Breeding & Nesting
Did You Know?
A sage grouse hen makes her nest on the ground – selecting a secret place under cover of sagebrush and often near tall grass. The nest is a bowl on the ground in soft soil that the hen lines with grasses, forbs, sagebrush and small twigs, plus downy feathers from her brood patch.
Courtship- Dancing males and picky females
Sage grouse courtship ranks as one of the top wildlife wonders of the world. Dozens of males gather as the sun rises on the prairie to display and vie for dominance in a show of strutting accompanied by an eerie popping sound as they inflate their chest air sacs. For grouse, it’s more than a two-step on a Friday night. It’s serious business. The males gather on a lek (open area in the sage brush) every morning before dawn throughout early spring, typically mid-March through early May.
The females show up about a week after the males established their territories and will move individually or in groups among the displaying males. By the end of the month, they will have made their selection. A female approaches her chosen mate by squatting low with her wings spread.
Female sage grouse are ready to breed as yearlings. A few dominant males tend to receive almost all the attention from the females. Peak mating time takes place shortly after sunrise, although the birds may occasionally mate at sunset or under a full moon. (For details on male behavior on the lek, see the behavior section).
Nesting– Hens in charge
Males play no role in nesting or raising chicks. After mating, the hens fly to suitable nesting habitat (from about a half mile to three miles away,but sometimes more than 12 miles off). Most hens scope out nesting spots one to two weeks in advance of mating. Yearling females sometimes wait until after mating to find a nest spot. The top choice is tall sagebrush with excellent canopy cover. Hens that nest under sagebrush have more than twice the success rate of hens that nest under other plant species.
Safe in the Sage
Sagebrush cover near nests is also important for success. Another key component is tall, dense grass—called residual grass, because it’s leftover from the last growing season. Making sure both residual grass and sagebrush are available for nesting hens greatly improves chances for nests to be hidden from predators. Herbaceous cover may give the birds extra scent barriers as well as hiding cover. The nest itself is a bowl-shaped depression that the hens scratch out and then line with soft materials—like leaves and feathers.
Some studies indicate hens favor nests with cover on two sides but not entirely surrounding their nest. This way, hens remain hidden but still have an escape route from predators. If a nest fails, females will re-nest—although this varies throughout their range. Adults will re-nest more than yearlings.
Egg-laying and Incubating
Sage grouse typically lay between six and 10 eggs that may range in color from olive-buff to greenish white with brownish dots. The first egg is laid from three to fourteen days after mating, and then at a rate of two eggs per three days. The hen begins incubating after laying the last egg. She leaves the nest briefly in early morning and evening to feed on leaves nearby. Her arrivals and departures are as stealthy as possible to avoid detection. She will even deposit large droppings away from the nest, likely to draw attention away from the actual spot.
Chicks –hatching and early life
The chicks hatch typically after 25 to 29 days. Not all chicks hatch- a brood may vary between 15 and 70 percent survival. Despite this great range, sage grouse are known for low reproductive rates and high annual survival compared to other game birds.
The chicks are precocial- covered in down with their eyes open. Soon after hatching, the brood follows the hen out of the nest to feed. In their first week, they often hide beneath the hen’s wings and ruffled breast feathers. The hen calls almost continuously to her chicks and her young call back in different pitches. The chicks are voracious eaters of insects and forbs, and grow quickly.
By 10 days chicks may start to fly weakly, and by five weeks are strong flyers. The broods stay together for 10 to 12 weeks. In late summer they head away from sagebrush that’s becoming too dry and find wet meadows and other sites that are high in leafy plants, wildflowers, and insects that also flourish in lusher habitats. After the broods split up, the juveniles may flock together or disperse as all sage grouse start to move toward their winter sagebrush habitats.