A message from Dr. Tara Stoinski, president and CEO/chief scientist, the Dian Fossey Gorilla Fund
We’ve heard so much about climate change in recent weeks, with the Trump administration’s decision to pull out of the Paris climate accord. The devastating impacts of this decision on our own species as well as those with whom we share the earth has been eloquently discussed by so many in the news media over the last few weeks. Today, I would like to talk about what it means for the animal that is closest to my heart—gorillas.
In my work as CEO and chief scientist of the Dian Fossey Gorilla Fund, it is increasingly important for our organization to understand and, as much as possible, plan for the effects climate change may have on the critically endangered gorillas that we protect every day in Africa. The gorillas, like all endangered species, already face so many human-induced threats—loss of habitat, hunting and poaching, and diseases. And like many field conservation organizations, we work every day to protect them from these dangers, staving off extinction as best we can.
The additional and very real threat to the gorillas represented by climate change is one, however, that it is much harder for us to protect against because it has the potential to affect so much of the gorillas’ environment. Changes in rainfall patterns and temperatures can affect the gorillas’ food supply, cause thermal stress, increase the chance that they lose habitat to forest fires, and enable the emergence of new diseases for which the gorillas have little or no immunity. Climatic change is also likely to have significant impact on the human populations living near the gorillas, which can in turn put more pressure on the gorillas themselves. For example, as food and water supplies of local populations are affected—such as in a drought that reduces crop yields—the already considerable pressures on the forest as a source of food and water are likely to increase even further.
We’re already seeing changes….
Sadly, we are already seeing changes in mountain gorilla habitat that are indicative of climate change, such as changes in temperature and rainfall. In addition, between the 1980s and 2000s, we saw altitudinal shifts—a pattern often associated with climate change—in some of the key gorilla food species, as well as a 50 percent decline in the biomass of the gorillas’ most preferred food. We do not know what is responsible for this latter result. It may have more to do with the increasing gorilla population than climate change. But it is obviously very worrisome and something we are continuing to monitor.
One piece of good news is that given their broad diet, mobility (they are not reliant on a specific nesting or breeding site), and behavioral flexibility, gorillas, like most primates, are likely to be able to buffer some of the effects of climate change better than species with more-specialized niches. As an example of how gorillas and other primates may be buffered from climatic extremes, take the severe drought that hit Kenya in 2009. The wildebeest and zebra populations of Amboseli National Park were devastated, with an estimated 98 percent and 75 percent, respectively, dying as a result, whereas mortality in the baboon population was less than 15 percent.
However, of concern for the mountain gorillas we protect is their extremely limited habitat. They are restricted to the top of six volcanoes, which are surrounded by some of the highest rural population densities in Africa. Simply stated, they don’t have much ability to go up or down should major changes to their habitat occur.
More strategic work to do
What can be done to protect gorillas from the inevitable changes that climate change will bring? Most importantly, it will take thoughtful leadership and commitment from governments around the world. I am happy that so many countries worldwide as well as state and local governments within the United States have emphatically stated their continued commitment to the Paris Accord in the aftermath of Trump’s decision.
And we at the Dian Fossey Gorilla Fund are also taking steps to ensure forward progress to protect some of the world’s most vulnerable species and environments from climate change. In our new strategic plan, we have committed to expanding our research into the overall biodiversity of the park where the mountain gorillas live. This will enable us to monitor what is happening to both key individual species and the overall health of the ecosystem. We are also expanding our work with the communities living in and around the gorillas’ habitat, providing more livelihood options and educational opportunities to lessen their dependence on the forest for resources and help buffer them from potential devastating climate change effects.
Also, see our recent collaborative publication in the journal Global Climate Change that looks at the effect of climate variability on survivorship and reproduction in seven primate species. (Campos et al., Does climate variability influence the demography of wild primates? Evidence from long-term life-history data in seven species. http://onlinelibrary.wiley.com/doi/10.1111/gcb.13754/full)