The decline of turtles could have ecological consequences

About 61% of the 356 species of turtles on the planet are threatened or already extinct and their decline could have ecological consequences.

These results are according to a new paper in Bioscience synthesizing the global turtle situation and their ecological roles by scientists from the US Geological Survey, the Tennessee Aquarium Conservation Institute, the University of California, Davis and the University of Georgia.

"Our goal is to educate the public about the many critical ecological roles played by turtles worldwide and to raise awareness of these iconic animals whose ancestors have walked with dinosaurs," said Whit Gibbons, professor emeritus at Savannah Ecology Laboratory. Odum School of Ecology, said. "These modern descendants of an ancient lineage are touchstones for explaining how human influences are causing the decline of much of the world's wildlife, and we hope everyone will be encouraged to make concerted efforts to conserve habitats. natural. "

"Turtles contribute to the health of many environments, including desert, wetland, marine and freshwater ecosystems, and declines can have negative effects on other species, including humans," he said. said Jeffrey Lovich, scientist and senior author of the USGS, "I said.

On the list of the most threatened

Turtles are now among the most endangered group of animals on the planet, more than birds, mammals, fish or amphibians.

These iconic animals have survived dinosaurs and have traveled the Earth for more than 200 million years. Habitat destruction, overexploitation of pets and food, diseases and climate change are the reasons for the desperate situation of turtles around the world.

Scientists have synthesized existing published studies to draw attention to the plight of turtles and identify what could be lost from an ecological point of view as they continue to decline and disappear. .

This article provides the first major revision of the various functional roles that large populations and diverse turtle communities provide from an ecological point of view. This includes maintaining healthy food webs, dispersing seeds and creating necessary habitat for other species.

Impact on the ecosystem

Turtles can be major players in ecosystem food webs because they can be herbivores, omnivores and carnivores. They range from specialists, or feed from one to a few food sources, to general practitioners, feeding on a wide range of products. Their varied eating habits allow them to influence the structure of other communities in their habitat.

Some species of turtles are numerous and can produce hundreds of pounds of turtles per acre, which makes them ecologically important because of their mass only. Such a mass of turtles equates to large amounts of potential food for organisms that feed on turtles or their eggs.

Turtles can play an important role in dispersing the seeds of dozens of plant species. Some turtle species may even be the main seed dispersal agents for some plants. All seeds are not destroyed by the digestive tract. In fact, there are specific seeds that have higher germination rates after being eaten and past.

Habitats for other species

Some turtles, such as the Agassiz desert turtle in the American Southwest and the gopher turtle in the southeastern US, are digging large burrows creating habitat for other species.

For example, the gopher tortoise can dig burrows longer than 30 feet. Soil mounds near the entrance to burrows can create new habitat for some plant species, increasing the diversity of plants near burrow entrances. Burrows are used by hundreds of other species, including spiders, insects, snakes, amphibians, other reptiles, rabbits, foxes and even bobcats.

"The ecological importance of turtles, particularly freshwater turtles, is underestimated and they are generally little studied by ecologists," said Josh Ennen, a researcher at the Tennessee Aquarium Conservation Institute. "The alarming rate of turtle loss could profoundly affect the functioning of ecosystems and the structure of biological communities around the world".

"We need to take the time to understand the turtles, their natural history and their importance to the environment, or risk losing them in a new reality where they do not exist," said Mickey Agha, a scientist at UC Davis. "People who are born in a world without large numbers of long-lived reptiles, such as turtles, may call this" the changing standard "as the new standard.