Much like I did last year, I’d like to start off this year’s CBC report with an administrative note. As we were gathering for the potluck-tally at the Matthaei Botanical Gardens, Mike Kielb pointed out that this year’s count really should be noted as Ann Arbor’s 72nd edition of the CBC, not the 71st. This due to the somewhat obscure 1947 edition, which was listed as count 1b in the booklet “Fifty Years & Counting,” written in early 1997 by Rob and Nancy French and Mike Kielb. Doing the math, Mike is absolutely correct: the 2017 Ann Arbor CBC was, in fact, the 72nd time the event was run! Amazing stuff, and as good an indication as any to show what a committed birding community the Ann Arbor area has—here’s to 72 more!
Speaking of a committed birding community: there were a whopping 62 observers out in the field, along with nine feeder watchers—both numbers are above our recent years’ averages of 58 and five, and are likely good indicators of the (relatively) pleasant counting conditions this year, particularly when compared to the rather abysmal conditions leading up to and during the 2016 count. That said, some counters reported some very slippery roads out there, so it would be a stretch to say that conditions were ideal. There were between four and six inches of snow on the ground throughout the circle and some light snow floated down from the clouds in the pre-dawn hours. Although a cold snap in the weeks leading up to the count had frozen all still and quite a bit of the moving water in our circle, on count day temperatures inched slightly above the freezing mark, causing some to remark they felt hot as they were counting! A funny bunch they are, those birders….
This ever-intrepid crew of volunteers scoured our count circle and turned up a very respectable 68 species (with three additional during count week), which is right about the average for the past decade or so. “Only” 18,104 individual birds were tallied, which is the lowest in some 25 years. Generally, the main determining factor for this statistic is the Ann Arbor crow roost, and this year the incoming birds were exceedingly hard to get a handle on. As a result, the tally for American Crow just barely surpassed the 3,000-mark—no doubt more birds were present, but we just did not get a chance to count them.
Perhaps the graph above can shed some perspective on this statistic. Between 1990 and 2017, we have counted as few as 713 and as many as 29,000 crows, all depending on how easily the roost could be assessed/accessed. As a result, our overall tallies ranged from as low as 13,305 to as many as 49,039 individuals: that is a spread in excess of 35,000 birds! However, when the crow tally is backed out of those totals, the spread goes down to 22,387 (low: 12,552 – high: 34,939). The overall average for 1990-2017 is 28,260, the average without crows is 17,763—that means that our overall count this year is more than 10,000 below the overall average, but only 2,800 below the average without crows! Clearly, the crows have a major impact on our CBC’s overall tally, and given that they are a fickle bunch as far as counting them is concerned, we shouldn’t make too much of the overall individual tally statistic.
Much like last year, a solid freeze ahead of the count severely limited sources of open water. All lakes and ponds in the circle were frozen over and only the Huron River and the larger creeks (Fleming, Mallett’s, among other) had open water. As before, this situation concentrated waterfowl in what open water there was and helped us count them more easily—species variety was similar to last year: not great, not bad. There were a few goodies in among the expected species, with a Ring-necked Duck as the main highlight. After last year’s unusual imbalance between Mute and Trumpeter Swans (3 versus 14), this year parity between the two was restored (33 v. 30). A count week Tundra Swan completed the swan trifecta for the third year in a row. Last year, I noted the lowest number of Canada Geese since the mid-90s, but this year they were out in force and exceeded the 10-year average by some 11%. By contrast, dabbling ducks all performed below average, Mallard being the only exception. In this category, the near-absence of American Black Duck is particularly worrisome—although we have found this species on every one of our 72 counts (with two occasions of count week only, in 2006 and 2012), this year’s two birds were the lowest since 1960, back when we had nowhere near the coverage we currently have. Hybrids between this species and Mallard have been noted on recent counts, which highlights the likely reason for the American Black Duck’s decline: ongoing genetic swamping by the ubiquitous Mallard. Compare the trends for both species in our CBC data in the graph, showing the relative abundance percentages of American Black Duck and Mallard—ever since the 1980s, the two species’ shares have settled into a 1-99 ratio:
This being the case, and with the continued presence of hybrids, we should not be surprised to bear witness to the American Black Duck’s continued struggle to persist on our count.Interestingly, though not necessarily surprisingly, the similarities between 2016 and 2017 extend to the other water-dependent species as well. Both Great Blue Heron and Belted Kingfisher were found in above-average numbers (the harsh conditions notwithstanding), and for the third year in a row Sandhill Crane was found. This count week record was only the ninth ever, but seven of those have occurred since 2000—clearly, increasing numbers for this species are getting reflected in our CBC tallies. Time will tell if Sandhill Crane is going to follow a trajectory similar to the Wild Turkey. Gulls had another so-so year, with only two dozen total for the two expected species. No grebes or coots were found.
Traditionally associated with water, Bald Eagles had a banner year, with eight birds reported, only one shy of the record high count from 2015. Interestingly, several of these birds were found in locations, including a juvenile at the Ann Arbor Landfill and a near adult on a south-bound trajectory that was noted both at County Farm and Mary Beth Doyle Park! Even if this concerns a large bird, methinks this is a good indication of how good our circle’s level of coverage is. For the second year in a row, another recovering species beat its previous high count: 32 Cooper’s Hawks bested the 2016 high count of 24 by 33%! Buteos posted the epitome of average: 79 Red-tails is an exact match of the recent 10-year average, a count week Red-shouldered Hawk indicates that species’s more or less expected nature, and missing Rough-legged Hawk is also the norm. About as unusual as that last buteo, finding a Northern Harrier is always a treat on our count. Settling in for a new normal, we counted the three falcon species for the 7th time out of the past 10 counts, albeit in very low numbers for all three—let’s hope Kestrels hang on, Peregrines continue to do well, and Merlins continue to show off their spunk for us.
Perhaps due to the thick layer of clouds covering the count circle during the pre-dawn hours, owling was challenging. I, for one, was amazed by how far human-generated noise carried and may have drowned out some owls. As a result, both Eastern Screech- and Great Horned Owls were counted in below average numbers, the latter almost 25% under. No other owl species were noted this year, although I am still expecting Barred Owl to become more regularly featured on our CBC. Maybe next year?
What more to say about the Pheasant-Turkey dichotomy? Pheasants continue their decline (we missed them altogether this year) and appear to be following the path of our circle’s Ruffed Grouse (last reported in 1996) and Northern Bobwhites (last reported with a count week record in 2000) into extirpation. By contrast, Wild Turkeys are still on the increase and posted a fifth-consecutive triple-digit tally – they were reported from six of our eight count areas, and I have no doubt that within the next few years they will be found in all eight. What a painfully stark contrast….
Looking over my notes from the past few years, I appear to have singled out our circle’s woodpeckers for honorable mention time and again and I’m afraid this year is no different. For the fourth time since the 2010 count, woodpecker numbers surpassed 450; this year’s record total of 489 renders a count of 500 overall a very real possibility! A comparison of recent averages clearly shows the upward trend (as does the graph below):
Although we missed our least commonly found species, Yellow-bellied Sapsucker and Red-headed Woodpecker (the latter by mere yards!), the other five species each posted stellar tallies. Red-bellied Woodpeckers missed last year’s record high by a mere half dozen, Downies surpassed the 200-mark yet again, Hairy Woodpecker beat its 2016 high mark by almost 10, and Northern Flicker posted a very respectable tally of 31, well above its recent 10-year average.
All of those impressive stats, however, pale in comparison with those posted by that most impressive of our woodpeckers, the Pileated. First noted on the 2008 CBC (only 10 years ago!), this species was found every year only since the 2011 count, seemingly settling in to an annual tally of 2-3. Well, this year’s count blew that assumption out of the water: fully half of our eight count areas reported Pileated Woodpecker, three of them each tying the previous record high count (3) for the species! When the dust settled, a dizzying total of 11 Pileated Woodpeckers was the end result. What the future will bring for this species, only time will tell, but maturing woodlots (and dead/dying ash trees) in our circle have clearly been beneficial for this stunning species.
As is almost to be expected for as varied a group as passerines, “mixed bag” certainly does seem to sum up this year’s results. In a way, our tallies were really quite similar to the 2016 count, with closely related species posting contradictory results:
- Blue Jays were more than 30% above the 10-year average, whereas American Crow was more than 70% below average.
- Although Black-capped Chickadee was only marginally below the average (about 3%), Tufted Titmouse surpassed it by some 10%—like woodpeckers, titmice appear to be trending upward overall in recent years.
- For the second year in a row, White-breasted Nuthatch posted a record high (going past the 300-mark for the first time in the process); its irruptive cousin, the Red-breasted Nuthatch, performed significantly below average, by some 80% – that said, when recent irruptive years (2007 and 2012) are backed out of the totals, this year’s three birds are “only” 45% below the recent average.
In line with the good/decent showing by their chickadee-titmouse-nuthatch brethren, Brown Creeper, Golden-crowned Kinglet, and both Winter and Carolina Wren put in a good showing—the latter passing the 50-mark for only the second time ever. No warblers of any kind were found, unfortunately.
Frugivores put in another rather abysmal showing. With the exception of Eastern Bluebird (+8%), all bread-and-butter fruit-eating species were way below the expected, ranging from 41% below for European Starling to a rather dizzying 82% below for American Robin – where they went is unclear, since our local berry crop did not strike me as particularly lacking. However dismaying the above is, this category also featured some of this year’s more positively exciting finds: a long-staying Northern Mockingbird at Gallup Park managed to avoid the local Merlin long enough to be counted, and for the first time ever TWO Gray Catbirds were found, one along the B2B Trail near Dexter, the other at the Ann Arbor Landfill. The last time two mimid species were found on count day was in 1980, almost 40 years ago!
Sparrow variety was so-so and numbers-wise rather interesting. The most exciting bird in this category was the stake-out Chipping Sparrow at Will Weber’s feeders —amazingly, in 2016 we turned up this rarity as well: at Will’s feeders! I need to get me some of what he puts in his seed stock! Our more-or-less resident Song and Swamp Sparrows were found in well above the recent 10-year average (86 and 122% respectively!), with the former surpassing 30 for the first time since the mid-1990s. However, the three regular migrant species (White-throated and American Tree Sparrow and Dark-eyed Junco) all seem to have either stayed farther north or moved on south. Interestingly, two other migrants from up north, Lapland Longspur and Snow Bunting, were also (nearly) absent, even if the Horned Larks they tend to be found with were located in very good numbers in several of our count areas.
I thought 2015 and 2016 were banner years for icterids, with low numbers of three species found in each of those years. Somehow, 2017 managed to surpass those lofty standards: when the dust settled, we had recorded five different blackbird species, spread in small numbers over five different count areas. The last time this range of variety was recorded on our CBC goes back to the early 1980s; the last (and first) time a Brewer’s Blackbird was found was in 1953! Hopefully, the documentation that was provided by the feeder watcher that submitted the record to me will be sufficient for acceptance by the State compiler.
Continuing the theme of similarities between 2016 and 2017, no unusual irruptive finches were present for the count. Both Pine Siskin (-73%) and American Goldfinch (-17%) were present in significantly depressed numbers, but, on the other hand, both House Finch (+38%) and House Sparrow (+11%) had a good year.
For the second year in a row, the 2017 edition of the Ann Arbor count was a proper “winter” count. Both this year and last, a relatively mild November was followed by a cold snap during the first two weeks of December, complete with considerable snowfall. That left still water completely frozen over and several inches of snow on the ground—it certainly felt like winter birding out there. Looking over the results by count area, each one listed several unusual species and was, as always, instrumental in making the 72nd edition of our count a valuable enterprise once again.
As always, I have summarized our finds in the accompanying spreadsheet, so please have a look at the results of everyone’s hard work. If you would like to read about the outcome of the 2016 and prior CBCs on a grand scale, please check out the CBC pages on the National Audubon website. This site serves as the interactive version of the “American Birds” magazine of years past, and, I can assure you, can and will send you down any number of rabbit holes—go check it out!
|Download the 2017 Ann Arbor CBC Data|
For the second year now, the Washtenaw Audubon CBC pages have featured a new, interactive way of signing up for our count. After last year’s inaugural run, WAS Webmaster Rob French tweaked and improved his sign-up document (thanks again for all your work, Rob!). This form is immensely helpful in that it assists greatly with assigning volunteers to count areas, so please make sure to use it for next year’s edition of the Ann Arbor CBC. In closing, I owe each of you, field observers, feeder watchers, area leaders, potluck contributors, and whoever I may be forgetting a great, big “Merci!” for all the hours you contributed to yet another successfully completed Ann Arbor Christmas Bird Count—please mark your calendars for the 2018 edition on Saturday, December 15, 2018, and I look forward to seeing you all out there!
Jacco Gelderloos, CBC Compiler