He's also a lagomorph expert for the International Union for Conservation of Nature Species Survival Commission.

The wildlife passages over the G7 Expressway, built on a total cost of more than 200 million yuan ($29 million), aim to minimize human intervention and guarantee safe passage for the animals. They are covered with sand and gravel to simulate natural conditions. The railway-wildlife passage-highway structure is an unprecedented trial in the country, Li says.

The expert believes the passages have met the basic needs of wildlife migration in the area.

At first, he opposed the construction plan because he thought the railway intersecting the highway meant the two enclosed roads would block animal migration from all sides.

However, he and his colleagues thrashed it out with decision-makers, architects and construction units and, together, conceived the wildlife-passage solution.

Li's team surveyed the progress of the project on-site and suggested where to set up some of these passages. They especially helped determine the elevation of the downslopes, which determines the height of the roadbed and directly affects the cost of the expressway project.

Li had to take the concerns of the construction team into consideration. Based on monitoring data, he put forward a minimum height of 3.6 meters instead of 4.5 meters, as they had originally presumed, which helped the construction in many ways.

Previously in the Kalamaili Mountain region, he and colleagues had just completed a similar three-year monitoring project after a railway was built. There, they also guided the animals with water, food and odor to help them adjust to wildlife passages.