Male and female Long-billed Curlews have identical plumage throughout the year so how do we tell them apart? This is the best single photo I’ve seen to show how.
1/1250, f/14, ISO 500, Canon 7D Mark II, Canon EF 500mm f/4L IS II USM + EF 1.4 III Extender, not baited, set up or called in
I took this photo yesterday morning on Antelope Island. The Long-billed Curlews were obviously a mated pair because it’s breeding season, they’re both adults and they stayed very close to each other for the entire time I was with them. Normally a shot like this would be demoted to my delete bin in a heartbeat because of the incredibly busy and unattractive background so close to the birds. That background was made even more distracting because in an effort to get both birds sharp I was shooting at f/14 which pulled all that brush into even sharper focus than it would otherwise be.
But despite its major flaws this is the best photo I’ve seen to illustrate the field marks that distinguish male curlews from females.
Most folks have a very difficult time telling males from females in the field because they have identical plumage throughout the year. But there are several distinguishing characteristics that can be used, especially when birds are very close together to make the differences more easily seen. It’s difficult to get two curlews in the frame in a photo where both birds are sharp and their poses illustrate the differences well but I think this shot does exactly that.
Here’s the differences:
- Females are significantly larger than males. Weight of males averages only 84% that of females.
- The bills of females are longer and a different shape than the bills of males. Male bills average 139 mm while female bills average 170 mm and female bills tend to be flatter on top while bills of males are gently curved throughout their length.
So in this photo and based on those differences the female is the larger curlew behind the male in front of her. In my opinion, having both curlews sharp and right next to each other in very similar poses makes this an excellent photo for distinguishing males from females.
But you have to try to ignore that ugly background.
Ron
Ron, thanks for posting this one. I appreciate good learning opportunities. And the background doesn’t bother me. If I were using my binoculars instead of my camera, this is what I would see. An occasional sharp background is a refreshing changed from the blurred background. But I respect your high standards, too.
In several books and apps nary a mention is made of gender differences in the Long-billed Curlew. Kudos for getting that photo and thanks for the lesson.
Far from scientific, that’s one of my favorite scientific methods! Thanks for the straight answer, much appreciated. I feel like I’m on the right track with aperture settings for some situations.
Yes, its a busy background and as as Jean and EC have noted, it’s their background – and they are probably not concerned with providing nicer looking stuff for those pesky creatures with the one big eye that they love to confound.
Nope, they don’t care, do they. And if birds like their habitat I like it too, I just don’t always appreciate it in my photos.
When you’re shooting at focal lengths like I am (usually 1120mm effectively) aperture often doesn’t make much difference in many situations with depth of field. But every little bit helps…
Nothing wrong with the background. They are in their natural habitat. Thanks for the info!
You’re welcome, Jean.
I don’t Have to try hard at all, it doesn’t distract my eyes. I love this shot and thought it extremely informative as well!
charlotte
Thanks on both counts, Charlotte.
DEFINITELY eye of beholder.
Yet again I yearn to go dumpster diving in your discards.
I love this photo.
That busy background tells me so much about their natural habitat and their spectacular camouflage adaptation.
And huge thanks for the lesson in indentifying the genders – something I suspect they do not need to depend on size and beak shape to do.
I suspect you’re right, EC. Thank you.
Excellent! 🙂 Also probably explains why, at times, we thought we were seeing a different Curlew. Our “curlew’s” were generally seen singly in the fields and, probably a female nesting. Small groups flying at other times were probably all males as they were notably smaller…….. GEEZ! When Joe was younger (he’s a ’29 model) they had many in one area close by that, at that time, had a pond – rarely seen now.
“we thought we were seeing a different Curlew”
I remember you mentioning that recently, Judy. Nice to have a possible explanation, huh.
YES particularly when there really weren’t any others that “fit” around here! 🙂
So clearly explained! Thanks! Usually when I ask a photographer how they identify male and female of a species, I get no reply.
Sheesh, wonder why they don’t respond, Sallie. Thanks.
Cool! Thank you!
Thanks, Mikal.
Argh! You’re killing me, Ron! This is a fabulous shot — I barely notice the background because the two birds are so striking and so sharp. I can’t believe this one almost “didn’t make it.” This isn’t just a wonderful documentary shot — it is a wonderful shot. Period. 🙂
Best part of this post for me is that you’ve cleared up a misconception I had. I knew that the females were larger and had longer bills, but I had also thought that their bills had the bigger curve. Now I know that it is the males who have the “Curlewier” bill. 😉
Marty, actually you weren’t completely wrong about the curve of the female’s bill, at least according to several sources I’ve read that say things like “the females have a more pronounced curve at the tip of their bills” than males do. But that’s only at the tip, not the entire bill.
And to my eye this photo seems to contradict that because I think the male’s bill (in this photo) has the most pronounced curve at the tip. Haven’t been able to reconcile that so far…
BOY! You ARE a nut case!!! Not only is that a great ID THE GENDER DIFFERENCES photo, buy I think it’s ‘s a beautiful photo on its own right!!!
Different strokes for different folks, Patty! Thank you.
🙂 this really made it easy for me to see the bill difference as well as the size. Thank you.
Good. Then the photo accomplished its purpose. Thanks, Arwen.
I recently became aware of the bird and nature photography of Eliot Porter, who worked 1940s-1980s. His bird pictures have incredibly busy backgrounds, often because he was taking pictures of birds at their nests. It set me to thinking that the basic aesthetic has changed though, and today we prefer an isolated bird, with little or not apparent background. I’ve even seen photos on Facebook where the photographer replaced the background with black! I think the curlews look great with their background, and I sure appreciate the lesson of how to tell them apart.
Yes, many photographers (far too many IMO) swap out backgrounds in their nature photos, Jan. Often they replace blue or featureless skies with skies that have beautiful clouds in them. Personally I think doing so is unethical in nature photography unless you disclose what you’ve done but most photographers don’t.
In general I’m not a fan of photo art in nature photography.
I don’t think I ever realized or appreciated how long their bills are, especially the female. Ron, how do you determine your f-stop when you are trying to put two birds at differing range into focus?
This is such a great shot that really sets the table for learning and your narrative wraps it up neatly.
One cup of coffee and this lesson and I feel better prepared to take on the day.
Dave, my method for determining aperture in these situations is far from scientific. Birds are usually constantly moving and there’s very little time to make adjustments so I just tend to spin the wheel on my camera that changes aperture and hope I turn it in the right direction! 🙂
Thanks very much for the kind comment.
Once again, Ron, beauty is in the eye of the beholder. I absolutely love the photograph, and I think that that delicate foliage is absolutely exquisite. The lack of definition between the birds in the background lead me to pay special care and give special appreciation to those two lovely birds. I wouldn’t find the photograph as compelling, if the background were plain. As I may have mentioned in the past, I speak as an artist and an illustrator, and I’m so glad that sometimes you include photos that broaden the range of inclusion from what a more classic approach to bird photography and delineation might include.
As always I’m interested in your perspective and your rationale for your position, Alison. I try to like that shot aesthetically but I just can’t.
“Eye of the beholder” is right!
Excellent capture and explanation!
Thank you, Ken.
If you had not mentioned the background I might not have taken notice. Interesting too about the bills. Had you not explained about the longer bill I don’t think I would have noticed the difference, but of course brought to my attention and it is easy to see. Pretty birds and a very nice photo. Thanks too for the education.
Everett Sanborn, Prescott AZ
Everett, as is probably obvious I really don’t like that background but I think the photo is excellent for the purpose of distinguishing sexes. Photos can have value for very different reasons.
What ugly background? I see a great shot of a pair of birds. Thanks for sharing.
Good!
Great teaching photo. Size is so relative to what one interprets…especially if it is a busy background. The height of grasses etc can add to the confusiont. This photo certainly eliminates any confusing factors. Her body is significantly heftier. Wish they were all this way to ID!
“Size is so relative”
Exactly, Kathy. We need a valid comparison to have it be of much value for ID in the field. Thank you.
WOW, Ron!! A terrific blog today. I’m always glad to learn something new about our birds. This lesson brings something to mind. I find it interesting that the curlews fall into the category of females being the larger of the two & when not together, hard to tell which sex the bird is – which is what you see with the Bald Eagles. Then there are birds like the Red-winged Black Bird or Painted Bunting where the male & female are totally different, the males being colorful & the female being very subdued in coloring so that it’s hard to believe they are the same bird. God, I love nature!!
Yup, that’s one of the things that makes birds interesting. And challenging for both bird photographers and birders. Thanks, Jo Ann.
Ron, would you consider sharing your photo with Cornell to use on their “All About Birds” section of their website? This would be a great tool for IDing these birds.
If they asked I would, Jo Ann. But I don’t offer any more because in the past when I’ve offered documentary photos to Cornell they have either ignored me or said they would use my photos and information when they never did.
For example, Cornell’s BNA Online says they have “no information” on pellet casting in Western Kingbirds. When I documented pellet casting in kingbirds in several very good photos I sent them to Cornell. They asked for permission to use them which I allowed but they never did. That was almost a decade ago but BNA still says “no information” on pellet casting and they never used my photos.
I don’t waste my time anymore. Otherwise I’m one of Cornell’s most enthusiastic supporters but not for things like that.
Well that really upsets me, Ron, because they are still asking for photos as they expand their “Merlin” app!! I really like their cams & website but by not using your photos, they deprive anyone who is using their site for IDs, etc.!! Grrr!!
Excellent! I’ve wondered about the bill length & slight differences in curvature. But, I’d never seen them side by side.
Seeing them side by side really helps, doesn’t it, Barbara. Thank you.
Great ID lesson…Thank You!
Thank you, LS.
Great lesson! And a real nice photo! It also illustrates how well the birds can blend in to their background.
Thanks, Joanne. I’d agree that it’s a “real nice photo” for the purpose I’ve used it here…