 Many populations of grassland birds and mammals
are in sharp decline. Black-tailed prairie dogs (candidate species) are much reduced, and
the obligate associated species, the black-footed ferret, is endangered. Populations of
other species of northern plains grassland vertebrates, such as the swift fox, mountain
plover (threatened), long-billed curlew, sage grouse, burrowing owl, Sprague’s pipit,
Baird’s sparrow, lark bunting, and chestnut-collared longspur are in various degrees
of chronic decline. The Breeding Bird Surveys, which began in the mid-1960s, indicate
consistent widespread declines of grassland birds across most of their breeding range.
Populations of at least 13 grassland bird species dropped significantly between 1966 and
1996.Furthermore, populations of
prairie nesting northern pintails have been dropping since the mid-1950's. Prolonged
drought of the late 1980's and early 1990's saw pintail breeding populations fall to 1.8
million birds, their lowest numbers ever recorded. In 1999, following 5 years of excellent
water conditions, the pintail population rebounded to 3 million birds, but this figure is
still far below the North American Waterfowl Management Plan (NAWMP) objective of 5.6
million breeding birds. Researchers speculate that much of the pintails' major prairie
breeding range in Saskatchewan, Alberta, Manitoba, and the Dakotas has been permanently
altered by modern agriculture, and these landscapes may never again be productive pintail
breeding habitat. Fortunately, many parts of Montana still have exceptionally high
nest success due to extensive tracts of rangeland and Conservation Reserve Program
grasslands and a coyote dominated environment with relatively few red fox, raccoon, or
striped skunk. This geographical area with intact ponds and grasslands remains a critical,
"source" recruitment area for continental pintail populations. |
