Migration, because the oil and gas industries threaten animals

In late spring, when the days begin to get longer, i mule deer (Odocoileus hemionus) of central Wyoming begin to search for mugwort. The animals stop for the winter in the low plains of the US state, where the first green shoots appear, offering a scarce amount of food but rich in protein and easily digested. These tender shoots quickly disappear, but the flowers keep moving, rising upward as the spring heat reaches colder climates. When this “green wave” of vegetation rises, the mule deer chase it. Sometimes mammals travel hundreds of kilometers, until they reach the mountain ranges where they spend the summer. Ideally, their journey is perfectly timed to ensure that they store enough fat on their legs to survive the summer and winter.

In recent years, however, at least for a group of mule deer following this green wave has become more difficult. The animals leave when the first vegetation begins to appear, but then their journey stops. The guiltyaccording to research released last week on Nature Ecology and Evolutionis humanity. Specifically, realization of two deposits of gas natural along the way deer, which involved a variety of very noisy activities, including drilling, explosions and truck movements. Although the animals spent only a short time near the drills, the researchers found that the operations had a huge impact on their spring passage, which should result in less fat, fewer pups and higher mortality.

I study

What surprised the researchers was the difficulty of adaptation of the deer. Despite the common idea that the inconvenience caused by oil and gas extraction decreases after the initial din of exploration and drilling, the deer also appeared to be disturbed by the following activities and apparently had difficulty in choosing a better path to get around the new obstacles. For their migrations, the animals continued to follow the ideal path they had memorized. “They are sensitive – explains Ellen Aikens, ecologist at the South Dakota cooperative fish and wildlife research unit, who conducted the study -. They are not that flexible when deciding where to go“.

The study looked at the individual movements of dozens of mule deer that had been captured over the years with mesh rifles mounted on helicopters, transported to a different location and on which gps collars were installed. “It is no small feat to put a collar on an animal“, says Teal Wyckoff, co-author of the study, and who now works for the non-profit Nature conservancy. The goal, explains Wyckoff, was to shed light on the movements of populations that had remained inscrutable to researchers, in an area they predicted a rapid boom in the energy sector.The monitoring project began in 2005, as companies were pouring into Wyoming to extract methane from the region’s coal fields.