Scientists advocate for the preservation of small mammals to safeguard critical ecosystems.

New article published in Journal of Animal Ecology It indicates that the current measures to protect grasslands in the Qinghai-Tibet Plateau are harmful to the ecosystem and should be stopped.

The current policy, introduced in 2000, calls for the elimination of small burrowing mammals. These include mountain-dwelling herbivores, plateau pikas, and other small rodents, the zukor. Both are basic species and are known as ecosystem engineers due to their modification and impact on the environment.

The report’s authors say current extermination programs are not based on studies that looked at the full effects of culling these rodents.

“The government agency’s policy of conducting large-scale animal cullings every year is not a good approach,” says Professor Johannes Knobs of the Department of Health and Environmental Sciences at Xi’an Jiaotong University Liverpool (XJTLU) and corresponding author.

Professor Nobbs and first author, Dr Wenjin Li of the School of Ecology at Lanzhou University, proposed replacing the eradication policy with a nature-based control strategy.

“Our research shows that using natural predators and other environmental factors to regulate mammalian burrowing can be a more sustainable and effective approach to grassland management.”

The study has important implications for grassland management practices around the world. Small burrowing mammals are common in grasslands, and their eradication can negatively affect ecosystem health and productivity.

Arbitrage

The grasslands of the Qinghai-Tibet Plateau play a crucial role in the quality of water flowing into major Asian rivers, including the Yangtze, Yellow, Lancang Mekong, Indus and Ganges. Grassland degradation can also increase the chance of flooding.

The campaign to permanently eliminate pikas and zocors is part of efforts by Chinese government agencies to protect the grasslands.

The policy is part of a national initiative, the Grassland Return to Grassland Project, and is based on the assumption that rodents cause damage to grasslands by consuming foliage, thereby competing with livestock for food, and causing soil erosion.

However, the new study discusses the irrationality and consequences of this policy and reports that small burrowing mammals could actually help prevent grassland degradation.

Professor Nobbs says: “If we look at grasslands, we will find many plant species, and not all animals eat the same plants, so it is necessary to look at the entire food chain rather than killing all the small mammals.”

The authors also say that burrowing animals can increase plant diversity because they increase seed dispersal and light availability by consuming taller herbivores. Their burrows provide refuge and habitat for other species and can help reduce surface water runoff and soil erosion.

The researchers advise that the eradication policy should be reconsidered and abolished, as small burrowing mammals play critical ecological roles in grassland management. They say that declining rodent numbers disrupt ecosystem processes and reduce biodiversity.

The research also indicates that the current poisoning method used to eliminate small burrowing mammals has many adverse effects that have been overlooked.

side effects

In the paper, the authors discuss the potential unintended consequences of using the highly costly and labor-intensive method of poisoning to kill small grassland mammals. These include the development of resistance to the toxins by the target species and potential harm to non-target species.

Additionally, this policy can increase human-wildlife conflict by reducing numbers of natural predators and creating imbalances in the ecosystem.

Professor Nobbs explains: “It is important to consider the indirect effects of reduced numbers of small burrowing mammals. If there are fewer small mammals, there is less food for their natural predators, such as red foxes, steppe cats, peregrine falcons, brown bears and mountain weasels.

“Not only will these large mammals start looking for alternative food sources and increasingly prey on livestock, causing more human-wildlife conflict, but their populations will also decline.

Thus, the policy of eradication causes the opposite effect of the intended policy, in that when the number of natural predators of pikas and zocors is reduced, the numbers of burrowing mammals can increase rapidly.

“This then requires more human control, which is costly and negatively impacts non-target species and the environment.”

Rethink control

The researchers suggest that the goal of controlling burrowing mammal populations should not be completely eliminated, but could be regulated through a nature-based control strategy that uses natural predators and other environmental factors such as their preferred plant species and vegetation height.

The report suggests measures such as providing nesting spaces for birds of prey and reducing overgrazing by livestock in grasslands. This allows the grass to grow and keeps the numbers of small mammals at a manageable level, as they prefer shorter plants.

The authors argue that this approach is more effective and sustainable for long-term grassland management than traditional approaches that rely heavily on human intervention and poisoning.

“By maintaining a low and constant densities of burrowing mammals using natural predators and environmental factors, we can promote sustainable livestock grazing practices while also preserving biodiversity and reducing human-wildlife conflicts,” says Professor Nobbs.

More research is needed to refine this approach and test its effectiveness in various grassland ecosystems. Nevertheless, the study findings provide important insights into the ecological roles of small, burrowing grassland mammals and how their presence may benefit ecosystem health and productivity.