Idaho and Western Montana: Winter 2020 – 2021

Winter 2020–2021: 1 Dec–28 Feb

Kate Stone

Recommended citation:

Stone, K. 2021. Winter 2020 2021: Idaho and Western Montana. <> North American Birds.

In general, the region experienced a mild winter with relatively warm temperatures. Low elevations experienced little snow at the beginning of winter, though parts of MT experienced one of the snowiest Februarys on record, as well as a subzero cold snap at the beginning of the month. Challenging weather (such as in Idaho and Montana in October) along the migratory paths of many species may have contributed to some of our more uncommon winter observations, as birds waylaid by inclement weather may have stayed and survived as conditions improved. Similar to patterns seen across temperate North America, several irruptive, seed-eating species made a good showing throughout the region.

Swans through Loons

MT observers noted a continued increase in overwintering Trumpeter Swans, including at locations in Flathead Co (Dan Casey), Beaverhead Co (Steve Sherman), and Ravalli Co (Eric Rasmussen). MT hosted its first overwintering record and Christmas Bird Count record of White-winged Dove; it was reported  16 Nov (John Parker) and was observed by many people in Bozeman, Gallatin Co until 16 Jan, when it met its demise as a meal for a Sharp-shinned Hawk (Sneed Collard and Braden Collard).

Anna’s Hummingbirds continued their decade-long winter presence and expansion in ID in several locations from Boise, Ada Co north to Hayden, Kootenai Co. Outreach and recent publications by the Intermountain Bird Observatory prompted an increase in citizen scientist reports, tallying approximately 60 in winter 20192020 and 170 this winter, though individual birds were likely documented by more than one report. This study also contributed a record-early ID date for egg-laying (estimated 23 Feb) at a home near Boise (Janice Engle). Western MT contributed one report of Anna’s Hummingbird 19 Dec on the Missoula Christmas Bird Count, Missoula Co.

Birders in southwest ID along the Snake River plain near Boise, Ada Co reported an uncommon influx of shorebirds in Jan and Feb, with state rare bird reports submitted for Least Sandpiper, Dunlin, Long-billed Dowitcher, and Greater Yellowlegs (pending review). The only species of this group observed in MT this winter was Dunlin; one to two were observed on the south shore of Flathead Lake, Lake Co from early Dec through late Jan (m. ob.).

A handful of Lesser Black-backed Gulls were reported from ID and western MT, continuing a trend of regular winter appearances in low numbers. MT’s overwintering record of Bonaparte’s Gull was on the south end of Flathead Lake, Lake Co; the lone gull persisted for more than two winter months, and was last seen on 5 Feb (Shawn Richmond). A Yellow-billed Loon was reported 20 Dec along the Snake River, Gooding Co, ID (Lauren Brockway and Patricia Weber).

Flycatchers through Mimids

Rare in winter, a Dusky Flycatcher was well documented  along the Clearwater River east of Lewiston, Nez Perce Co, ID on 20 December (Carl Lundblad). Multiple observers in Missoula Co documented MT’s first record of an overwintering Say’s Phoebe, though the bird was not observed after frigid conditions in early February.

Winter numbers of Blue Jay continued to increase throughout the region, including reports of the highest numbers in at least nine years in north-central ID; all winter, a flock of up to six resided at the University of Idaho Arboretum and Botanical Gardens, Latah Co, while a group of at least seven occupied central Lewiston, Nez Perce Co (Carl Lundblad). Winter records were numerous in MT both east and west of the Continental Divide, and observers look to the day when resident populations establish in the southern half of the state. A record-shattering and conservative count of 615 Clark’s Nutcrackers passed through Maclay Flat in Missoula, Missoula Co, MT on 13 Dec (Tom Forwood, Andrew Guttenberg). Observers elsewhere in western MT confirmed relatively high numbers of this seed-caching corvid throughout the winter; pine cones were abundant and available both on trees and on the snow-free ground (Cynthia Hudson, Eric Rasmussen, Kate Stone).

A winter high count of 150 Horned Larks was seen near Plummer, Benewah Co, ID on 21 Feb (Jon Isacoff). For the second year in a row,a Bewick’s Wren was found just south of Lolo, Missoula Co, MT; it was first seen this year on 21 Feb (Eric Rasmussen). Though not unusual in ID at any time of year, this species is still uncommon in MT, and this bird’s presence beyond winter has birders anticipating a breeding attempt. Observers in both states detected Ruby-crowned Kinglets in all winter months; in MT, numbers were higher than the previous winter, and several Christmas Bird Counts included them on their lists (m. ob.). Both states had multiple to numerous records of Mountain and Western bluebirds and Hermit Thrush; there were more detections in ID than MT (m. ob.). The most unusual thrush detected was a Swainson’s Thrush on 24 Dec in Boise, Ada Co, ID (Ken Miracle). Northern Mockingbirds dotted the Snake River Plain in ID from the Boise area east to Archer, Madison Co (m. ob.).

Finches through Warblers

Finch numbers appeared high, though concentrations varied regionally. A flock of 86 Gray-crowned Rosy Finches was near Plummer, Benewah Co, ID on 21 Feb (Jon Isacoff). A single Purple Finch was seen in Bozeman, Gallatin Co, MT on 3 Feb (Andrew Guttenberg), and two more occurred at multiple but close locations in Boise, Ada Co, ID 31 Dec–17 Feb (m. ob.). Cassin’s Finches flooded feeders in the Bitterroot and Missoula valleys of western MT from late Jan into Feb, and in ID by mid Feb (m. ob.). The Ruby Valley Christmas Bird Count in Madison Co, MT had a record high count of 37 Cassin’s Finch on 1 Jan (Tom Forwood). Birders in both states also reported good numbers of Red Crossbills and Pine Siskins throughout the winter (m. ob.). Lesser Goldfinch sightings also increased and expanded in the Missoula and Bitterroot valleys (m. ob.).

MT gained its first overwintering Lark Sparrow record, with observations spanning 13 Dec through 12 Feb in Missoula, Missoula Co (Jalalieh Morrow). A Field Sparrow was reported 1 Dec near Holbrook, Oneida Co (m. ob.). Single “Slate-colored” Fox Sparrows were reported in one area of Boise, Ada Co, ID (m. ob.) and at one location in Garden Valley, Boise Co, ID (Sheri Foote). The Missoula Christmas Bird Count contributed the region’s only record of Green-tailed Towhee, with two seen on 19 Dec in Missoula, Missoula Co, MT (Bob Petty). A female Bullock’s Oriole was found on 5 Dec near Nampa, Canyon Co, ID (Christi and James Jarrett).

Rusty Blackbirds occur sporadically throughout the region in winter, though more infrequently in ID than MT. One was found by two independent observers in Moscow, Latah Co, ID on 4 and 5 Dec; it continued through the month (Kevin Murphy, Carl Lundblad). A second individual was observed near Grangeville, Idaho Co, ID on 16 Dec (Kris Hazelbaker). Similar to past winters, Rusty Blackbirds occurred in seven MT counties and were more frequently observed east of the Continental Divide. Numbers ranged from one to six at locations near Helena, Lewis and Clark Co (Coburn Currier), and seven were seen near Creston, Flathead Co (Craig Hohenberger). The first Common Grackle for Latah Co, ID was found on 20 Jan in Moscow and continued through winter (Carl Lundblad). Common Grackles are infrequent in northern ID in any season, and winter records are rare anywhere in the state.

A lone Western Tanager occurred 1527 Dec in Boise, Ada Co, ID (m. ob.). A beautiful adult male Pine Warbler graced Susan Hovde’s yard in Red Lodge, Carbon Co, MT from 29 Nov until 7 Feb, when a subzero cold snap occurred. Though observations of Yellow-rumped Warblers are relatively regular and well distributed in southern ID, northern ID and MT had a few more than normal (m. ob.), including observations from one yard in Missoula, where one to four individuals of both the “Myrtle” and “Audubon’s” populations were seen the entire winter (Eric Rasmussen). MT had two Common Yellowthroat observations, including one on the Bitterroot River floodplain near Florence, Missoula Co on 4 Dec (Kate Stone) and one on 26 Dec for the Troy Christmas Bird Count, Lincoln Co (Darin Newton).

Report processed by Michael L. P. Retter, 19 Jun 2021.

Photos–Idaho and Western Montana: Winter 2020 – 2021

Click image to view fullscreen with caption.