Estimating Abundance of African Wildlife

by Jachmann, Hugo

• ISBN13: 9780792379591
• ISBN10: 0792379594
• Format: Hardcover
• Copyright: 2001-01-01
• Publisher: Kluwer Academic Pub

Summary

Estimating abundance of wildlife is an essential component of a wildlife research program, and a prerequisite for sound management. With the exception of a few highly mathematical volumes, there are no books on the subject for use by students and field workers. Also, the various techniques for counting animals found in scientific journals are often not accessible to African managers. The unavailability of the diverse literature necessitated the production of a textbook or field manual that covers the ground. The book compiles the most relevant techniques for counting African mammals, illustrated with many examples from the field. It provides guidelines for selecting the appropriate methodology for a range of conditions commonly found in the field, in terms of different animal species, habitat types, and management objectives.

Table of Contents

List of Figures	ix
List of Tables	xvii
List of Boxes	xx
Foreword	xxi
Preface	xxiii
PART 1: INTRODUCTION	1	(36)
Introduction to Estimating Wildlife Abundance	3	(10)
A Brief Overview of Techniques	4	(6)
Selection of a Technique	10	(3)
Interpretation of Population Estimates	13	(24)
Population Estimate	13	(2)
Variance, Standard Error and Confidence Limits	15	(6)
Bias and Accuracy	21	(1)
Stratification	22	(2)
Random Sampling versus Systematic Sampling	24	(1)
Sample Count Theory	25	(7)
Categorisation of Data	32	(5)
PART II: DIRECT COUNTS	37	(1)
PART IIa: GROUND COUNT TECHNIQUES	37	(56)
Ground Count Techniques; An Introduction	39	(6)
Total Ground Counts	39	(3)
Total Ground Counts of Hippos and Crocodiles	40	(1)
Total Ground Counts Using Individual Recognition	41	(1)
Sample Ground Counts	42	(3)
Line Transect Counts	45	(48)
Theoretical Background	45	(8)
Conceptual Background	47	(1)
Different Shapes of the Detection Function	48	(5)
Software to Analyse Line Transect Data	53	(1)
Survey Design	54	(3)
Stratification of the Survey Area	55	(2)
Field procedures	57	(5)
Precision and Accuracy of Line Transect Results	62	(3)
Data Analysis with Program Distance	65	(12)
Analysing the Lupande Warthog Data with Program Distance	67	(6)
Analysing the Lupande Elephant Data with Program Distance	73	(4)
The Mean Perpendicular Distance Method	77	(9)
Data Analysis using the Mean Perpendicular Distance Method	78	(4)
Analysing the Lupande Warthog Data with the MPD Method	82	(1)
Analysing the Lupande Elephant Data with the MPD Method	83	(3)
Vehicle Counts	86	(5)
Road Counts	86	(5)
Comparative Costs of Sample Counts on the Ground	91	(2)
PART IIb: AERIAL COUNT TECHNIQUES	93	(46)
Aerial Total Counts	95	(18)
Sources of Bias in Aerial Total Counts	96	(2)
Census Design	98	(4)
Aerial Total Counts of Hippos and Crocodiles	102	(1)
The Double Count Method	103	(4)
Field Example of Observer Bias Experiments	107	(4)
Field Example of Visibility Bias and Sighting Probability Bias Experiments	111	(2)
Aerial Sample Counts	113	(26)
Choice of Sample Unit	113	(4)
Blocks	113	(3)
Transects	116	(1)
Survey Design	117	(4)
Positioning the Streamers	121	(2)
Analysis	123	(3)
Jolly's Method 1 for Equal Sized Sample Units	124	(1)
Jolly's Method 2 for unequal Sized Sample Units	125	(1)
Precision in Relation to Density and Sampling Intensity	126	(5)
Density and Precision	127	(3)
Sample Size and Precision	130	(1)
Field Example of an Aerial Survey	131	(6)
Analysis of a Stratified Design	136	(1)
Comparative Costs of Aerial Counts	137	(2)
PART III: INDIRECT COUNTS	139	(1)
PART IIIa: SPECIAL AND INDEX TECHNIQUES	139	(28)
Special Techniques	141	(14)
The Mark/Recapture Method	141	(1)
Field Example	142	(3)
Estimating Abundance through Radio-Tracking	145	(6)
Field Example	151	(2)
Estimating Abundance using DNA Analysis	153	(2)
Index Counts	155	(12)
Field Example of a Patrol Index Count	162	(3)
Monitoring of Sex and Age Ratios, and Juvenile Mortality	165	(2)
PART IIIb: INDICATOR TECHNIQUES	167	(28)
Dropping Counts	169	(22)
Theoretical Concept	171	(2)
Dropping Counts in Woodland Savanna	173	(5)
Defecation Rate	173	(2)
Decay Rate	175	(1)
Analysis	176	(2)
Dropping counts in Forests	178	(2)
Defecation Rate	179	(1)
Decay Rate and Analysis	179	(1)
Dropping Counts on Roads	180	(8)
Validity of the Method	181	(2)
Sample Design and Analysis	183	(1)
Field Examples	183	(5)
Sources of Error	188	(1)
Faecal Counts of Other Species	189	(2)
Footprint Measurements	191	(4)
Concept, Sample Design and Analysis	191	(1)
Field Example	192	(2)
Costs of Indicator Counts	194	(1)
PART IV: ANALYSING DISTRIBUTION DATA AND POPULATION TRENDS	195	(18)
Analysing Animal Distribution, Movements and Population Trends	197	(16)
Analysis of Animal Distribution and Movements	199	(2)
Field Example	201	(4)
Analysing Population Trends	205	(4)
Field Example	209	(4)
PART V: SYNTHESIS	213	(26)
Deciding on a Technique	215	(24)
The Reasons for Counting	216	(1)
The Animal Species	217	(3)
The Habitat Type	220	(1)
The Budget	221	(2)
Making a Decision	223	(16)
References	231	(8)
APPENDICES	239	(38)
Appendix I: A Brief Manual To Program `Aerial'	241	(4)
Appendix II: Program `Aerial' in Quickbasic 4.5	245	(32)
Index	277