is used until weaning in mid-May. Areas inhabited nonseasonally by wolverines are thus restricted to zones with late-spring snowmelts. This fact has led to concern that global warming will shrink the ranges of wolverine populations. This requirement for large territories brings wolverines into conflict with human development, and hunting and trapping further reduce their numbers, causing them to disappear from large parts of their former range; attempts to have them declared an endangered species have met with little success. In February 2013, the United States Fish and Wildlife Service proposed giving Endangered Species Act protections to the wolverine due to its winter habitat in the northern Rockies diminishing. This was as a result of a lawsuit brought by the Center for Biological Diversity and Defenders of Wildlife. The Wildlife Conservation Society reported in June 2009 that a wolverine researchers had been tracking for almost three months had crossed into northern Colorado. Society officials had tagged the young male wolverine in Wyoming near Grand Teton National Park, and it had traveled southward for about . It was the first wolverine seen in Colorado since 1919, and its appearance was also confirmed by the Colorado Division of Wildlife. In May 2016 the same wolverine was killed by a cattle ranch-hand in North Dakota, ending a greater-than-800-mile (1287 km) trip by this lone male wolverine, dubbed M-56. This was the first verified sighting of a Wolverine in North Dakota in 150 years. In February 2014, a wolverine was seen in Utah, the first confirmed sighting in that state in 30 years. In captivity Around a hundred wolverines are held in zoos across North America and Europe, and they have been bred in captivity, but only with difficulty and high infant mortality. Name The wolverine's questionable reputation as an insatiable glutton (reflected in the Latin genus name Gulo) may be in part due to a false etymology. The less common name for the animal in Norwegian, fjellfross, meaning "mountain cat", is thought to have worked its way into German as Vielfraß, which means "glutton" (literally "devours much"). Its name in other West Germanic languages is similar (e.g. ). The Finnish name is ahma, derived from ahmatti, which is translated as "glutton". Similarly, the Estonian name is ahm, with the equivalent meaning to the Finnish name. In Lithuanian, it is ernis; in Latvian, tinis or āmrija. The Eastern Slavic росомаха (rosomakha) and the Polish and