Following our last posting of 15th October, we are issuing an interim report on the impact of the drought on wildlife losses so far prior to a detailed report to be submitted to the Amboseli Ecosystem Trust (AET) and partners and to the Southern Rangelands Coalition (SRC) in late November. Reports of the AET and SRC meetings called in response to the drought are posted on our website.
The Ministry of Tourism and Wildlife called on the Conservation Alliance of Kenya on 4th November to submit a report on wildlife mortalities around the country, and to recommend immediate and longer-term steps to combat drought. Amboseli Conservation Program (ACP) data contributed substantially to the report. A copy of the report presented to the Cabinet Secretary, Ms. Peninah Malonza, and Principal Secretary, Dr. Susan Koech, by the southern and central Kajiado conservation partners will be posted on the ACP website.
It is worth pointing out in that estimates of drought losses can’t be made simply by driving around the worst hit areas and counting carcasses. Estimating the number of deaths and drought recovery prospects calls for a systematic method of counting both the live and dead animals simultaneously. Here is why:
- Accurate estimates of animal deaths need to be done across the entire dry season range, not only in areas where dead animals are most visible. In the case of Amboseli, few carcasses are found where wildebeest and zebra are feeding. Most carcasses are found on open ground where herds bed down at night to avoid predators and fail to recover from cold stress in the morning and move onto their feeding grounds.
- Since it is not possible to count all carcasses reliably, there is need to use an intensive sampling system in which both live and dead animals can be counted and used to calculate numbers for the whole dry season range or park.
- Carcasses are difficult to detect in heavy vegetation cover and when eaten by predators. Accurate counts can be done by scanning and counting a small area intensively.
- Most early drought deaths are of young animals which are quickly eaten by predators, resulting in an underestimate of the numbers which have died.
- Counts of dead animals alone are not sufficient to gauge the impact of a drought. The bigger the population of animals, the larger will be the number of deaths for a given mortality rate. A ten percent mortality rate in a population of 10,000 wildebeest will produce 1,000 carcasses compared to 100 in a population of 1,000. Clearly, the prospects of wildebeest surviving the drought and recovering is far better for large than small populations.
- Because the size of the population matters to how many carcasses are produced and the prospects of recovery from a drought, we need a good estimate of the numbers of each species before, during and after a drought. If numbers drop below a level too low to combat post-drought predation, recovery could be stalled, calling for restorative measures. If sufficient numbers survive to recover naturally, no action is needed or justified.
Here are the results of the live numbers and carcasses for species:
We have used the total areal counts of October 9th 2022, for elephants, buffaloes and hippo numbers. Estimated losses of elephants and buffalo are 5%. We observed no giraffe death in the park. Reedbuck numbers increased sharply in Amboseli in recent years with the expansion of the swamps have suffered a modest loss. The losses for Thomson’s and Grant’s gazelle, impalas and other small species are negligible. We have not given any figures for livestock mortality at this point. Sakimber Kamiti is collecting information directly from herders and will give estimates for cattle, sheep and goats when compiled.
As high and alarming as the number of carcasses is in Amboseli, and as distressing as the hundreds of carcasses is to tourists, we need to keep an eye on the number of live animals and rate of decline to assess the impact of drought and prospects for recovery. Here the results are more reassuring.
The only species suffering substantial losses so far are zebra, wildebeest, buffaloes and elephants. Compared to the 2009 drought when over 95% of the wildebeest, 60% zebras, two third of the buffaloes and a quarter of the elephants died, the current drought is far less severe. We started the current drought with far larger populations of each species, current mortality rates are far lower, and the swamps are far more extensive than in 2009. In many places the swamps are still expanding and providing fresh forage.