Snapshot Serengeti is a long-term camera trapping study that helps researchers monitor wildlife populations and overall biodiversity in Serengeti National Park, Tanzania. The grid consists
Observing animals in the wild
Over the last 45 years, the University of Minnesota Lion Project has discovered a lot about lions – everything from why they have manes to why they live in groups. Now we’re turning our sights to understanding how an entire community of large animals interacts. We currently monitor 24 lion prides in Serengeti National Park, Tanzania, using radio-tracking. To collect information about other species, we’ve set out a grid of 225 camera traps. With photographs from these cameras, we’re able to study how over 30 species are distributed across the landscape – and how they interact with lions and one another.
Our scientific questions
Understanding how competing species coexist is a fundamental theme in ecology, with important implications for food webs, biodiversity, and the sustainability of life on Earth. Much of our current research focuses on how carnivores coexist with carnivores, herbivores with herbivores, and the joint dynamics of predators and their prey. These insights will guide strategies for species reintroduction, conservation, and ecosystem management around the world.
Carnivore Coexistence: Carnivores eat meat. If two carnivore species eat the same prey, one of those species can outcompete the other, preventing coexistence of both species in the same area. Even where carnivores don’t compete for the exact same prey, aggressive interactions such as scavenging from and killing each other can prevent coexistence. Research in other parts of the world suggests that when one species avoids the other, the two species might be able to coexist, but coexistence may depend on the structure and complexity of the habitat. Our cameras reveal whether lions, leopards, cheetah and hyenas avoid each other in space or in time and the extent to which this varies across the landscape.
Herbivore Coexistence: Herbivores eat plants. The Serengeti supports sixteen different species of hoofed herbivores. Although these species don’t kill or steal food from each other, we still don’t really understand how they all manage to coexist in this system. Herbivores that are able to feed most efficiently may also be more likely to be killed by predators, and this could explain some of the coexistence. Another possibility is that different herbivores may specialize on different habitat areas. We are using the camera traps to investigate these ideas, as well as study how the annual migration of 1.5 million wildebeest and zebra through our study area affects changes these dynamics.
Predator Prey Relationships: Recent advances in ecology have suggested that there may be costs to herbivores when they avoid predators. For example, if predators hunt in areas with the best plants, herbivores may avoid those areas and only be able to eat plants that aren’t as good. We are using the camera trap data on herbivore distributions to study whether herbivores are found where the best food is or where the risk of being killed by predators is lowest.
What we do
We check on the camera traps in the course of daily lion monitoring. We change batteries, exchange the SD cards, and cut tall grass in front of the camera so that grass waving in the wind doesn’t accidentally trigger the sensor. 225 cameras are a lot of work! When things run smoothly, a camera can last about two months before needing maintenance. But that’s not always the case – sometimes we return to a camera only to find it chewed on by hyenas or torn down by elephants, waterlogged from a heavy rain or infested by ants.
How the cameras work
The cameras use passive infrared sensors that are triggered when an object warmer than the ambient temperature moves in front of the sensor. This is usually an animal…but tall sunlit grass can also trigger the camera when it blows in the wind. We currently use the Scoutguard 565 and DLC Covert Reveal models – these are incandescent flash cameras (with a white flash). Some people worry that incandescent flashes startle the animals, but in our study area the same individuals often come back to the same camera site night after night!
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