I was hiking up a ridge near Dan Moller cabin with a friend late one fall. It was a soggy, quiet morning and we were wading through wet plants up to our knees, a little above tree line, when what sounded like a small explosion a few feet away sent me slithering a few steps downhill.
With my heart thumping, it took a few seconds to identify the dark shape flapping away — a grouse was the culprit!
Most people don’t give sooty grouse, aka “hooters,” much thought except in spring, when their deep hooting reverberates throughout the rainforest. I certainly wasn’t ready when I nearly got scared out of my Xtratufs! These birds, however, are year-round inhabitants of Southeast, skillfully moving below the radar most of the time.
Sooty grouse live as far south as California, reaching the northern part of their range in Southeast around Glacier Bay (with the exception of Prince of Wales Island). Sooty grouse live mostly in coastal forests, while the similar dusky grouse prefers drier inland habitat. Briefly considered two species in the 1930s and 1940s, for most of the twentieth century they were combined under the alias blue grouse. In 2006, however, DNA research revealed that the coastal birds and their inland cousins were genetically different enough to be considered two species after all. Of the two, only sooty grouse live in Alaska.
The spruce grouse is another species of forest grouse in Southeast. Although widespread in the Interior and Southcentral parts of Alaska, they have a much smaller outpost in Southeast than sooty grouse, mainly on Prince of Wales Island and a few neighboring islands. Spruce grouse don’t hoot; instead, they make a loud clapping sound with their wings to attract the ladies. They also look different than sooty grouse. Sooties have a dark gray-brown chest and belly, while spruce grouse have white striping on their undersides. In Southeast, spruce grouse have a black tail with white spots at the base, while sooties have a black tail with a light gray stripe across the end.
The most intriguing difference between spruce grouse and sooty grouse is only revealed during breeding season. Male sooties have air sacks that show as bare patches of skin on the sides of the neck, usually hidden underneath their feathers. When a male is trying to attract females, he inflates the air sacks and fluffs open the feathers so the air sack is ringed dramatically with white feathers. In Southeast, the air sacks are usually a deep reddish-purple, although in other regions they are bright yellow. The air sacks allow the sooty grouse to boom out his love song, sometimes so low-pitched you feel the sound more than hear it.
Sooty grouse have two survival tricks: hide or flee. Their shadowy coloration helps them hide in the dim light of the forest. Only females incubate eggs and care for the chicks, relying heavily on camouflage when sitting on a nest. The female only leaves the nest occasionally for short periods to feed until the eggs hatch. She’ll bravely stay on the eggs, hiding them with her body, until approached within a couple feet. Some people think this means the birds are “foolish,” but for every bird that you spot, you have no idea how many hidden birds you walked past!
Unlike the naked, helpless chicks of songbirds, grouse have “precocial” chicks: they are developed enough to walk soon after hatching. Mobility provides a better chance at survival. The female usually lays between six and eight eggs in a nest on the ground, tucked under a log, rock overhang, or vegetation cover. Usually all the eggs hatch within 24 hours of each other. The chicks are covered with down, which after a few hours of drying out helps keep them warm. The mother grouse will usually lead her family away from the nest the morning after the last chick hatches. The chicks still have some nutrients left from the yolk of the egg in their bodies, enough to provide food for about three days while they learn to grab insects and other food.
Being on the lam makes young grouse more difficult targets for would-be predators. Grouse chicks hatch with the flight feathers on their wings already growing. Within a week or so the sooty chicks practice flying by hopping and gliding. Just a few days later they can fly about 30 feet. The chicks’ escape plans change depending on their growing stage. For the first week or so, they freeze in place when danger looms. After that, they may spring from cover and fly a short distance away. This strategy remains the same the rest of their lives. The grouse I spooked flew, at most, a few hundred feet before diving into the brush again. In denser cover, a grouse may simply run from danger, preferring to stay as hidden as possible.
The structure of grouse wings makes them especially suited to ducking and dodging in forests. Their short, rounded wings provide enough power to lift off the ground explosively. The loud pounding of wings and sudden motion serve to startle predators, hopefully long enough for the bird to escape. Rapid wingbeats mean grouse are strong, fast flyers over short distances. This propulsion combined with a long tail for their body size allows them to maneuver in tight spaces between trees. Such flight is very tiring, however, so in open areas they may flap a few times then glide for a bit, often flying downslope to maximize distance and minimize effort.
Grouse are homebodies. The trade-off for high maneuverability and speed is that the birds simply can’t travel long distances without becoming exhausted. They don’t undertake epic migrations for the winter. Instead they shift locations within their home neighborhood, usually changing altitude. In the summer and fall, the grouse feed in muskegs and alpine areas, moving into heavier forest for the winter. They don’t need to leave; the forest provides all the food they need to survive even a long winter.
Except for a few weeks as chicks when they feed mostly on insects, the majority of a sooty grouse’s diet is plants. In spring and summer, they dine on buds, leaves, flowers and berries. In winter, only one kind of food is on the menu: conifer needles. Mountain hemlock, Sitka Spruce, and sometimes pine trees are the restaurants of choice for more than 80 percent of the grouse winter diet. To digest such rough fare, sooty grouse rely on the grit and gravel in their muscular crop, a chamber in the digestive system of birds that stores and grinds up food before it passes to the stomach. A grouse can snip off the tasty ends of the needles until its crop is bulging, then perch somewhere safe and digest the matter, so to speak.
The next time a grouse startles you out of your skin, or you spy one holding motionless in a tree, take a moment to stop and marvel at a bird that is so perfectly suited to living year-round in our forests it doesn’t even need a winter holiday in Mexico.
• Beth Peluso is a freelance writer, illustrator, and avid birder. She enjoys spying on wildlife around Alaska.