Idaho – 117th (2016-2017)
Christmas Bird Count Summary
Idaho Christmas bird counters experienced some challenging weather in the form of sub-freezing temperaturess but pulled off another highly successful and illuminating count. Overall, 31 counts were conducted during the 2016-2017 (117th) Christmas Bird Count period, and birders recorded 389,141 individuals of 168 species. The species count (168) was the lowest in 5 years but only slightly below the 5 year average of 171 species. The number of participants (507) and party hours (1,228) declined slightly for a 3rd year in a row. Despite the participation decline the number of counts remained steady at 31, although several of these are at risk over the next few years. Please see the concluding remarks for ways you can help keep Idaho CBC’s going!
Idaho CBC’s are well distributed throughout the state with 7 in the panhandle region, 5 in the central region, 8 in the southwest region, and 11 in the eastern region. Overall and southwest region high count honors go to Hagerman Valley, which managed the always impressive feat of breaking the century mark with 102 species. In the southeast region, Pocatello was top with 67 species, Salmon was top in the central region with 52 species, and in the panhandle Lewiston-Clarkston was top with 88 species. Craters of the Moon had the lowest count total with 16 species but arguably the most interesting landscape with its extensive lava fields.
Idaho’s autumn weather was relatively benign with average to above average temperatures across most of the state. Winter weather conditions, however, arrived in force across the state at the start of the CBC period (which runs from December 14 – January 5). The first CBC weekend featured frigid temperatures and at least some snow on the ground on all CBC’s. Even the birds appeared to be caught off guard by the sudden onset of winter with some having lingered perhaps farther north than usual. Notable weather refugees were out of place American Pipits recorded along several rivers in northern Idaho. Almost all Idaho counts throughout the period reported snow on the ground and only a few counts managed to get above freezing temperatures on count day. Despite this, few counts experienced precipitation on count day resulting in mostly manageable (if uncomfortably cold) conditions.
There were no new species for the cumulative Idaho CBC list although Red-breasted Sapsucker was recorded for only the second time with an impressive 3 individuals on 3 counts. The 5 most abundant species statewide in order were European Starling, Canada Goose, Mallard, Horned Lark, and House Sparrow. Only Mallard and Common Raven were reported on all 31 counts with European Starling and Red-tailed Hawk reported on 30 counts. Complete results for all Idaho counts for this and prior periods are available on the Audubon CBC web site: http://netapp.audubon.org/CBCObservation/. Summaries for other regions and the count overall can be found here: http://www.audubon.org/summary-117th-christmas-bird-count-2016-2017. Highlights for the 117th Idaho CBC follow in roughly taxonomic order.
Waterfowl diversity statewide was fairly good with 28 species but numbers were lower than in recent years. Highlights included only one Eurasian Wigeon for the state, recorded at Sandpoint, while 8,300 Ring-necked Ducks was impressive, with most of these (6,320) coming as usual from Hagerman Valley. Mallard numbers (60,849) were sharply down, roughly 30% lower than the previous year, and well below the five year average of 117,000. Nevertheless, Mallard counts have fluctuated quite a bit over the preceding 10 years and a variety of factors including challenges in counting large waterfowl flocks may come into play here.
Among diurnal raptors, an Osprey was at Boise for a rare Idaho CBC record. Idaho now has a healthy population of wintering Bald Eagles and was reported on 27 of 31 counts for they’re second highest total of 636 individuals. A fairly typical 5 species of shorebirds were reported including two Dunlin at Hagerman Valley along with singleton Spotted Sandpipers at Salmon and Twin Falls. Rare gulls were fairly scarce during the CBC period although they showed much better in Idaho later in the winter. Notable CBC gull records were all of single individuals including Mew Gull (Boise), Thayer’s Gull (Coeur d’Alene), now annual Lesser-black Backed Gull (Hagerman Valley), and Glaucous-winged (Bruneau).
Surprisingly, Eurasian Collared-Doves (7,386) declined by 28% from the prior period. This is the first decrease since collared-doves arrived in Idaho CBC’s in 2001 and lends support to the idea that their population growth may be stabilizing. Although interesting we will have to wait a few more years to declare this a trend. A total of 5 Anna’s Hummingbirds is now typical for Idaho but based on other observations and studies it’s clear that many more Anna’s are now wintering in Idaho, especially in the Treasure Valley (often in residential areas that may be under-surveyed on CBC’s). Woodpeckers of note include a Williamson’s Sapsucker at Garden Valley and and a total of 3 Red-breasted Sapsuckers, one each at Boise, Lewiston-Clarkston, and Moscow-Pullman (on the Pullman, WA side of the count). A total of 6 Blue Jays on 3 counts was about average for a non-irruptive winter although one of those in Idaho Falls was notable with the other 5 more expected in the panhandle.
A total of over 16,000 Horned Larks on 21 counts was remarkable and were the fourth most abundant species reported. A reasonable hypothesis is that the pre-count winter weather concentrated many Horned Larks into snow-free areas including rural roads making them accessible to CBC counters. This was certainly the case on the Moscow-Pullman count where a large lark flock of Horned Larks also included 2 locally rare Snow Buntings. Very unusual were 2 reports of American Pipits from northern Idaho including 6 at Juliaetta and 4 at Lewiston-Clarkston. Both of these groups were concentrated along rivers also likely due to snow-covered and frozen fields. Despite the warm autumn, semi-hardy species like Say’s Phoebe and Hermit Thrush were not present in higher than usual numbers, possibly impacted by sudden onset of severe winter conditions in mid-December.
A major and perhaps unprecedented invasion of Varied Thrushes in northern Idaho started just prior to the count period and resulted in 532 individuals being recorded on 9 counts. Undoubtedly a number of northern Idaho broke count records for Varied Thrushes, such as Moscow-Pullman with 124. The Varied Thrush influx was localized to northern Idaho with only a single individual recorded on a count south of 45 degrees latitude at Boise. Similarly, Bohemian Waxwings were present in large numbers and were more widespread with 4,693 on 21 counts. Many were in northern Idaho such as c. 2,400 at Moscow-Pullman but other impressive counts included 650 in the far southeast corner of the state at Bear Lake Valley. It is unclear the cause of these invasions but winter storms farther north in Canada preceding the count period may well have played a role.
Montane species prone to altitudinal movement, including Mountain Chickadee and Red-breasted Nuthatch, were in typical numbers suggesting a non-irruption winter for this group. Irruptive “winter finches” likewise had a poor showing with some virtually absent (e.g. Pine Grosbeak, Common Redpoll). Even Gray-crowned Rosy-Finches (129) were scarce and this despite the count period snow which often drives them out of higher elevations (but perhaps coming too late this year?). Sparrow highlights included 2 Golden-crowned Sparrows at Nampa, 6 Harris’s Sparrows on 5 counts, and 5 Swamp Sparrows on 3 counts. A few Brown-headed Cowbirds are recorded by patient observers picking through large blackbird flocks, usually in the Treasure Valley, and this year a total of 9 were found on Nampa (6) and Bruneau (3).
As always, big thanks go to all the volunteer participants, especially compilers, for their efforts! You all are vitally important to the continuing success of the Christmas Bird Count. A special note of appreciation and thanks go to Shirley Sturts, who is stepping down as compiler of the Spirit Lake count after about 15 years while continuing into her 14th year as compiler of Coeur d’Alene count. We also take this opportunity to remember Shirley’s good friend and birding partner of many years, Kris Buchler, who contributed greatly to northern Idaho CBC’s and other citizen science projects. Kris will be greatly missed in the Idaho birding and environmental education communities. Special thanks again this year to Stoddard Davenport for help in reviewing southern Idaho counts and for organizing the Idaho CBC data into a usable format.
Finally a special plea for assistance with organizing and reviewing Idaho’s Christmas Bird Counts. Please watch for opportunities which may arise to help local counts or contact count compilers directly if you are willing to offer assistance. In particular, please consider taking over from retiring compilers of your local counts when needed. This is vital to keeping counts going in the long term. New counts are welcome where there is a sufficient level of support to make them successful and we could always use more help reviewing counts and creating this summary. Please feel free to contact me at chaetura@gmail.com if you are interested or have questions or suggestions. Please watch for information on forthcoming (2017-2018) counts on the Audubon Christmas Bird Count web site (http://www.audubon.org/join-christmas-bird-count), email lists, social media, and bird club newsletters/web sites. Thanks, good birding, and good counting!
Charles Swift