Spring 2014 Migration Report

Spring 2014 Migration Report
by Steve Kolbe, Hawk Counter Spring 2014

Season Overview

From 1 March to 31 May 2014, 56,531 migrant raptors of 17 species were noted during 591.5 hours of coverage from the North and South Lookouts at Derby Hill Bird Observatory, Oswego County, Mexico, New York. While most raptor species were detected in average or above-average numbers for the season, new season and single-day records were set in 2014 for both Turkey Vulture and Bald Eagle. Rarities for the season included three Black Vultures and one Swallow-tailed Kite. Non-raptor flights were monitored during good migratory conditions in March and April and throughout the month of May.

Monthly Review

A long, cold winter in Central New York (as well as in much of North America) lingered well into spring 2014. The first three weeks of March featured conditions usually reserved for winter (very cold temperatures, northerly winds, and frequent snow showers), and as a result hawk flights were lacking for much of the month. The first triple-digit flight of the season did not occur until 18 March, during which 384 raptors were tallied; 19 March produced the season-high count for Cooper’s Hawk as well as Golden Eagle and Merlin among 407 raptors counted. Another significant flight did not occur until 25 March, when 749 raptors—mostly Turkey Vultures—were counted. Finally, 31 March showed that winter’s grip was indeed loosening: 1,228 raptors migrated past, comprising the peak flight of the month.

Throughout March and into the first week of April, portions of the near-shore waters of Lake Ontario were covered in ice; the volume and location of the ice changed daily due to shifts in wind direction. Raptors, most notably adult Golden Eagles and Rough-legged Hawks, were consistently observed migrating over the ice edge rather than the shore adjacent to the North Lookout.

In March, 4,060 raptors of 14 species were counted in 175.75 hours of coverage.

Once the winter-like weather broke in early April, raptors started pouring past Derby Hill every day, almost regardless of wind direction. It was clear that birds wanted to move and had been pent up waiting for a break in the weather. After a nearly unbearable March, April featured a large amount of southerly winds, and the birds responded; 15 days in April produced flights of over 1,200 raptors each. The peak-season flights of Red-shouldered and Rough-legged Hawks were observed on 1 April, and a single-day record Turkey Vulture flight occurred on light northwesterly winds on 2 April. Peak-season flights for four species (Northern Harrier, Sharp-shinned Hawk, Northern Goshawk, and Red-tailed Hawk) occurred on 10 April, and the peak flight of American Kestrel and Merlin occurred on 14 April. Additionally, all three of the Black Vultures tallied in 2014 were counted in April.

In April, 39,319 raptors of 16 species were counted in 236.25 hours of coverage.

Early May was a bit cooler than average, but did feature a few large flights. The second half of the month was quite slow migration-wise with weather characterized by warm temperatures, light winds, and lake breeze. The largest Broad-winged Hawk flight of the season occurred on 1 May. 9 and 10 May produced the last two four digit flights of the season. Season high counts of Osprey, Bald Eagle, and Peregrine Falcon occurred on 9 May along with an impressive tally of juvenile Golden Eagles. A Swallow-tailed Kite was a major season highlight when it passed on the morning of 14 May.

In May, 13152 raptors of 14 species were counted in 179.5 hours of coverage.

Species Accounts

Black Vulture
Three Black Vultures passed Derby Hill in 2014, all in the month of April. The first was spotted cruising on a blustery west wind amidst a rather modest flight on 5 April. This bird was a special treat for attendees of the Raptor Academy field trip. The second Black Vulture occurred during a large flight on 14 April, and the final bird, the only Black Vulture in 2014 seen from the South Lookout, migrated past during a large South Lookout Broad-winged Hawk flight on 27 April. Three Black Vultures is one more individual than the 10-year and historical averages at Derby Hill.

Turkey Vulture
The 22,438 Turkey Vultures counted in 2014 smashed the record of 15,894 set the previous year. I suspect it may take a few years to exceed this total at Derby Hill. I also suspect that the harsh winter (and its continuation into March) played a significant role in the large numbers of Turkey Vultures passing this spring. Only the hardiest of Turkey Vultures could have survived the 2013-2014 winter in the northern portion of the species’ range; more birds were forced to leave, and as a result more migrated past Derby Hill. The first Turkey Vultures were not spotted until 11 March, with the first triple-digit flight occurring a week later on 18 March. Turkey Vultures finally started rolling in large numbers near the end of March, and an epic South Lookout flight of Turkey Vultures unfolded on 2 April, with 4,318 individuals counted by day’s end. This flight set a new day record by nearly 1,600 birds. Other notable flights included 1,974 on 9 April and 1,657 the following day. By 10 April, the previous season record had already been eclipsed, and by the end of the count period, the record was bested by over 6,500 Turkey Vultures. On 4 May, a Turkey Vulture with a wing tag was observed and photographed moving past the South Lookout. This record has been submitted to the U.S.G.S. Bird Banding Lab. We hope the lab will tell us where this individual was tagged.

In spring 2014, 663 Osprey passed Derby Hill on their way north. The first were counted on 29 March, and by early April Osprey were seen nearly every day. Osprey movement peaked in late April and early May, although smaller numbers continued to move past through the end of the count period. The peak flight in 2014 occurred on 9 May, when 86 were tallied. The 663 Osprey counted this year is above both the 10-year and historical averages at Derby Hill.

Swallow-tailed Kite
On 14 May, a Swallow-tailed Kite appeared in front of the North Lookout, slowly proceeded east over the third field, and was eventually spotted making the turn and following the eastern shore of Lake Ontario northward. This bird was the third record in Derby Hill’s history and the second in the last three seasons. I don’t suppose anyone would object if this trend were to continue.

Bald Eagle
The 680 migrant Bald Eagles counted in 2014 constitute a new record for Derby Hill. Bald Eagles were seen throughout March in small numbers, things started to pick up in April, and the so-called “Florida” Bald Eagles arrived in early May. The peak fight occurred on 9 May, when 91 Bald Eagles were counted. This is a new single-day record at Derby Hill.

Northern Harrier
In 2014, a total of 489 Northern Harriers winged past Derby Hill. The first Northern Harrier was counted on 11 March, but the first notable flight for the species occurred on 28 March, when 26 were noted on a cold, rainy day with blustery south winds. These are some of the most fun days at Derby Hill because, although they usually do not produce massive numbers, the views they afford are often spectacular. A number of the Northern Harriers that migrated past along the bluff on 28 March were so close that I could not even get the entire bird in my binocular field! April proved to be the best time for harriers in 2014, with the season’s peak flight of 39 on 10 April and other notable flights of 34 on 7 April and 25 on 25 April. A count of 28 Northern Harriers on 9 May presumably consisted of mostly immature birds, and was the last significant push of the season.

Sharp-shinned Hawk
A total of 4,259 Sharp-shinned Hawks were counted at Derby Hill in 2014. The first Sharpies passed Derby Hill on 19 March, and numbers peaked in early to mid-April, with a season-high flight of 605 on 10 April. Observations of Sharp-shinned Hawks dropped off sharply after mid-May. Other notable flights included 519 on 14 April and 429 on 9 May. The 4,259 Sharp-shinned Hawks is above both the 10-year and historical averages at the site.

Cooper’s Hawk
Cooper’s Hawks numbered 307 this spring. The peak flight of the season occurred on 19 March, when 38 adult Cooper’s Hawks were tallied. The first migrant Cooper’s Hawk was noted on 7 March, and the final immature was counted on 15 May. Other notable flights were 21 on 1 April and 25 on 10 April. The count of 307 Cooper’s Hawks is below both the 10-year and historical averages at Derby Hill.

Northern Goshawk
Only 17 Northern Goshawks were counted passing Derby Hill this spring. The first Northern Goshawk, an adult, was detected on 7 March, and the final, an immature bird, passed on 27 April. All days with Northern Goshawks featured single birds except the peak count of two on 10 April.

Red-shouldered Hawk
In the spring of 2014, the first three Red-shouldered Hawks were counted on 11 March, but the first notable flight occurred on 19 March, when 42 were tallied. Other notable flights in March included 51 on 25 March and 41 on 31 March. The season’s peak flight occurred the following day, when 110 were counted on 1 April. As expected, Red-shouldered Hawk numbers dropped off dramatically after early April, and by mid-April only a few more young birds were counted. On 5 May the last immature of the season straggled past. All told, 482 Red-shouldered Hawks were counted in 2014. The final count of 482 is significantly below the 10-year and historical averages for Derby Hill.

Broad-winged Hawk
2014 was a good season for Broad-winged Hawks at Derby Hill, with a final tally of 21,799 migrants counted. The first seven Broad-winged Hawks were noted, perhaps a tad early, on 10 April, and the first triple-digit flight occurred three days later. Notable flights included 1,493 on 20 April, 1,418 the following day, and 1,868 on 28 April. The two peak flights of the season were 3,769 on 27 April and 4,051 on 1 May. All told, six days had four-digit flights of Broad-winged Hawks. Small numbers of Broad-wings continued to be seen through the end of the count period, and the largest immature flight—884 birds—was on 9 May. A season total of 21,799 Broad-winged Hawks is well above both the 10-year and historical averages at Derby Hill.

Red-tailed Hawk
A single Red-tailed Hawk opened the count season as the only migrant on 1 March, despite more than seven hours of coverage and southerly winds. Numbers slowly improved through the month, and by mid-April, Red-tailed Hawk numbers were peaking at Derby Hill. On 10 April, 862 Red-tailed Hawks were counted, and this proved to be the peak flight of the season. Other notable flights were 365 on 2 April and 445 on 13 April. Small numbers of immature Red-tails were still moving through the area at the end of May. The final season tally of Red-tailed Hawks in 2014 was 4,509 birds, which is on par with the 10-year average but well below the historical average for Derby Hill.

Rough-legged Hawk
This spring, 192 Rough-legged Hawks were counted at Derby Hill, and this number is below both 10-year and historical averages for the site. The first Rough-legged Hawk was counted on 9 March, and the final immature passed on 28 April. Peak flights were 21 on 19 March, 25 on 1 April, and 21 the following day.

Golden Eagle
An excellent total of 71 Golden Eagles were counted passing Derby Hill this past spring. The first adult was detected on 6 March, and the final two immatures passed on 14 May. Peak flights of seven Golden Eagles occurred on 7 March, 19 March, and 9 May. Especially encouraging was the relatively large proportion of juveniles. The final total of 71 Golden Eagles is well above both the 10-year and historical averages at Derby Hill.

American Kestrel
The first American Kestrel passed Derby Hill on 10 March, although numbers were relatively low throughout the first month of the count. April saw an increase in Kestrel migration, and ramped up to the season’s peak count of 96 on 14 April. Other notable flights were 40 on 10 April and 60 on 29 April. American Kestrel numbers dropped sharply in early May, and none were even counted in the second half of the month after the final bird on 14 May. All told, 465 American Kestrels passed, and this number is well above the 10-year average and slightly above the site’s historical average.

The first Merlin of the season passed on 10 March and the final bird was counted on 15 May. Peak flights of seven occurred on 19 March and 14 April, and a total of 69 Merlin were counted. This number constitutes the second-highest count in Derby Hill history after last year’s outburst of 102. Hours of coverage and a growing population are the factors most likely explaining these two consecutive years of high Merlin counts. A local pair of Merlin appeared to be nesting somewhere east of Derby Hill, as the pair was occasionally seen calling back and forth to each other, and Merlin were frequently seen in May carrying prey to the east over Derby Hill.

Peregrine Falcon
The first Peregrine Falcon was counted on 10 March and the last passed on 29 May. A total of 18 Peregrine Falcons passed Derby Hill this season, well above both the 10-year and historical averages at the site. The peak one-day count for the species, four, occurred on 9 May.

Non-raptor highlights
Once again, on promising mornings in March and April and every day in May, morning passerine flights were observed from the North Lookout. Notable were morning flights on 28 March (short-distance migrants, dominated by American Robins and blackbirds), 13 April (again mostly short-distance migrants such as blackbirds, American Robins, Northern Flickers, and Yellow-rumped and Pine Warblers), and 8, 9, and 14 May (long-distance migrants, dominated by Baltimore Orioles, Bobolinks, Eastern Kingbirds, and many warbler species). Below are a few non-raptor highlights from the spring season.

Snow Goose. On 29 March, the biggest Snow Goose flight of the season occurred, with 83,600 tallied by day’s end. Among these were at least two Ross’s Geese.

Ring-necked Pheasant. A crowd-pleasing Ring-necked Pheasant pair took up residence at Derby Hill this spring.

Great Blue Herons. A dreary 28 March produced 83 migrant Great Blue Herons.

Snowy Egrets. Two Snowy Egrets passed on the evening of 16 May.

Least Bittern. A very vocal Least Bittern seemingly set up shop in Sage Creek Marsh in May.

Common Nighthawk. Wayne Fidler counted 183 Common Nighthawks passing over the hill in May.

Northern Flicker. A huge Northern Flicker flight took place 13 April, with over 1,200 counted in the morning and an additional 400-plus in the evening, producing a single-day count of 1,640 flickers passing the North Lookout.

Red-headed Woodpeckers. A very good spring for Red-headed Woodpeckers, with at least nine detected.

American Crows. A peak flight of 1,660 American Crows passed on 7 March.

Carolina Wren. A Carolina Wren put in a few days at the North Lookout starting on 7 April.

Warblers. A decent showing of warbler species occurred in 2014, with nice numbers of Cape May, Blue-winged, Tennessee, Chestnut-sided, and Wilson’s Warblers, in addition to the ubiquitous American Redstart and Yellow, Palm, and Pine Warblers. The season’s highlights included Hooded, Cerulean, Prairie, Orange-crowned, and Prothonotary Warblers.

Clay-colored Sparrow. Three Clay-colored Sparrows throughout the spring were very nice.

Orchard Oriole. At least 14 Orchard Orioles passed Derby Hill this spring including seven on 9 May.

Winter irruptive species (including Common Redpoll, Pine Siskin, Bohemian Waxwing, Evening Grosbeak, Red-breasted Nuthatch, and Black-capped Chickadee) were all non-existent this spring. This is an amazing illustration that food (seed crop) availability, not weather, is what drives these irruptions. The 2012-2013 winter was orders-of-magnitude harsher than the previous one, but very few birds moved south because, unlike the previous winter, there was plenty of food in the north. Even Blue Jay numbers were much reduced.
(A complete list of species seen over Derby Hill in spring 2014 can be viewed on the web at https://onondagaaudubon.com/derby-hill-bird-observatory/XXXXXXXXXXXX)

I am grateful to many people who made my second year counting migrating birds at Derby Hill just as special as the first. Thanks to all the folks who attended the Raptor Academy; I hope you learned something! A big thank you is due to Bill Purcell for providing days off and information on the region’s birding. Thanks also to David Wheeler, who provided help in spotting birds and interesting conversation when things were slow. I enjoyed spending time with Jim Tarolli during the morning flight hours and appreciated his enthusiasm. I was encouraged by Wayne Fidler’s energy and his Common Nighthawk count. Pete Davidson and Phil Taylor were faithful visitors on both slow and busy days. Thanks to Gerry Smith for again sharing his knowledge about Derby Hill’s history. Jay and Pat Chapman, as always, were excellent companions during the early morning flight hours in May. Chris and Sally Holt were also wonderful additions when they could pry themselves out of Maine. Mary and Mark Magistro were both excellent companions on the Hill as well as bearers of gift baskets filled with food. Thanks! I very much enjoyed spending time with Kevin McGann, Rose DeNeve, and Michele Neligan. Finally, thanks to Ken Karwowski for logistical support throughout the season and for all his hard work making the Raptor Academy go smoothly. I sincerely thank everyone who stopped by to enjoy the migration or to help spot birds.