By David Cronenwett
Among the many avian rites of spring on the Rocky Mountain Front, and across much of Montana’s open country, is the return of our Long-Billed Curlews (Numenius americanus) to their prairie land breeding grounds. It’s a less gaudy event than the typically massive snow geese migration, but spectacular in its own way. Sometimes these creatures can be found “staged up” on the grass in concentrations of nearly a hundred as they come into the country. It doesn’t last long though; they will quickly pair up and become territorial during the nesting process. Long bills are the largest sandpiper in North America and one of the largest on earth. The females are significantly larger than the males and have noticeably longer bills. These birds return to Montana’s grasslands between April and May from coastal or inland valley wintering areas in California, Central America and the Gulf of Mexico. These curlews are ground nesters; a small depression is created in exposed areas of short-grass prairie and lined with available soft material. Four-egg clutches are most typical. After a nearly 30-day incubation period, the precocial young are born and ready to move.
Soon after hatching, curlew parents will usually relocate the new family to the cover of taller grass as a precaution against predation. Then, in about 2–3 weeks, the female will essentially abandon the young, leaving the remaining chick-rearing to dad. The curlew’s ridiculously long bill is actually a well-adapted foraging tool in both its wintering and breeding habitats. In Montana, much of what curlews consume are grasshoppers and other insects, which can occur in great abundance. Many people find the plaintive cry of these birds to be strongly evocative of Montana’s wide-open, native grasslands. Until recently, very little was known about migration routes and other basic facets of this bird’s ecology. Nearly all wildlife agencies in the U.S., Canada and Mexico consider Long-Billed Curlews to be an “at-risk” species because of threats to its breeding habitat. Once again, this may speak to the cultural bias many of us have against grasslands as anything other than grain-growing, energy-producing areas that lack aesthetic appeal or biological value in general. But nothing could be further from the truth. The grassland habitats upon which curlews and other species depend are some of the richest and threatened ecosystems in all of North America. Because only 1 to 2 percent of relatively intact, native prairies exist on the continent, the concern for long-term viability of many creatures is serious. While we can find curlews in intact grasslands, working ranchlands, and even with a mix of cropland, they are still an uncommon bird. Ecologists estimate a global population of about 123,000 individuals. Although greater than some earlier estimates, research points to an overall decline and suggests a need for immediate, international conservation measures. Not surprisingly, Long-billed Curlews in Montana seem to be doing better than in other states, and collaborative efforts to protect grasslands and enhance working ranchlands may be helping our populations.
My connection with curlews is strongly associated with the Front; I’ve watched them go about the business of life in that beautiful but unforgiving landscape over many springtimes. High winds and predictably unpredictable, late snowstorms probably kill birds with some regularity. Then there are the many eaters of curlews; I have watched nest raids by coyotes, ravens, badgers and foxes as well as the outright slaying of adult birds by falcons and golden eagles. And it’s hard to watch knowing what we know about the sober conservation challenges for this and all grassland species that lie ahead. If we consider the stress of natural predation in addition to habitat loss due to wind farms, oil and gas development, invasive species and conversion of native prairie to crop production, things can look dire indeed.