Wednesday, December 7, 2011

Historic Turkey Vulture Flight

The Boothe Park Hawk Watch has now closed for the 2011 season with a sensational 12,215 raptors counted in only 115.5 hours. This is the first of a series of pieces that I, as the coordinator of the site who spent the vast majority of those hours there, will be writing during the offseason on some of the special sightings and notable numbers we enjoyed this year.

One of the many Turkey Vulture kettles from 10/28/11

On October 28, 2011, the hawk watch at Boothe Memorial Park in Stratford experienced an unprecedented event as those on hand tallied 521 migrant Turkey Vultures in only 7.5 hours of observation, obliterating any known flight record in New England and even some beyond. This astounding total was supplemented by 218 Red-tailed Hawks, a sum not to be relegated to an afterthought. The Red-tail count is believed to be the third highest in New England history, falling short of a Lighthouse Point total of 237 on November 7, 1999, and Boothe’s own total of 249 on November 1, 2010, the current record holder. Not coincidentally and as will be examined, that day held Boothe’s previous Turkey Vulture high count of 190, also one of the best ever in the northeast. In only the third year of opportunistic observation, Boothe has established itself as a regional force to be reckoned with when it comes to buteos and vultures, and a strong site for nearly every other Connecticut migrant raptor species.


It is safe to say that no one could have predicted the enormity of the Turkey Vulture explosion of October 28 as such a sum has traditionally been reserved for an elite group of watch sites with decades of experience. Many of these sites are far to our south, like Kiptopeke in Virginia, or buoyed with supreme geographical aids, as is the case in Cape May each fall or Braddock Bay in the spring. Cape May was one of my first thoughts at the conclusion of the epic day – specifically, had we come even close to touching one of their best flight days for Turkey Vultures? One has to bear in mind that they hold records that the vast majority of count sites can never dream of impinging upon. Seeing 1,023 Osprey or 278 Northern Harrier in one day is laughable for us here in Connecticut, but still not as impossibly insurmountable as daily totals of 7,000 Sharp-shinned Hawk or 1,231 Cooper’s Hawk are. For now, I can only dream that Boothe Park will complete an entire season with those sorts of numbers in the not too distant future.

Cape May’s top three Turkey Vulture flights are “only” 784, 607, and 602, still comfortably beyond the 521 we witnessed on October 28, but not at all embarrassing in comparison to Boothe’s new record. This immediately invigorated me, and I looked at many other sites in New England and the Mid-Atlantic, finding few if any that came even close to this spectacular fall flight. I already knew that Connecticut’s two major sites, Quaker Ridge in Greenwich and Lighthouse Point, in a combined total of over 80 years of observations, were nowhere close to our new record. Their top flights were 192 and 135, respectively. Moving out of state to a couple of other infamous sites, Franklin Mountain in New York topped off at 136 Turkey Vultures and Hawk Mountain Sanctuary in Pennsylvania peaked at 123, and several more locations were around these numbers. I should add one condition to these decades and decades of observations - the Turkey Vulture population is increasing to our north over time, and it must be understood that more migrants will be passing through, generally, every year. Regardless of that fact, Boothe’s total remains almost supreme amongst many similar and strong opponents.

The day’s weather

After that examination, the most obvious question remained: why did such an extremely high number of Turkey Vultures take to the skies to head south on this particular day? October 28 is in a range of time quite conducive to significant flights, though it is still relatively early in the season, with the last Boothe record occurring four days later the previous year, and the instant conclusion being that the date did not act like a late trigger to suddenly spur the birds south. One would presume beforehand that they would have kept migrating in a regular manner for another few weeks at the very least. I have already discussed the lack of totals approaching this one at other sites, thus for the moment making the small sample size of Boothe’s data somewhat less of a confounding variable, and this flight more of an anomaly. For the sake of argument, let us assume it was - that leaves us to wonder what exactly that trigger was and what in the world could have prompted this.

What remains is the weather, the conditions on and around this special day that helped to allow such an event to take place that Friday morning. The Tuesday before, October 25, had actually been a very productive day at Boothe Park with 276 raptors tallied, 76 of them Turkey Vultures, despite crystal clear blue skies. This flight in itself provides evidence that there were not birds being “backed up” by poor conditions for a week or more, and many had been able to move through Connecticut already. If there had been only a few raptors counted in the days before, or a continual southerly flow of some sort, a subsequent record flight might have been more understandable. That Tuesday movement came after a cold front passed through from a low centered well to the north in Canada and on northwest winds from high pressure moving through the Ohio Valley.

Realistic view of streaming Turkey Vultures going behind the clock tower earlier in the week before the historic flight

On that Wednesday and Thursday, October 26 and 27, the northeast region was plagued by a series of lows along a cold front that finally passed through Thursday night. As that front swiftly cleared our area and headed southeast, one of the biggest keys to the event came in the form of a superbly placed high moving in from the Great Lakes towards western New York and Pennsylvania just in time for the daytime hours on Friday. The pressure gradient was not very strong because of the rapid exodus of the front, and the high provided northwest winds of approximately 4-7 MPH for most of the day on Friday, a perfect strength to aid raptors moving south and gently push them to follow the coastline, but not thrust them all the way to the shore. This wind speed and direction has been shown to be optimal for Boothe Park on numerous occasions with it being a few miles off Long Island Sound.

2010 flight conditions

These conditions were, not coincidentally, nearly indistinguishable to the ones that provided the terrific flight at Boothe Park previously mentioned on November 1, 2010. The movement of the cold front, the placement of the high, wind speed and direction were all essentially the same, though there had been no cloud cover whatsoever that day. Turkey Vultures do sometimes fly by Boothe Park at high altitudes, though most go through at a moderate height compared to other species, and nearly all are detectable to the naked eye or binoculars even against the deep blue sky with their dark color and slow drifting style. Even when streaming through they often come in groups, thus the likelihood of missing a significant amount because of a lack of clouds, or finding more because of even partial cloud cover, is negligible.

Typical streaming Turkey Vultures at Boothe Park

Looking past the weather and at the personnel, I was the official counter on both of the record days, and I had either two or three people with me for the most part, with Charlie Barnard joining me both years, Tina Green and Frank Mantlik assisting for parts of the 2010 flight, and Bill Banks on hand for the day in 2011. We actually put in 8.25 hours on November 1 compared to the already stated 7.5 hours on October 28.  Calculating the Red-tailed Hawk average per hour for the November 1 flight yields 30.18, and for the October 28 movement it comes in at 29.07, a minuscule difference. Obviously, the Turkey Vulture rates are much greater, with 23.03 per hour on November 1 and a mind-blowing 69.47 on October 28. Nearly every factor between the two days is identical except for this extremely abnormal Turkey Vulture count.


After examining every detail and nuance of the day of the historic flight and those leading up to it, I was left to scrutinize what came after, and having the very next day go down in New England weather history was a heck of a coincidence. Snowtober became a popular social media name for the devastating classic “winter” nor’easter that struck Connecticut and surrounding states on October 29 and 30, leaving catastrophic damage in its wake and well over a foot of snow in many areas. There are absolutely no comparisons to a storm of this magnitude occurring in October in any year, decade, or century, even apocryphal tales from colonial history. It was undoubtedly a multi-century event that left some birds in desperate straits, having to cope with an early snowfall of such a depth when many of those ill prepared for it had yet to vacate the northeast. 

Frank Mantlik spent 1.25 hours at Boothe after the storm ended on the afternoon of October 30 with brutally strong northwest winds and saw 135 Turkey Vultures go by, as they were evidently still moving in marvelous numbers over the snow-covered landscape. I considered all of this more and more on Halloween, as it was a particularly “birdy” day on the shores of Long Island Sound, with birds like Savannah Sparrow and Eastern Bluebird flying in to Stratford Point in the middle of the day from the north. Stratford Point had no snow left whatsoever already after only a few inches falling that weekend and quickly melting on the comparably warm coastline. Had the Turkey Vultures been able to deduce that such a snowfall was on the way and planned their escape from the north the day before with such favorable conditions? Could they have possibly surmised a nor’easter would bury the ground and make finding carrion all the more difficult?

I readily admit such a suggestion may seem ludicrous, but after investigating all of what I have I am left with little other conclusion beyond tremendous coincidence and sheer luck. One might fall back to the fact we have scant data at Boothe Park in comparison to other sites, and although these sites have not had similar flights, we just be on the premiere Turkey Vulture flight path in the northeast United States. I wholeheartedly embrace such a title and welcome it with open arms, though I do not think we can make our acceptance speech quite yet. One remaining matter needs to be mentioned – what occurred at Lighthouse Point on October 28, 2011.

Will a sight like this from the historic day be common multiple times each year for us?

That other record

While we at Boothe Park were celebrating a wondrously successful day, the observers stationed at Lighthouse Point were shattering the previous record as well, as they tallied an astonishing 371 Turkey Vultures in 8.75 hours. As I mentioned earlier, their previous record, in over 40 years of nearly constant vigilant hawk watching, was only 135. This new total, nearly tripling the historic high count, is a strong piece of evidence in the argument that something was in the air on that day. If Lighthouse Point had totaled say, 150 or so Turkey Vultures, I think it could be seen as a new high count on a terrific day that could be expected as the population has grown to the north in recent years. But to so decimate the record that has been derived from decades of data suggests that this was truly a special event and gives us a hint that maybe, somehow, someway, these birds may have known what was in store for them had they not departed from the region as quickly as possible.

Perhaps results from next year will render all of this moot with an even more stupendous flight, but either way, a vulture’s ability to anticipate poor weather conditions it is something to consider. I cannot wait to see what the 2012 season has in store for us, and though it may be some time away, I invite you all to join us whenever possible as Connecticut Audubon Society increases monitoring efforts at Boothe Memorial Park. Once again, you can see more information, from directions to all of this data, on our HawkCount page here: 

Scott Kruitbosch
Conservation Technician

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