2015 Spring Season Overview
By David Wheeler, Derby Hill Hawk Counter, Spring 2015
From 1 March to 31 May 2015, 46,483 migrant raptors of 16 species were noted during 567 hours of observing from the North and South Lookouts at Derby Hill Bird Observatory near Mexico, NY, Oswego County. Rarities included 3 Black Vultures and on 29 May, 3 Glossy Ibis. Swainson’s Hawk was missed for the third year in a row. Timing of count landmarks such as peak flights and first arrivals was very similar to that observed in 2014.
Monthly Review
March
Another cold winter with heavy snow graced Central New York. After a record-cold February, the hawk count began with 2-3 feet of snow at both Lookouts. Surprisingly, upon shoveling it was discovered that the ground underneath had not frozen. A small plowed area near the North Lookout kiosk served as count headquarters, and days often began with temperatures in the low teens. Virtually all water not kept open by movement was frozen. By the end of the month, pack ice on Lake Ontario was being blown out of Mexico Bay on south wind and back in on north wind. In spite of it all, our raptors seemed to be right on time. Perhaps more remarkably, so did our early-arriving songbirds.
In March, 7,516 raptors of 15 species were counted in 127 hours of coverage.
April
Early April saw enough snow melted off the North Lookout to take up the normal count location mid-way to the first hedgerow. Winter relinquished its grip on weather and birds of all kinds arrived on schedule. Floating pack ice on Lake Ontario went out in the first few days of the month and never came back. Good flights ensued early and mid-month, but a stationary front dangled south over Central New York during the last week of April, preventing the pulse-and-recharge cycles that allow for big hawk counts at Derby Hill. The big flights of 21-22 April proved to be the last and this unfortunate weather pattern cost us many Broad-winged Hawks and Osprey that might have been seen during what is the species’ peak flight period.
In April, 30,951 raptors of 16 species were counted in 240 hours of coverage.
May
Most of May saw weak, slow-moving systems control our weather. Ill-defined fronts and troughs passed with little notice and few birds. Most days with south wind saw poor counts and Lake breeze taking over the near-shore environment. This was especially noticeable in the sunny second half of the month. Best flight unfolded over several hours during the Onondaga Audubon Society’s Birdfest on 9 May. Songbird morning-flights were much less intense than hoped for. No substantial late-May movement of immature buteos or Bald Eagles occurred, in spite of seemingly favorable conditions at the watch site.
In May, 8,016 raptors of 15 species were counted in 200 hours of coverage.
Species Accounts
Black Vulture
Two Black Vultures traveling together passed the South Lookout on 19 March during the 3-4 pm hour. The day started cold but unexpectedly light north wind gave us a decent flight for the date. A third BV was spotted on 3 April, also during the 3-4 pm hour and also at the South Lookout, amidst a massive flight of Turkey Vultures (see below). Small numbers of BV are expected every year, but numbers have not exploded the way some have predicted. 3 is an average count for the last ten years, and this season our nearest neighboring hawkwatch at Braddock Bay missed the species altogether.
Turkey Vulture
The 2015 Turkey Vulture flight very much mirrored the 2014 flight in timing and numbers, with a near-record 22,226 counted. The first 2 Turkey Vultures passed on 10 March, a typical date given the wintry weather that preceded and only one day different from 2014. Our peak day this year yielded 4,108 birds on 3 April (compared to 4,318 on 2 April, 2014). The day started with counting at the North Lookout on south wind and a massive pulse of Turkey Vultures in a very short time. After Lake breeze took over, the watch shifted to the South Lookout where the flight continued unabated. The second week of April brought several other good flights of this master-soarer before dropping to a trickle as most of the adult birds had passed through. After three weeks with few TVs, 653 birds soared with many Broad-winged Hawks in big kettles over a two hour period during the Onondaga Audubon Society’s 4th annual Birdfest. The spectacle left many in attendance speechless and was to be the last decent vulture flight of the season. 2014’s record of 22,438 was missed by just 212 birds. Both years were huge increases over previously. Why? Is the population really increasing this fast? Did the harshness of the previous two winters really force ~6,500 more birds (vs. 2013) to winter south of the Great Lakes? Are there really that many north of us in a typical or mild winter? Does the sudden jump reflect more favorable conditions at the watch site? This is the second year in a row where the South Lookout figured heavily in the count. Has this always been the case? Might unusual shifts in wind have increased recirculation by the count site? Higher overwinter survivorship? The next five years of counts should be very interesting, but whatever they bring the species continues to be a hawkwatch favorite. Easily visible with the unaided eye, a swirling group of vultures riding a thermal serve as a “beacon” in the sky for other soaring raptors. Finally, at least four Turkey Vultures were seen this season that had no tail feathers. These are seen every year and combined with the small head of the species, strike an unforgettable “flying wing” silhouette.
Osprey
Spring 2015 gave us 404 Ospreys, 79 birds shy of the 10-year average but substantially below the last three years. The first bird arrived on 27 March (right on time) and 7 April had 38 birds passing, a good number for the date. Few Osprey were seen during late April and early May, traditionally the big period for the species. Weather conditions during that period likely explain some of the missing birds. Peak flights of 45 and 70 came on 8-9 May. In the last ten years, Osprey numbers have fluctuated between 300-700 birds.
Bald Eagle
469 Bald Eagles were officially counted passing Derby Hill, slightly above the 10-year average of 426 but substantially below the last four years. After juvenile (this year’s hatches) “Florida” Bald Eagles arrived in early May, peak days of 69, 35, and 35 occurred on the 8th, 9th, and 15th of the month. Like Osprey, BE numbers in the last ten years show substantial variation. 2014’s May count of 456 nearly equals 2015’s entire season. Whether this reflects breeding success or is related to weather is unknown, but it is worth noting also the difficulty in counting BE (and Osprey too) as some repeatedly cruise the Lakeshore.
Northern Harrier
In 2015, a total of 331 Northern Harriers were counted, substantially below the recent 10-year average of 517. As with other species, considerable variation in annual counts is noted. The first two of the season passed on 14 March and immatures were seen soaring high through the end of the count period in May. Peak days were 9, 10, 13, and 20 April with 29, 25, 26, and 24 birds, respectively. Since Harriers are readily identified to sex and age they provide a reminder of migratory timing: adult male “gray ghosts” first, adult females next, immature birds last. Whether passing low on “off” winds in March or early April, or just a gorgeous silhouette in late April and May, they are a hawkwatch favorite.
Sharp-shinned Hawk
With 2,329 counted, 2015’s Sharp-shinned Hawk total is 917 birds shy of the recent 10-year average. The first Sharpies noted were on 16 March and the flight reached its peak with 458 counted on 13 April. Decent numbers continued through the first half of May then tailed off sharply thereafter. Variation in annual numbers may be partially due to the difficulty in counting this species accurately. Big Sharpie flights often have birds passing along the bluff, high overhead, inland, and on every other trajectory possible. Sometimes a massive flight is seen looking west from the North Lookout, with birds moving right to left across the horizon and not being seen again. Birds may continue to fly low along the bluff after the count has relocated to the South Lookout. Many factors should be considered when evaluating data for our smallest accipiter.
Cooper’s Hawk
Cooper’s Hawks numbered 313 this spring, very close to the 2014 count of 307 and the recent 10-year average of 323. Highlights were 102 birds on 25 March and 57 on 2 April. Derby Hill has had for many years a “local” Cooper’s seen display-flapping along the west horizon (presumably near the woods at Mexico Point). This bird was often flying high arcs on deep wingbeats and seen escorting other Cooper’s out of its airspace. Several times it proceeded as far as the North Lookout, taking up a sentry-like position atop one of the hilltop trees as the intruder continued its journey. Eventually the local bird flew back toward Mexico Point. As with other potential nearby breeders that might contribute repeatedly to the count, its appearance stood as a good reminder to evaluate migratory intent before clicking.
Northern Goshawk
Only 9 Northern Goshawks were seen passing Derby Hill this season, only half the 2014 count and under the recent 10-year average by 15 birds. 16 March gave us 2 birds, our first of the season and only day with more than one. The last Northern Goshawk went by on 5 May. Braddock Bay reported a similarly poor season with only 7 birds, off their 10-year average of 20. Data from both sites shows substantial variation from year to year.
Red-shouldered Hawk
The Red-shouldered Hawk count for 2015 was 541. This is above the recent 10-year average of 451 and the best number since 2006, but pales in comparison to historical counts at the site. Harshness of the previous winter, both cold and snow depth, may have contributed to more moving farther south and thus available to pass Derby Hill in spring. The first bird was seen on 13 March, building to peaks of 168 on 25 March and 103 on 2 April. Immatures took over quickly with a nice flight of 22 on 13 April. The last Red-shouldered of the season was observed on 29 May, the final six weeks of the season giving us only 10 birds.
Broad-winged Hawk
First Broad-wingeds of the 2015 season were noted on 12 April, and 1,048 birds the next day is an excellent number for only the second day after arrival. Our best day came on 21 April when 5,074 were counted, with the following day giving 2,035 BWs. An abrupt weather change on 23 April was the beginning of a lengthy period of high pressure and a stationary front controlling migration throughout upstate NY. Happening as it did during the peak of adult BW migration likely prevented thousands of birds from being seen at Derby Hill, movement reduced to a dispersed trickle instead of a massive lakeshore flight. When favorable weather was finally restored in the first week of May it became clear another adult Broad-winged super-flight would not be happening this year. 1,161 birds, now mostly immatures, contributed to the festivities on 9 May and was the best of the month. Certainly many more than this are possible but did not arrive before the end of the official count period. Best flight of late May was 467 on the 25th with the season total of 15,573 about average for the last 10 years (15,849). Several leucistic small buteos were believed to be Broad-wings.
Red-tailed Hawk
Spring 2015 saw 3,637 Red-tailed Hawks counted passing Derby Hill, just a bit off the 10-year average of 4,236. First birds were on 6 March and the first substantial flight happened on 13 March with 82 seen migrating. Peak flights included 304 on 25 March, 461 on 2 April, 410 on 12 April, and 412 on 13 April. Small numbers of immature birds wandering past the lookout were counted into late May and can be seen into summer on appropriate winds.
Two dark-morph western Red-tails passed within a few minutes of each other on 10 April. While it’s difficult to know how much plumage variation exists in each subspecies of Red-tailed Hawk, as a species it is one of our most variable. Even considering only the “light” birds that dominate at Derby Hill, a whole spectrum was seen – from very pale birds with little belly band to boldly-marked ones and everything in between. A leucistic bird was noted on 24 March. I wondered if it might be the wintering (or resident) leucistic RT that lives 30 miles south of the watch site. That bird has been seen since the end of the count season, lending support to it as a permanent resident.
Rough-legged Hawk
This spring, 170 Rough-legged Hawks were counted passing Derby Hill, 69 shy of the recent 10-year average. Our signature bird, the first was noted on 10 March. The peak day was 2 April when 40 birds passed, about 10 of them dark morph (a typical fraction). The last of the season were noted on 2 May.
Did a substantial number of Roughies remain to our north? Snow depth throughout most of upstate NY was unusually high and few were seen wintering in the area. Braddock Bay’s count was also about 25% short of their average.
Golden Eagle
The 59 Golden Eagles that passed Derby Hill this year were just about right for the site in recent years – 60 is the 10-year average. The first two birds arrived on 16 March, while 13 April gave us a nice peak of 19 birds. 5 were visible at once, flying low late in the day! Numbers tailed off quickly thereafter, with the last immature bird seen on 8 May. This is seemingly now a typical last date for the species, which had formerly been seldom seen in May.
American Kestrel
The first two American Kestrels of the season were counted on 10 March and the final bird on 16 May. The first three weeks of April gave us most of our birds with peaks of 74 on 13 April, 57 on 20 April, and 42 on 9 April. The final tally of 333 was slightly higher than the 10-year average of 309 but only half the 677 counted in 2013. Aside from the two previous years, 2015’s count of 333 is good by recent standards and more than twice the number counted in 2010. Numbers aside, the species is in decline due to competition from other cavity-nesters such as European Starling. Loss of the Kestrel’s preferred habitat, overgrown fields, is also a factor.
Merlin
Another good year for Merlins relative to the recent 10-year average of 46, 2015’s count of 61 is still the least of the last three years. First of the season was 10 March, with a peak on 20 April of 12 birds. This is only two below the all-time record of 14 set on 19 April 2013. Merlins were reliably seen through early May with the last noted on the 16th. Clearly, the species is increasing as a breeder and winterer in NY and it seems reasonable that more will be seen as migrants. In contrast to its smaller cousin, more nesting sites may be available as second-growth evergreens reach towering heights.
Peregrine Falcon
Spring 2015 saw 10 Peregrine Falcons officially counted passing Derby Hill. This is slightly below the recent 10-year average of 13 birds, but migrating Peregrines might as easily overfly Lake Ontario as follow its shore. First bird of the season was seen on 16 March and there were no multiple-bird days. Last came on 15 May. Often assumed our 15th species in order of abundance, this is the third time in four years the Peregrine count has surpassed Northern Goshawk.
Non-raptor Highlights
Songbirds, waterfowl, and other visible non-raptor migration was followed as time and weather allowed. Short-distance migrants that winter in North America dominate in March, with long-distance neotropical migrants arriving in late April and May. Morning flight of songbirds in May was disappointing relative to the last several seasons.
Snow Goose – The first bird arrived on 20 March. In some previous years the entire flight was done by this date. Most days in late March saw aborted migrations where passing Snows were later seen going back to the Finger Lakes, having found deep snow and frozen water unsuitable for continuing the journey. This phenomenon is seldom (if ever) observed with other species at Derby Hill. 9,700 birds were counted on 31 March (some were seen going back on 1 April) and a similar number again on 2 April, but are small maxima by recent standards. At least one Ross’s Goose was seen, plus a probable albino Snow Goose.
Ring-necked Pheasant – 2014’s crowd-pleasing pair were nowhere to be seen this year. Depth of the snow pack presumably took its toll.
Common Loon – 96 were counted on 22 April.
Herons – No big flocks of Great Blues were seen and no Great Egrets passed at all (two dropped into Sage Creek Marsh on 9 May). An early-arriving Green Heron on 20 April was two weeks before the next, and the max of 6 came on 19 May.
Glossy Ibis – Three flew south over the North Lookout on 29 May. Strictly speaking this was our most unusual bird of the season, though it seems to have been a good spring for them in upstate NY. Last seen at Derby Hill on 13 April 2001.
Sandhill Crane – 16 total for the season, the first on 9 April, then scattered throughout mid-April with the last bird on 9 May. Many passed low. Max group was 6 on 10 April.
Shorebirds – Killdeer arrived on 10 March with 15, a good number for the date. Max was 51 on 2 April. 60 Dunlin passed low on 19 May. Only 1 Woodcock was heard all season (on 13 April), presumably due to persistence of deep snow through late March. 10 Solitary Sandpipers on 15 May.
Gulls & Terns – A Glaucous Gull was seen at the North Lookout on 13 March, while another made a very rare appearance at the South Lookout on 3 April. Both were first year birds. 4,350 gulls, mostly Ring-bills, were counted flying west late in the day on 21 March. 12 May brought a Forster’s Tern on Lake Ontario, while 15 May saw the season’s only Black Tern in Sage Creek Marsh.
Common Nighthawk – A good year for the species at Derby Hill, with 489 counted between 16 May and 29 May. Peak days were 106 on 18 May and 189 on 26 May.
Red-headed Woodpecker – A poor year for this species, with birds seen only on 4 and 8 May. Additionally, a bird was seen in the swampy area at the end of Grand View Ave on 29 May, which is also accessible from the Derby Hill trail system.
Northern Flicker – Best day was 13 April with 380 birds.
Blue Jay – Obvious northbound migration began on 26 April. Peak flights were 2,800 on 4 May and 1,700 on 5 May.
American Crow – Good flights in March included 1,930 on the 10th and 2,050 on the 16th.
Common Raven – Much scarcer just 10 years ago, ravens were seen or heard most days during the count period. On 24 March a raven mercilessly harassed a passing Golden Eagle. Photos of the engagement showed the two birds exchanging glares and emphasized the eagle’s massive size.
Black-capped Chickadee – Best day was 13 April with 291, else mostly small movements.
Eastern Bluebird – Late-May movement of bluebirds along the Ontario lakeshore is an interesting phenomenon. Are they young birds, or possible nesters that lost boxes to House Sparrows? Best day was 25 May with at least 30 birds.
American Robin – Best flights were 2,000 on 2 April and 2,900 on 7 April.
Northern Mockingbird – One bird on 4 May. Usually considered non-migratory, the species is always scarce at Derby Hill.
Cedar Waxwing – Peak days for this late migrant were 25 May with 800 birds and 29 May with 500.
Warblers – Good morning flight of Pine, Palm, and Yellow-rump on 13 April. Most May flights were dominated by American Redstart and Yellow-rump, while Cape May and Wilson’s made a strong showing on the bluff and in the hedgerows. No Prairie, Orange-crowned, or other unusual warblers were found this season.
Sparrows – Excellent fallout on 17 April with all the typical species in good numbers at both lookouts and adjacent roads. A Clay-colored Sparrow was heard then seen at the North Lookout on 4 May.
Blackbirds – Conspicuously low-flying morning and evening migrants. Best days for Red-winged Blackbirds were 5,000 on 2 April and 7,450 on 7 April. Common Grackles peaked at 1,500 on 2 April and 1,680 on the 7th.
Orioles – Many lingering Baltimore Orioles were seen around the North Lookout, with best morning-flights on 4, 8, and 15 May. Max was 150 on the 8th. Only a couple Orchard Orioles were noted this year, more in line with what would be expected as we are already at the northern edge of the species’ range.
Winter Irruptives – Not a great year except for redpolls and siskins. No Bohemian Waxwings, Red-breasted Nuthatches, or Evening Grosbeaks were detected, and only a light movement of Purple Finches.
Common Redpoll – A small flock was seen on the first day of the season and birds lingered at the feeders making an accurate count difficult. Peak was 145 on 11 March and the last were noted on 13 April.
Pine Siskin – First birds were noted on 11 April and small flocks continued through the end of the watch and into June. Possible nesters?
American Goldfinch – Peak flights were 200 on 1 May and 300 on 8 May.
Gray Fox – Heard barking and seen in the second field during March.
Milk Snake – A first for me at Derby Hill, this beautiful snake was found by Wayne Fidler near the garage.
Acknowledgments
A successful season at any hawkwatch is a team effort and I would like to offer sincerest thanks to the many people who contributed their time, talent, and heart. Bill Purcell again provided days off for the counter, many eBird checklists, and often kept track while I was moving between lookouts. Observers pointed out many birds: Jim Tarolli, Kevin McGann, Phil Taylor, Pete Davidson, Mary & Mark Magistro, Jeff & Theresa Covington, Judy Thurber, Jay & Pat Chapman, Ken Burdick, and many others are greatly appreciated. Gerry Smith provided historical perspective and with Dave Fitch managed the site. Dave also contributed new bird feeders. Judy Wright and Brian Miller had quick eyes in counting the first stages of a big Broad-winged flight that started unexpectedly after a rainy morning. Tom Riley did an amazing job of updating the Derby Hill Facebook page with daily counts and narrative. Wayne Fidler contributed many off-hour eBird counts of raptors and non-raptors alike, and was tireless in monitoring the evening nighthawk flights in May. Jim Mahoney provided much-needed snow plowing at both lookouts. Mike Tetlow of the Braddock Bay hawk watch provided advance warning of flight volume, rarities, and weather coming our way. Jason Sodergren of HMANA recovered the Hawkcount.org website after multiple server failures. Bill Evans continued his night migration monitoring and daily breakdown of flight calls recorded by the Derby Hill microphone. Steve Kolbe provided moral support. The entire Birdfest committee & volunteers, led by Maryanne Adams, is highly commended for pulling off another successful event. Ken Hodgson continues to maintain the grounds and keep the trails and lookouts in excellent condition. Linnea Rowse maintained our Bluebird/Tree Swallow boxes. Many of our regular visitors contributed bird seed for the Derby Hill feeders. A huge thanks to all and apologies in advance to anyone I may have missed.
onondagaaudubon.com 