113th CBC Michigan Regional Summary

By John L. Trapp

The 113^th Christmas Bird Count (CBC) yielded results from 68 Michigan circles. In total, these 68 circles have contributed an impressive 2156 count-years of data to the CBC database. The number of years that individual circles have conducted counts ranges from one (Tittabawassee Valley being new this year) to 90 (Detroit), with 14 circles having contributed 50 or more years of data. The regional distribution of circles (and counts) pretty much reflects the distribution of the human population in the state, with 13 (273) in the Upper Peninsula, 21 (533) in the Northern Lower Peninsula, and 34 (1350) in the Southern Lower Peninsula.

Three circles had counts exceeding 40,000 individuals (Anchor Bay 49,635, Rockwood 49,528, and Monroe 42,283), and three reported more than 80 species (Anchor Bay 98, Clinton 87, and Rockwood 87) with 10 others exceeding 70 species. Seven species exceeded 20,000 individuals—Canada Goose (80,332), European Starling (79,484), Mallard (41,204), American Crow (39,525), Ring-billed Gull (26,781), House Sparrow (24,665), Mourning Dove (23,392)—while 11 others exceeded 10,000. Three species were seen on all 68 circles (American Crow, Black-capped Chickadee, and White-breasted Nuthatch) while 23 others were seen only on a single circle.

Well-documented vagrants or seasonal rarities (species with annual frequencies of less than 50% in the previous 10 years) included the following: Blue-winged Teal—four at Muskegon Wastewater (a total of two birds reported in 2 of the previous 10 years); Barrow’s Goldeneye—one at Tittabawassee Valley (the first reported since 2001); Eared Grebe—one at Rockwood (three in 3 years); Western Grebe—one at Holland (four in 2 years); Virginia Rail—a total of three, with singles at Allegan State Game Area, Battle Creek, and Kalamazoo (three in 2011); Greater Yellowlegs—one at Anchor Bay (first since 1987); Little Gull—one at Higgins Lake-Houghton Lake (four in 2003); Rufous Hummingbird—one at Detroit (three in 3 years); Ovenbird—one at Ann Arbor (first since 1993); Cape May Warbler—one at East Lansing (one in 2010); Savannah Sparrow—one at Rockwood (four in 4 years); Lincoln’s Sparrow—one at Anchor Bay (two in 2 years). Additionally, there were count-week sightings of Ross’s Goose at East Lansing, Sanderling and Red Phalarope at Rockwood, and Black-legged Kittiwake at Berrien Springs.

Borderline species (defined as those encountered in 5 or 6 of the preceding 10 years) included Greater White-fronted Goose—five on three circles, with one at Clinton, three at Dowagiac, and one at Huron County (reported in 5 of the previous 10 years, averaging 1.1/year); Harlequin Duck—one at Muskegon (5 years, 1.7/year); Northern Bobwhite—one at Port Huron was just the second sighting in the last six years (formerly detected annually and averaging 21 birds/year as recently as the 1990s); Sharp-tailed Grouse—21 at Les Cheneaux (5 years, 3.1/year); Iceland Gull—two at Anchor Bay (6 years, 0.8/year); Townsend’s Solitaire—one at New Buffalo (6 years, 0.8/year); Common Yellowthroat—five on two circles, with four at Anchor Bay and one at Pontiac (5 years, 0.8/year); Chipping Sparrow—five on two circles, with four at Port Huron and one at New Buffalo (6 years, 2.9/year); Hoary Redpoll—26 on nine circles (5 years, 2.5/year), a new record-high count as this species staged a major irruption.

Of the 155 species recorded, 134 are considered to be of regular occurrence on Michigan CBCs, having been recorded in seven or more of the previous 10 years. The remainder of this review will focus on the 57 regular species reported in numbers that were above or below expected levels based on historical CBC results. The status of a species is considered to be “changed” (i.e., substantially above or below average) if the number reported was more than one standard deviation above or below the average of the previous 10 years. That analysis reveals that 42 (31%) of the 134 regular, or expected, species were present in above-average numbers, 15 (11%) were below average, and 77 (57%) did not differ markedly from their respective 10-year averages (2002-2011). Looking at changes in numerical abundance of 135 regular species from 2011 to 2012, we find that 80 species (59 percent) remained status essentially unchanged (continuing in above average, average, or below average numbers) while 55 (41 percent) switched from one numerical abundance category to another, 33 in a positive direction (from lower to higher abundance) and 22 in a negative direction (from higher to lower abundance).

Fifteen of 16 waterfowl species showing significant changes in numbers were above the 10-year average: Canada Goose (up 25 percent); Mute Swan (up 25 percent); Trumpeter Swan (up 86 percent, as the recently established resident population continues to grow); Tundra Swan (up 54 percent, as the upswing in early winter numbers continues); Gadwall (up 331 percent); American Wigeon (up 308 percent); Mallard (up 24 percent); Northern Shoveler (up 601 percent); Northern Pintail (up 1788 percent); Green-winged Teal (a 10-fold increase from the previous year and 3158 percent above average); Ring-necked Duck (up 162 percent); Bufflehead (up 143 percent); Hooded Merganser (up 197 percent); Red-breasted Merganser (up 116 percent); and Ruddy Duck (up 764 percent). The sole species of waterfowl to exhibit a significant decline was the Canvasback, whose numbers were 77 percent below average. Also, American Black Ducks returned to normal numbers after a poor showing last year while Black Scoters tumbled from high numbers last year to within the expected range this year.

Common Loons and Pied-billed Grebes returned to near-normal numbers following high counts last year. The 171 Horned Grebes (up 121 percent) on 17 circles was the second-highest tally ever, eclipsed only by a count of 309 on the 92^nd CBC. The count of 51 Red-necked Grebes on eight circles, an all-time high, was 267 percent above average. Following their first report on a Michigan CBC in 1979, Double-crested Cormorants have increased slowly but inexorably, six of the last 11 annual counts registering in triple digits and this year’s 221 birds (up 82 percent) on eight circles being the second-highest. Great Blue Herons and Black-crowned Night-Herons rebounded from low populations last year to near-normal numbers this year while the Great Egret, detected in each of the seven previous years and with a 10-year average of 3.5, failed to appear.

Turkey Vultures have been reported in double or triple digits in eight of the last 11 years, with 80 this year being the third highest in that time span and 125 percent above average. Bald Eagles have exceeded the 100-bird threshold in each of the last 16 years, with this year’s total of 566 birds (up 52 percent) establishing a new high. With the exception of Northern Goshawk, which was present in average numbers, the Accipiters showed poorly this year. The 62 Sharp-shinned Hawks was the second fewest in 18 years, down 31 percent from an average of 90. Similarly, Cooper’s Hawk was present in the lowest numbers in the last nine years, some 15 percent below average. A total of 56 Red-shouldered Hawks was seen on 27 circles, both figures establishing all-time highs, the former being 116 percent above average. Rough-legged Hawks were recorded in their lowest numbers in 11 years (121 birds vs. a 10-year average of 149, down 19 percent).

Tallies of American Coots and Sandhill Cranes have mushroomed in recent years, and counts this year did not disappoint. The 13,634 coots (the first year to top 10,000) exceeded the next largest tally (8784 birds on the 100^th CBC) by 55 percent and the 10-year average (2286) by 496 percent. Not to be outdone, cranes also established a new high count, the 5362 birds being 399 percent above average.  The Killdeer seems to exhibit a boom-bust pattern of abundance on Michigan CBCs—while generally present in single digits, there are occasional break-out years when it occurs in double-digits—and 2012 was one of 17 boom years in the last 53; while the 21 birds doesn’t come close to the all-time record of 83 on the 88^th CBC, it is 250 percent above the 10-year average. The three Purple Sandpipers, a rare but regular winter visitor to Michigan coastal areas, was the third-highest tally in the last 15 years and 131 percent above average.

Three of the four regularly occurring species of gulls that differed significantly from expected values were above average for the second year in a row. Twenty-six circles (the most ever) yielded a remarkable total of 4195 Bonaparte’s Gulls (1620 of them at Anchor Bay, 1246 at Rockwood), being 250 percent above the 10-year average and the second highest count in the last 22 years. Lesser Black-backed Gull remained in high numbers for the third year running, with 14 birds being 61 percent above average and the second highest count since first reported 25 years ago. Following last year’s record count of 49 Glaucous Gulls, the 40 reported this year were 71 percent above average.

Mourning Doves rebounded to near-normal numbers following an inexplicably low count last year. Three species of owls (Great Horned, Snow, and Barred) that were unusually abundant last year returned to normal or near-normal numbers. The number of Belted Kingfishers detected jumped to 151 individuals, the highest total in 14 years and 48 percent above average. The 28 Red-headed Woodpeckers reported is the lowest total in nine years and 37 percent below the 10-year average; early winter populations of this species have been depressed in recent years, as reflected by average yearly counts of 90 from 1970-2001 vs. 44 from 2002-2011, a decline of 51 percent. Black-backed Woodpecker was missed for just the third time in the last 10 years. After being present in near-record numbers last year, Northern Flickers declined to their lowest numbers in 11 years, some 42 percent below average (338 vs. 587); what factor, or combination of factors, could account for such striking differences in abundance between two adjacent CBC seasons that experienced nearly identical weather conditions? Pileated Woodpecker (291 birds) remained unusually abundant for the second straight year, some 52 percent above average.

While the count of 419 American Kestrels appears robust by recent standards (29 percent above the 10-year average of 324), it is just the 23^rd highest count in the last 39 years, placing it slightly below the 38-year average of 437. The Merlin appeared in record numbers for the second year in a row, with 20 birds (vs. 22 last year) being 77 percent above average. Northern Shrikes remained unusually abundant for the second straight year, the 101 birds (up 50 percent) ranking as the third-highest total in the last 30 years. Both jays were unusually difficult to find; the single Gray Jay reported at Whitefish Point puts this year’s count in a two-way tie for the lowest total in the last 30 years (down 90 percent), and the 6969 Blue Jays (down 23 percent) was the fifth fewest in 30 years. American Crows and Common Ravens both returned to near-normal numbers after being unusually abundant last year, with ravens seen on a record-setting 29 circles. Annually one of the most abundant species recorded on Michigan CBCs, the Black-capped Chickadee was unusually so this year, the 19,294 individuals being the second-most ever reported and 21 percent above average. Both nuthatches were super abundant; the 1426 Red-breasted Nuthatches was a new high count and 87 percent above average, while the count of 3894 White-breasted Nuthatches (up 10 percent) is eclipsed only by the 4231 seen on the 110^th CBC.

Among the half-hardy mimids, Gray Catbird was down (1 vs. 3.9) while Northern Mockingbird was up (12 vs. 9). Bohemian Waxwings staged a major incursion with 4211 individuals (up 374 percent) being a new high count. Cedar Waxwings, on the other hand, were down 63 percent (2285 vs. 6155). The downturn in Yellow-rumped Warbler numbers was even more dramatic than that of the Northern Flicker, going from 172 last year (the highest ever) to 16 this year (the fewest in 12 years, a one-year decline of 91 percent, and 85 percent below average).

Of five sparrow species with depressed populations last year, three (American Tree Sparrow, Swamp Sparrow, and Dark-eyed Junco) rebounded to near-normal numbers, while two others remained well below normal: White-throated Sparrow down 70 percent vs. 55 percent last year, and White-crowned Sparrow down 64 percent in both years. Northern Cardinals rebounded to near-normal numbers from last year’s unusually low tally. Eastern Meadowlark was missed for the first time in 60 years! Even a cursory glance at the CBC data leaves little doubt that meadowlarks have declined dramatically as early winter residents; consider, for example, an 89 percent decline in average numbers, from 38 (1953-1989) to four (1990-2012).

Three winter finches of regular occurrence staged major incursions into the state—Pine Grosbeak up 169 percent (826 birds, the fourth-highest count in the last 30 years), Red Crossbill up 333 percent (81 birds, the fifth-highest total in 30 years), and Common Redpoll up 522 percent (8303 birds, the fourth-highest total in 30 years)—while four others (Purple Finch, White-winged Crossbill, Pine Siskin, and Evening Grosbeak) remained in relatively normal numbers. Numbers of American Goldfinches were down 19 percent, while House Sparrows were below average for the second year in a row (18 and 13 percent in 2011 and 2012, respectively).

While no new species were added to the Michigan CBC checklist, there were frequent additions to the lists of individual circles. Thirty-four (62 percent) of 55 circles with 10 or more years of CBC data added an average of 1.8 species. And, remarkably, count longevity apparently has little effect on the probability of adding new species, as 71 percent (5) of seven circles with a count history of at least 50 years added an average of 1.6 species. The most frequent local additions were Trumpeter Swan, Ring-necked Duck, and Hoary Redpoll (each newly reported on four circles), followed by Cackling Goose and Bonaparte’s Gull with three each.

This report requires the cooperation of many CBC compilers and numerous participants, and to them I extend my thanks for their invaluable contributions. Once again, I wish to thank Adam M. Byrne and Jonathan Wuepper for reviewing and evaluating all reports of rarities.