113th CBC Idaho Regional Summary

By Charles Swift

Idaho birders and bird enthusiasts conducted 30 counts during the 2012-2013 (113^th) Christmas Bird Count period and recorded over 425,000 individuals of 179 species plus three count week only species. The total number of counts (30), party hours (1277), number of observers (564), and number of species, are the highest in ten years and very likely all time. Thanks to the efforts of many, the Christmas Bird Count is alive and well and growing in Idaho!

Looking statewide there were a number of highlights in addition to the total stats. The state added three new counts in a variety of settings: Challis in the upper Salmon River Valley of eastern Idaho; Cascade in the Long Valley of west-central Idaho (the first for this region); and Juliaetta-Lower Potlatch River in the Clearwater Basin of north-central Idaho. Count day species totals across the state ranged from 26 to 107. High count honors go to a couple of southwest Idaho counts breaking the 100 species mark—both Nampa (105) and Bruneau (107), the latter a new all-time high count record for the state! It has only been a few years since an Idaho count broke the century mark and now a few do so every season. High desert counts such as Craters of the Moon, Jim Sage Mountains, and Trapper Creek regularly average between 20-40 species and represent unique Idaho settings in the CBC totals. Almost all regions of the state now host a Christmas Bird Count and all of the counts make valuable contributions to our understanding of Idaho’s wintering bird populations.

Weather plays an important role in Christmas Bird Counts in a number of respects. Count day weather is crucial for actually recording a representative sample of birds in each count circle not to mention for the comfort and safety of participants. For most Idaho counts, weather in the 113^th count period was favorable for a change, with birders enjoying generally seasonal temperatures and avoiding disruptive winter storms. Beyond count day, both short-term weather and long-term climate events are important factors in understanding emerging winter bird occurrence patterns. In the short term, regional weather immediately preceding the count period likely affects movements of waterbirds and semi-hardy species (i.e. those that may linger farther north in warmer winters such as some shorebirds, woodpeckers, some sparrows, etc.). Idaho had a warm and dry summer and a warm autumn (one of the top ten on record), which was also apparent at the regional northwest scale. The region also avoided extended periods of below normal temperatures in the fall leading up to the count period. This kind of benign autumn weather may result in waterfowl staying farther north and lingering semi-hardy species staying in place (or merely surviving). Idaho mountain snow packs started out the winter below average in most parts of the state, though it is unclear whether or what the impact of snow packs on early winter bird movements might be. Alpine zone altitudinal migrants, such as rosy-finches, may be affected, but these were nonetheless reported this season in average numbers on the usual Idaho counts. In the longer term, trends such as shifts in wintering ranges of some species and prevalence of semi-hardy species are likely related to long-term climate change. Generalizing weather (not to mention bird movements!) across a large, geographically diverse state like Idaho is challenging, and correlating such weather patterns with bird movements is speculative best (at least in this venue).  Nonetheless, it is useful to keep the weather factors in mind while perusing the species summary below.

Despite the overall high number species (179) no “mega-rarities” were discovered on Idaho counts this period. There were, however, an abundance of highlights, noteworthy finds, and interesting phenomena from the counts summarized below in (more or less) taxonomic order. The five most abundantly recorded species statewide, in descending order, were European Starling, Mallard, Canada Goose, American Coot, and American Robin. The most prevalent species included Common Raven and Song Sparrow, reported on all 30 counts, with Eurasian Collared-Dove and Red-tailed Hawk being reported on all but one count. Bald Eagles were recorded on all but two counts, an encouraging sign (in addition to its steady increase), and providing a great opportunity for casual birders to see one of the most beloved of wintering birds in Idaho.

All of the regularly occurring geese and swans were reported including a Ross’s Goose at Bruneau and 21 Mute Swans on three counts between Twin Falls and Nampa. Mute Swan appears to be slowly increasing in the southwestern portion of the Snake River plain. Over the prior ten years, the total number of Canada Geese and Mallards reported has accounted for between 25% and 46% of total individuals reported statewide. This period they declined by approximately 100,000 from the prior period to 110,000, accounting for 25% of individuals and well below the five- and ten-year averages for this group. (Not surprisingly, European Starling also accounts for large percentage of total individuals reported.) An excellent 22 species of ducks was reported highlighted by singles of Long-tailed Duck and White-winged Scoter on Lewiston-Clarkston and 37 Red-breasted Mergansers on Nampa. Impressive counts among the gallinaceous birds included 186 Chukars at Challis and 51 Sharp-tailed Grouse at Bear Lake. The ever increasing Wild Turkey was reported from 17 counts and topped 1000 statewide with the largest proportion of the count coming from northern Idaho. A well-documented Pacific Loon was recorded at Spirit Lake in the Idaho panhandle. This species is an uncommon but regular late-fall visitor to Idaho but rarely lingers into the winter period. Single Clark’s Grebes, reported from Nampa and Bruneau, are winter rarities and require careful study due to their similarity in winter plumage to the more prevalent Western Grebes and the ever-present possibility of confusing hybrids.

Lingering shorebirds were well represented and included five Greater Yellowlegs on three counts as well as Least Sandpiper (1), Dunlin (2), and Long-billed Dowitcher (4) on single counts. Gull numbers and variety were generally unremarkable although 179 Herring Gulls on 11 counts was notable. Eurasian Collared-Dove (EUCD) continue to increase dramatically in Idaho with this year’s count of 5279 finally breaking the 5000 mark. This is roughly a 62% increase overall and 41% increase in birds per party hour from the 2011-2012 count period. The first EUCD count record was of three birds in 2004 and today the species is found in almost every region of the state. This winter’s echo of the 2011-2012 Snowy Owl irruption resulted in a count day sighting for Coeur d’Alene and count week sighting for Bonner’s Ferry.

Turning to the passerines and near-passerines, unseasonal woodpeckers included single Lewis’s Woodpeckers at Pashimeroi Valley and Boise in addition to two Red-naped Sapsuckers, also at Boise. An impressive 120 Pinyon Jays (out of a total 142) were at Pocatello, the state stronghold for this species. Two each Barn Swallows and Northern Rough-winged Swallows were well documented at Hagerman Valley, foraging at the bottom of Upper Salmon Falls Dam on the Snake River. A Sage Thrasher was at Bruneau and represents one of very few winter records for Idaho. Almost half of the state total of Spotted Towhees (41 out of 97) came from Juliaetta-Lower Potlatch where they appear to be attracted to extensive thickets of Eurasian blackberries. A total of five Swamp Sparrows came from Bruneau (3) and Hagerman Valley (2) where the species is now essentially annual. Also notable among sparrows were four Golden-crowned Sparrows on three counts including one in the far northern part of the state at Bonner’s Ferry. Irruptive finches put on an excellent show, notably Pine Grosbeaks (399 on 13 counts) and Common Redpolls (3040 on 19 counts). With all of the redpolls around it was almost inevitable a few Hoary Redpolls would show up and this was the case with one at Lewiston-Clarkston and three at Bear Lake Valley in the far southeastern corner of the state just north of the Utah border. Lesser Goldfinch numbers continue to explode in the lower Clearwater Basin of north-central Idaho, where it is a recent immigrant. Almost 630 Lesser Goldfinches were recorded at Lewiston-Clarkston and the new Juliaetta-Lower Potlatch counts and make up the bulk of the statewide total.

As always, thanks to the compilers and participants for their efforts to document Idaho’s early winter avifauna. Compilers in particular put in a great deal of work to keep their respective Christmas Counts going and deserve much of the credit and thanks for the successes noted above. Good birding and we look forward to seeing you during the 2013-2014 count period!