Colorado officials are preparing a lawsuit challenging the federal government’s decision to protect the Gunnison sage grouse. The Attorney General’s Office notified the Interior Department and the U.S. Fish and Wildlife Service on Friday that the state planned to sue. The state says that in listing the bird as threatened, the Fish and Wildlife Service failed to rely on the best available science, consider conservation efforts by landowners and state and local governments and study the economic effects of the designation. The Fish and Wildlife Service listed the bird as threatened in November, and about 5,000 remain, only in Colorado and Utah. Some environmental groups also plan to sue, saying threatened status is too weak and the birds should be considered endangered, which carries stronger protections. Federal protection could bring restrictions on agriculture and oil and gas wells. The decision is considered a precursor to a decision on the Greater Sage Grouse, which has been thriving in Colorado and Wyoming, and is present in 11 western states.