In North America there are thousands of populations. The total adult population size is probably in the hundreds of thousands or millions. It is still widespread and common in many areas, especially in lowland areas, but many other populations appear to have declined, especially in the Rocky Mountains of Colorado, Wyoming, and Montana, where the species no longer is extant in most localities where historically it occurred (Corn and Fogleman 1984; Corn et al. 1989; Koch and Peterson 1995; J. Reichel, unpublished map, 1996). It has nearly disappeared from the Greater Yellowstone ecosystem, though natural wetland habitats remain apparently undisturbed with acceptable water quality (Koch and Peterson 1995). It is apparently extirpated from most of its historical range in Washington (Leonard et al. 1999). It has not been observed in recent years in the few historical localities in Oregon (Csuti et al. 1997). Local extirpations have been reported for Alberta (Russell and Bauer 1993) and British Columbia (Orchard 1992). In Panama it can be common in some areas but declining in parts of its range.

Decreasing