Whether chimpanzees, bonobos or gorillas: the African great apes are already seriously threatened. But it gets worse: The combination of climate change, land use changes and population pressure could shrink primates’ habitats by 85 to 92 percent over the next 30 years, according to researchers. For the long-term protection of the populations, the previous protective measures are therefore not sufficient.
Scientists have been sounding the alarm for a long time: many great apes are on the verge of extinction due to poaching and the loss of their habitats. In addition, climate change and the associated changes in weather patterns and precipitation are also changing the natural habitats of primates. That could accelerate their decline. Ten years ago, chimpanzees were predicted to lose 50 percent of their habitat due to climate change, and even 75 percent for gorillas.
How do climate change and co. Affect habitats?
According to the current state of knowledge, an international team of researchers led by Joana Carvalho from Liverpool John Moores University has now examined how the situation of primates could develop. For their analysis, they quantified for the first time the total impact of changes in the climate, land use and population numbers in the distribution areas of the African great apes for the year 2050. In addition, they used data from the International Union for Conservation of Nature (IUCN) on the occurrence of around 5,200 African great apes together. They provide information about the status of the populations over the past 20 years, the threats and protective measures.
In their forecasts, the research team took into account best- and worst-case scenarios with regard to climate protection. “Best case means that carbon emissions are slowly falling and that suitable measures are taken to contain them,” explains Jessica Junker from the German Center for Integrative Biodiversity Research in Leipzig. “Worst case assumes that emissions will continue to rise unchecked.”
Move or die
The modeling showed: Both scenarios differ in their effects, but both result in an enormous loss of habitat for the African great apes. Under the “best-case scenario”, the primates will lose around 85 percent of their range in the next few years, around half of these areas are outside national parks and other legally protected areas. In the worst-case scenario, the prognoses even showed a loss of 94 percent of the habitat, 61 percent of which is attributable to unprotected areas.
For chimpanzees, gorillas and bonobos this means: If they want to survive, they have to adapt and leave their traditional range. Because due to climate change, the forests they inhabit are becoming increasingly drier and hotter and the vegetation is changing. In order to still find enough food and sleeping trees, they have to move to cooler areas – for example to higher areas. The populations that have this option could survive, according to the scientists, and even increase their range – by 20 to 50 percent, depending on the species and scenario.
Previous protected areas are not enough
The problem, however, is that not all great ape populations have this option – for example because there are cooler refuges in their surroundings or because the vegetation there does not change according to their nutritional requirements. It is therefore all the more important to take protective measures that secure suitable habitats for our closest relatives: “The fact that the greatest losses of the range outside of protected areas are to be expected clearly shows that the current network of protected areas in Africa is still inadequate to preserve the habitats for great apes To effectively link great ape populations, ”says Carvalho.
The research team therefore demands that effective conservation strategies be planned for each primate species, taking into account existing and proposed protected areas. The habitat suitability models could help here. In addition, they believe that maintaining and establishing connections and corridors between habitats will be critical to the survival of African great apes. Land use planning and measures to mitigate climate change urgently need to be integrated into the government policy of those countries where great apes live, according to the research team.
Source: German Center for Integrative Biodiversity Research, Article: Diversity and Distributions, doi: 10.1111 / ddi.13358