January and February

As we reach early January, a few seeds may continue to fall from the Western Redcedars and Paper Birches, though many of them have already dropped to the ground.  Foods like these may be getting harder to find for seed specialists such as Pine Siskins, and flocks may roam far in search of food sources, perhaps descending on a bird feeder in the lowlands.  Bird feeders undoubtedly change the dynamics of winter survival for seed-eating birds such as Siskins and Black-capped Chickadees.  In fact, there is some concern that feeding birds in the winter makes life more challenging in the summer for long-distance migrants such as Western Tanagers, Swainson’s Thrushes, and Nashville Warblers.  In the breeding season, the vast majority of songbirds – including some common feeder birds, like Black-capped Chickadees – feed their young on insects.  An overabundance of feeder birds, subsidized by sunflower seeds, may compete with migrants for resources – bird feeders may be helping some species at the expense of others. 

Fortunately, for those of us who want to help the birds, there is an exciting alternative to bird-feeding: growing native plants.  Our endemic flora is an ecological foundation upon which essentially all birds and other animals ultimately depend.  Native plants are uniquely well-adapted to the local conditions they have evolved in response to, and many are also aesthetically pleasing in a garden.  Planting natives doesn’t just feed the birds, it restores habitat for shelter, nesting, and food.  Some plants provide food directly, even in the winter: the fruits of Snowberry and the seeds of Paper Birch are examples.  Even more important, though, native plants support a much more diverse insect fauna than alien ornamentals do, feeding birds throughout the year.  During the breeding season, 96% of terrestrial birds feed their young insects, so encouraging robust native “bug” populations by planting their indigenous food plants is a very positive thing that we can all do.

Warm days followed by frigid nights may put a crust on the snow, allowing some animals to walk on top.  Species like Canada Lynx and Snowshoe Hares have large, furry feet, allowing them to move over the snow with ease.  For others, such as White-tailed Deer, deep snow makes life very challenging, and the crust gives way with each step, making travel exhausting and dangerous.  Not surprisingly, Deer seem to do their best to avoid these conditions, traveling under thick trees or in the trails of other animals, and perhaps concentrating in areas with good browse.  Stark and bare against a bitter gray sky, the red-tipped branches of Rocky Mountain Maple may show signs of pruning by ungulates.

In a wet area along a stream, the burgundy stems of Red-osier Dogwood, another popular winter browse, contrast sharply with the snow.  Ice coats the boulders in the creek, and makes incredible formations in the faster stretches, sculpted by the power of the cold.  It’s no sort of weather for swimming – and yet you might find an American Dipper foraging among the cobbles, submerging itself completely in the icy water to snatch a caddisfly larva from under a rock.  These birds spend most of their lives along fast-flowing streams.  Pairs who breed in the upper reaches have probably descended in altitude for the winter, and Dippers may be numerous along creeks and rivers at the lower elevations.

As early as the first week of February, Great Horned Owls might be beginning to nest.  Pairs often remain on territories year-round, but their deep hooting is heard most often in the fall and winter.  These awe-inspiring raptors don’t build their own nests.  They often usurp the abodes of other species, particularly Red-tailed Hawks, or use a tree cavity.  For over a month, the female will incubate her almost-round, white eggs, usually two of them.  In the meanwhile, the male will hunt and bring her food.  Great Horned Owls eat a wide variety of prey.  Although they most commonly take nocturnal mammals, they will also hunt birds, and on occasion they catch day-active mammals.

Hiking in the winter coniferous forest, sign of one of these occasional prey species is hard to miss.  The Red Squirrel leaves obvious middens where it has retrieved conifer cones from storage and torn them apart, eating the seeds and leaving the bracts.  Take a look at these bracts – those of different tree species have different appearances.  What species have the Squirrels harvested, and are those the dominant trees in the vicinity?

Red Squirrel cone caches are not the only debris that you might find under the trees.  On warm days, water may drip from the drooping, snow-covered conifer branches as the sun softens the snow’s grip.  The continuous sound of dripping water may be punctuated with a loud splash as a limb drops all of its snow and bounds up, as if relieved to be free of the weight.  Weather like this carries more than just snow to the forest floor.  You might find dead needles, green conifer twigs, lichens, and even live branches scattered under the trees, a testament to the cumulative power of featherlike snowflakes.

By the middle of February, if you are lucky, you might observe a pair of Gray Jays breaking small, dead twigs from a conifer and carrying them away.  These incredible birds nest very early, and have been known to incubate eggs at temperatures as low as -30°C (-22°F).  The male appears to choose the nest site, often on the south or west side of a conifer’s trunk for maximum solar heating.  He also does most of the building at the start, creating a framework of twigs and using old Forest Tent Caterpillar cocoons to fill the gaps.  As the nest grows, the female takes on a larger role in the construction.  Around three weeks after the start of nest building, the cozy, well-insulated cup nest will be complete, lined with feathers or hair.  The female will lay three or four spotted, gray-white eggs.  They are this pair’s only chance for nestlings this year – if the clutch is unsuccessful, they will not renest later in the season.

On the high slopes, the narrow-crowned Subalpine Firs seem even pointier than in the summer, their branches drooping with snow.  Possibly in a scree field bordered by Firs, a female Wolverine may be giving birth to two finely furred kits.  She tunneled far into the deep snow high up on the mountainside, making her den in the protection of large rocks or logs.  Perhaps she has cached meat, scavenged from a carcass, in the vicinity.  Until her kits become more mobile, she will carry food to the den in her stomach, and feed them regurgitated meat.   She is well-adapted to scavenge in the cold, snowy mountains she inhabits.  Her huge paws support her on top of deep snow, allowing her to travel long distances in search of carrion.  This summer, she may hunt with her kits for American Pikas in this same talus slope – then seemingly a different world, without the snowy mantle it now bears.

 

Scientific Names of Species Mentioned

Western Redcedar – Thuja plicata

Paper Birch – Betula papyrifera

Pine Siskin – Carduelis pinus

Black-capped Chickadee – Poecile atricapillus

Western Tanager – Piranga ludoviciana

Swainson’s Thrush – Catharus ustulatus

Nashville Warbler – Leiothlypis ruficapilla

Snowberry – Symphoricarpos albus

Canada Lynx – Lynx canadensis

Snowshoe Hare – Lepus americanus

White-tailed Deer – Odocoileus virginianus

Rocky Mountain Maple – Acer glabrum

Red-osier Dogwood – Cornus sericea

American Dipper – Cinclus mexicanus

Great Horned Owl – Bubo virginianus

Red-tailed Hawk – Buteo jamaicensis

Red Squirrel – Tamiasciurus hudsonicus

Gray Jay – Perisoreus canadensis

Forest Tent Caterpillar – Malacosoma disstria

Subalpine Fir – Abies lasiocarpa

Wolverine – Gulo gulo

American Pika – Ochotona princeps

Retrieved March 24, 2015 from the Integrated Taxonomic Information System on-line database, http://www.itis.gov.

 

References
 
Able, Kenneth P., Ed. 1999. Gatherings of Angels: Migrating Birds and Their Ecology. Ithaca, NY: Cornell University Press.
 
Artuso, Christian, C. Stuart Houston, Dwight G. Smith, and Christoph Rohner. (2014). Great Horned Owl (Bubo virginianus). The Birds of North America Online (A. Poole, Ed.), Ithaca: Cornell Laboratory of Ornithology; Retrieved from the Birds of North America Online database: http://bna.birds.cornell.edu/
 
Belzer, Harold O., and Robert C. Morris. 1978. “Forest Tent Caterpillar.” Forest and Insect Disease Leaflet 9. Broomall, PA: USDA, Forest Service, Northern Area State and Private Forestry.
 
Dawson, William R. (2014). Pine Siskin (Spinus pinus). The Birds of North America Online (A. Poole, Ed.), Ithaca: Cornell Laboratory of Ornithology; Retrieved from the Birds of North America Online database: http://bna.birds.cornell.edu/ 
 
Ehrlich, Paul R., David S. Dobkin, and Darryl Wheye. 1988. The Birder’s Handbook: A Field Guide to the Natural History of North American Birds. New York: Simon and Schuster.
 
Elbroch, Mark, and Kurt Rinehart. 2011. Behavior of North American Mammals. New York: Houghton Mifflin Harcourt.
 
Elbroch, Mark. 2003. Mammal Tracks and Sign: A Guide to North American Species. Mechanicsburg, PA: Stackpole Books.
 
Foote, Jennifer R., Daniel J. Mennill, Laurene M. Ratcliffe, and Susan M. Smith. (2010). Black-capped Chickadee (Poecile atricapillus). The Birds of North America Online (A. Poole, Ed.), Ithaca: Cornell Laboratory of Ornithology; Retrieved from the Birds of North America Online database: http://bna.birds.cornell.edu/
 
Idaho Department of Fish and Game. 2014. “Management Plan for the Conservation of Wolverines in Idaho.” Boise: Idaho Department of Fish and Game.
 
Kershaw, Linda, Andy MacKinnon, and Jim Pojar. 1998. Plants of the Rocky Mountains. Edmonton, AB: Lone Pine Publishing.
 
Parish, Roberta, Ray Coupe, and Dennis Lloyd, eds. 1996. Plants of Southern Interior British Columbia and the Inland Northwest. Vancouver, BC: Lone Pine Publishing.
 
Reid, Fiona A. 2006. A Field Guide to Mammals of North America, 4th ed. New York: Houghton Mifflin Company. 
 
Strickland, Dan, and Henri Quellet. 2011. Gray Jay (Perisoreus canadensis). The Birds of North America Online (A. Poole, Ed.), Ithaca: Cornell Laboratory of Ornithology; Retrieved from the Birds of North America Online database: http://bna.birds.cornell.edu/ 
 
Tallamy, Douglas W. 2007. Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens. Portland, OR: Timber Press, Inc.
 
U.S. Fish and Wildlife Service. 2013. “Wolverine (Gulo gulo luscus).” Accessed March 9, 2015. http://www.fws.gov/mountain-prairie/factsheets/Wolverine-122010.pdf.
 
Willson, Mary F., and Hugh E. Kingery. (2011). American Dipper (Cinclus mexicanus). The Birds of North America Online (A. Poole, Ed.), Ithaca: Cornell Laboratory of Ornithology; Retrieved from the Birds of North America Online database: http://bna.birds.cornell.edu/