Spring 2013 Migration Report

By Steve Kolbe, Derby Hill Hawk Counter, Spring 2013

Season Overview
From 26 February to 31 May 2013, 47,094 migrant raptors of 16 species were noted during 739 hours of coverage from the North and South Lookouts at Derby Hill Bird Observatory, Oswego County, Mexico, N.Y. While most raptor species were detected in average or above-average numbers for the spring season, in 2013 new season records were set for Turkey Vulture, Bald Eagle, and Merlin. The single-day Merlin record at the site was tied. Notable was the best American Kestrel flight since 1995. A new record for coverage hours was also set. Expected rarities for the season included three Black Vultures but no Swainson’s Hawks. Morning passerine flights were quantified in late April and throughout May, leading to new high counts for many species at the site.

Monthly Review
Two days with southerly winds in the last week of February were covered to initiate the 2013 season at Derby Hill. Adult Red-tailed Hawks were the major migrants this early in the season, with other early raptors including Golden Eagles, Rough-legged Hawks, Bald Eagles, and Northern Goshawks (all adults). A total count of 114 raptors was recorded in 11.75 hours in those two days.

What a difference a year makes! Just one year ago, 24 days in March saw some coverage at the North Lookout. In 2013, winds and relatively balmy conditions of this nature did not occur, with only 11 days receiving any coverage at the North Lookout and only half of those days seeing all-day coverage there. Of that subset, only three or four days featured southerly winds for the right reason – the region being sandwiched in the wedge of warm air between a passed warm front and an approaching cold front.
As a result, significant March flights were rare in 2013. The tenth of March produced the first notable flight of the season , highlighted by the season’s high count of Rough-legged Hawks and excellent looks at three adult Northern Goshawks. The day’s 275 migrant raptors were the most tallied in the first half of the month. Mid- to late March produced the first of two Omega Block weather patterns for the season. This particular system positioned itself so that Derby Hill received a brutal amount of northwesterly winds. Despite these winds, migration refused to quit. The unstoppable waves of Turkey Vultures were rocking and rolling past the site in large numbers as the month moved to a close, but diversity was still rather slim. Eventually the Omega Block system moved off, and conditions improved for both hawks and hawk watchers. A nice highlight despite the northerly winds on 26 March was the first Black Vulture of the season over the South Lookout.
Fortunately, March has 31 days. The last two days of the month were easily the two best. Easter Sunday, 31 March, produced 1,528 raptors—the top flight of the season to date. Turkey Vultures and Red-tailed Hawks led the charge, followed by the season’s best Red-shouldered Hawk flight. Without these two flights, the 2013 March totals would have left much to be desired.
Despite the sometimes trying conditions, March was covered for 216.25 hours, and 5,625 migrant raptors of 15 species were counted in 30 days of coverage.

After the wonderful flight on 31 March, the first few days of April produced a couple of gut-check days at the South Lookout, with very strong westerly or northwesterly winds making for some seriously uncomfortable conditions and much huddling behind vehicles. Fortunately, the weather quickly improved, and the birds followed suit. An excellent flight developed on 7 April, which produced season highs counts for four species (Turkey Vulture, Northern Harrier, Cooper’s Hawk, and Red-tailed Hawk) among 3,552 raptors counted at the North Lookout. This flight would prove to be the largest of the season. The peak migration period of mid-April did not disappoint, with six days of 1,000-plus migrants in a week’s time. The first Broad-winged Hawks of the season appeared right on schedule on 13 April, making for the season’s only “sweep” of the 15 expected raptor species in one day. The fifteenth of April produced the high Sharp-shinned Hawk count of the season. The peak Broad-winged Hawk flight day occurred a week later on 23 April, with the majority of birds detected in the scope cutting the corner of Lake Ontario.
The second Omega Block system of the season moved into place over the Northeast in late April, giving the region unbelievable weather by just about any standard—besides hawk watching. Clear blue skies and light winds prevailed for the next twelve days. Unlike the earlier Omega Block system, which fed Derby Hill’s faithful a steady diet of northwesterly winds, this second Omega Block was positioned to provide Derby Hill and the surrounding region with southeasterly winds, and lots of them. While this sounds terrific on paper (after all, visitors are told again and again southeast winds are the best at the site), this weather system seemed to be a classic example of too much of a good thing. Hawk watches along the Great Lakes rely on boom and bust weather cycles to stockpile eager migrants during unsuitable migration conditions and loose them when these conditions improve. This year, there was nothing to stop migration for nearly two weeks, and as such no large, concentrated flights (notably Broad-winged Hawks) developed. I think it was great for the birds, but not nearly as great for those watching for them to pass along the Lake. Additionally, the southeast winds were not being produced for the right reason—they were not associated with the passage of any frontal systems.
In 2013, April was covered for 270.5 over 30 days. During this period, 30,696 migrant raptors of 16 species were counted.

The Omega Block system continued to sit stationary over the Northeast through the first week of the month. Who would have expected to be cursing so much southeasterly wind? Eventually, observers were simply rooting for a change, any change, in the weather pattern. The first few days of a system that produced nice flights seemed like a distant memory. The weather eventually did change, but failed to produce any large flights until a decent flight on 15 May and a nice flight on 22 May, when the largest immature Broad-winged Hawk flight of the season occurred, along with a nice (presumably immature) Turkey Vulture push. The final week of the count period was mostly slow but featured a few good immature Broad-winged Hawk and Florida Bald Eagle flights.
May was covered for 240.5 hours on 30 days, during which 10,659 migrants of 14 species were counted.

Species Summaries
Black Vulture

The 2013 season produced three Black Vultures, one each on 26 March, 30 April, and 5 May. The first and last birds of the season were seen from the South Lookout, while the second individual was initially spotted by Kevin McGann at Sunset Bay Park and eventually slowly drifted around in front of the North Lookout. It took so long to arrive that it was lost for quite a while, but was eventually relocated by David Wheeler after it turned the corner to head north along the eastern edge of the Lake. A season with three Black Vultures is one individual above both 10-year and historical averages. These averages figure to increase as more individuals wander north each year.

Turkey Vulture
Another season, another record. Not surprisingly, a Turkey Vulture season record was set in 2013. The season total of 15,894 bested the 2012 record by more than 600 birds. Every few years a new record is set, and it will be interesting to see how long the Northeastern Turkey Vulture population can continue to expand. The first Turkey Vulture of the season wobbled past on 28 February, and decent numbers were still on the move in late May. The major window of Turkey Vulture movement for the season was mid-late March to mid-April; it contained the season’s peak flight of 1,998 individuals on 7 April. Other notable flights included 844 on 31 March and 1,294 on 4 April. At Derby Hill, once the Turkey Vultures start rolling, there is no safe day to write off as a bust because the vultures seem to relish migrating in strong winds, regardless of the direction. Particularly memorable this year was a very cold, very windy 3 April with 271 raptors counted, of which 261 were Turkey Vultures. These vultures certainly do not get enough credit for their ability to harness the wind.

This year, 713 Osprey passed Derby Hill as migrants. This total is well above both the 10-year (423) and historic (409) averages for the species, but below the all-time record of 1,063 set in 1998. The first Osprey of the season flapped past on 26 March, and by mid-April the Osprey migration was in full swing. The season’s peak flight was 63 Osprey on 3 May. Another notable flight included 52 on the previous day. It is amazing to note that when all of Central New York’s local Ospreys are seemingly on territory, peak numbers of the species continue to migrate past, presumably to far northerly haunts.

Bald Eagle
The 638 Bald Eagles tallied in 2013 represent a new season record at Derby Hill. Bald Eagle movement was fairly slow throughout March, picked up by mid-April, and continued strong through May with the arrival of so-called Florida eagles. The season’s peak flight was 46 and occurred on 22 May. Other notable flights included 37 on 31 May, 30 on 3 May, and 29 on 23 April. A wonderful success story, Bald Eagles at Derby Hill have become so common that many seasoned hawk watchers hardly glance at them. While this is certainly understandable, we should remember the history of the species as well as the power just a single Bald Eagle sighting has on a member of the non-birding public.

Northern Harrier
A very respectable 710 Northern Harriers were counted in 2013 at Derby Hill. This is above both ten-year and historical averages for the species at the site (511 and 606 respectively). The peak flight was 71 harriers on 7 April. The increased coverage in 2013 certainly allowed more harriers to be counted, as this species is noted for moving early and late in the day as well as in some rather uncertain weather conditions.

Sharp-shinned Hawk
All told, 4,778 migrant Sharp-shinned Hawks passed Derby Hill this season. This is well above the ten-year average of 2,996 and also above the historical average of 4,055. The peak Sharp-shinned Hawk flight of the season was 666 individuals on 15 April. Other notable Sharpie flights this season included 368 on 7 April and 524 on 16 April. The species was essentially absent until the end of March, with a sharp increase until the peak flights of mid-April. Immature Sharpies continued to be seen regularly, albeit in small numbers, until the last week in May. One of the spectacular happenings that occurs a few times each year at Derby Hill is a morning Sharp-shinned Hawk flight that is low and slow, seemingly just out of reach above onlooker’s heads. I am happy to report that such a flight happened a few times in 2013.

Cooper’s Hawk
2013 was an average year for Cooper’s Hawks at Derby Hill, with 371 counted. The ten-year average at the site is 343, and the historic average is 423. The peak flight of the season was 46 on 7 April, and another notable flight occurred a week before, with 37 on 31 March. The local pair of Cooper’s Hawks was kept relatively busy ushering out and displaying at migrant Coops that were passing over their territory. I believe they nested somewhere just southwest of the North Lookout. Cooper’s Hawks were most commonly detected as migrants during the period from mid-March to mid-May.

Northern Goshawk
Numbers of Northern Goshawks are very difficult to predict year to year, and the 40 counted in 2013 is above the ten-year average of 30 but below the historic average of 54. The fall of 2012 saw a small but better than average number of juvenile Northern Goshawks moving south along the East Coast. As a result, a few more immature Northern Goshawks passed by Derby Hill this spring than in a normal year. Adults moved much earlier than juveniles and also were much scarcer; presumably very few, if any, adults joined the immature birds during the fall flights south. The high count for Northern Goshawks this season (4) occurred on three dates: 15, 16, and 18 April. Three adult Northern Goshawks were a highlight on 10 March. Adult goshawks were already moving in late February, and the final immature passed on 27 April.

Red-shouldered Hawk
The Omega Block system that parked itself over the Northeast during mid-late March did no favors for the Red-shouldered Hawk numbers at Derby Hill this season. Unlike some other raptors, Red-shouldered Hawks seem to keep to a set schedule of movement regardless of the weather. After the Omega Block finally moved out, 30 and 31 March saw 48 and 173 Red-shouldered Hawks pass Derby Hill, respectively, and these days were the two best flights of the season. Despite the less-than-ideal conditions, 527 Red-shouldered Hawks is just above the ten-year average (516). However, it is well below the historic site average of 724. The Northeastern population of Red-shouldered Hawks should be given more attention to see how it really is faring these days.

Broad-winged Hawk
It was a fight to the finish, but Broad-winged Hawks pulled ahead of Turkey Vultures late in the season to grab the title as the most numerous species tallied in 2013. In total, 17,118 Broad-winged Hawks were counted from Derby Hill. The first two Broad-winged Hawks were spotted late in the afternoon on 13 April, and the first triple-digit day followed just two days later. Over 1,000 Broad-winged Hawks passed each day from 22 to 25 April, with the season’s high count of 2,021 occurring on 23 April. A few adults straggled past into May, and then the immature flight began to pick up. The immature Broad-winged Hawk numbers culminated in a peak flight of 1,868 on 22 May. The season total of 17,118 is above the ten-year average (15,095) and on par with the historic site average (17,191).

Red-tailed Hawk
The 5,096 Red-tailed Hawks counted in 2013 is significantly above the ten-year average of 4,419 but below the historic average at the site of 5,997. Red-tailed Hawks were already on the move in late February. Their large numbers peaked in mid-April, while juveniles were still on the move throughout May. The peak flight of the season occurred on 7 April when 862 Red-tails were counted. Other notable flights included 322 on 31 March, 268 on 13 April, and 366 on 16 April. A few dark Red-tailed Hawks were spotted over the course of the season, with two on 13 April and another on 21 April. A leucistic adult Red-tail, spotted by Pete Davidson, passed just south of the North Lookout on 16 April.

Rough-legged Hawk
The number of Rough-legged Hawks detected at Derby Hill was a slight surprise to some of the regulars at Derby Hill because the previous winter saw very few Rough-legs hanging around the region, even in areas where they typically can be seen most years. Wherever they spent the winter, 234 Rough-legged Hawks passed over the course of the 2013 season. The best flight of the season consisted of 64 Rough-legged Hawks that passed on 10 March, with an additional 20 the following day. No other notable flights occurred until 31 March, when 32 Rough-legged Hawks were counted and another 30 on 7 April. While 234 Rough-legs made for a seemingly nice year given the previous winter’s observations, this number still remains below both ten-year and historic averages (274 and 298, respectively). The first Rough-legged Hawk passed on 26 February, the first day of counting, and the final juvenile passed on 30 April.

Golden Eagle
In 2013, 60 Golden Eagles passed Derby Hill. One of the highlights of the season was seeing adult Golden Eagles migrating past in fairly steady snow showers on 19 March. Disturbing was a lack of juvenile Golden Eagles, indicating either a poor reproductive year or poor overwinter survival (or both). Even so, Golden Eagle numbers continue to increase at the site. While 60 Golden Eagles is right at the ten-year average, it is still well above the historic average of 39. Adult Golden Eagles were on the move on 26 February, the first southerly winds in the last week in February, and the final two Golden Eagles passed on 5 May.

American Kestrel
The American Kestrel flight was a very good one for recent times. In total, 675 American Kestrels passed Derby Hill, which is well above ten-year (253) and historic (362) averages for the site. While not record-breaking, it is the best flight since 1995 by wide margin. Although one good year doesn’t indicate any trend, it can provide hope that American Kestrel populations are doing better. The season’s best kestrel flight was 137 on 18 April, with 117 the following day. These two days alone would have combined for a near-average season. American kestrel numbers were low throughout March, peaked in mid-April, and tapered off quickly in early May.

Merlin saw a record-breaking season at Derby Hill in 2013. On 19 April, 14 Merlins blasted past the North Lookout, tying the single-day record set in 1996. The all-time season record of 53 was crushed this year, with an amazing 102 individuals counted. Why was there so many more Merlins this season? I can think of at least three reasons: increase in Merlin populations, increase in coverage hours, and location of that coverage. Obviously, if there aren’t any Merlins to count, it doesn’t matter how long you sit out looking for them. Merlin populations have been expanding in recent years as the species adapts to nesting in more suburban (and even urban) environments. The population increase doesn’t fully explain the increase, however, because it’s not as if the population doubled over the course of a year. Additional coverage hours, especially late in the day, likely increased detection of this species , which is noted for late-day movement. Lastly, during much of the peak Merlin season, wind direction allowed the count to be conducted from the North Lookout, the location where the majority of Merlin pass Derby Hill regardless of which direction the wind is blowing.

Peregrine Falcon
The 17 Peregrine Falcons represent a good but not record-breaking count at Derby Hill. The historic average is seven and the ten year average is 12. If you are coming to Derby Hill to see Peregrine Falcons, you are coming for the wrong reason. Still, a few nice looks of Peregrine Falcons were had over the course of the season including one hunting an American Crow next to the South Lookout on a frigid March morning.

Non-raptor Highlights
Derby Hill Bird Observatory has a long history of being the location to go and watch raptors. While this is obviously true, it is better described this way: Derby Hill is the place to go to see visible bird migration. Birders in the region are blessed with a location where they can witness visible migration in a way that most birders only dream about: in an open expanse, on top of a hill, next to a large migration barrier. On the morning of a good migration day, an observer can see thousands of passerines—including warblers, grosbeaks, tanagers, and sparrows—flying east along the lakeshore. I understand that flight identification of passerines isn’t for everyone. It does have a steep learning curve, but it can be done. It’s a challenge, and it’s fun! In a birding rut? Think your warbler ID skills are honed? Try something new—pin a name to a bird flying (and calling, one hopes) overhead at Derby Hill. Derby Hill isn’t just for raptors, and it’s not just the other few species (American Crows, Northern Flickers, Blue Jays) that continue to migrate when birders finally show up on the Hill. I challenge anyone not to be impressed by the waves of blackbirds and American Robins in March or the Baltimore Orioles, Rose-breasted Grosbeaks, and Scarlet Tanagers in May. Take a look at some of my counts from this season, and I hope you will agree that this is an area that deserves more attention at Derby Hill. After all, where else are you going to go to see nearly 300 Eastern Kingbirds and 1,200 Bobolinks in a day’s birding?
Common Loon. Peak flights were 45 on 15 April and 55 on 16 April. Notable were very high flying, tightly packed groups of over 25 loons. Where were they coming from?
Tundra Swan. A group of 43 dropped into the Lake off the bluff on 11 March.
Greater White-fronted Goose. One flew past the South Lookout with a group of Canada Geese on 22 March.
Snow Goose. The Snow Goose flight was remarkable this year. On 12 March, over 110,000 Snow Geese were counted moving past. Over the course of the next week, cold temperatures pushed many of these birds back south. Eventually most of these geese went north past Derby Hill, so we must have seen lots of them more than once.
Ross’s Goose. Ross’s Geese were spotted in large flights of Snow Geese on 24 and 25 March.
Sandhill Crane. 25 Sandhill Cranes passed Derby Hill from late March through the end of May. The largest flock was 6 on 22 May.
Green Heron. High count was 18 on the morning of 30 May. A very common early morning migrant past the Hill in late April and May.
Killdeer. High count of the season was 91 on 7 April.
Solitary Sandpiper. 41 on 15 May. Easily the most common shorebird migrant seen at Derby Hill.
Common Nighthawk. A remarkable Common Nighthawk year that produced a few large flights. A total of 93 nighthawks were seen on 22 May, including a foraging flock of 77 in sight at one time.
Ruby-throated Hummingbird. 44 zipped past on 19 May.
Chimney Swift. 65 on 15 May.
Red-headed Woodpecker. Four adults migrated past in May.
Red-bellied Woodpecker. Approximately 20 Red-bellied Woodpeckers migrated past during the last week of April and the first week of May. This is a behavior that should be monitored more closely at Derby Hill as the species continues to expand its range northward.
Northern Flicker. A disappointing Northern Flicker flight occurred in 2013, with the best flight of 100 on 16 April and a total of 500 for the season.
Eastern Kingbird. An extraordinary flight of 293 occurred on 15 May. Scattered rain and overcast conditions conspired to create early morning conditions favorable for much of the day. Also notable was a very early Eastern Kingbird on 18 April.
Northern Shrike. Early in the season, a Northern Shrike was patrolling the fields adjacent to the South Lookout.
Blue Jay. From the last week in April until the end of May, over 30,000 Blue Jays were counted from the North Lookout. Peak flight was 2,550 on 7 May.
American Crow. Over 13,000 American Crows were counted from late February to mid-April. Peak flight was 5,400 on 10 March. At least three leucistic American Crows passed Derby Hill this spring.
Fish Crow. Fish Crows were detected moving past Derby Hill on 9 and 10 May.
Black-capped Chickadee. An amazing Black-capped Chickadee migration occurred this year along the bluff. This was one of my personal highlights of the season. Over 3,600 chickadees migrated past from mid-April through the first week of May. The peak flight was 660 on 1 May, during which I spent a day off to conduct a dedicated chickadee count next to the bluff. I am certain there were significantly more Black-capped Chickadees that moved past than were counted because of the covert nature of their movement. Groups of usually around 20 but occasionally up to 60 chickadees would poke their heads out at the hedgerow behind numbers 0, 1, and 2, immediately decide there was no way they could cross such a wide open expanse, and would head directly to the trees along the bluff. Once there, they would jump tree-to-tree on their way east.
American Robin. Over 13,000 American Robins were counted passing Derby Hill, including 6,500 on 7 April.
Northern Mockingbird. One each on 28 April, 3 May, 22 May, and 28 May.
Bohemian Waxwing. Bohemian Waxwings were detected on 11 days from late February until mid-April. Peak day was 75 on 1 March.
Cedar Waxwing. One of the latest species to arrive in numbers, the peak flight of Cedar Waxwings of 1,650 occurred on 28 May.
Warblers. – A disappointing year of warbler migration at Derby Hill. I did relatively little walking of the hedges in the morning, but rather chose to see what species were continuing to appear during morning flight over the North Lookout. Species that seemed to be surprisingly low in numbers this year included Northern Parulas and Magnolia Warblers. Species detected flying over in seemingly good numbers included Tennessee Warblers, Cape May Warblers, Blackburnian Warblers, and Ovenbirds. American Redstarts and Yellow Warblers were ubiquitous. A few impressive Yellow-rumped Warbler flights occurred, including a season high count of 780 on 29 April. Three Prairie Warblers were also a nice addition to the count.
Scarlet Tanager. Always a treat to see flying over mixed in with the more common Baltimore Orioles and Rose-breasted Grosbeaks, Scarlet Tanagers were seen in morning flight in small numbers throughout May. The season’s high count was 14 on 15 May.
Rose-breasted Grosbeak. 58 passed on 10 May among a flurry of Baltimore Orioles and Scarlet Tanagers.
Bobolink. 15 May produced 1,200 Bobolinks flying rapidly past.
Rusty Blackbird. An impressive 1,800 Rusty Blackbirds moved past on 29 April.
Other Blackbirds. As always, massive waves of Common Grackles, Red-winged Blackbirds, and Brown-headed Cowbirds passed Derby Hill in early spring, one of the truly amazing spectacles at the site.
Baltimore Oriole. Starting the first week of May, numbers of Baltimore Orioles increased, with peak flights of 385 on 10 May and 240 on 15 May.
Orchard Oriole. Seven Orchard Orioles were spotted on four days in the first two weeks of May.
Evening Grosbeak. After fall 2012’s irruption, small numbers of Evening Grosbeaks moved past Derby Hill from mid-April to late May, including a peak flight of 15 on 3 May.
Red Crossbill. One flock of Red Crossbills was heard from the South Lookout on 8 March.
White-winged Crossbill. A few individual White-winged Crossbills were heard passing the North Lookout in late May.
Common Redpoll. Large numbers of Common Redpolls passed the North Lookout including 870 on 31 March and 990 on 7 April.
Pine Siskin. Large groups of Pine Siskins bounced past the North Lookout in late April to late May, including a peak flight of 555 on 15 May.
All this data is available online at http://www.eBird.org. I hope that Derby Hill will encourage future counters to quantify as much as possible of the migration that passes the Hill each spring and to enter it online using this resource.

I immensely enjoyed my first visit to Central New York and Derby Hill. While I have to admit the birds were (and always are) the primary draw, I also am thankful for the many wonderful folks who shared time with me at the North and South Lookouts throughout the season. A big thank you is due to Bill Purcell for providing days off and the voice of experience. David Wheeler was helpful in spotting birds and as a sounding board for many of my (crazy?) ideas. Kevin McGann was invaluable with his excellent eyesight and sense of humor. Pete Davidson and Phil Taylor were faithful visitors both on slow and busy days, as well as bearers of much appreciated food. Thanks to Gerry Smith for sharing his vast knowledge about Derby Hill’s avian history. Jay and Pat Chapman were excellent companions during the early morning flight hours in April and May. Chris and Sally Holt were also wonderful additions when they could pry themselves out of Maine. Both Mary and Mark Magistro were incredible additions of energy and enthusiasm to the regulars on the Hill. I very much enjoyed spending time with Rose DeNeve, Wayne Fidler, and Michele Neligan. Finally, thanks to Ken Karwowski for logistical support throughout the season and to all those who stopped by to enjoy the migration or help spot birds.