Species Profile: McCown's Longspur

A Prairie Classic

McCown’s Longspur is the quintessential bird of the shortgrass prairie. Its breeding range is center on the two northern shortgrass Bird Conservation Regions – the Badlands and the Prairies (BCR 17) and the western Prairie Potholes (BCR 11) and its winter range confined to the two southern shortgrass BCRs - the Shortgrass Prairie (BCR 18) and Chihuahuan Desert (BCR 35). It shuns the relatively lusher sites preferred by its relative, the Chestnut-collared Longspur, keeping to starker sites once presumably created by bison and now maintained by intense grazing by cattle.

Like many other shortgrass birds avoiding predation in an environment with essentially no cover, McCown's Longspur is drably plumaged. Lacking perches from which to sing, as with several other shortgrass birds; the male makes note of himself with an aerial display of song and exposure of bright white underwing linings. Females build their nests on the ground, often adjacent to clumps of vegetation.

The number of species of birds characteristic of the shortgrass is small, but as a whole the group warrants considerable conservation attention. Population trends in these birds are difficult to assess because most of them shift around in their breeding range in response to weather. Lark Buntings, in particular, are renowned for mass movements tracking pattern of the region's scant rainfall. Population size at any one spot is therefore erratic, but careful analysis of range wide trends show that at least some of these birds are suffering steep declines. Evidence for the status of McCown's Longspur is probably too weak to draw inferences one way or another. It surely suffers when grassland is converted to agriculture, but its preference for overgrazed sites may make it more resilient than others in its species suite.

The long-term future of McCown’s Longspur and many other grassland birds is closely tied to the health of the ranching economy of the Great Plains. Huge expanses of grasslands are not going to be managed primarily for conservation with disturbance driven by bison, prairie dogs, or fire. Cattle grazing is the best viable means of recreating that situation. Alternative land uses, notably agriculture, essentially eliminate habitat for all but the most tolerant bird species.

As with most of our birds, it is not clear which forces within their yearly life cycle limit McCown's Longspur population size. It is often assumed that limitations of reproductive success on breeding grounds are key, but observations that many species that co-winter in the Chihuahuan Desert are in decline suggest that there are winter population limiting factors. Further, the impact of adult mortality during migration is unclear (some of the current concern regarding communication towers is rooted in a huge mid-migration kill of Lapland Longspurs, a close relative of McGown's on the Great Plains). The Western Great Plains has the most cohesive year-round avifauna in North America, and all of these potential limiting factors for McCown's Longspur and many other grassland birds can be dealt with in this latitudinal swath of four Bird Conservation Regions. The fact that these BCRs extend from Canada through the United States and deep into Mexico emphasizes the need for and value of trinational collaboration within the North American Bird Conservation Initiative.