Not much has been known about the distribution and range of some of Africa’s most secretive predators, including leopards and other big cats that hunt at night and sleep during the day. Where do they prowl after dark? Do they steal across farms when everyone is asleep?
By using a network of more than 400 camera traps, researchers have been able to monitor a number of carnivores as they move around in darkness across the northern part of the East African country Tanzania.
NGS camera trap shot of a leopard by Michael Nichols
The result of the investigation, according to the study by the Zoological Society of London (ZSL), the Wildlife Conservation Society (WCS), and the Tanzania Wildlife Research Institute (TAWIRI), is that the meat-eaters tend to stay within specific habitat, avoiding other areas.
“Surprisingly, all the species surveyed tended to avoid croplands, suggesting that habitat conversion to agricultural land could have serious implications for carnivore distribution,” said Wiley-Blackwell in a statement about the research. The study was published in the current issue of the Wiley-Blackwell research journal Animal Conservation.
NGS portrait of a leopard (Panthera pardus) in Africa by Chris Johns
The cameras recorded 23 out of 35 carnivore species known to occur in Tanzania.
Unsurprisingly, the cameras demonstrated that carnivore biodiversity tended to be higher in national parks than in game reserves and forest reserves.
Photo of serval caught in camera trap courtesy of Zoological Society of London
“We explored habitat use for seven species for which we had sufficient information. All species tended to be found near rivers and southern Acacia commiphora woodlands (except one mongoose species), and avoided deciduous shrubland, favouring deciduous woodland and/or open grassland,” the researchers said in their paper.
“Camera traps provide a fantastic opportunity to gain knowledge on habitat use and spatial distribution of otherwise elusive and poorly known species,” said Sarah Durant from ZSL. “This methodology represents a powerful tool that can inform national and site-based wildlife managers and policy makers as well as international agreements on conservation.”
Nocturnal species under-reported
Until now, many of the species had been under reported because of their nocturnal habits, or because they live in heavily forested areas.
Photo of caracal caught in camera trap courtesy of Zoological Society of London
“The strength of the technique to document habitat preference of elusive species is highlighted by camera trap observations of bushy tailed mongooses–including the first ever records of this species from one of the most visited areas in the country,” the researchers said.
Previously thought to be rare, the bushy-tailed mongoose (Bdeogale crassicauda) is in fact much more widely distributed in northern Tanzania than had been known, the scientists found by studying the camera trap images.
“These data can also be used to understand how Tanzania’s carnivores may respond to habitat changes caused as a result of environmental change,” the researchers noted.
Carnivores are sensitive to development
“Carnivores are generally thought to be relatively tolerant to land conversion, yet our study suggests that they may be more sensitive to development than previously thought, and that protected areas need to be sufficiently large to ensure that these charismatic animals will roam in Tanzania for the decades to come,’ said Nathalie Pettorelli from ZSL.
All species were also foiund the be affected by rivers and habitat, and the analysis provides important information relevant to the examination of future impacts of climate change, the scientists said.
The project continues to map carnivore distribution across the country, working closely with the wildlife authorities to support local conservationists and to generate information that is used to inform conservation planning.
“Our study provides a first example where camera-trap data are combined with niche analyses to reveal patterns in habitat use and spatial distribution of otherwise elusive and poorly known species and to inform reserve design and land-use planning,” the scientists said.
“Our methodology represents a potentially powerful tool that can inform national and site-based wildlife managers and policy makers as well as international agreements on conservation.”
Photo of wild dog and warthog caught in camera trap courtesy of Zoological Society of London
Lions, cheetahs, leopards, jaguars, and other top felines are quickly disappearing, all victims of habitat loss and degradation as well as conflicts with humans.
To address this critical situation, the National Geographic Society has launched the Big Cats Initiative, an emergency intervention to halt the alarming decline of big cats combined with longer-term strategies to restore populations. For more information and to learn how you can help, visit the Big Cats Initative Web site.