Sharing space with humans doesn’t necessarily contribute to population decline among some endangered species, according to a study with African forest elephants.
Conservation of a protected or endangered species requires frequent monitoring and the dynamic techniques biologists utilize to ensure the survival of threatened animals. Often, scientists study biodiversity at all levels—from genes to entire ecosystems.
For a new study, researchers used genotyping to study the movement patterns of African forest elephants in protected and unprotected regions of Gabon to better understand how human occupation of these areas might affect elephants on the African continent.
Genotyping is helping conservation biologists determine the best course of action to ensure biodiversity and the preservation of various species in the US and abroad.
“Many times, analyzing dangerous animals with a hands-on approach is risky, so genetic samples and traces collected through hair samples, fecal samples, and other noninvasive means offer a safer technique to examine species,” says Lori Eggert, associate professor of biological sciences at the University of Missouri.
“In Africa, protected areas are often designed around sites that support endangered species such as large mammals. We were tasked with studying elephants outside a protected region in an area that includes humans, oil-drilling platforms and disturbances by machinery.
“We examined population structure, movement patterns, and habitat use by sex and age group. We also studied how the elephants moved between the protected regions and the unprotected regions during wet and dry seasons.”
Year-round elephant habitat
Between 2002 and 2011, the population of Central African forest elephants declined by 62 percent and their geographic range decreased by 30 percent. The largest remaining concentration of this species, approximately 53,000 individuals, is in Gabon where officials have established 13 national parks designated as habitats for elephants.
Eggert and fellow researchers from the Smithsonian Conservation Biology Institute (SCBI), were tasked with determining movement between two of the parks that were separated by an unprotected area and how the elephants migrated between them. What the scientists found was that the interconnected region not designated as a national park provides year-round habitat for elephants and is important to the conservation of the species.
“We discovered that elephants tend to use the unprotected area as much as they do the protected parks,” says Eggert “A resident population exists in the unprotected area, even though drilling occurs there and humans are present. Some of the elephants seem to consider this their home range and, instead of moving back and forth between the national parks, they inhabit the unprotected area during the rainy and dry seasons.
“What perhaps is most important is that a relatively large number of females inhabit this area, making this region much more important than we first realized.”
A keystone species
For the study, published in Conservation Biology, researchers collected samples from elephant droppings in the unprotected area and in the national parks. They then extracted DNA from more than 1,000 samples and genotyped them.
Eggert and colleagues detected more than 500 elephants in the unprotected area during both the wet and dry seasons, suggesting the region supports a resident population.
“Elephants are considered to be a ‘keystone’ species, or a species that is especially important to the health of ecosystems in Africa,” Eggert says. “We’re all affected by the health of the forests in Africa, Central America, and here in the US. The fact that elephants are surviving in a place where drilling for oil is happening is exciting and gives us a glimpse at how to study species in our own country.”
The work conducted with elephants in Africa involves methods that can be used to study species worldwide, Eggert says. Her lab recently worked with the Missouri Department of Conservation to analyze black bears in Missouri and Arkansas, and also has collaborated on the analysis of otters and hellbenders in Missouri rivers.
Researchers at the Smithsonian Institution, the University of Groningen, the University of Oxford, and the Centre National de la Recherche Scientifique et Technologie in Libreville, Gabon contributed to the study.
Source: University of Missouri