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Nighthawk ID (1 Viewer)
- Thread starter Ingo
- Start date
Dave B Smith
Well-known member
Ingo,
I don't have a list for this area but assume the candidates are:
Lesser Nighthawk (probably a very rare occurence)
Common Nighthawk
Antillean Nighthawk
I think we can rule out Common Nighthawk based on the primary projection. The common has longer primaries/to tail than your bird.
We can also rule out female Antillean because of the strong white throat marking.
Now is where I run into problems. The Antillean has more of a brownish coloring and also has contrasting pale tertials both of which appear to be evident in this photo. However, the male Lesser has a nice little row of white diamonds on his shoulder which also appear to be evident in this photo.
The Lesser would be out of range I believe (not sure if they have been sighted on the Tortugas but they are regularly seen in Florida). So, if I was trying to ID this for my personal list, I would go with Antillean.
I don't have a list for this area but assume the candidates are:
Lesser Nighthawk (probably a very rare occurence)
Common Nighthawk
Antillean Nighthawk
I think we can rule out Common Nighthawk based on the primary projection. The common has longer primaries/to tail than your bird.
We can also rule out female Antillean because of the strong white throat marking.
Now is where I run into problems. The Antillean has more of a brownish coloring and also has contrasting pale tertials both of which appear to be evident in this photo. However, the male Lesser has a nice little row of white diamonds on his shoulder which also appear to be evident in this photo.
The Lesser would be out of range I believe (not sure if they have been sighted on the Tortugas but they are regularly seen in Florida). So, if I was trying to ID this for my personal list, I would go with Antillean.
Ingo
Well-known member
Dave B Smith said:
Thanks, Dave,
yes, a Lesser would be a very rare occurence, I think.
I added a photo from the other side - you can now see that the pale bar on the primaries is probably much too far back from the tip of the tertials for a Lesser, and I cannot see any buffy spots on the primaries. Sorry for not posting that photo before, but I wanted to know how much the diamonds are diagnostic without spoiling the fun
. Also, I wasn't that sure that it couldn't be a Common, because (apart from the Sibley) my books tell me that they are undistinguishable without call ... so thanks for reassuring me.
Ingo
Attachments
Dave B Smith
Well-known member
Nice photos, both, and thanks for the second one.
Katy Penland
Well-known member
Since we get both the Common and Lesser Nighthawk here in AZ, I was curious about your last sentence.Ingo said:
Were you referring to these two species; or did you mean Common and Antillean, or Antillean and Lesser, cannot be distinguished except by call? Just wondering because in my experience, the Commons and Lessers are quite easy to distinguish in flight (which of course doesn't apply to your grounded bird), so was intrigued by why this would be said in other field guides. :t:
Katy Penland
Well-known member
Thanks, Luke, I figured that was the combo referred to but just wanted to clarify.
Ingo
Well-known member
Katy Penland said:
Yes, I was referring to the distinction between Common and Antillean, and by the way, I did see this guy flying, I never thought it was a Lesser, I was just curious because of the wide mixture of what I find in the litterature. From the Sibley Guide I thought it quite safe to ID as an Antillean, but Cleere's and Nurney's book states the possibility of ID on the ground somewhat less confident, and I got a book on birds in the West Indies that simply states: indistinguishable in the field unless heard.
So, I wondered what people really think, Dave's reasoning is completely consisting with Sibley's Guide, and all photos I found by googling seem to confirm the features. So I keep this as an Antillean in my records (there were Commons on Dry Tortuga, too with wings longer than tail and no contrasting pale tertials).
Thanks everyone,
Ingo
Hi Ingo,
I hate to through a spanner into the works but it seems that things aren't quite as easy as checking how far the wings extend past/along the tail. I'm no nighthawk expert - in fact it was interesting to see your pics and do some research. Perhaps you should try posting to ID Frontiers and get some more experienced thoughts http://virtualbirder.com/bmail/idfrontiers/latest.html - These pics that were posted on identification frontiers are all thought to be of Commons note bird 4 with the short-winged look: http://www.martinreid.com/nighthawk.html
Luke
I hate to through a spanner into the works but it seems that things aren't quite as easy as checking how far the wings extend past/along the tail. I'm no nighthawk expert - in fact it was interesting to see your pics and do some research. Perhaps you should try posting to ID Frontiers and get some more experienced thoughts http://virtualbirder.com/bmail/idfrontiers/latest.html - These pics that were posted on identification frontiers are all thought to be of Commons note bird 4 with the short-winged look: http://www.martinreid.com/nighthawk.html
Luke
Ingo
Well-known member
Luke,
thanks for advicing caution. I joined and posted the photos to ID-frontiers, I'll update this thread when I receive answers.
Martin Reid's bird number 4 is indeed puzzling, I gather a Lesser was really excluded in that case? But note that the bird (actually none on that page) does not show the contrasting tertials. Let's say I'm still optimistic for Antillean....
Cheers,
Ingo
thanks for advicing caution. I joined and posted the photos to ID-frontiers, I'll update this thread when I receive answers.
Martin Reid's bird number 4 is indeed puzzling, I gather a Lesser was really excluded in that case? But note that the bird (actually none on that page) does not show the contrasting tertials. Let's say I'm still optimistic for Antillean....
Cheers,
Ingo
Ingo said:
Hi Ingo,
I'm optimistic for you as well but I was just doing research to entertain myself really. We only have Commons up here so I was intrigued as to why a couple of my books suggested identification was almost impossible when the Sibley seems to show some obvious differences. I assume most books assume identification is being attempted in flight.
Luke
First off, I believe that the quotes on "not safely told by plumage" is basically a copout; the species were split relatively recently and we still need to assemble more information on the variation within each of the two species. For example: the birds within common that are most like antillean, where in the range do they belong?
Looking at your picture, the only thing that I wonder about is the color: it seems very dark almost blackish in places. Antillean is supposed to have relatively warm colors ("buff"). I found this in Howell and Webb: "penultimate primary tip spacing usually shorter than adjacent inner primary tip spacing at rest (longer in common)". I am not sure that I really know what a "primary tip spacing at rest" is.
HTH
Niels
Looking at your picture, the only thing that I wonder about is the color: it seems very dark almost blackish in places. Antillean is supposed to have relatively warm colors ("buff"). I found this in Howell and Webb: "penultimate primary tip spacing usually shorter than adjacent inner primary tip spacing at rest (longer in common)". I am not sure that I really know what a "primary tip spacing at rest" is.
HTH
Niels
Andrew Rowlands
Well-known member
njlarsen said:
Niels,
I think this attachment illustrates the spacings and measurements (I doubled the pic before adding the rule and cropping).
Cheers,
Andy.
Ingo
Well-known member
Thanks guys,
so far just one input from ID-froniters from Matt Sharp voting for Common (based on the dark plumage and light vent), but Matt said he had no field experience with Antillean.
Check out
http://www.acnatsci.org/~wechsler/lightbox/ID-Front/Antillean Nighthawk f20-5-166.jpg
http://www.worldbirder.com/photonew/xpages/photo.asp?PhotoID=1890
The primary spacing seems a bit hard to verify because it almost certainly depends on how the wing is held, if you observe the bird for a long time, changing positions, etc. then maybe, you can be sure ... also just google for Common Nighthawks and Antillean and judge yourself on how useful that seems to be.
The photo from worldbirder.com (if properly Ided - Matt claims this to be a Common, too) looks pretty much like my bird - the color balance is off to the blue and it has been lightened a bit, a proper exposure, and the bird looks like a twin to mine.
From the (few) photos labelled Antillean on the web, I'm not convinced that the dark plumage really makes it a Common, check out also
http://www.camacdonald.com/birding/Fernandez/AntilleanNighthawk(EF).jpg
but then maybe, some are wrongly identified.
I searched the internet for pix, there are some of mainly dark Commons with pale tertials, but the tertials do not contrast with the rest of the wing, check for example
http://chandra.as.utexas.edu/~kormendy/nighthawk-big.jpg
http://www.birdersworld.com/brd/objects/images/brdpw030831.JPG
http://www.timboyer.com/images/001-003_common_nighthawk.jpg
Still puzzled,
Ingo
so far just one input from ID-froniters from Matt Sharp voting for Common (based on the dark plumage and light vent), but Matt said he had no field experience with Antillean.
Check out
http://www.acnatsci.org/~wechsler/lightbox/ID-Front/Antillean Nighthawk f20-5-166.jpg
http://www.worldbirder.com/photonew/xpages/photo.asp?PhotoID=1890
The primary spacing seems a bit hard to verify because it almost certainly depends on how the wing is held, if you observe the bird for a long time, changing positions, etc. then maybe, you can be sure ... also just google for Common Nighthawks and Antillean and judge yourself on how useful that seems to be.
The photo from worldbirder.com (if properly Ided - Matt claims this to be a Common, too) looks pretty much like my bird - the color balance is off to the blue and it has been lightened a bit, a proper exposure, and the bird looks like a twin to mine.
From the (few) photos labelled Antillean on the web, I'm not convinced that the dark plumage really makes it a Common, check out also
http://www.camacdonald.com/birding/Fernandez/AntilleanNighthawk(EF).jpg
but then maybe, some are wrongly identified.
I searched the internet for pix, there are some of mainly dark Commons with pale tertials, but the tertials do not contrast with the rest of the wing, check for example
http://chandra.as.utexas.edu/~kormendy/nighthawk-big.jpg
http://www.birdersworld.com/brd/objects/images/brdpw030831.JPG
http://www.timboyer.com/images/001-003_common_nighthawk.jpg
Still puzzled,
Ingo
Andrew Rowlands said:
Andy thanks, I feel really dense right now; it just shows that I have never been a ringer or seen a measurement like that done before. Talking about a pen-ultimate feather, the neighboring one must be the ultimate, which I guess it the frontal one when the wing is stretched. Is that the one to the left or right in your image? And if as I guess the ultimate is the left, then we are comparing gap no 2 with gap no 3?
Thanks
Niels
Andrew Rowlands
Well-known member
njlarsen said:
No worries Niels, that's terminology for you
.I think I managed to line up the rule so that zero is at the tip of the 4th visible primary, to measure the pre-penultimate spacing (Gap #3 from the wingtip - almost completely shadowed). This measures approximately 72 Pixels.
The penultimate (Gap #2) spacing measures (134 -72) 62 Pixels (again, approx.).
Therefore this bird (using the Howell and Webb method) tends towards being Antillean rather than Common.
Andy.
Andy,
thanks! I tried to do the same thing with the first picture (i.e., using the other wing), using the measure tool in Photoshop. Results were 0.455 for the penultimate gap and 0.510 for the next one, again indicating Antillean. Photoshop did not tell me what the units were, by the way
cheers
Niels
thanks! I tried to do the same thing with the first picture (i.e., using the other wing), using the measure tool in Photoshop. Results were 0.455 for the penultimate gap and 0.510 for the next one, again indicating Antillean. Photoshop did not tell me what the units were, by the way
cheers
Niels
Andrew Rowlands
Well-known member
So where are we at with this bird, Niels? I was too busy last night to study this Thread. Overall, does it tend towards one species or the other? Is there more to investigate?
Andy.
FYI, I used >JR Screen Ruler< (Freeware size: 494 Kb). An alternative, for Windows and DOS, would be >Cool Ruler< (Freeware size: 886 Kb). The measuring units can be changed on both Apps. There are probably similar Apps. out there for Mac/*nix users too.
Andy.
FYI, I used >JR Screen Ruler< (Freeware size: 494 Kb). An alternative, for Windows and DOS, would be >Cool Ruler< (Freeware size: 886 Kb). The measuring units can be changed on both Apps. There are probably similar Apps. out there for Mac/*nix users too.
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