Habitat
This species breeds in the Great Plains of Canada through Montana and Wyoming and barely into Colorado. Ideal nesting habitat consists of blue grama and buffalo grass, with scattered purple three-awn, western wheatgrass, needle-and-thread grass, and taller vegetation such as opuntia cacti, broom snakeweed, rabbitbrush, and prairie sagebrush. In this semiarid shortgrass-steppe habitat, Chestnut-collared Longspurs use areas of taller vegetation, sometimes called “mid-grass" or "mixed-grass" prairie. Overgrazed pastures may, in some cases, mimic the structure of shortgrass prairie and host breeding Thick-billed Longspurs. During migration and in winter, Thick-billed Longspurs use similar short, open habitats, as well as agricultural fields and dry lake beds.
Back to topFood
Thick-billed Longspurs forage on the ground, walking along in search of seeds, insects, and other invertebrates. When an insect such as a grasshopper flushes, these birds may run rapidly after it or sometimes pursue it into the air. For smaller or less mobile prey, such as ants or caterpillars, they simply pick the items from low vegetation or the ground. During the summer, they feed their young mostly insects, particularly grasshoppers, stripping the wings and legs before giving the items to chicks. Among the many species they consume are dusky grasshopper, speckle-winged rangeland grasshopper, club-horned grasshopper, and clearwinged grasshopper. They consume seeds year-round, but seeds of grasses and forbs, as well as grains (such as oats and wheat), form most of the diet in winter. Seeds of knotweed, sunflower, goosefoot, needlegrass, and sedges are important parts of the diet.
Back to topNesting
Nest Placement
The female makes initial nest scrapes at several sites, usually at the base of taller vegetation such as a bush, bunchgrass, or cactus, and then chooses which will be the nest site.
Nest Description
The nest is very similar to Horned Lark nests: a small cup built into a scrape (flush with the ground). It's made of grass stems (sometimes with lichen, bark, roots, and weed stems) and lined with fine grasses, fur, hair, wool, or feathers. Nests average about 3.4 inches across, with the interior cup 2.5 inches across and 2 inches deep.
Nesting Facts
Clutch Size: | 2-6 eggs |
Egg Description: | Eggs white to pale olive, with brown scrawls and lavender or rust-colored speckling. |
Condition at Hatching: | Helpless. |
Behavior
Male Thick-billed Longspurs begin breeding displays soon after returning in spring, though in very cold, snowy springs they may remain in flocks for some time in breeding areas. Males sometimes arrive on breeding grounds a few days before females. Males display to females directly, on the ground, by raising one wing (to show the snow-white underwing) and singing. In their captivating aerial display they flutter upward, then drop toward earth on raised wings and spread tail while singing. Often they land right next to potential mates, circling the female and raising one wing. Receptive females bow and flutter their wings in response. Males continue to display in the air right over incubating females and chase rival males away in flight. Thick-billed Longspurs are typically monogamous in their mating system, but some males have two female partners (and nests) simultaneously. Females select the nest site and build the nest. The male sometimes parades around with grasses in the bill, staying close to the female, probably guarding her in case other males appear. Both adults incubate the eggs and feed the young. After the breeding season, Thick-billed Longspurs form flocks that soon begin the southward migration.
Back to topConservation
Populations declined by an estimated 5.9% per year between 1968 and 2015, according to the North American Breeding Bird Survey—equivalent to a cumulative decline of 94% over that period. Partners in Flight estimates a global breeding population of 840,000 and rates the species a 15 out of 20 on the Continental Concern Score, placing it on the Yellow Watch List for declining species. At current rates of decline, the species will lose another half its population by 2080. Habitat destruction in the prairies and Great Plains has been the primary driver of their population collapse. Secondary causes include pesticides and other pollutants.
Back to topCredits
Partners in Flight (2017). Avian Conservation Assessment Database. 2017.
Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2017). The North American Breeding Bird Survey, Results and Analysis 1966–2015. Version 2.07.2017. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.
Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.
With, Kimberly A. (2010). McCown's Longspur (Rhynchophanes mccownii), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.