American Birds 2011-2012, Summary of the 112th Christmas Bird Count

In this issue of American Birds you’ll find a series of feature articles that highlight many aspects of the Christmas Bird Count. Leading things off is an announcement of two important changes to the Christmas Bird count. In a nutshell, the participant fee for the CBC has been eliminated, and to financially enable this decision American Birds will no longer be mailed in printed form, and instead will be delivered in an online format. In our second feature, Steve Hampton details his work to create an index to analyze CBC data and applies this to four species impacted by West Nile Virus. Dusti Becker writes about the efforts of participants in the Loma Alta, Ecuador CBC to break their own record for species counted on their CBC day. Then Royce Pendergast tells us about Bill Graber, who has been compiler of the Bolivar Peninsula count in Texas for 50 consecutive years.

A new record total of 2248 CBCs are in the 112th season’s database (up 88 from last year’s one-year-wonder record high), including 410 in Canada, 1739 in the United States, and 99 counts in Latin America, the Caribbean, and the Pacific Islands. Results such as these cannot be generated without the inclusion of a wealth of new circles, including 46 new CBCs in the 112th Count (15 in Canada, 26 in the United States, and 5 in the Caribbean and Latin America).

Not surprisingly, given the number of CBCs and remarkably favorable weather, another new record level of participation is included in the 112th Christmas Bird Count—63,227 observers (54,262 in the field and 8965 at feeders) contributed their time and effort this season. That total is 603 higher than last year’s record tally, swelled mostly by an increase in field participation, even though the number of feederwatchers slightly declined.

The 112th Christmas Bird Count 

December 14, 2011, to January 5, 2012 

The anticipation has been building for weeks; the long-range weather forecast gets checked nearly daily. What unusual birds have been around as reported on the rare bird alerts and listserves? What about that huge snowstorm or cold snap back in October—how, if at all, will those have affected the birds that are around to be discovered in mid-December? These may be some of the thoughts that pass through the minds of birders who participate on the Christmas Bird Count. And each season all are rewarded in one way or another; it may be a fantastic bird turned up on the count, an all-too-infrequent day of catching up with old friends, or the satisfaction of braving less-than-ideal conditions and still successfully complete the count. Such has been the mind-set of conservation-minded birders since December of 1900, and new horizons for the CBC program are still opening up. 

The 112th Christmas Bird Count indeed was a snowy season—though not in terms of the depth and expanse of crystalline H2O, but instead in a rather remarkable geographic coverage of Bubo scandiacus, Snowy Owls. With reports of southbound Snowy Owls beginning in the end of October and high numbers recorded in November of 2011, it seemed that a big irruption was under way of these magnificent Arctic predators. And while the 112th CBC season did not disappoint Snowy Owl watchers in many areas, there were other events of significant note as well. 

Arguably the most notable feature of the 112th count was the weather— it was to prove to be one of the least snowy, or wintry, Christmas Bird Counts on record. From Atlantic Canada to coastal British Columbia, and from the Prairie Provinces to the Gulf Coast, compilers and regional editors alike remarked on the mild and open conditions. There was little snow cover or frozen water anywhere in the geographic area of CBC coverage, and in many regions where winter conditions are usually braved the weather on count day was downright balmy. Even more remarkable (and certainly a welcome break from the past couple of seasons), the weather conditions from coast to coast during the weekends of the 112th count period were nearly storm-free.  

Furthermore, for the most part the fall leading up to the count period had also been very mild in general, according to the National Climatic Data Center maps online. Much of the United States had been in warmer than average or record warm conditions, although the Southeast was cooler than normal. For precipitation, the fall had been much wetter than normal in the Northeast, with continuing dry conditions over much of the west. All in all, the stage was set for a most interesting CBC. 

The end result was another remarkable and record-setting season for the Christmas Bird Count. A new record total of 2248 CBCs are in the 112th season’s database (up 88 from last year’s one-year-wonder record high), including 410 in Canada, 1739 in the United States, and 99 counts in Latin America, the Caribbean, and the Pacific Islands. Results such as these cannot be generated without the inclusion of a wealth of new circles, and the roster of the 46 new CBCs in the 112th Count (15 in Canada, 26 in the United States, and 5 in the Caribbean and Latin America) is listed in Table 1. Among the new circles are two in the Caribbean that contribute results on islands long missing from the CBC—Cuba and Jamaica. We hope for many years of coverage (and perhaps more counts) from these fascinating and species-rich locations. 

In addition to the new counts included this season, as was mentioned last year we always welcome the return of data from circles that have lapsed over time. Significant efforts have been made in Canada (many thanks to the efforts of Bird Studies Canada and all the Canadian CBC Regional Editors) as well as in Minnesota, Wisconsin, and other regions in recent seasons. This year we welcome back into the fold six re-started Christmas Bird Counts, and we will always look forward to hearing from compilers hoping to re-start other existing historical counts. 

One focus of Audubon’s bird conservation efforts is to use the lens of the four main migratory flyways that birds use during their movements across the Americas. The flyways view also helps connect conservation goals for species both north of the United States in Canada and to the south in the Caribbean and Latin America. Long-term Christmas Bird Count results are highly informative to staff and researchers working to preserve and protect species in the flyways, and the current breakdown of active CBCs in the United States as measured by this ruler is 568 CBCs in the Atlantic Flyway, 540 in the Mississippi Flyway, 451 in the Central Flyway, and 280 along the Pacific Flyway. Each season these numbers will likely increase as more and more CBCs are conducted, providing an ever more important data set for the protection of birds across the Americas. 

Not surprisingly, given the number of CBCs and remarkably favorable weather, another new record level of participation is included in the 112th Christmas Bird Count—63,227 observers (54,262 in the field and 8965 at feeders) contributed their time and effort this season. That total is 603 higher than last year’s record tally, swelled mostly by an increase in field participation, even though the number of feederwatchers slightly declined. This is not unexpected given the spectacular counting conditions that would have enticed folks into the field. The regional breakdowns for the participation totals are as follows: in Canada, 12,019 observers (8635 in the field and 3384 at feeders); 49,158 birders (43,635 afield and 5523 at feeders) in the United States; and 2050 (1992 observers in the field and 58 at feeders) in the Caribbean, Latin America, and the Pacific Islands of Johnston Atoll, Guam, Saipan, and Tinian. From the boreal regions of Alaska and Canada to the Neotropics, compilers of many circles are blessed with an abundant wealth of observers to manage for their counts. Table 2 lists the 60 counts reaching or exceeding the 100-observer mark in the 112th CBC. 

So that’s a summary of the conditions, effort, and coverage—now what about the birds? As is invariably the case, millions upon millions of birds of thousands of species were tallied during the 112th count; 64,989,719 of our fine feathered friends in total. National and regional results by CBC observers included 3,943,480 birds in Canada, 60,502,185 in the United States, and 544,054 birds in other countries. Looking at the cumulative tallies of types of birds, 2298 species were reported on all circles combined, not surprisingly up considerably from other seasons given the new counts in Jamaica, Cuba, and Colombia, where endemism is incredibly high. In the United States, 666 species and 48 infraspecific forms (some of those potential future splits!) were tallied, including three new species to the cumulative 112-year CBC database: Gray-tailed Tattler and Millerbird, both from Laysan Island, Hawaii; and (unfortunately count week only) Dusky Thrush at Anchorage, Alaska. That pesky Dusky Thrush was a particular frustration for CBC participants in Anchorage; it had been present for weeks visiting a yard in Anchorage, and was seen both the day before and the day after the census, but could not be located on count day. In Canada, CBC participants tallied a new record total of 303 species, including one new species for the cumulative Canada list, the Lazuli Bunting discovered at Cape Sable Island, Nova Scotia. Counters there had an entirely different experience from those in Anchorage—please have a look at Dick Cannings’ 112th Canada summary for the details! 

Tens of thousands of birders in more than 2000 locations finding tens of millions of birds should come up with some pretty impressive count-specific species totals, and the 112th CBC was no exception to that rule. Table 3 lists all the counts this season tallying 150 species or more, and it’s quite interesting to peruse the list in light of the weather conditions during the 112th count period. This season there are 104 counts in the U.S. and Canada on this list (up from 98 last season), and a considerable number of those tallies are higher than last year. While the number of counts in Latin America on the list is a similar roster to previous seasons, many of those species totals are actually much lower than before. Both factors can likely be attributed to the weather—amazingly favorable in the U.S. and Canada, but considerably more inclement in Latin America. Lousy weather negatively affects both the number of birders in the field and the detectability of birds, likely hence these contrasting numbers. 

Topping the list of counts north of the Mexican border in Table 3, as has usually been the case for the past decades, is Madagorda County-Mad Island Marsh, Texas, with a species tally of 244, skirting again with the 250-species mark and their third highest tally since the start of the count in the 94th CBC. They have retained their top spot for the entire run of that count except for the 107th CBC, when Corpus Christi, Texas, prevailed. Other counts in both California and Texas knock on the door; who knows what future seasons will bring! One major exception to the rule of depressed species totals in Latin America during the 112th count, however, as also seen in Table 3 is Yanayacu, Ecuador, out-tallying their hard-working neighbors at Mindo-Tandayapa with 492 species, nearly breaking the 500-species barrier. Some of the same observers participate on both of these awesome Ecuadorian counts, and one can only wonder what future tallies will achieve! Many thanks and congratulations go to all participants on each and every CBC, whether your species total remains at one (for Prudhoe Bay, Alaska) or skirts with 500 in the Neotropics. Every person on every one of the 2248 counts included this season contributes valuable data, and no field checklists go unappreciated. 

However, every year each group on every CBC competes with themselves as well as with their neighboring parties, and also of course with their neighboring counts. Table 4 displays the roster of regional high species tallies in the 112th Christmas Bird Count, with both species totals and the number of counts in the region listed.  

So what about the aforementioned avian snow cover during the 112th Christmas Bird Count? Was it really all that big—and how did it compare to other “big” Snowy Owl seasons? While the total number of Snowy Owls reported in Canada and the United States this season (546) was the highest of any year since the 60th CBC, the additional measure (usually used in analyses of CBC data) is to look at the effort-weighted data, using the birds per party hour. By that measure, the 75th CBC, the first season of the historic big double invasion event of Snowy Owls, has the highest number at 0.063 birds per party hour. In the 112th count, this yardstick shows 0.033 birds per party hour; thus almost two times as many Snowy Owls were likely to be encountered per hour by parties during the 75th count. 

However, the most remarkable thing about the Snowy Owl irruption this season was its geographic expanse. While there were not many Snowies that reached record southern areas, from the Pacific Ocean to the Atlantic shores Snowy Owls were found in good numbers on 256 counts across southern Canada and the northern tier of states, far exceeding the number of counts tallying this species than ever before; the previous high was 513 birds on 193 counts in the 97th CBC. Perhaps most unique about this flight was the fact that it was a wide geographic swath across the Canada–United States border; most other irruptions include a significant push southward either in the east, central, or western parts of the continent. Numbers of Snowy Owls were somewhat higher to the west—Regina, Saskatchewan, had the greatest number at 45, followed by Ladner, British Columbia, at 37—but there were double-digit counts in Ontario, and high count or unusual species records from Nantucket Island, Massachusetts, through Iowa to Colorado. Snowy Owls, especially young birds, move southward in good numbers approximately every three to five years following the crash of small mammal populations in the Arctic, and this was a big year indeed. Will the 115th CBC be the next big irruption of Snowy Owls? Only the birds…and the lemmings…will be able to predict the answer to that question. 

Another factor affecting birds on Christmas Bird Counts at a continental level is the ongoing and drastic drought in the Southwestern states, and especially in portions of Texas. Texas had the driest year on record in 2011, and New Mexico, Oklahoma, and Louisiana all had much below-average precipitation. Please read Brent Oretgo’s Texas CBC regional summary for a more in-depth (and firsthand) view of this event. Productivity for many species in drought-stricken areas is likely very low, and birds that winter in these regions are showing up as vagrants in far-flung portions of the continent, both on CBCs and at other times of years. Green-tailed Towhees and Black-throated Sparrows are examples—each of these species has been tallied in regions where they would not normally occur in the past few CBCs. As the drought continues (though we hope it will not!) other southwestern wintering species may show up to the north and east in unexpected areas. 

Of note continentally are three continuing long-term declines as documented on Christmas Bird Counts—Northern Bobwhite, American Kestrel, and Loggerhead Shrike. Bobwhites across the board in their range are mentioned by birders, compilers, and regional editors as in decline, and this trend has been significant since the last relatively high season in the 83rd CBC. In some areas where this jaunty quail was formerly commonly found it is now only present as a result of introductions for hunting stock. Quail in general have been declining for some time, likely as a result of loss of fallow fields and shrub land needed for breeding. But the Northern Bobwhite seems to be the poster child for this unwelcome phenomenon. 

Meanwhile, American Kestrel has demonstrated a long, slow decline over the past 30 years. That decline seems to be flattening a bit, and in some regions even seems to be showing a rebound, but the overall trend is still negative. As with the kestrel, Loggerhead Shrike has been in trouble for decades, and while the numbers for this species on CBCs are still significantly depressed over historic times, again there is cause for hope as the trend has slightly reversed over the past three seasons. There have been similar up-ticks in the trend data for shrikes over the past 20 years, but if this slow increase continues it could be very good news for the predatory passerine species. 

Another persistent pattern developing in Christmas Bird Count data is an increase in Northern Rough-winged Swallow reports and numbers, away from the southern regions of the continent. In years past, the only “expected” swallows to the north during the Christmas Bird Count period were Tree Swallow continentally and Violet-green Swallow on the West Coast. However, that may be changing. In the 112th CBC, Northern Rough-winged Swallows were reported (and documented) in small numbers in Connecticut, Tennessee, Indiana, and Illinois, and a flock of 150 was present at Pennypack Valley, Pennsylvania. They were also recorded away from their usual haunts on many CBCs in Florida. This species is among the earliest of northbound migrants in the spring; perhaps as winter temperatures moderate with a concurrent increase in availability of flying insects Northern Rough-winged Swallows will linger farther and farther north as well. 

Important changes are coming for the Christmas Bird Count program. Audubon Science solicited your comments in an online survey earlier this year, and we thank the thousands of participants and compilers who responded. Your input helped Audubon to make two critical revisions under consideration for the CBC. Please take a look at the feature that begins on page 10, announcing these changes and summarizing the results of the online survey. In a nutshell, the participant fee for the CBC has been eliminated, and to financially enable this decision American Birds will no longer be mailed in printed form, and instead will be delivered in an online format. 

Lots of interesting ideas were mentioned in the comment sections of the online survey, and one recurring theme that deserves mention here is the use of tapes, iPods, “pishing,” and other attractant noises on Christmas Bird Counts. Such methods and devices are strictly forbidden on the Breeding Bird Survey, Breeding Bird Atlas, and other surveys of birds in the breeding season. However, because the CBC is monitoring birds in the non-breeding season (and most species are not singing, at least in North America) the use of tapes and attractant noises has always been allowed on the CBC. With the advent and proliferation of iPods and other hand-held devices that can readily play bird vocalizations and elicit responses from otherwise hidden birds, this use is reported to be on the rise. 

The prohibition of the use of attractant noises on CBCs would be a relatively major programmatic decision that could quickly change the data collected by observers on many counts, and thus we need to continue their use at least for now. However, the use of such devices should be very judicious, and never done in a fashion that could affect the behavior of target species in any significant way. If you use iPods or tapes on your CBC, please keep this in mind! 

This is the 25th Christmas Bird Count I’ve had the honor of summarizing in these pages. Those years have spanned a lot of major changes in the CBC program. Early in my tenure the 87th CBC issue was the one-off and universally disliked “tabular” format, and participant fees were raised from three, to four, and then five dollars. On a hugely more positive note, the entire data set was made available in an interactive, free, online database, and an online data entry application was developed. The number of counts included in the 88th CBC (my first summary) was 1531, and 25 years later that number is 2248. With the advent of the free Christmas Bird Count starting in the upcoming 113th CBC and online delivery of American Birds, a whole new era of communication and conservation action lies ahead. 

I’ve been doing Christmas Bird Counts since before I ever thought it could be possible to work for Audubon, and my traditional CBCs have been, and continue to be, the Newport-Westport and South Kingstown CBCs in Rhode Island. This past season we discovered some amazing avian changes on the Newport-Westport count, where over the past decades occasionally we hope to find one or two lingering Great Egrets. This season a guttural squawking caught our ears while we were combing the shores of Briggs Marsh; at first it sounded like a Sandhill Crane, but it just wasn’t quite right. As we slowly rounded the corner of a cove, three, then five, then a dozen and eventually 21 Great Egrets were roosting in the trees—and equally amazingly, so was one Snowy Egret. This wasn’t Florida, folks, but Rhode Island. It was a truly exciting moment in the field. 

The global climate is changing, and the numbers and movements of birds are shifting in response. We can’t be sure how this will all turn out in the long run, but we can be sure that citizen science programs as epitomized by the Christmas Bird Count will help understand what’s happening and, as both birders and ornithologists are asked all the time, will continue to tell “So, how are the birds doing?”