HawkArtScience: Hawksaloft.com blog

(Archive: Fun with Accipiters)

18 October 2009, Sunday
The Laws of Birding, an introduction

All good, and esp. great lessons are delivered with a sense of humor. The punchline to the joke is that memorable catch phrase or moral to remember the story by. This exercise is all a playful look at human tendencies when it comes to observing, and it applies to everything we look at. Even when you're not looking at hawks.

I started these 'Laws' by accident with a cadre of 11-year olds (like Groundhog Day, it happened over and over). While birding with them through their high school years, this handbook evolved and took on a life of its own, but was never nailed down, in writing (and there in lay some of the whimsy, as I could twist and turn on the fly for even a bigger laugh at our tendencies to misidentify). My adult apprentices, have enjoyed and gravitated to all of the same lessons that interest kids, go figure.

For example the First Law of Birding recommends, "The shorter the look, the better the bird will be." Limit the information part of an observation and it's just plain old human nature to bulk up the results. We do it everyday. Again, you are making an observation and gathering information, but as Clint Eastwood's Dirty Harry once said, "A man needs to know his limitations." Go ahead, repeat after Clint, in a whispering scientific snarl, "Need to know your limitations..." Identifying the limits of your study is nearly the first law of science.

Each time you look at a bird it's always observation, information, and assessment of the limitations. Interpreting anything is that, and knowing the universal tenancies of the beginner's mind is a skill that can be practiced while birding, to improve your birding. Sounds easy enough, but one can't go out to a hawkwatch and not see this first Law stomped to death on any day of the week (unless it's raining). Combine it with the Second Law and you've a real typical day out hawkwatching. These laws are heavily in play at a hawkwatch or seawatch because the birds are moving and therefore will be gone, shortly.

Second Law of Birding: "The further away it is the better it is." Now, what is far away for one is perfectly identifiable for another. "How do you know that's what that is?" Common question for a distant raptor in view that might come closer. My stock and trade answer: "Okay, I've told you what it is, now you watch it come in and let me know when you know it too... today, that might be as it's right overhead (or even a bit behind us)... but soon, you'll get it just out front, and then out there far enough that someone will ask you, 'How'd you get that bird way out there!'... and hopefully you'll tell them just what I've told you."

I not only watch hawks, but I watch people watch hawks. Eight out of ten observers lower their optics to ask the above question and don't raise them again, even though I've engaged them with some casual sounding, but direct, direction. One observer in ten gets it and reengages the bird, while there's that other watcher who asks the question from behind their optics having never broken the hawk-hawkwatcher connection. I saw that.

We get to the element of experience and its best uses in later laws... when you have some... tempered by a comfortable grasp of observation, the info gathering, and knowing your limitations and those of the day's conditions. In the meantime it's observation, information, limitations and the first two Laws of Birding.

3 November 2009, Tuesday
Third Law of Birding: "The newer the birder, the better the bird."

To recap:
First Law of Birding: The shorter the look, the better the bird.
Second Law of Birding: The farther away it is, the better it is.

The next laws — all, also know as the Laws of Thermal Dynamics — get into the application of experience to reining in our human tendencies for making the worst of an observation situation, while expanding our precision and enjoyment in the moment. The worse part in the situation, with young or new birders, is when finally a new species is seen well... it's disappointing to check the life list and see the thing already checked off.

I've always liked this quickie definition of knowledge: knowledge is information plus experience. "She's a knowledgeable birder." Like the sound of that? Read on...

Picture a thoroughly suburban bird feeder, say on Long Island, with a sparrow-sized reddish bird at it. The phone rings and the new feeder watcher wants to 'alert the birding media' that they have a Cassin's Finch in their backyard. We go from there to Purple Finch and begrudgingly arrive at House Finch after much debate and disappointment. It's a familiar tale for those of us who have spent any time at a nature center or on-call with a bird club — both in my case. It's just human nature: "the newer the birder, the better the bird."

In the field, for birders who have a full year's adventuring and are not new to birding, new also means, new to that species, or even new to that whole group of species. Working through the newness presents a unique puzzle each time a new bird is encountered, until. Until the information and the experience become knowledge. Each birder is different when it comes to crossing this threshold in building up a knowledge base. Legendary ecologist Robert MacArthur, who with EO Wilson, wrote The Theory of Island Biogeography (1967) put it this way in Geographical Ecology (1972), a book about detecting patterns in the face of complexity:

The only rules of scientific method are honest observation and accurate logic.

Wow. Keep the first two Laws in mind and be honest with yourself about what is possible, probably and therefore likely.

Okay: hawks. With size being one of the most talked about but misleading indicators of identity, you can imagine the fun there is to have with accipiters — Sharp-shinned Hawks, Cooper's Hawks, and Northern Goshawks. A visitor of the accipiter persuasion is my calling lately, but I also seek out images online. I look at a lot of accipiter (mostly) picts annually, a lot, and provide lengthy comments to hopefully enlighten... and a lot of decent birders have trouble with this little North American complex. I mostly point out things that are apparently new to the perplexed. A while back I finally made a composite illustrating how different the immatures of the three species really are (click to enlarge): while you can find this one's tail too long or too short or that one's too round or square or purple, the pattern of breast streaking is very different in these birds, so I guess you could say it's the key to this new door.

And from my little survey, guess what, many people are sure they have a Goshawk — the least common accipiter — at their feeder, or along the roadside. And guess what, it basically never is. Of course, the Cooper's Hawk has become a very common yard accipiter, with its delicate streaking that is concentrated on the upper breast and then thins and fades downhill from there. The Sharpie and Gos are thickly and thoroughly streaked. By the by, seeing an image or actual Goshawk shocks most seasoned observers. It is a distinctly spotted beast in its markings. I'll have a flight shot of a Gos, here on Friday accompanying the bad ID hall of fame post. I'm not going to put up hundreds of words here and now about this complex, just check out the crystal clear hard work of Wheeler and Ligouri.

Some hawkwatchers never lose their new car smell (that's a bad thing in the context of the Third Law). A fleeting glance at a perched hawk while going around the sharp curves of a highway off ramp by a fellow in eastern Mass caused me to hawk-up a big web loogey called Wintertails. Started in '02, it has careened across twentysomething pages and several years.

Concluding, the 3rd Law of Birding — the newness of someone else — comes into play when deciding whether to chase a sighting or vouch for the reporting of others. Inexperience with a species or its kin, enters into ARC decision-making. Of course, it should factor in when it comes to announcing, your own observations!

6 November 2009, Friday
Bad Hawk ID: Hall of Fame

 

This is a classic scene from Woody Allen's Annie Hall (1977 ), and as Woody says, wouldn't we all like to have the authority in question step out and correct another party right when we need them. Only in the movies, you say... or maybe it can happen in hawkwatching!

A hawkwatcher cites Wheeler and Liguori (played in the movie by Marshal McLuhan) to make the case for the identification of a seen-by-all, flyby, and photographed Goshawk at their official hawkwatch. It's my blog, so I'll be Woody Allen (in the sequel below, involving the other two accipiter species).

Now it is a lot of work and promises full disclosure to put the photos online, for all to see and this hawkwatcher/hawkwatch did just that. But, it's a new dawn and the Rockfish Gap accipiter 'quiz page'* was posted to school us, not ask for input, really. The problem was that the feedback from the book authors cited and many other elite birders was unanimous — not a Goshawk, but a Cooper's Hawk. The bird is still labeled a Goshawk because, all evidence to the contrary, they simply deny it. Let's see if I understand their logic: on the one hand, here's the reference material to support our identification; on the other hand, all you guys disagree, well you weren't there and didn't see the UFO, we did. Compare and contrast the quiz bird* with my (clickable) image of an actual Northern Goshawk.
*[link to their Cooper's Hawk image, labelled Goshawk, has been pulled]

For every hundred hawk images I get to look at and comment on, there is rarely even one that ends up with the image taker offended or refusing to consider the identification points presented clearly and respectfully. It's always the influences of some old and in the way hawkwatch or watcher... akin to deniers and safekeepers of the stiff and old everywhere (idea-wise).

So now, the "Fun with Accipiters: return to Virginia" movie-in-your-head sequel. And I'm Woody. The same folks have some other hawk images online, all correctly identified except for the Sharp-shinned Hawks where all three hawks are not Sharpies, not even one of them. All are Cooper's Hawks, likely all males (with the Coop images being represented by females mostly, so there's that). I emailed the source of the images and got back this:

Thanks for your comments.

Cooper's vs. Sharp-shinned in flight continue to plague even the more experienced hawk watchers. Be that as it may, each of the three images are in fact Sharp-shinned and not Cooper's.

One image, in particular, shows the diagnostic squared off tail with center notch. (Brian Wheeler - Raptors of Eastern North America; Pete Dunne, David Sibley and Clay Sutton - Hawks in Flight..., Ned Brinkley - Field Guide to Birds of North America, etc.

I reply in two parts, first just to clear up the out-of-date info that square and even notched tails are a Sharp-shinned Hawk tell, I make reference (below) to how Wheeler handles the square issue in the text and then shows a Cooper's Hawk image with a notch too. FYI, especially adult male Coops will display a squarish tail, even flying, with a dent in the center perched. Here's my email back with text and image, exactly cited:

Regarding that one perched bird, check Plate 197 in Wheeler 2003, Eastern NA -- it's a pretty good match. Ahead of that, his Cooper's Hawk text, now contains: "Tail can appear square-shaped when closed...", page 172.

For the three birds, represented by four images, I continue in my next message to lay out the case for Coop over Sharpie, but no reply to this info, you can play along at home comparing this info to the images:

The first and third of your Sharpie set are young birds:
1. Fine, inverted/attenuated streaklets diminish from upper to lower breast.
2. Both photos show the underside of the tail and therefore allow you to see a short outer feather on each side -- shorter by a bandwidth!
3. The third bird with its head turned away a bit exhibits a pale nape and some raised feathers there.
All ID points for Cooper's Hawk.

The middle bird has two images of an adult bird, likely a male too:
1. The breast barring is very very fine due to only the slightest contrast at the tips of each breast feather, hence the delicate look there].
2. As with the immies above, the outer pair of retrices are shown and short.
3. Ignore the shorter appearing tail length -- that all adult accipiters have compared to immies -- the head extension and straight leading wing edge are Coop tells.
4. Looking right the face, both of these adult images show a long face with a small eye by proportion and a dark cap that vanishes onto an elongated neck. Aren't Sharpies known for their rounded heads with big eyes by scale and a dark cap that runs onto the back where it joins a back of the same color?
5. Adult Sharpies would show a dark-strong set of concentric bars on both the primaries and secondaries; Coops have a fine barring that becomes thin and paler on the secondaries almost vanishing on older males... you be the judge here.
I think all ID points for Cooper's Hawk.

Again thanks for the images and taking the time to reply.

Tom Carrolan
www.hawksaloft.com
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"Doubt it."
-- George W. Bush
[When asked if he'd ever see "An Inconvenient Truth"]
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Another oldie but no longer goodie is the accipiter big head equals bigger size/species. Like bears... wait for it... the head size maxes out, so a really big (male)bear will have a tiny head, proportionately. In most of our hawks, the females are larger than the males, so the normal-sized head will look tiny on the large females. For an example of this here and now, take another look at my image above of a the young (female) Goshawk: on that body, the face/head looks freakishly small. We're not holding this bird up next to a Cooper's Hawk, just look at the shrunken head on this beast. This big bird, small head thing works on most accipiters and buteos (see the two Redshoulder picts below). Snowy Owls are one of the best cases: males have this bulbous head and then seem to just taper to the tail from there — like a nightjar. The female Snowy is a loaf of bread with a tennis ball on top. I'll come back around to my point with other photo illuminations down the road.

 

16 November 2009, Monday
Wayback Machine: Crowchaser

Here's another sequence of hawk action. This one is already online in all its primitive graphical glory from November '06. Crow activity in familiar fields caused me to stop and find an adult female Cooper's Hawk in enemy territory — surrounded, not defeated, just annoyed. What followed was a quick encounter that lead back to its starting point with a surprise.

Just like at a hawkwatch, but different. This focus flips the effects of space and time by visiting the same places over and over... a route, a routine, a ritual. There's a rhythm to all sorts of things that's not rote, but all about extreme attention, the paying thereof.

For hawks, I use a car; for mushrooms or animal tracks, I walk (crawl some). Always though, I'm employing the old and familiar to see new stuff. Our tendency is always to go someplace else, we say this is to avoid boredom... because you only go around once in life, and apparently it's the easiest path. Over and over is harder than, over there. In this sameness, the new and the amazing will enter. Give it a try.

In eastern MA, I sort of stumbled into this, maybe through my play as a student and teacher of Tai Chi. More likely this was a meeting of the minds. But I came to studying the very familiar: American Kestrels, Red-tailed Hawks, Thoreau's Nine Acre Corner and so on. All common and I made them even more familiar, intimate.

Search it out... keep this idea of wild intimacy, playfully, in your peripheral vision.

4 December 2009, Friday
Seinfeld Science: "I stop short"

 

Jerry Stiller's Frank Costanza character is a man with a move. If you are under fifty years old, you might need some background: the front seat of the majority of cars used to be a couch (no bucket seats, as they were know in the day), seat belts weren't installed in most cars until the early '70s (not required to be worn until later), therefore movement was unrestricted in the automobile of Mr. Costanza's day (safe and sex were in another context back then). It was a common practice for men to protect both women and children from lurching forward as the driver stopped abruptly, by the extension of the right arm. But it was also a move on date night.

The Seinfeld Science theme, is clearly aimed at poking fun at worthy causes. I hadn't thought much about one silly idea in hawk migration studies until it lurched back onto the highway in a recent HMANA blog entry:

Is this due to there being fewer redtails, or as in the case of the Sharp-shinned Hawk, are more Red-tailed Hawks migrating shorter distances, wintering farther north, or even wintering on their breeding grounds now than in the past?

Short stopping entered the raptor lexicon as Hawk Mt.'s "move" when Cape May declared Sharp-shinned Hawk numbers were in "free-fall" according to the largest dataset of Sharpie numbers in the known universe.

After being, shall we say, rear-ended at the 1988 HMANA Conference at Cape May by Paul Kerlinger's presentation centered on a very simple, but striking, line graph showing the decade plus descent of Sharp-shinned Hawk numbers at Cape May Point, I remember the question (to which he already knew the answer) ... was Hawk Mt. seeing this at their station? Among us hawk folks at the time, this was high drama as the answer came slowly from the back of the room that they were not detecting a decline, but it might be the nature of the age classes — immature birds at the coast and adults on the ridges — causing a lag, and they would have to look into it. Kerlinger was well-known for poking those around him with the sharp stick of his intellect, and at this point, he was thoroughly enjoying his home field advantage.

The eventual Hawk Mt. article had enough hedges in it to be a movie location for a Jane Austen adaptation, and every single hawk counter, bander, and ornithologist, that I asked about it (granted, a sample of thinking biologists) gave the idea of short stopping its due, not for science, but for grand slicitude... it was a clever retort to say the problem was solved, by not actually being a problem, you see, there's no real decline going on.

The real stink eye though was cast their way for using Christmas Bird Count data to make the case. But also: add some small numbers to some even smaller numbers, regress the bejezus out of that mean, sell it with a set of steak knives, and it's still don't make your case. What, steak knives without a case... no sale.

The problem with using CBC data for Sharpies, in addition to the very small numbers compared to the loss of birds at Cape May, is the question of identification. If there is a sample group of birders less able to tell Sharpies from Cooper's Hawks than hawkwatchers, it would be Christmas counters, especially feeder watchers! I guess I have a problem with using CBC data for anything (for which you don't already have an answer through other means), but a hawk count conducted over a three-week period by observers looking out their kitchen windows, while others work out the ID of perched birds flushed around a corner, well, is just asking for it.

HMANA's Hawk Migration Studies published a very readable and straight to the point piece by Nick Bolgiano in 2005. Nick examined a hypothesis that had been in the wind for a couple of years. As many daily hawkwatch counts began on the downside of the 1970s spruce budworm infestation, it took some time for the events to also drag down the populations of the "budworm warblers" (Tennessee, Cape May, Bay-breasted), and with them the budworm warbler raptor — the Sharp-shinned Hawk.

Nick guides us along the hawkwatch site numbers (mentioning that two graphs are used because of the 3x scale difference needed to accommodate the Cape May numbers). The CBC data is looked at, but the warbler numbers are graphed using Breeding Bird Survey data from eastern Quebec! Everything just overlays and synchs up, as he unfolds this story. Nick has provided this paper in a PDF for the first time, and you can read it here or save a copy for later.

While the spruce budworm hypothesis has been duly noted in all the Hawk Mt. work on the status of the Sharpie, including the venerable BNA species account, there's still this on their website today... haven't found those hedge clippers yet:

Sharp-shinned Hawk populations may have declined in eastern North America over the last 20-30 years, as suggested by declines in migration counts in the northeast and near the Gulf of Mexico (particularly the Florida Keys). Evidence from CBCs, however, suggests that the declining migration counts may be due, at least partially, to migratory short-stopping.

 

23 November 2009, Monday
Seventh Law of Birding: ID is not a democracy

To recap the Laws of Thermal Dynamics:
First Law of Birding: The shorter the look, the better the bird.
Second Law of Birding: The farther away it is, the better it is.
Third Law of Birding: The new the birder, the better the bird.
Fourth Law of Birding: Beware of he who only sees good birds when by himself.
Fifth Law of Birding: The rule of 100
Sixth Law of Birding: The one-mile limit

Majority does not rule in matters of bird identification; taking a vote doesn't make it so. But we reached a consensus, you say, but it does change the substance of the organism, I retort... you (all) could be wrong. Calling out a name does not transform a single molecule, or feather. The alchemists are now voting with their feet.

You say, avian records committees do it all the time. With a records committee, they weren't there, so they're like the jury system: not direct witnesses to the crime, but will take in all the evidence and render a verdict. The good news is that more and more reports of rarities are coming in with supporting digital images and many ARCs are both requesting and actively seeking the photo documentation.

Back to the scene of the crime: six hawkwatchers concur on the ID of an accipiter and someone marks the sheet with a pen, a seventh birder says nothing. Content with the vote five of the original six move on to other matters... other birds, local sports team highlights, lunch, but knowing this Law of Birding the sixth turns to the seventh. The Seventh (not their real name), waiting patiently for the look, returns a rye smile and the vote is overturned, at least in the mind of Mr. Six, who heard the silence (it's that zen thing again).

The hawkwatch might be a social activity, might be science, but like gravity, you can't overrule the science with a potion of friendship (friends don't let friends make bad calls). This is another one of those laws where knowing the birders is as important as knowing the birds. And you want to be the birder who knows enough to look for help beyond your peers, even if they give you your own vote!

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25 November 2009, Wednesday
Wayback Machine: Whack-a-mole

I used to call this "Creationist Science," but denial is just so fashionable nowadays and for these folks there never is enough evidence: evolution, man on the moon, climate change, presidential citizenship, death panels, 2012 (the rapture-y scenario/movie, not the election year, although SNL combined the two last Saturday night)... and telling Sharp-shinned Hawks from Cooper's Hawks. "Teach the controversy" sounds so open-minded, but that's how old ideas keep popping back up. On the other hand when deniers get sick or their cars break down, then conventional wisdom — accumulated and peer-reviewed — is welcome and true.

Staying away from the facts is important and however enlightened we think we are, all of us gravitate to those whose point of view agrees with ours, studies say. For Old Testament hawkwatching that means staying away from professional counters and their sites. Plus each and every time a factoid about the difficulties separating the two species is floated, well, these birders are quickly onboard.

"Wayback" posts are about things already written. That will be the meat of the post, but let's add a couple of side dishes... for the holiday. Over a decade ago, I used "current events" as a sarcastic pointer to the old and in-the-way ways... if our primary mission was protecting what we loved watching, then keeping up-to-date shouldn't be an issue. Here's a quickly timeline:

Late 1970s: Pete Dunne writes a piece on telling Sharpies from... Kestrels!
Fast forward...

1980: Derby Hill NY, a Spring site, has a terrific accipiter season, with a 13:1 ratio (7974 Sharpies, 618 Coops). Keep this number in mind when you get all the way down to 2009.

1995: I printed my annual color handbill with a Current Events rant quoting the eastern MA hawk org newsletter with out-dated ratios and reference to one of those "new studies" that allowed for the accipiter coin flip to continue. There was an editor's note inserted to provide an "official" decree:

MR. ED NOTE OF EASTERN MASS. WRITES:
"The rule of hand in the east is that the Cooper's:Sharpie ratio is 1:20, although Cooper's counts have been increasing recently while Sharp-shinned counts have been dropping."

Dear Edward: First, hawks are identified, or not, one at a time. We've never noted any hawk watchers checking the ratio during the day at the watch. "Hey Ed, how we doin' vis-a-vis the Ratio today." "Well, we're running at 1 to 12 as of noon, we'd better ease up on those pesky Coops." However, we haven't been on the summit[of Mt. Wachusett] for a few years, maybe things have changed.

In the case of California v. Tiny Raptors [Golden Gate RO, California], it's not surprising that advanced beginner to intermediate level hawk watchers are guessing. Another study on a grander scale has been underway at Cape May since Frank Nicoletti arrived in the early '80s and began aging and sexing accips. diving into banding stations at 500 yds. One day this fall Jerry Ligouri, the current Cape May top gun, shook his head sympathetically at the thought of making a study out of accipiter i.d. as he stood amongst many other excellent hawk watchers who are all capable of identifying accips. at the limit of optics using actual field marks and having it hold up in front of hundreds of skeptics day after day. Others shall we say were less understanding of the old days and ways.

Current events: In 1995, based on a CH & SS sample size of roughly 70,000 from Derby Hill, Braddock Bay, Cape May, and Kiptopeke identified by professional counters, the ratio for the east was about 1:6. Cape May 1996 ran about 1:6 again.

We look at eastern sites with ratios of 1:10 or lower and know that there's someone there who has been hanging out with the big boys and girls at the top four sites... paying attention too.

2004: There are laws according to the Old Testament of Hawkwatching. On Sept 11 '04, the following was contained in a report from Blueberry Hill MA. Detection of humor in this offering is noted, but their season's final ratio (2009 too) bowed to the teachings, nearly so:

An anomaly in the count: we logged 5 Cooper's Hawks and 11 Sharp-shins, a signal violation of Kellogg's Commandment ("Thine ratio of Cooper's to Sharp-shinned Hawks shall not exceed the tenth part.")

This was prelude to the Old Testament's magnum opus, in reply to a birder's email about the subject of Sharpie and Cooper's Hawk ratio, which is really about deploying new information re: identification and thus having water run uphill from the coastal sites, with their young professional counters and banding stations (where ID is measured). Interesting, the total of all these numbers equals a couple of nice days at Cape May. Even more interesting, this data toss doesn't include New England's premiere accipiter site, Lighthouse Pt. CT:


In the last 13 years the ratio of Sharpshin to Cooper's per hour has not changed significantly at the 52 northeast sites... of the Northeast Hawkwatch Report. At all these sites since 1990 the ratio has varied from 8.2 to 1 (2003) to 12.9 to 1 ((1995).

However, from 1978-1990 the ratio did change significantly due to a
drastic drop in Sharpshin numbers and a slight increase in Cooper's numbers.

Hope the numbers come through to you clearly.

YR SITES HRS SS C RATIO
1978 8 1850 875 10 86.1
1979 10 1990 1011 15 67.7
1980 13 2800 775 12 67.0
1981 15 2720 1287 24 53.0
1982 18 3059 927 15 59.9
1983 18 3372 698 14 49.0
1984 19 3460 799 13 62.0
1985 23 4320 808 19 42.8
1986 23 4618 879 22 39.7
1987 23 5096 648 23 27.8
1988 26 5849 523 20 26.0
1989 27 5624 652 34 19.4
1990 35 6984 604 48 12.7
1991 49 7119 430 45 9.6
1992 51 6436 438 46 9.6
1993 53 6584 568 56 10.1
1994 57 8606 431 33 12.9
1995 59 8942 417 35 11.8
1996 59 9004 330 31 10.6
1997 64 10864 407 35 11.6
1998 70 11206 368 35 10.6
1999 57 10110 399 41 9.6
2000 58 9290 306 35 8.7
2001 60 10323 363 34 10.7
2002 51 8421 374 37 10.0
2003 52 8656 346 42 8.2

AVG 78-2003 6435 602 30 28.7
AVG 94-2003 9542 374 36 10.5

Undated: Being the last week in September, when juvenile male Cooper's Hawks are moving on the heels of the young female Sharpies across New England, the year wouldn't matter for this one (SS:CH) — East Shore Park CT-- 90:9; Lighthouse Pt. CT-- 350:75 — these sites are a mile or so apart, and no other factor plays into these shockingly different ratios, 10:1 vs. 4.7:1, other than to say one count was Old and the other New Testament hawkwatching at its finest. The guy at East Shore has his name in the Old Testament (along with the fellow who compiled the numbers in the '04 email above)! Want to be scientific, sure. Stand one person from each site side-by-side and you'll get these results on just about any day. The only factor in play here is knowledge (information, plus experience with that info), as we see in this next entry...

2007: At the Plum Island Hawkwatch, this study in non-science took place... sorry I missed it, but it is a scene I've observed there so many times. Speaking of side-by-side, two groups counted migrating hawks from the same location (just meters apart)... here we go — the hawks at Plum on this May 1st morning were all low and accessible to both groups, so we should achieve similar results, right?! Those there to specialize in the hawks, reporting to Hawkcount.org via official forms, and so on, had half as many hawks as three birders (yes, one of them is easily one of the very best birders in MA and another hosts the website on Plum sightings). Still. I've distilled the divergent counts, again same day & time frame, from an email posted on Massbird:

Sharp-shinned Hawk: hawk experts - 6; birders - 40
Cooper's Hawk: hawk experts - 9; birders - 0
American Kestrel: hawk experts -20; birders - 40
Merlin: hawk experts - 2; birders - 5
Peregrine falcon: hawk experts - 5; birders - 1

First, It's clear the "official" hawk count is useless for accipiters, those conducting the hawkwatch didn't have a clue and missed a lot of birds. The falcon numbers are trash can-worthy as well. After the hawkwatchers demurred, in a responding email, that it wasn't likely that the lead birder made any errors, the count has not been updated or altered to this day. In baseball terms, no asterisk next to the report.

2008: ABA Online Bird Quiz for October is your classic hawk in flight, scroll down to see the vote tabulation by species.

2009: Where the word of the day is "intriguing." And "seeing" is used, where "identifying" might be more accurate and honest. As you read the linked piece for intrigue, refer back up to that Derby Hill 1980 ratio.

While not everyone can identify everything and some are better than others, the information needed to tell Sharp-shinned Hawks from Cooper's Hawks — the various ages and sexes — isn't controversial, and hasn't been for a very long time.

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15 January 2010, Friday
Cooper's Hawks — adults

Some pretty good snapshots of accipiters in MA have been posted recently, IDs changed, and while it's common Winter fare — telling Cooper's Hawks from Sharp-shinned Hawks — these images are about the adults. Turns out, the adults are a little trickier than the young ones, although you've narrowed the choice to a coin flip... Coop or Sharpie... no problemo with the adult Goshawk, right?! More adult accipiter images are also cached over on the right, in the "Fun with Accipiters" archive. Because, it's fun.

But, again, telling our three accipiter species apart is not controversial, just a skill set known better to some birders than others through facts and experience, where these facts do not include: long or short tails, round or square tails, notched tails, fierce looks, etc. This stuff varies enough betwixt and between the ages and sexes of these species to work, except when it doesn't. This will not be a comprehensive ID clinic... as Brian Wheeler's Raptors of Eastern North America (2003) volume covers it completely.

The oldest image set here was posted by Phil Brown back before Christmas. It's of an adult male Cooper's Hawk with a lovely dent in the center of his nearly closed tail. From the back and fully relaxed, the tail on the Coop would look square, dented, and not that long... being a male of the species, either one. The bird is pretty riled up and has the hackles up which lengthens the head, front-to-back, making the eye appear set farther forward than it would on a relaxed crown. Phil put this known Coop on his website as one of a few Cooper's Hawks he's had visiting his yard.

Another Coop image set was posted on Massbird by Erik Nielsen in the new year, originally he had it labeled as a Sharpie, because the head's rounded here making the eye position a bit harder to judge, and the gaze calm... not angry. But the dark cap contrasts with the nape of the neck heading us in the ID direction of Coop. In addition, the wing is opened enough to see icy gray bars on the secondaries, while the primaries are blacker. A lot of other possible puzzle pieces, some useful – some not, are mentioned in the discussion and that's perfectly okay, as long as the true stuff wins out. With an update, Erik has now included a summary of the information he received from other Massbird readers atop his images, very nice.

Erik's other Cooper's Hawk, clearly a different bird, is like Phil's bird showing a lizard-like head shape by way of the textbook raised hackles and a very pale breast, often a Coop tell. Looks too like it was photographed on a cold day (very puffed out appearance). If you like your Coops with long broad tails, here's your chance to see the opposite of that. If this tail were a tie, you'd be wearing a jacket with the sleeves rolled up plus the collar up and cool... see Road House (1989) with Patrick Swayze, Sam Elliot, and Kelly Lynch... as Dalton, Wade Garrett, and Doc.

Both posters received many private messages discussing the images, and both summarized this info. For what it's worth, the two public posts were not so useful. The first one here all depends on whether the bird has flattened out the head... or not (and as Erik learned, that's a Coop option, not a requirement) and the primary reason this accipiter was missed as a Cooper's Hawk on the first go-round was the non-reptile looking head shape... kind of looks Sharpie-round. BTW, instead of the position of the eye (which we now see can move about) work on a sense of the size of the eye on the bird's head: where the smaller species will have the proportionately larger eye.

One last field mark is the placement of the eye on the head being forward of center creating a fierce look while Sharp-shinned has the placement of the eye centered and with the rounded head gives quite a gentle(r) look.

Back noise — white feather edging on the upper wing surface— mentioned in the post below: is greatest in young/brown Northern Goshawks where it can be extensive; present in many juvenile Cooper's Hawks as upper wing covert flecking (although it's hard to see in late Spring when the back of this species can fade to a light sandy brown); and immie Sharpies' upper wing surfaces are often noted for their smooth, not noisy at all, almost spray-painted look. Perched, the presence of a few large spots has been associated with the Sharpie, but immie Coops can have something similar, so there's that. But-but, the images in question are all blue-backed adults, not immature accipiters. So, huh?

Eric, excellent! I like everything you said.

I vaguely remember reading some material on the occurrence of light spots on the backs of accipiters. Not sure, but I seem to remember that the bigger birds had more white spots. Anyway, I see some white spots on the alleged COHA, but not on the alleged SSHA. So that might be helpful--if my memory of who gets white spots is correct.

Another interesting thing: Though both birds are clearly "adults" by the standard of ruddy breast barring, in fact both have light eyes (nicely captured in your photos, thank you) and are therefore rather young (not juv, of course). Adult eyes become brown and increasingly darker as they age.

To the second point above, Erik's two sets show both birds with red or nearly red adult eye color that all three of our accipiter species attain eventually/mainly, so I don't know if this public poster needs a new monitor, or a second look!

 

15 March 2010, Monday
The Daily Show, #2

"The pursuit of truth and beauty is a sphere of activity in which we are permitted to remain children all our lives," said Albert Einstein (b. 14 March 1879).

Each Spring, a dozen to twenty Northern Goshawks cruise by Derby Hill, many low and on the prowl. Today's image is from last Thursday and the bird was just about gone when I got the camera up and running.
[Note: this pict is clickable for a larger view and more detail.]

From the more distant bar image above, we can see this a Goshawk not only by the very gray appearance, but also the bulging buteo-like secondaries. This feature is striking in the adults, but more confusing with the tail appearing shorter on the overall bulky bird.

This is an adult Gos, or nearly so... as I never saw the upper wing surface where there might have some young adult browns remaining. None of the images I have for this bird show a black mask; it's light gray in all. The eye color is not blood red, but orangey.

On soar, at a distance — and on their first turn — Northern Goshawk and Peregrine Falcon look remarkably similar, as both species get your attention with a long pointed hand.

 

7 April 2010, Wednesday
FC or NFC?

For a few thousand accipiters and other coastal migrating hawks, I made a notation next to the time for each bird: FC or NFC — "full crop" or "not full crop" based on whether I could or couldn't see a bulge indicating a recent kill and meal. I'm sure there's a better shorthand, but I was also trying to discover a better hawkwatch on Outer Cape Cod. Dealing with a bushel of myths and misinformation, plus a dozen recommended sites that sucked... the technical term we use in hawk migration science... that's what I've used over the years. Then on Plum Island, I was both relocating the site slightly and dealing with nonsense about the flight there.

That was all awhile ago, but the other day I was pointing out all the early NFC birds, that followed a long (and optimal) flight day prior. Then, the later birds came up and by with FCs. Maybe the NFC birds took care of business on the previous evening, maybe not. But that's what we were seeing. Seeing preceeds discussing.

In any event, I look to see if this feature shows or doesn't just as I would ID the bird or look at its plumage. I do it without having to think to do it from all the years along the Atlantic coast. In addition to looking at the crop for a study, one can do it for the interesting addition it makes to the other things to see and think about.

But there was a time, not too long ago, when that bulge indicating a recent meal, was a bit controversial. At the Cape May HMANA Conference in the mid-80s I was on one of the panels with someone else who was looking at full crops on migrating hawks. When the panel entertained questions, one of the old guys — a founding board member of New England Hawk Watch from Connecticut — rose not to ask a question, but to correct that presenter. He pointed out that the bulge wasn't a full crop. It was merely the bird either tucking or not tucking its head... "like a heron," he said. He finished his statement, remained on his feet, maybe to intimidate "the girl" or maybe to better debate the point. Silence from the presenter, as I don't think she knew quite where to begin.

From the side gallery, came another question directed at me... it was Pete Dunne, not debating that old smelly point, but blowing right past it. Along the same lines, but not, Pete asked me, since I had also collected crop data, "How does your coastal data compare to this ridgeline work?" It took me a (long) second to realize what Pete was doing, but when I caught up, I just answered his question, then to complete the loop, I asked her a follow up for clarification, and on went the Q&A. I listened for it over the next months and years. This "heron" comparison never reared its ugly head again.

That was then, this is now.

23 April 2010, Friday
The Daily Show, #10

At first glance this accipiter, from a couple of days ago, might generate a bit of controversy, by way of debate, and then it is gone, so mis-ID maybe. But accipiter ID is not controversial, just tricky at times. One builds a case — on the fly, so to speak — adding one working fieldmark to the next and next until a clear picture comes into view.

This includes surmising when one point of ID isn't working right... on this day, under these conditions, or just for some reason, on this bird. We know this, having not stopped at one fieldmark, and it is contradicted by the next thing we look at (in building a bird... to species). Toss it quickly, as we have many more colors, plumage features, etc. to apply and confirm/deny. Identification of hawks is best done without gestalt, potions, spells or silhouettes.

Sticking with the thumbnail, at the right, for a moment, we have a bird with a head not hidden/retracted in a tuck of the wing; a bird with a long-look, both in the wing and tail; maybe "a flying cross" describes; the bird looks pretty pale too, awfully gray(?). In conclusion, having made a vague case for this bird being a Cooper's Hawk or Northern Goshawk, what is there about this bird to say it is a Sharpie?

Lanky look aside, even deploying old school chestnuts like straight leading edge, long tail and even rounded tail (based on the spread and those central bumps), this still isn't a Coop. The leading wing edge is bowed forward, in a soaring posture, not held straight out in a glide. And while you can't always slow the image down in flight (you can work on that though), here you can actually see that the outer tail feathers — even when spread — match the rest in length. So, still not a Cooper's Hawk.

If you've been taking some New School of Accipiter courses, it looks like this bird must have a long hand, but in this still image, we can count in from the outside (to 10, primaries) and see that the hand is actually small (accounts for maybe, and only, the outer quarter of the overall wing chord). Alternatively, you can judge the placement of the wrist another way and come to the same conclusion: small hand; not Coop. On the leading edge first, we can see a subtle "knuckle" or small bump at the wrist; on the trailing edge — on both wings — we see a bright "pointer" cutting into the shadowed underwing coverts. Either or both of these mark the location of the wrist, and again, the hand portion is a very small percentage of the overall wing length. This long hand is an optical illusion that you can train yourself to dismiss, and get the bird right... Sharpie.

Both in the thumbnail here and upon clicking the image, for the three pict collage, this Sharp-shinned Hawk displays a killer ID feature to culminate our look: this bird lacks a final sharp dark band along the trailing edge of the wing. On the one hand, a backlit bird shows us less color and detail, but here it highlights the presence (Coop) or absence (Sharpie) of this fieldmark. Now the band is technically there in both species, but it is a blur in Sharpies and sharp in Cooper's Hawks. One can also start out in the open hand and see that final band there in both species, but then note that while there is room for it, it's not visible inward on the Sharpie. Use Google or your hawk field guide (Wheeler, with photos) to see it in the Cooper's Hawk. At this date, a single Coop in a day of Sharpies is often this bird... just too many compact mini-accips, then this bird.

One last thing: the head. Is it large or is it small? Old School would, at this point when their Coop has been cooked, claim it is not large enough to make this bird a Coop, knew it all along. But those too cool for school might point out that a small head — actually a small face in the context of the neck and body at length — tells us nothing about the species of raptor, but it indicates, quite reliably, that this bird is a female.

 

29 April 2010, Thursday
A shadow of its former self...

The new and improved HMANA silhouette hawk guide kinda sucks. In the original version, none of the species looked much like the thing in flight, but spread uncomplicated over the page, none of them were really that wrong either. Now, with the addition of inaccurate noise, shape tweaking, and a bad design decision to eliminate white space between birds... well, they all look alike: accipiters, buteos, falcons, and the rest!

The "and the rest" part is the problem when you stick with the simple-tone approach. Emphasis on silhouette with today's knowledge and optics is such a waste, and so not the reality; the state of the art.

Even a quarter of a century ago, Pete Dunne found the flaw when he penned an article discussing the problems telling Sharp-shinned Hawks from American Kestrels... accipiters from falcons. And I've mentioned here before that I've observed distant adult male Red-tailed Hawks were being regularly counted as Sharpies at an established hawkwatch... a buteo recorded as an accipiter.

On another front, David Sibley has a new series of rugged folding bird guides, and this includes one for the hawks (in color, and priced very favorably to the HMANA product). Of course, it's well-designed — note how he uses the blocks of text as white space to make the images stand out.

Now, I think you should cherish the oldie, moldie version of the hawk silhouette guide with the three black and whites on the cover, but then, turn the page into the 21st Century of hawk identification.

They've got the urge for going, and
they've got the wings so they can go.

— Joni Mitchell

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Truth and beauty. Art and science. Entries here will be on that flightline, although I will stray from the hawk-part on occasion, or will I? I aiming this beast at hawkheads and/or the young seasonal revolutionary biologists. It's for the flexible and young-at-heart too.
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