Drought and human intervention
Droughts and wildlife deaths: an opinion
Many of the savannah (mixed grass and woodland) ecosystems of Eastern Africa are “non-equilibrium”, meaning that the response of grasses, shrubs and herbs to rainfall, temperature and soil types varies unpredictably over time. This year’s rain has been very patchy with only about half of our expected rainfall since January. As a result, we are experiencing six months of low rainfall since December 2021, which can be classed as a “drought period”.
Animal numbers are regulated by food availability, disease, and predators, with some predictable consequences and some outcomes that are hard to forecast. As is typical for ecosystems such as Amboseli, recent good years of rain have led to a major pulse in the production of baby wildebeests, buffalos, zebras and elephants. Cattle and other small grazing livestock have also thrived over the past four to five years. When times are good, animals survive well and produce many offspring. Now, however, as less food is able to grow and more mouths are competing for the same dwindling food stocks, the numbers of grazing animals will decline through both death and dispersal, while rare predators including vultures, cheetahs and small cats will in turn thrive. Peaks of births and abundance are entirely natural and expected, as are losses during drought periods, especially of the oldest and youngest individuals.
We can ask if animal suffering should be stopped at all points by human intervention, or if we should allow natural processes to proceed? The Amboseli ecosystem is currently large enough to sustain most natural processes in wildlife without our help, and the effect of any intervention can only be to defer suffering and death to a later period, as the restoration of natural food availability will take many months. Interventions will have consequences for other species too like predators, possibly leading to the chaotic spread of death or disease. If we haven’t learned yet that tinkering with wild animal populations has the potential for human and animal catastrophe (Ebola, Sars-Covid-2, Mers, Monkeypox, Avian flu), now is the time to pause for thought before we suggest intervention.