Central Africa
Provisional African Elephant Population Estimates: update to 31 Dec 2013
- Reports
- 2013
- Africa
- Central Africa
All Years for Central Africa:
2016 —
2013 —
2007 —
2002 —
1998 —
1995Summary Totals for Central Africa
| Estimates from Surveys | Guesses | % Known and
Possible Range | Area (km2) |
|---|
| Survey category | Estimate | ± 95% CL | From | To | | |
|---|
| Aerial Total Counts | 1,225 | — | — | — | 2.5 | 19,647 |
| Aerial Sample Counts | 415 | 582 | — | — | 2.8 | 21,766 |
| Reliable Dung Counts | 10,549 | 2,495 | — | — | 8.0 | 62,325 |
| Other Dung Counts | 1 | — | 39,683 | 65,373 | 10.6 | 83,287 |
| Informed Guesses | 2,509 | — | 14,222 | 21,094 | 12.4 | 97,016 |
| Other Guesses | — | — | 3,500 | 4,113 | 3.8 | 29,492 |
| Degraded Data | — | — | 5,327 | 5,327 | 1.1 | 8,229 |
| Modeled Extrapolation | — | — | 32,378 | 32,378 | 20.9 | 163,629 |
| Totals 2015 | 14,699 | 2,562 | 95,109 | 128,284 | | |
| Totals 2006 | 14,639 | 4,260 | 261,714 | 266,263 | | |
| Assessed Range | 62.0 | 485,392 |
| Unassessed Range | 38.0 | 297,693 |
| Total Range | 100 | 783,085 |
Summary Totals for Central Africa
| Data Category | Definite | Probable | Possible | Speculative |
|---|
| Aerial or Ground Total Counts | 1,225 | 0 | 0 | 0 |
| Direct Sample Counts and Reliable Dung Counts | 8,402 | 2,562 | 2,562 | 0 |
| Other Dung Counts | 1 | 43,700 | 8,490 | 0 |
| Informed Guesses | 2,509 | 0 | 46,600 | 6,872 |
| Other Guesses | 7 | 0 | 0 | 8,827 |
| Totals 2013 | 12,144 | 46,262 | 57,652 | 15,699 |
| Totals 2006 | 10,379 | 46,773 | 45,221 | 184,283 |
Interpretation of Changes in Estimates from Previous Report
| | Estimates from Surveys | Guesses | Area |
|---|
| Cause of Change | Estimate | ± 95% CL | From | To | % Known and Possible | Total |
|---|
| Repeat Survey | -1,290 | ±2,424 | -7,814 | -1,869 | 3.8 | 29,849 |
| New Population | +1,999 | ±732 | -156,282 | -141,001 | 8.4 | 65,715 |
| Different Technique | +4,001 | ±985 | -171,128 | -172,153 | 2.9 | 22,799 |
| Different Area | +3,483 | ±1,301 | -5,330 | -3,042 | 9.3 | 73,144 |
| New Guess | -3,852 | ±4,081 | -168,094 | -155,739 | 30.6 | 239,722 |
| Data Degraded | 0 | 0 | 0 | 0 | 0.8 | 6,357 |
| Totals | +4,341 | ±5,072 | -508,648 | -473,804 | 55.9 | 437,586 |
Interpretation of Changes in Estimates from Previous Report
| Cause of Change | Definite | Probable | Possible | Speculative |
|---|
| Repeat Survey | -2,767 | -2,623 | +1,006 | -177 |
| New Population | +840 | +17,541 | +10,342 | -15,184 |
| Different Technique | +2,619 | +2,745 | -1,341 | -19,422 |
| Different Area | +2,217 | +4,260 | -4,123 | -630 |
| New Guess | -207 | -26,132 | +17,407 | -10,876 |
| Data Degraded | 0 | 0 | -4,098 | +4,319 |
| Totals | +2,701 | -4,208 | +19,192 | -41,970 |
Interpretation of Changes in Estimates from Previous Report (2007 scaling)
| Cause of Change | Definite | Probable | Possible | Speculative |
|---|
| Repeat Survey | -5,999 | -4,700 | +784 | -672 |
| New Population | +1,821 | +31,435 | +8,056 | -57,671 |
| Different Technique | +5,677 | +4,919 | -1,045 | -73,768 |
| Different Area | +4,806 | +7,634 | -3,212 | -2,393 |
| New Guess | -449 | -46,830 | +13,559 | -41,309 |
| Data Degraded | 0 | 0 | -3,192 | +16,404 |
| Totals | +5,855 | -7,541 | +14,950 | -159,409 |
Area of Range Covered by Each Data Category (km²)
| Data Category | Known Range | Possible Range | Total Range |
|---|
| Aerial or Ground Total Counts | 8,446 | 11,200 | 19,647 |
| Direct Sample Counts and Reliable Dung Counts | 69,202 | 14,889 | 84,091 |
| Informed Guesses | 99,464 | 161,181 | 260,646 |
| Other Dung Counts | 79,994 | 3,293 | 83,287 |
| Other Guesses | 32,529 | 5,192 | 37,722 |
| Unassessed Range | 163,815 | 133,878 | 297,693 |
| Totals | 453,452 | 329,633 | 783,085 |
Elephant Estimates
| Estimates from Surveys | Guesses | Range | | |
|---|
| Country | Estimate/Number Seen | ± 95% CL | From | To | Area (km²) | % Regional | % Assessed | IQI1 | PFS2 |
|---|
| Cameroon | 2,834 | 604 | 8,446 | 11,375 | 89,718 | 11 | 55 | .10 | 2 |
| Central African Republic | 709 | 245 | 652 | 1,181 | 24,619 | 3 | 89 | .29 | 2 |
| Chad | 887 | 0 | 18 | 227 | 61,490 | 8 | 39 | .31 | 2 |
| Congo | 1,051 | 236 | 21,896 | 41,559 | 150,937 | 19 | 37 | .01 | 1 |
| Democratic Republic of Congo | 2,076 | 571 | 10,050 | 12,990 | 223,248 | 29 | 45 | .06 | 1 |
| Equatorial Guinea | 884 | 676 | 0 | 0 | 19,701 | 3 | 100 | .57 | 2 |
| Gabon | 6,258 | 2,302 | 58,877 | 65,782 | 213,373 | 27 | 100 | .08 | 1 |
| Totals | 14,699 | 2,562 | 95,110 | 128,285 | 783,085 | 100 | 62 | .06 | 1 |
Elephant Estimates
| Country | Definite | Probable | Possible | Speculative | Range Area (km²) | % of Regional Range | % of Range Assessed | IQI1 | PFS2 |
|---|
| Cameroon | 2,230 | 4,234 | 4,870 | 2,575 | 89,718 | 11 | 55 | .25 | 2 |
| Central African Republic | 464 | 245 | 397 | 529 | 24,619 | 3 | 89 | .38 | 2 |
| Chad | 894 | 0 | 18 | 196 | 61,490 | 8 | 39 | .32 | 2 |
| Congo | 4,298 | 25,435 | 8,012 | 0 | 150,937 | 19 | 37 | .29 | 1 |
| Democratic Republic of Congo | 1,729 | 3,823 | 5,223 | 3,687 | 223,248 | 29 | 45 | .17 | 1 |
| Equatorial Guinea | 208 | 676 | 676 | 0 | 19,701 | 3 | 100 | .57 | 2 |
| Gabon | 3,956 | 7,498 | 46,004 | 17,887 | 213,373 | 27 | 100 | .15 | 1 |
| Totals | 16,234 | 39,232 | 60,171 | 24,874 | 783,085 | 100 | 62 | .24 | 1 |
1IQI: Information Quality Index: This index quantifies overall data quality at the regional level based on the precision of estimates and the proportion of assessed elephant range (i.e. range for which estimates are available). The IQI ranges from zero (no reliable information) to one (perfect information).
2PFS: Priority for Future Surveys, ranked from 1 to 5 (highest to lowest). Based on the precision of estimates and the proportion of national range accounted for by the site in question, PFS is a measure of the importance and urgency for future population surveys. All areas of unassessed range have a priority of 1. See Introduction for details on how the PFS is derived.
Note that totals for the Definite, Probable, and Possible categories are derived by pooling the variances of individual estimates, as described at http://www.africanelephantdatabase.org/reliability. As a result, totals do not necessarily match the simple sum of the entries within a given category.
