I hope this report is not too much out of place here. I've discussed the Block Island winter counts with many New York birders over the years, and I hope that the idea behind them might be of interest to people here as well. For those unfamiliar with these counts, we have been bracketing the CBC with counts on Veterans Day in mid November (after most nocturnal-migrant landbirds have completed the bulk of their regular southbound migration) and Presidents Day in mid-late February (after the worst of the winter but before north-bound migration begins for most nocturnal-migrant landbirds). We chose Block Island for a number of reasons. It lacks a number of resident species that are common on the mainland, making detection of migrants/dispersants much easier; and its isolation means that sedentary species like Carolina Wren will not be arriving or departing throughout the winter, so changes in numbers from Nov to Dec to Feb reflect only detection and mortality. With this independent control for detection rates, we have been interested in measuring post-migratory movements by more mobile species, as well as charting mortality through late winter.
If you have a CBC module that you enjoy and that is relatively rich in thicket birds, consider working it again now and noting carefully how many Song Sparrows, Cardinals, and other species are present, relative to what you saw in December. ________________________________________ From: Shaibal Mitra Sent: Tuesday, March 1, 2016 7:55 AM To: [email protected] Subject: 21st Block Island Presidents Day Count Nine observers conducted the 21st annual Block Island Presidents Day Count on 15 Feb 2016. Pre-dawn temperatures were near 0 F at Pt. Judith and about 10 F at Block Island, but warmed to 24 F by the time most of us left on the 2:30 ferry. Winds were calm, however, and conditions were actually very good for detecting birds (apart from deep snow drifts along the edges of open areas). The species total of 76 was close to average. Among several notable species recorded, none was extremely rare or surprising. The highlights were: 2 Wilson's Snipe (both found by Doug "Snipe-dog" Wilson) 1 Thick-billed Murre (mid-crossing, a.m. ferry) 1 Snowy Owl 1 Yellow-bellied Sapsucker (historically very rare on BI in winter) 1 Eastern Phoebe and a count-week Common Raven The motivation for this project, and much of whatever interest it might inspire, centers on carefully selected sets of numbers of common species--not only across years, but also across winter seasons, from a mid-November VDC, to the CBC, to this winter wrap-up. We've already verified the long-suspected (but much debated) process whereby many species of landbirds make major post-migratory movements between mid November and mid December: https://sora.unm.edu/sites/default/files/journals/nab/v055n04/p00499-p00503.pdf --and the extent to which many supposedly "half-hardy" species survive through February, even during severe winters: https://sora.unm.edu/sites/default/files/journals/nab/v055n01/p00007-p00012.pdf If ever there was a year in which the hard-weather "bounce" of half-hardies might be expected to occur between Dec and Feb, rather than during the now well-documented period Nov to Dec, this winter (2015-2016) was that winter: unprecedentedly mild conditions extended through year's end, and the winter's snow and cold was unusually concentrated between the CBC and PDC. In other words, we almost expected to see an increase in the numbers of Gray Catbirds, Eastern Towhees, etc., between the CBC and the PDC this year. I haven't had a chance yet to fully correct for effort and wind speed, but the raw data (e.g., 14 GRCA in Feb, vs. 4 in Dec) actually seem to support the amazing idea that nocturnal-migrant passerines are capable of escaping poor conditions over long distances as late as January and February! (Why not?--ducks do it.) With this year's PDC, we completed our 20th full winter season, and I calculated a trend index comparing the first decade to the second. I also independently scored high and low counts, in traditional CBC fashion. Interestingly, among ten species whose numbers were high this year, nine show increasing trends over the course of the past 20 years. Similarly, among 14 species whose counts this year were low, 11 show decreasing trends over the past 20 years (the other four species showed no major historical trend). This year's PDC results are copied below, and a detailed table summarizing the historical trends is available on request. Shai Mitra Bay Shore, NY Canada Goose 129 Mute Swan 5 Gadwall 34; high count & increasing trend American Wigeon 5 American Black Duck 108 Mallard 329 Green-winged Teal 2 Ring-necked Duck 53; high count & increasing trend Greater Scaup 10 Lesser Scaup 1 Common Eider 941; high count & increasing trend Surf Scoter 84 White-winged Scoter 1380 Black Scoter 755 Scoter Species 350 Long-tailed Duck 91; high count & increasing trend Bufflehead 84 Common Goldeneye 140 Hooded Merganser 9 Red-breasted Merganser 105; low count & decreasing trend Ring-necked Pheasant 3; low count & decreasing trend Red-throated Loon 6 Common Loon 106 Pied-billed Grebe 1 Horned Grebe 52 Red-necked Grebe 2 Northern Gannet 1; low count & decreasing trend Great Cormorant 50 Northern Harrier 7 Cooper's Hawk 4 Virginia Rail 1 Black-bellied Plover 6 Sanderling 48 Purple Sandpiper 4 Wilson's Snipe 2; unusual species Bonaparte's Gull 2 Ring-billed Gull 11 Herring Gull 175; low count Great Black-backed Gull 91; low count & decreasing trend Common Murre 2 Thick-billed Murre 1; unusual species Razorbill 6 Black Guillemot 1 Rock Pigeon 14 Mourning Dove 99 Snowy Owl 1; unusual species Red-bellied Woodpecker 3; high count & increasing trend Yellow-bellied Sapsucker 1; unusual species Downy Woodpecker 22; high count & increasing trend Northern Flicker 7; low count & decreasing trend Eastern Phoebe 1; unusual species Blue Jay 32 American Crow 110; low count Fish Crow 10 Black-capped Chickadee 135 Carolina Wren 23; low count Ruby-crowned Kinglet 1 Hermit Thrush 5 American Robin 184 Gray Catbird 14 Northern Mockingbird 5; low count & decreasing trend Brown Thrasher 2 European Starling 182; low count & decreasing trend Myrtle Warbler 70; low count & decreasing trend Eastern Towhee 3; low count & decreasing trend American Tree Sparrow 2; low count & decreasing trend Field Sparrow 5; high count & increasing trend Fox Sparrow 2 Song Sparrow 199 Swamp Sparrow 3 White-throated Sparrow 136 Slate-colored Junco 21 Northern Cardinal 151; high count Red-winged Blackbird 15 House Finch 49 American Goldfinch 2; low count & decreasing trend House Sparrow 312; high count & increasing trend ________________________________ Got 20 Minutes?<http://www.csi.cuny.edu/climatesurvey/> You could Win FREE Parking for a Year, $200 in MetroCards, an iPad Mini, and other prizes! -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME http://www.NortheastBirding.com/NYSbirdsRULES http://www.NortheastBirding.com/NYSbirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/[email protected]/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L 3) http://birdingonthe.net/mailinglists/NYSB.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --
