Posted by: 3pomjaeger3 | 24 October 2013

Dark-morph Broad-winged Hawks!

bwha-juv-dark-4of7-smithpoint-10-19-13-tl-1-cropscreen-lowresFour dark-morph Broad-winged Hawks among “lesser” Broadies.  All photos are copyright 2013 by Tony Leukering.  Click on image(s) to see larger version(s).

This season has seen an incredible and unprecedented incursion of dark-morph Broad-winged Hawks to Smith Point.  The general birder tends to know little or nothing of these birds (some/many having never heard of them), but they are one of the Holy Grails for raptor heads.  Their restricted distribution — the northwest corner of the species’ breeding range, their absolute low numbers, and their generally western migration routes put them in front of few birders.  They occur regularly in small numbers at virtually all of the western hawkwatches, but there are so few of those.  I have seen them as far east as Whitefish Point, MI, and there is even a record of one at Cape May, NJ.  Unfortunately, that bird occurred during one of the two years that I counted at Cape May and I did not see it!  Bummer!  The form is nearly annual at Smith Point, but in tiny numbers, typically vying with Ferruginous Hawk and Golden Eagle for non-zero low-count honors in any season.

It all started on Saturday, 19 October, when I tallied 28 of ’em.  This incredible flight continued on Sunday, when I counted 29 (!), putting one nearly to bed at the end of the day.  I, presumably, saw that bird on Monday afternoon when the rain finally stopped, but the Broad-wingeds that got up did not go anywhere, so I expected to see it again on Tuesday, when Tad Finnell would be counting.  As I was not counting on Tuesday, I concentrated on finding “interesting” birds (such as dark-morph Broad-wingeds), photographing a goodly number of ’em.  From studying my pix, I can identify eight different dark-morphs from that day, though I saw many more than that.  On Wednesday, the incursion continued, as I tallied 27.  On Thursday, the Broad-winged flight, in general, reduced in magnitude (it had to at some point!), but I still found five dark-morphs among the 345 Broad-wingeds counted.  Actually, I saw six, but one of ’em (see below) was a bird that I photographed — and counted — on Wednesday, so I did not count it on Thursday.

Assuming that few, if any, more will be tallied this year, I figured that a summary would be apropos, so provide a numerical summary followed by a photographic one.

19 Oct:  5477 Broad-winged Hawks, 28 dark

20 Oct:  2758, 29

21 Oct:  no counted Broad-wingeds

22 Oct:  3657, 8+

23 Oct:  2120, 27

24 Oct:  345, 5

Six-day totals:  14,017 Broad-winged Hawks, 97 dark morphs!

Below, I present some of the better pictures of dark-morph Broad-winged Hawks that I took during this phenomenon, illustrating at least some of the variation in plumage color and pattern.  All but one of the individuals that I was able to age were juveniles; the sole adult went by on the 24th.

bwha-juv-dark-firstofday-smithpoint-10-19-13-tl-02-cropscreen-lowres19 October:  Note the condition of the plumage, with no significant holes, breaks, or other damage to flight feathers.  Also note the few missing outer greater secondary coverts on the bird’s right wing that form a vague gray ‘U’ and the smaller number of missing coverts on the left wing.  Finally, note the pattern of the greater primary coverts on both wings:  extensive white bases with wide, gray tips.  This was the first individual noted of the incursion.

bwha-juv-dark-smithpoint-10-20-13-tl-06-cropscreen-lowres20 Oct:  Though the bird is far away, we can still note the missing innermost greater secondary coverts on the bird’s left wing, creating a wedge of pale between the dark wing lining and the dark body.  It is distinctive features such as this that allows individual identification of birds such as this.  In fact, these sorts of features are what enabled Jerry Liguori (author of Hawks From Every Angle and Hawks From a Distance) to determine that an adult light-morph Harlan’s Red-tailed Hawk that he photographed flying north past a hawkwatch in eastern Alaska was the very same individual wintering in Boulder County, Colorado!

bwha-juv-dark-smithpoint-10-22-13-tl-06-cropscreen-lowres-arrow22 Oct:  The arrow points to a small imperfection in the bird’s right wing at the junction of primaries and secondaries.  While I’ve had trouble deciding whether that tear is on the first primary or the first secondary, it doesn’t really matter.  Regardless, I used that break to identify this individual from another picture taken some six minutes later.  Because of this, I did not double-count it.  Even without that break, this bird is still distinctive.  Note the extensive chunk of either missing or gray greater secondary coverts on each wing and the color and pattern of the greater primary coverts — darker tips and with a minor secondary dark bands within the white bases.  Finally, note the few vague brownish streaks on the chest; this is another feature that is probably helpful in identifying the individual.

bwha-juv-dark-smithpoint-10-22-13-tl-05-cropscreen-lowres22 Oct:  By comparing the various distinctive characteristics of this bird with those of the bird in the picture above, we can see that the two pictures are of the same individual, even if we cannot see that distinctive break in one of the flight feathers from this angle.  The identical features are the greater secondary coverts, the greater primary coverts, and the brown chest streaking.

bwha-juv-dark-spotted-smithpoint-10-22-13-tl-01-cropscreen-lowres22 Oct:  This individual is interesting from a number of perspectives.  On an individual dark-morph Broad-winged perspective, this individual is incredibly distinctive — at least, among the birds that I photographed this week — in its spotted/streaked underparts and wing linings.  This was a feature easily visible in the field.  Note also the white-banded undertail coverts.  The other important perspective with this bird is related to Short-tailed Hawk.  I have not been able to figure out any particular feature that would rule out an identification of juvenile dark-morph Short-tailed Hawk for this bird!  Upon doing some research, no one seems to have tackled this field-ID problem.  Pyle (2008. Identification Guide to North American Birds, part II. Slate Creek Press, Bolinas, CA.) presents a wing-formula difference for in-hand differentiation that may or may not work on photographs.  Despite Broad-winged’s absolutely distinctive wing shape among U.S. and Canada migrant buteos, Short-tailed Hawk’s wing shape is incredibly similar and the wing formulae presented in Pyle (2008) for the two species are very similar, so I am not particularly sanguine about the use as an in-flight ID character.  I would love to hear from anyone that might suggest how to definitively identify this bird.  Yes, it’s almost certainly a dark-morph Broad-winged, one of ~100 found here in five days during an unprecedented occurrence, but….

bwha-juv-dark-smithpoint-10-22-13-tl-04-cropscreen-lowres22 Oct:  Do you recognize the dark-morph individual?  No?  Good, because it is not the same bird as in the picture above.  Yes, it’s spotted on the underparts and sports white barring on the undertail coverts, but details of the greater primary coverts (this bird’s coverts sport two obvious parallel bands of white – both wings; the above bird’s do not), among other features point to it being a different individual.  That whitish thing off to the dark bird’s left in the picture is “just” a “regular” juvenile Broad-winged Hawk (note the similar shapes of the two).

bwha-juv-dark-smithpoint-10-24-13-tl-01-cropscreen-lowresis 24 Oct:  Another individual with spotted/streaked underparts and wing linings.  This bird’s greater primary coverts are subtly differently-patterned than are those of either of the other two spotted birds (above), with the white ‘bands’ in this bird’s primary-covert patch breaking through the trailing edge dark band.

bwha-ad-dark-smithpoint-10-24-13-tl-01-cropsmaller-lowres24 Oct, 10:46:  This bird’s hole in its right wingtip makes it quite distinctive, but even if it lacked that hole, it would still be immediately obvious as a different individual from all of the others presented in this essay!  That is because this is an adult, not a juvenile, as discerned by the wide and very black trailing edge to the wing and the single white band just about centered on the tail.  This is the only adult that I noted during the incursion.  Juvenile Broad-wingeds of both color forms lack the obvious black trailing-edge band typical of adults.  I have heard numerous birders on the tower this season suggesting using the presence of this band to identify flying Broad-winged Hawks, but it works only for adult Broad-winged Hawks!  Additionally, most adult ABA-area buteos sport wide, blackish trailing edges to the wing, with Ferruginous being a notable exception.

bwha-juv-dark-smithpoint-10-24-13-tl-02-cropscreen-lowres24 Oct:  This bird’s missing/broken individual secondaries — two on the left wing, one on the right — enabled me to identify it as the same individual that I photographed at three different times on 23 Oct, 12:06, 12:18, and 2:32!  The tally of dark Broad-wingeds from the 23rd includes this bird only once, while the tally from the 24th does not included it at all.

bwha-ad-dark-smithpoint-10-24-13-tl-02-cropsmaller-lowres24 Oct, 11:08:  Look familiar?  Of course it does!  The adult with the hole in the right wingtip.  But, this picture was taken 22 minutes after the previous iteration, after the bird had disappeared.  Obviously, it had not yet crossed Trinity Bay!

bwha-ad-dark-juv-dark-smithpoint-10-24-13-tl-01-cropsmaller-lowres24 Oct, 11:08:  Does either bird look familiar?  This picture has both of our individuals with significant holes in flight feathers in the same picture!  And I did not “Photoshop” them together!

bwha-juv-dark-smithpoint-10-24-13-tl-04-cropscreen-lowres24 Oct:  While this bird does have a small break in a feather on the right wing and we might think that it was the same individual as presented above and photographed on the 22nd, the placement of that break is different.  This bird’s break is around the fourth primary, not the first primary or first secondary.  So, it’s a different bird!  Also note this bird’s distinctive nearly-all-white right-side greater primary coverts!

bwha-juv-dark-smithpoint-10-24-13-tl-05-cropscreen-lowresArtsy alert!  Artsy alert!  Here’s the same individual as in the picture directly above, but very close to the sun (not actually, but, you know) with light streaming through the flight feathers.  I like it!

Perhaps I’ll get lucky and one of these dark-morph Broad-winged Hawks will get photographed elsewhere and we can have another long-distance photo recovery!

Advertisements

Responses

  1. Hey, what do you think of this individual ?

    It has a break on its right wing. It was photographed on 1st of november in El Salvador… would it be possible ????

    It seems to me very similar to the individual you saw on octobre 22nd… what do you think ?


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Categories

%d bloggers like this: