Battling For Biodiversity
In war, the humans engaging in battle are not the only ones affected. Armed conflict is an important driver of ecological change, and one that is often understudied and overlooked in the literature. Loss of biodiversity secondary to armed conflict is a particular concern in Africa, which is home to an abundance of wildlife, and is also the setting for the majority of wars since 1950.
There are many reasons human conflict has negative repercussions for wildlife. War may displace humans from their homes, leading them to encroach on the habitats of other species. War also incentivizes the hunting and exchange of animals for weaponry, and diverts government attention away from conservation.
Large mammals such as elephants, hippos, and lions are the primary victims of ecological destruction resulting from armed conflict. This study sought to inform post-war efforts to recover large-mammal populations by charting the decline and recovery of wildlife populations as a result of the Mozambican Civil War from 1977 to 1992.
This study assembled data from 15 aerial wildlife counts of Mozambique’s Gorongosa National Park (GNP) pre-war (1968-1972) and post-war (1994-2018). The GNP was chosen as the study site because it supported great biodiversity prior to the Mozambican Civil War, and was greatly affected during the war period.
By running a spatial analysis on the aerial maps they collected, the researchers were able to calculate both the total biomass of wildlife in the GNP and the abundance of individual species. They measured both the decline of populations and their recovery. Nine herbivorous species were monitored–elephants, hippos, buffalos, elands, zebras, sables, hartebeests, wildebeests, and waterbuck. In addition to plotting the recovery of these nine focal species, the researchers also collected data on over twenty other species.
The results revealed that total biomass density fell by over 90% from the pre-war to the post-war period. The largest herbivores – elephants, zebras, hippos, buffalos, and wildebeests–took the hardest hit. By 2018, the total biomass had recovered to about 95% of the pre-war baseline. However, the recovery was asymmetrical, with waterbuck contributing the most to the total biomass by 2018 and replacing buffalo as the dominant species. Zebra, baboons, hyenas, jackals, and leopards were rarely sighted in the post-war years, although the lion population remained stable.
While the recovery of total biomass to 95% of the pre-war baseline is considered a success by many, when the results are divided by species, it becomes obvious that many species are still struggling in the post-war era. Surprisingly, waterbuck accounts for much of the total biomass. The decline in the predator population potentially contributed to the waterbuck’s success, as did the decline of competitors, namely the buffalo. Additionally, waterbuck were able to survive year-round in the floodplain grasslands, a habitat inaccessible by humans, which may have sheltered them from direct war impacts.
Large-scale human intervention is necessary to prevent the waterbuck from outcompeting other herbivorous species to extinction, and to encourage the recovery of species hit hardest by the war. These results suggest that wildlife censuses during and after wartime are necessary to inform rehabilitation of large-mammal populations that have been impacted by human conflict. Animal advocates should take note.