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Differentiating Female (and male) Goldfinch Species

I was on travel for work this week which mean any blogging or work on my website was delayed. When I returned, I had an email that was thanking me for my “Difficult Bird ID” page, where you can find information on differentiating between commonly confused species. There was also a request to add another page, discussing how to tell apart the three North American goldfinch species. I don’t normally think of goldfinches as a particularly difficult group to identify, but then again, here in eastern South Dakota, we only have the one species. Overall, geography is obviously a huge part of identifying goldfinches, as in the eastern half of the country, the only species of goldfinch you’ll find are American Goldfinch.  However, if you happen to find yourself in parts of the southwestern US, you have three goldfinch species you may potentially encounter, with Lesser Goldfinch and Lawrence’s Goldfinch join the party.

The woman who sent the email lived in California and specifically was trying to figure out how to easily identify female goldfinches. That does represent more of a challenge than differentiating male goldfinches, and given that my Difficult Bird ID pages are some of the most visited pages on my entire website, I thought tonight I would go ahead and create another page that talks about ID keys for the three species.

As with many “difficult” IDs, for birders I think that difficulty melts away with experience, particularly when given keys to look for.  Creating a page such as this helps me as well!  I don’t run into Lesser Goldfinch, for example, unless I travel, but I don’t know if I could have identified a female goldfinch as either Lesser or American in the areas they overlap in range, until creating this page. Now I’ll know what to look for (bill color, and undertail covert color are giveaways).

A bit of a pain to create these pages, but as I said, they are frequently visited.  Click below for the new Goldfinch ID page.

Identifying North American Goldfinch Species

Identifying Goldfinch Species (female)

Females of the three North American goldfinch species. Males in breeding plumage? Piece of cake. A little bit harder for the females (particularly American and Lesser), but not bad when you know what to look for.

Pondering Petrified Wood

Human beings are funny creatures. When we see something, we immediately want to categorize it.  For a birder, identifying and tallying species is a huge part of the hobby. For my work as a scientist working with satellite imagery, my task is to categorize the types of land cover (cropland, urban, deciduous forest, etc.) on the earth’s surface.  For a rockhound?  I’m struggling with identification as a rockhound newbie, just as I did 20 years ago when I was a birding newbie.

Petrified wood is one category of material I thought was easy to identify. When I’m out on the Buffalo Gap National Grasslands, there is a LOT of petrified wood lying around. By that, I mean there’s a lot of easily identifiable pieces that look exactly LIKE wood, with obvious grain patterns.  But as with anything in life, it’s not that easy.  Below are some of the obvious, and not so obvious pieces I’ve found on the Grasslands. Thoughts? Are all of these petrified wood?

Petrified Wood - Buffalo Gap National Grasslands, South Dakota

First, an obvious piece of petrified wood. This is what I find the most of…gray exterior pieces with clear grain patterns, some of which are so detailed they look like fresh pieces of wood.

Petrified Wood - Buffalo Gap National Grasslands, South Dakota

Another obvious one. Both of these first two pieces have also been tumble polished to a nice shine.

Potential Petrified Wood - Buffalo Gap National Grasslands, South Dakota

And this piece? This is the most colorful piece I’ve found, for something that’s possibly petrified wood. You certainly see a linear “grain” running throughout. Petrified wood? Perhaps an agatized petrified wood?

Potential Petrified Wood - Buffalo Gap National Grasslands, South Dakota

Same piece as above, except on the flip side. Again, you see the grain pattern throughout.

Potential Petrified Wood - Buffalo Gap National Grasslands, South Dakota

A less obvious one. The photo doesn’t show it as clearly as what you see through a loupe, but there are rough “grain” patterns. They’re more little streaky nodules all oriented the same direction. I know there’s petrified palm that can be found in this area, but I don’t know what exactly the palm looks like from this area.

Potential Petrified Wood - Buffalo Gap National Grasslands, South Dakota

A similar one, with little linear nodules lined up in the same orientation like a wood grain (again, a bit hard to see in this photo).

Potential Petrified Wood - Buffalo Gap National Grasslands, South Dakota

The photo of this piece does a better job showing the type of “grain” seen in the previous two pieces as well. Obvious, and all oriented in the same direction.

Telling the difference between hawks (Buteos)

Ferruginous Hawk - Buteo regalis

When this guy flew by and I took photos, what first came to mind was dark-phase of a Rough-legged Hawk. It’s actually a dark-phase Ferruginous Hawk. The vast majority of Ferruginous Hawks that you run across are light phase, so this guy is a perfect example of how confusing it can be sometimes to identify Buteo hawk species.

As I look through visitor stats for my main website, one of the sections that is visited the most is a “Difficult ID’s” section.  That actually surprised me a bit, given that it’s a fairly small part of the website, and not a section that I’ve revised for quite some time.  The section is devoted to helping birders differentiate between certain species that tend to be difficult to identify, with photos, identification tips, key plumage characteristics, and other information.  I only had 10 different classes of birds that it helped to differentiate…thus my surprise to see how many visitors those pages get.  For the first time in probably 7 or 8 years, I updated several of those pages, providing more detailed identification keys, new photos, and range maps to help people see where and when certain species are likely to be present. I also started to think about other species that birders may have trouble identifying.

As I was going through my photos from my day-long trip to central South Dakota to look for winter raptors, one bird had me stumped.  It was a dark-plumaged bird that I originally was sure was a dark-morph Rough-legged Hawk.  After processing the photos, however, it became clear that it was actually a dark-morph Ferruginous Hawk, a color morph I just haven’t run across very often.  Given the variability between the different “Buteo” Hawk species, and given the variability WITHIN a single species in terms of plumage differences between different color morphs, and between adult and juvenile birds, what better addition to the “Difficult ID’s” pages than a very detailed description of how to tell apart Buteo hawks?  I’ve just uploaded the following new page:

How to differentiate between “Buteo” Hawk species

On these pages, I’ve restricted myself to the more common Buteo species that are found in South Dakota and the U.S. as a whole. The more rare or geographically restricted species, such as Gray Hawk, Zone-tailed Hawk, or Short-tailed Hawk, were excluded, so the page could concentrate on the more common species in the U.S.  Species included are Red-tailed Hawk, Ferruginous Hawk, Swainson’s Hawk, Rough-legged Hawk, Red-shouldered Hawk, and Broad-winged Hawk.

For these 6 species I have several pieces of information to assist birders in identification challenges.  That of course include photos that offer a variety of angles, color morphs, bird ages, etc., as well as identification keys and species range maps.  The Buteo Hawk page is undoubtedly the most comprehensive of the “difficult ID’s” pages that I’ve put together to date…I hope that people find it helpful!

Given how much attention those pages are getting, I will likely add new categories of “difficult ID’s” in the coming weeks. If you have any suggestions, let me know!  In the meantime, here are the other species groups that are offered on the difficult ID’s page:

Trying to stump “Merlin”

Cassin's Sparrow - Peucaea cassinii

A Cassin’s Sparrow, a rather plain, non-descript sparrow found in parts of the southern Great Plains and Southwest. Merlin was able to easily ID all of the “little brown job” sparrow species I tried, including Cassin’s, Vesper’s, Rufous-winged, Rufous-crowned, Black-throated, Black-chinned, and other sparrow species.

I’ve been birding 15 years now, and there aren’t really many occasions any more where I’m stumped on a bird ID.  The only occasions I have any difficulty are with species that are inherently damned hard to tell apart by sight, things like the Empidonax flycatchers or others where hearing a song/call or other audio clue might be needed to make a positive ID. I rarely ever even have a field guide with me when I’m out birding.  I do love field guides in general, and they certainly were a godsend when I first started birding, I hate to say it, but they’re a bit obsolete now, when you can put the equivalent of every major field guide directly on your cell phone.  I DO nearly always have my cell phone with me, and while I don’t use it much for visual ID issues in the field, it is handy for trying to figure out what call or song I heard.

I knew Cornell’s “Merlin” app has been out a little while, but hadn’t downloaded or tested it.  Merlin is an app for IOS or Android that allows you to identify birds in two ways.  If you see a bird but are stumped on an ID, you can enter the location, size, colors and other characteristics, etc., and Merlin will spit out the likely species.  More intriguing to me is the photo ID option.  You can simply choose any photo on your device, or take a photo, and have Merlin try to identify the species.  The “Take a Photo” option isn’t very useful, as your iPhone or Android phone just aren’t going to be able to get good bird photos unless  you’re at a feeder or other setting where birds are extremely close. However, I was intrigued by the option to identify the species from an existing photo, so I gave it a spin.

I have a huge number of bird photos, but most are on my desktop computer’s hard drives. The only ones I actually had on my phone were ones I processed on my iPad that got integrated with my photostream, from a trip to Arizona.  Still, I did have photos from quite a few species.  Some were quite clear and distinctive, photos that should be easy identifications. Others weren’t so clear, and I also had photos of several species that just aren’t that common in the U.S. How would Merlin do in identifying my Arizona bird photos?

Black-tailed Gnatcatcher - Polioptila melanura

OK, I probably wasn’t being fair to Merlin with this one, but I tried photos of a female Black-tailed Gnatcatcher. Both photos are of the same bird, but different angles and postures. For the first, Merlin mis-identified it as a Blue-gray Gnatcatcher, without giving the option of Black-tailed, even when I told it the photo location. The second photo it handled without problem, likely because in that photo, you can see the distinctive darker coloring on the underside of the tail. Even there though…Merlin was impressive! The tail underside is shaded and not all that distinguishable, but Merlin handled it.

In short…pretty damned good!  It took me a while before I was able to stump Merlin.  I started with some easier ID’s. I had been to Madera Canyon south of Tucson, and had a number of hummingbird species at the feeders there.  Merlin easily handled all the male hummingbird photos, and to my surprise, did a good job on identifying female and immature hummingbirds as well.  I was fortunate to see and get decent, but not great, photos of an Elegant Trogon in Florida Canyon.  Merlin handled the rarity without issue (OK, that one SHOULD be easy to identify!!).  Lawrence’s Goldfinch, partially obscured by a weed?  No problem, although it did give me “alternative” answers other than the primary choice of Lawrence’s Goldfinch.  Multiple different sparrow species with sometimes not so obvious plumage differences?  No problem.  Birds in flight?  Did just fine on White-tailed Kites, a Gyrfalcon flight shot I happened to have on my phone, and other flight shots.  I quickly went through about 35 species, and Merlin handled them all flawlessly (although like the Lawrence’s Goldfinch example, there were a some cases where “alternative” ID’s were provided in addition to the primary ID).

I was thinking Merlin was infallible!  It is awfully good, but it has trouble with some of the same species I might have trouble with in an ID.  I tried two photos of a Black-tailed Gnatcatcher, one of which was at an angle that was “unfair”, in that you really couldn’t see the tail characteristics that might distinguish it from a Blue-gray Gnatcatcher.  It missed the ID in that photo, but was able to correctly ID the same bird in a photo from a different angle.  Another it had trouble with is one that I myself would definitely have trouble identifying.  I had a photo of a Gray Flycatcher (one of those nasty, hard to ID Empidonax flycatchers), and Merlin whiffed. It was a clear photo, and I even entered the photo location, but that was the one case where Merlin didn’t find a single “match”.

Merlin is a really nice piece of software, and it’s an app I’ll keep on my phone.  In the real world though…it’s an app that’s going to be most useful to new or casual birders.  For an experienced birder, Merlin is going to have the same identification troubles that we may have. Feed it a bad photo, or a photo of species that are just difficult to visually identify, and Merlin will struggle just as a birder might struggle. There’s also the issue of actually getting a photo to the app to be identified.  As I said previously, people just aren’t likely to take good, identifiable bird photos with their cell phones, so Merlin is likely most useful for photos taken on a DSLR or other camera body.  For me and my Canon 70D, it’s always an adventure trying to get photos transferred from my camera body to my iPad or iPhone, with a wireless app that is balky even on its best days.  For that reason alone, even if I were a beginning birder, Merlin might be less useful to me (through no fault of Merlin itself).  Merlin also might be less useful for rarities, as it seems to cover most native/common birds in the U.S. and Canada, but misses some of the rarer or exotic ones.

Overall though, very cool piece of software, and one that I do wish I had when I had started birding 15+ years ago.

 

Birds & the Bees – Identification challenges

Carpenter Bee species

A (new favorite!) photo of a Carpenter bee on a bloom. The species of Carpenter Bee? Uh…WHOA…would you look at the time…uh…I gotta run, I’ll catch up to you later!!

When I started photography 15 years ago and started shooting birds, I knew absolutely nothing about my subject matter.  Species identification?  Hah!  For the first several months I was constantly bugging my friend Jim at work with identification questions, showing him photo after photo while he patiently helped me identify birds.  After this much time, I’ve photographed most birds you could expect to find in South Dakota, and I have very little trouble identifying birds from sight or from a photo (by ear is another matter…).

It did take a while though to become proficient in bird identification.  After all, there are about 430 species that have been seen in South Dakota.  Now as I’m getting into macro photography, i”m having the same issue with insects and spiders, but the magnitude of the problem is MUCH worse!  In the continental U.S. and Canada, there have been over 900 different bird species sighted, including many stray birds, and many pelagic birds you’d never see unless you were off the coast some distance.  In the U.S. alone, there are over 4,000 BEE SPECIES ALONE!!! Many insect species are also differentiated from each other by only very small ID keys. In other words…it’s DAMNED hard to nail many insects down to a given species.

I’m not satisfied taking a bird photo, but not knowing the exact species.  With macro photography and insects…I’m going to HAVE to be satisfied in most cases not knowing the exact species, but perhaps only arriving at the basic genus that species belongs to.  The photo above of a Carpenter Bee (I think!!) is a good example.  There are over 500 species of Carpenter Bees worldwide. .But as soon as I took this photo and looked at it on my screen yesterday, I knew it was instantly one of my favorite  photos!

And that’s going to have to be good enough, as I may NEVER know the exact species shown here…

Revisiting Dowitcher Identification

Short-billed Dowitcher - Limnodromus griseus

Photo of a Short-billed Dowitcher. At least now, after 15 years, I’m finally making a call that this is one, given the advice of several folks. Click for a larger view.

Ok, after much debate and consulting with other folks, I think I have a better handle now on identification of Short-billed Dowitchers vs. Long-billed Dowitchers. It’s still not an easy call, but after 15 years of birding, I’d never mentally/physically “checked off” Short-billed Dowitcher on my life list.  Long-billed Dowitchers are the ones that are more often found in fresh water areas, and are more often found on the interior of the continent, and until this point, I’d just mentally called any Dowitcher I saw in South Dakota as a Long-billed.

I’m now adding Short-billed Dowitcher to my list, based on the top photo here and the advice of several folks.  I had a photo of about 10 different Dowitchers, but this is the one (a crop of the photo showing 10 birds) that most people pointed to as being most clearly a Short-billed Dowitcher  What’s interesting is that opinions varied as to why, but the ID points hit the ID points provided in the exhaustive SurfBirds page on Dowitcher identification.  For this bird, ID keys are the following:

 

  • V-shaped lower coverts with white running up the sides of the feather more than a Long-billed Dowitcher.  Long-billed Dowitcher lower coverts are described as more “squared off”, with white that doesn’t run up the side of the feather a bit.
  • Droop in last 1/3rd of the bill.  You definitely see that on this bird.  I’m not totally sold on this ID mark though, as I’ve seen conflicting information online about whether this is diagnostic.
  • Primary projection.  Short-billed Dowitchers are supposed to have slightly longer wings, and have primaries that extend out from the tertials more. This guy has long primaries.
  • Slimmer shape than a Long-billed Dowitcher.  I forget whether I read it or whether it was an ID key someone sent me, but supposedly Long-billed Dowitchers are chunkier looking, with the description being that they look like they “swallowed a grapefruit”. In terms of shape/structure, this also results in a straighter back for the supposedly slimmer Short-billed Dowitcher, while in profile a Long-billed Dowitcher has a kink/dip/indentation in the back towards the tail.
  • “Arched” supercilium. This is a mark from the SurfBirds article online, and there are also other sites that note Long-billed Dowitchers seem to have a straighter, less steep slope on the forehead than Short-billed Dowitchers. The result is supposedly a straighter supercilium on a Long-billed, with a Short-billed Dowitcher having the “arch” in the supercilium shape.
  • Light looking underparts with modest barring/spots.  Hard to see in this angle, but the bird does seem to be relatively light-colored underneath, with lighter/white areas.  Long-billed Dowitchers are supposed to be more uniform and colorful below.

 

Dowitcher Tails in Flight

Three dowitcher tails captured while in flight. Black-and-white barring thickness is supposed to be diagnostic for Dowitchers, with Short-billed Dowitchers having wider white bars than Long-billed Dowitchers

One other potential difference between the two species is the width of the black-and-white barring in the tail (visible in flight).  As this group of birds flew by at one point, I did get a (rather bad) photo that captured parts of 6 birds. For Long-billed Dowitchers, the black bars in the tail are supposed to be significantly thicker than the white bars.  For Short-billed Dowitchers, the white bars are wider, and can be as wide as the black bars.  This 2nd photo shows the 3 tails captured in that bad flight photo.  To me, the white bars in that bottom photo are definitely wider than the white bars in the top 2 photos.  I of course have no idea which bird may be the wading bird depicted in the top photo, but it could be possible 2 of these 3 birds are Long-billed Dowitchers, and the bottom one is Short-billed.

I also find it interesting how the relationship between leg length and tail differs between the top 2, and the bottom image.  In the bottom image, the legs appear to stick out further from the tail than in the top 2 photos.  It could just be the poor quality of the photo, or the fact that in the bottom bird, the tail isn’t fanned out as much.  But Long-billed Dowitchers ARE supposed to a have a longer tail than Short-billed Dowitchers.  Could that be while the tail seems to cover more of the legs and feet int he top two birds, compared to the bottom one?

Whew.  If you take just one of any of the ID keys above, there’s no way I’d make a call, particularly on my own.  But given the “match” of several different ID keys, and given the opinions of others, I’m (finally) comfortable calling the bird in the top photo a Short-billed Dowitcher.

Short- vs. Long-billed Dowitcher

Short-billed Dowitcher vs. Long-billed Dowtitcher

Which kind of Dowitchers are these? Click to get a much higher-resolution version.

Alright, I admit I have no freakin’ clue how to tell apart Short-billed Dowitchers vs. Long-billed Dowitchers.  I DID find this great website:

http://www.surfbirds.com/ID%20Articles/dowitchers1005/dowitchers.html

More info than you can shake a stick at!  But I’m still not sure that it helps me.  Given that I live in South Dakota, where we’re much, much more likely to find Long-billed Dowitchers, I have pretty much always called Dowitchers I take photos of here Long-billed Dowitchers.  But over the years, I also have no doubt I’ve seen, if not photographed, Short-billed Dowitchers.

So, tonight I was birding around Newton Hills State Park, and came across a group of 15 Dowitchers.  Long- or Short-billed?  Check out the photo above.  What are they?  All Long-billed?  A mix?  Bill length, as expected, is one of the ID marks in the SurfBirds article above.  Check out the 2 birds with an “A” by them.  The one on the left has a much longer billl than the one on the right.  Leg length is supposed to be another mark, with Long-billed Dowitchers having longer bills.  Again check out the birds labeled “A”.  The one on the right has the water reach his belly, while the birds right around him have leg showing.  Same for the one bird in the back by the “B”, where one bird has water reaching the belly, and the other two don’t.

The SurfBird site has many more ID keys, such as a supposedly straighter supercillium on the Long-billed, but even on their example images I find that hard to see.  Plumage differences and shape differences are noted there as well.  Any thoughts out there? What are the Dowitchers in this photo?

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