack of displacement with time, except with males during the breeding season. Greatest acti­ vity and dispersal was found in August in first season males, but June and July with second season. Abax parallelepipedus beetles were found to be most active early in the season. Very few beetles of the species were found to disperse 100 metres or more within the study area. The concept of home range was examined in relation to ground beetles. Site attachment could not be demonstrated in any species, although other aspects of the trapping results indicated some form of home ranging behaviour. IV ACKNOWLEDGEMENTS This project was supervised by Dr. A.J. Pontin and his advice and support has been very much appreciated. Useful discussions with other staff and research students in the Zoology Department at Royal Holloway College also deserve my thanks, and in particular R.B. Angus, P.A. Jewell, M.E.N. Majerus and N.J. Reeve. Correspondence with other workers was a great source of advice and support; particularly M.L. Luff, but also M.E.G. Evans, C. Haines, P. Hammond, J.L. Mason, C. Nield, M.R. Speight, and G. Varley. The mammal ecology research in the Department created a strong atmosphere in which to work on ecological subjects generally, and for this, and the general facilities of the Department, I would like to record my thanks to the three Heads of Department who cover my period of research: P.A. Jewell, G. Twigg and C.T. Lewis. Technical help was provided by L. Healing and M. Colthorpe. The library facilities of the College are also to be congratulated on their ability to supply everything requested. Thanks are also due to Sir Michael Sobell, the owner of the woodland in which the study took place. The project was funded by a Tutorial Research Studentship awarded by Royal Holloway College. The task of typing the manuscript was undertaken by Mrs. W. Smith - the final product speaks for itself. Finally, I would like to acknowledge the continued interest and prompting from present colleagues in the Estates Advisory Office of the National Trust, at Cirencester, Glos., and, of course, from family and friends. CONTENTS PAGE 1. General Introduction............................. .......... 1 2. The Study Site 9 2.100 2.110 Location .......... 10 2.120 Environs .......... 10 2.200 Geology 14 2.300 Vegetation 14 2.400 History 17 2.500 Weather Conditions 1975-78 18 2.600 Species list of Carabidae 19 3. Methods 22 3.100 Introduction 23 3.200 Capture techniques 23 3.210 Introduction 23 3.220 Direct observation 23 3.230 Soil and litter sampling 25 3.240 Refuges 26 3.250 Pitfall trapping 27 3.260 Conclusions 29 3.300 The Pitfall trap ; sources of variation in catch size and composition 30 3.310 Introduction 30 3.320 Intrinsic properties of the trap ...... .. 30 3.330 Pitfalling technique 31 3.340 Climatic and biotic factors 33 3.350 Other considerations 34 3.351 Stochastic effects ^4 VI PAGE 3.352 Activity and Abundance 35 3.353 Sampling area 36 3.360 Pitfall trapping methods used in this study 36 3.400 Investigations of certain aspects of pitfall trapping and the interpretation of catch composition 37 3.410 Introduction 37 3.420 The possibility of active aggregation of beetles in pitfall traps 38 3.430 Retaining efficiency 41 3.440 The effects of the time interval between capture and release 47 3.450 The effects of catch size on subsequent behaviour of beetles 59 3.500 Individual Marking Techniques 63 3.510 Introduction 63 3.520 Labelling 64 3.530 Coloured paints and dyes 64 3.540 Mutilation 66 3.550 Handling techniques 68 3.560 Conclusions 70 3.600 Investigations into any effects of mutilation marking on subsequent behaviour and longevity....... 71 3.700 Release procedure 75 3.710 Introduction 75 3.720 Location of release 78 3.730 Time of release 79 vil PAGE 3.740 Conclusions 79 3.800 Summary of Chapter 79 4. Life histories of the commonest larger woodland Carabidae 82 4.100 Introduction 83 4.200 Nebria brevicollis 83 4.300 Pterostichus madidus 95 4.400 Abax parallelepipedus 107 4.500 Carabus violaceus 113 4.600 Pterostichus niger 123 4.700 Field Observations 123 4.800 Lifespan 130 4.810 Mortality 130 4.820 Longevity 130 4.900 Summary of Chapter 135 5. The mark-release-recapture programme 1975-77: a baseline study 136 5.100 Introduction 137 5.200 Methods 137 5.300 Results and Discussion 141 5.310 Weekly catch totals 141 5.320 The spatial distribution of the species 151 5.330 Variation in catch size per trap location 160 5.340 Frequency of recapture of the marked beetles ...... 166 5.350 Dispersive behaviour of the marked beetles 168 5.360 Density effects ...... 208 5.370 The source of unmarked beetles in the study area........................ ...... 215 Vlll PAGE 5.380 Estimation of the abundance of the beetles 217 5.400 Conclusions 227 6 . Experimental displacement of individual beetles. 229 7. Mobility at the individual level 252 8 . General Discussion 289 8.100 Introduction 290 8.200 The role of Carabidae in woodland, and their life cycles. 291 8.300 Mobility of the different stages in the life cycle. 310 8.400 Adult Mobility 312 8.500 Spatial Strategy 342 8.600 Dispersive behaviour of Carabidae : general conclusions 350 References 353 Appendices 376 IX LIST OF TABLES AND FIGURES PAGE Tables 3.1 Catch composition of experimental pitfall traps, for Pterostichus madidus. 40 3.2 Frequency of escapes of beetles from pitfall traps under different laboratory conditions. 44 3.3 , Losses of bait beetles from pitfall traps in the field: (i) Nebria brevicollis, and 46 (ii)Pterostichus madidus 46 3.4 Comparison of field and laboratory results of retention of Nebria brevicollis beetles in pitfall traps 47 3.5 Nebria brevicollis, Sept-Nov 1970: recapture results following various procedure timings 50 3.6 Pterostichus madidus, May-Aug 1976: recapture results following various procedure timings 52 3.7 Abax parallelepipedus, May-July 1976: recapture results following various procedure timings .......... 53 3.8 Nebria brevicollis, Sept-Nov 1976: displacement of recaptured beetles following various procedural timings. 54 3.9 Pterostichus madidus, May-Aug 1976: displacement of recaptured beetles following various procedural timings. .. 55 3.10 Abax parallelepipedus, May-July 1976: displacement of recaptured beetles following various procedural timings. .. 55 3.11 Nebria brevicollis, March-May 1976: recapture results following different procedure timings 58 X List of Tables and Figures (Cont) PAGE Tables 3.12 Nebria brevicollis, survival results of beetles in­ dividually marked and released during the period Sept-Nov 1976, following various procedural timings.......