National Summary of Aerial Census Results for Elephant in Zimbabwe: 2001
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NATIONAL SUMMARY OF AERIAL CENSUS RESULTS FOR ELEPHANT IN ZIMBABWE: 2001 K.M. Dunham & C.S. Mackie WWF - SARPO Occasional Paper Number 1 June 2002 This census was carried out jointly by the Department of National Parks and Wild Life Management and WWF-SARPO (WWF Project No: ZW 0025). This report has also been published by the Department of National Parks and Wild Life Management. The 2001 aerial survey and this publication were made possible through support made available by the Office of USAID Harare under the terms of project 613-0241 and grant 690-0251-4-9001-00. The opinions expressed herein are those of the author and do not necessarily reflect the view of USAID. This material has been produced by the authority of, and for the use of CAMPFIRE in Zimbabwe, for information purposes only. 1 SUMMARY The principal populations of elephants in Zimbabwe were surveyed from the air during the period July to October 2001. These populations are located in north-west Matabeleland, the Sebungwe region, the unflooded Middle Zambezi Valley and the south-east lowveld. The total area surveyed was 66 651 km2. This was the first time since 1998 that all these populations were studied during the same year. The surveys were sample counts and the methods followed those used during previous surveys. The Save Valley Conservancy was included in the national elephant survey for the first time. There were estimated to be 88 123 elephants (+/- 95 % confidence interval 8.0 %, or 7079 elephants) in the regions surveyed from the air. This was the highest and most precise estimate ever obtained for the total number of elephants in Zimbabwe’s principal populations. The lower and upper confidence limits of this mean estimate were 81 044 and 95 202 elephants. There are known to be several small sub-populations of elephants occurring outside these survey areas, and estimates or ‘guesstimates’ of the numbers of animals in these sub- populations were obtained from people familiar with them. Elephants occurred at 12 locations outside the survey regions and the total number of elephants in these sub-populations was probably about 1000. Thus, there were estimated to be, in total, 89 123 elephants in Zimbabwe during the 2001 dry season. It is more practical to take account of the confidence limits for the estimate from the air surveys and state that there were between about 82 000 and 96 000 elephants in Zimbabwe during the 2001 dry season. Almost 90 % of these were in the Parks & Wild Life Estate and about 50 % were in Hwange National Park. In the regions surveyed from the air, there were, in total, an estimated 86 ‘fresh’ carcasses of elephants, 186 ‘recent’ carcasses and 3209 ‘old’ carcasses. Overall, these carcasses formed 3.8 % of all elephants (live and dead) estimated to be in these regions. The carcass “ratio” varied from 1.7 % in the Save Valley Conservancy to 5.8 % in the Sebungwe. 2 TABLE OF CONTENTS SUMMARY................................................................................................................................1 LIST OF TABLES......................................................................................................................3 LIST OF MAPS..........................................................................................................................5 INTRODUCTION......................................................................................................................6 METHODS.................................................................................................................................6 Aerial Surveys .........................................................................................................................6 Survey Areas........................................................................................................................6 Transect Surveys..................................................................................................................6 Block Counts........................................................................................................................9 Data Analysis.......................................................................................................................9 Small Populations .................................................................................................................10 RESULTS.................................................................................................................................10 Small Populations .................................................................................................................10 Aerial Surveys .......................................................................................................................13 North-west Matabeleland......................................................................................................13 Zambezi Valley......................................................................................................................13 Sebungwe...............................................................................................................................13 South-east Lowveld ...............................................................................................................13 Zimbabwe ..............................................................................................................................16 Elephant Carcasses...............................................................................................................16 REFERENCES .........................................................................................................................17 ACKNOWLEDGEMENTS......................................................................................................18 APPENDIX. Tables of population estimates and statistics for elephants, elephant bulls, elephants in cow herds, and elephant carcasses in Zimbabwe during 2001. Population estimates by region (Tables 5-10) and by administrative area (Tables 11-16). .......................24 Notes about Tables................................................................................................................24 3 LIST OF TABLES Table 1. Summary of sampling statistics for the 2001 aerial surveys........................................8 Table 2. Definitions of categories used to record time since death for elephant carcasses........8 Table 3. Status of small populations of elephants during the dry season of 2001 ...................11 Table 4. Summary of the population estimates for elephants in Zimbabwe during 2001........14 Table 5. Population estimates and statistics for elephants in the aerial survey regions of Zimbabwe during 2001.............................................................................................................25 Table 6. Population estimates and statistics for elephant bulls in the aerial survey regions of Zimbabwe during 2001.............................................................................................................25 Table 7. Population estimates and statistics for elephants in cow herds in the aerial survey regions of Zimbabwe during 2001 ...........................................................................................25 Table 8. Population estimates and statistics for fresh carcasses of elephants (age category 1) in the aerial survey regions of Zimbabwe during 2001................................................................26 Table 9. Population estimates and statistics for recent carcasses of elephants (age category 2) in the aerial survey regions of Zimbabwe during 2001............................................................26 Table 10. Population estimates and statistics for old carcasses of elephants (age category 3) and carcass ratios (for all elephant carcasses) in the aerial survey regions of Zimbabwe during 2001 ..........................................................................................................................................26 Table 11. Population estimates and statistics for elephants, by administrative area, in regions surveyed from the air................................................................................................................27 Save Valley Conservancy ......................................................................................................27 Gonarezhou ...........................................................................................................................27 North-west Matabeleland......................................................................................................27 Zambezi Valley......................................................................................................................28 Sebungwe...............................................................................................................................28 Table 12. Population estimates and statistics for elephant bulls, by administrative area, in regions surveyed from the air...................................................................................................29 Save Valley Conservancy ......................................................................................................29 Gonarezhou ...........................................................................................................................29 North-west Matabeleland......................................................................................................29