They also argue that out West the population is too thin for the wolves to set out from the recovery zones and into their former ranges in the southern Rockies and the Pacific Northwest.

• 他们也说，在美国西部以外的地方，灰狼的族群数目仍旧太少，还不足以从复育地区扩展开来、回到牠们原先在洛矶山南部与西北太平洋岸的分布地区。