The 118th CBC in Michigan

The 118th Michigan Christmas Bird Count (CBC), while not a block-buster in terms of number of species, was nevertheless quietly successful. Highlights include   a count-week Western Tanager at Midland (the first ever on a Michigan CBC, even if a day late) and an American Woodcock at Anchor Bay (just the second occurrence on a Michigan CBC).

Of the 70 CBCs conducted in count-year 2017–2018 (hereafter CY-118), 67 were repeats from CY-117, two were new (Oceana and Rudyard), one returned after a one-year absence (Neebish Island-Dunbar), and one active count from last year was not completed this year (Seney N.W.R.). Geographically, 12 counts were conducted in the Upper Peninsula (UP), 24 in the Northern Lower Peninsula (NLP), and 34 in the Southern Lower Peninsula (SLP).

At a minimum, 1317 field observers (129 in the UP, 343 in the NLP, 845 in the SLP) in 615 parties (66 in the UP, 154 in the NLP, 395 in the SLP) travelled 23,262 miles in 3150 hours (including 379 miles by foot in 779 hours, and 22,405 miles by car in 2356 hours). Additionally, 614 hours were spent watching feeders, and 592 miles were traveled in the 189 hours spent listening for owls.

Ann Arbor took top honors for field observers (62), foot hours (62), and total party-hours (131); Barry County took top honors for parties (33), nocturnal hours (17), and nocturnal miles (110); Albion and Niles for feeder watchers (17 each); Mount Pleasant for feeder hours (109), East Lansing for foot miles (56); Detroit for total party-miles (753); Pontiac for car hours (93); and Port Huron for car miles (716). Nine circles were conducted with fewer than 10 participants (field observers plus feeder watchers), the recommended minimum number of participants for adequate coverage, with seven of those located in the sparsely populated UP or NLP.

Participants had to contend with unusually cold temperatures and a relative abundance of snow, both of which reared their heads on the very first weekend of the count period. Freezing rain also presented problems early on at a few circles. Temperatures on respective count days ranged from a low of -12° F at Lake County on 4 January to a high of 45° F at New Buffalo on 19 December. Average high temperatures were relatively chilly: 16° in the UP, 23° in the NLP, and 26° in the SLP. The overwhelming weather factor of the 118th CBC was the presence of snow, generally in substantial quantities. Maximum snow depths averaged 12 inches in the UP (maximum of 30 at Houghton County), 10 inches in the NLP (maximum of 24 at Beulah and Grayling), and 8 inches in the SLP (maximum of 36 at Holland).

A total of 565,330 individuals of 150 definitive species was documented. Two additional species were reported during count week but not on count day, and one identifiable subspecies was noted on count day.

The median number of individuals/circle was 4342, with half of all circles reporting between 2228 and 8700 individuals. Honors for the highest number of individuals goes to Anchor Bay (82,339), with honorable mentions awarded to Rockwood (34,186), Monroe (24,060), Ann Arbor (23,180), and East Lansing (20,319). Ten thousand or more individuals were tallied in each of 12 circles, all in the SLP. Among the 97 species found on at least 10% of circles, maximum counts of 14 species were tallied at Monroe, 13 at Ann Arbor, nine at Anchor Bay, and six each at Port Huron and Rockwood.

The median number of species/circle was 53, with half of all circles reporting between 39 and 61 species. In addition to having the highest density of individuals, Anchor Bay also laid claim to the highest species total in the state and the SLP with an incredible 102; five other circles in the SLP had 70 or more species, including Monroe with 86, Rockwood with 83, and Port Huron with 81. Midland topped the NLP with 66 species followed closely by Bay City and Beulah with 63 each, and Lake Leelanau with 61. In the UP, Marquette had 49 species while Little Bay de Noc reported 41.

Four species (Blue Jay, American Crow, Black-capped Chickadee, American Goldfinch) were seen in all 70 circles. Another six species were seen in at least 90% of all circles, with Mourning Dove, White-breasted Nuthatch, and European Starling on 69 each; Hairy Woodpecker and Dark-eyed Junco in 68 each; and Downy Woodpecker in 67. Contrastingly, nearly half (72) of the species recorded were restricted by habitat or range, thus appearing in less than a fifth of circles.

Seventeen species exceeded 10,000 individuals statewide: European Starling (59,998), Canada Goose (59,801), Mallard (38,652), Canvasback (35,319), American Crow (27,060), Herring Gull (25,320), Common Merganser (21,000), Mourning Dove (18,696), Dark-eyed Junco (18,516), House Sparrow (17,706), Black-capped Chickadee (16,561), American Goldfinch (15,143), Redhead (13,854), Blue Jay (12,938), Rock Pigeon (11,379), Ring-billed Gull (10,665), and Common Goldeneye (10,333). Meanwhile, about a quarter of species (35) were simply numerically rare, as they did not exceed 10 individuals statewide.

Nine circles accounted for the 15 species that appeared on just a single count: Anchor Bay (1 American Woodcock and 1 Yellow-headed Blackbird), Ann Arbor (1 Chipping Sparrow), Eagle Harbor (2 Black-backed Woodpeckers and 3 Boreal Chickadees), East Lansing (1 Northern Bobwhite), Holland (1 Black-legged Kittiwake), Huron County (1 Townsend’s Solitaire), Little Bay de Noc (1 Canada Jay), Monroe (8 Great Egrets, 3 Wilson’s Snipe, and 5 Eastern Meadowlarks), and Rockwood (2 Long-eared Owls, 1 Common Yellowthroat, and 3 Savannah Sparrows).

Despite a tripling of the number of active circles (from 23 in CY-71 to 70 in CY-118), the number of individuals of 14 species this year ranked in the bottom 20% of 48 count-year totals since CY-71 (unless otherwise indicated, all mentions of declining trends are for the period from CY-71 to CY-117):

  • Northern Bobwhite—1 individual of questionable origin at East Lansing (the decline has been so severe in recent decades that it is doubtful if self-sustaining wild populations still exist in Michigan);
  • Ring-necked Pheasant—124 birds in 15 circles, with a maximum of 29 at Lapeer in The Thumb (a decline of >90%);
  • Wilson’s Snipe—3 birds at Monroe (a decline of ca. 77%);
  • Bonaparte’s Gull—30 birds in three circles, with 25 (83%) at Anchor Bay (while low, this number is of little concern as this species’ abundance is extremely variable from year to year);
  • Common Loon—3 birds in two circles, with 2 at Anchor Bay and 1 at Marquette (this low total appears to be an outlier, with double-digit or high single-digit totals recorded in most recent years);
  • Long-eared Owl—2 birds at Rockwood (a decline of ca. 80%);
  • American Kestrel—218 birds in 30 circles, with a maximum of 30 at Hudsonville (a decline of ca. 60% since CY-96);
  • Gray Jay—a single bird at Little Bay de Noc (a decline of ca. 50%: average totals of 11 and 4, 1970-2016 and 2007-2016, respectively);
  • House Sparrow—17,706 birds (the lowest total in the last 48 years) in 62 circles, with highs of 1357 at Port Huron and 1299 at Western Macomb County, both in the highly populated southeastern portion of the state;
  • Purple Finch—193 birds in 37 circles, with a high of 31 at Beulah (a variable species with no obvious trend);
  • Evening Grosbeak—a total of just 14 birds, with 8 at Neebish Island-Dunbar in the UP and 6 at Grayling in the NLP (a decline of >95%: statewide totals in the thousands were commonplace in the 70s and 80s);
  • Field Sparrow—5 birds in 2 circles, with 4 at Albion and 1 at Waterloo State Recreation Area (a decline of ca. 85%: double-digit statewide totals were commonplace through the early 2000s);
  • Song Sparrow—360 birds in 37 circles (a decline of ca. 60%);
  • Swamp Sparrow—56 birds in 12 circles, with 19 (34%) at Monroe (a decline of ca. 67%).

In CY-118, 10 species were recorded in their highest numbers since at least CY-71, a span of 48 years. For each of the following species, the CY-118 high is compared to the previous high and the previous 47-year (CYs 71-117) and 10-year (CYs 108-117) averages:

  • Trumpeter Swan—366 birds compared to a previous high (in CY-116) of 286 birds, and long- and short-term averages of 67 and 218 birds, respectively;
  • Sharp-tailed Grouse—195 birds compared to a previous high (in CY-117) of 104 birds, and long- and short-term averages of 6 and 25 birds, respectively;
  • Iceland Gull—12 birds, compared to previous highs (in CYs 89 & 96) of 9 birds, and long- and short-term averages of 3 and 4 birds, respectively;
  • Bald Eagle—886 birds, compared to a previous high (in CY-116) of 649 birds, and long- and short-term averages of 167 and 534 birds, respectively;
  • Red-shouldered Hawk—76 birds, compared to a previous high (in CY-113) of 56 birds, and long- and short-term averages of 20 and 39 birds, respectively;
  • Golden Eagle—7 birds, compared to a previous high (in CY-96) of 5 birds, and long- and short-term averages of 1 and 2 birds, respectively;
  • Red-bellied Woodpecker—2571 birds, compared to a previous high (in CY-117) of 2307 birds, and long- and short-term averages of 1011 and 2040 birds, respectively;
  • Pileated Woodpecker—468 birds, compared to a previous high (in CY-115) of 424 birds, and long- and short-term averages of 107 and 311 birds, respectively;
  • Blue Jay—12,938 birds, compared to a previous high (in CY-115) of 12,522, and long- and short-term averages of 8256 and 9978 birds, respectively;
  • Gray Catbird—8 birds, equaling the previous high (in CY-104), and compared to long- and short-term averages of 2 and 4 birds, respectively.

Additional rarities not already mentioned included single Harlequin Ducks at Holland and Houghton County; single Virginia Rails at Battle Creek and Hudsonville; a count-week Eastern Phoebe at Western Macomb County; single Marsh Wrens at Monroe and Muskegon; single American Pipits at Battle Creek and Monroe; a single “Oregon” Junco at Oscoda, plus a count-week individual at Waterloo State Recreation Area; and single Brewer’s Blackbirds at Anchor Bay, Huron County, and New Buffalo.