Fun Challenges and Cautionary Tales from Fall Banding

Steve BrennerBanding, Identification, Migration0 Comments

Fall migration out east is a conflicting time for birders: the rarity machine is usually churning out goodies after goodies. Also, fall warblers dressed in brand-new plumage are pulsing through the woodlots of every town. These days most birders have come to appreciate the subtle nuances of fall warblers. The ID challenge is fun and rewarding, and in a way it’s like looking at a whole new bird from gaudy spring colors and obvious feather patterns to drab earthy tones and faded wingbars. But inside every birder lies some frustration with fall songbirds. They don’t sing, they are far more sneaky, and yes, they are sporting a completely different look.

While a bevy of excellent resources exist that continue to enhance our understanding and identification abilities for fall birds, little reminders every so often are always helpful. So why not check out some birds in the hand to help hone our birder skills?

A caveat: birds in the hand are a great way to study birds, but sometimes this doesn’t always translate to useful birding tips. For one, behavior and vocalizations are completely eliminated from the equation. In that sense, general impression is replaced by field marks. Also, some birds really can look different in hand vs. in a tree or in the sky. But this does not discount the value of studying birds up close in order to improve ID skills. So, on with the post.

Some fun warbler examples

A lot has been said about fall warbler ID. Honestly, there is not much I can add that hasn’t already been said by far better birders, banders, and scientists than myself. Warblers up close, regardless of the season, are extraordinarily beautiful and downright cool. So basically enjoy these close up shots.

The magnolia vs. canada warbler is a nice little comparison in fall. While for the most part, well marked canadas in the fall should be pretty obvious, a lightly marked individually could definitely get mistaken for a magnolia if seen in poor light or obscured views. Both are very yellow with white undertail coverts and bold eyerings and superficially similar in size and shape. But canadas have a very yellow superloral area (front of face near the bill) and a clean slate-colored back. Magnolias have gray in front of the eye (no yellow) and a lime greenish yellow rump. The streaking arrangement is also different between these two species (canada warbler has the necklace across the chest and no streaking down the sides while magnolias have faint side streaking), but this can be difficult to see sometimes depending on plumage, lighting, bird behavior, or foliage.

Lime-yellow rumps is not always a slam dunk for magnolias, however (or for that matter, yellow-rumped warbler!). With a brief glance at the bird below, one might lean towards maggie or yellow-rumped. But seen from the front, this is obviously not a magnolia warbler. The fine streaking, bold face pattern, white tipped wing, and subtle orange in the face point to cape may warbler. Not the shabbiest looking bird by any stretch.

Cape May warbler from the top. Yellow-green rump evident. (photo by Steve Brenner, RI 2016)

Cape May warbler from the top. Yellow-green rump evident. (photo by Steve Brenner, RI 2016)

Cape May warbler. Tiny white wing patch, bold facial pattern, and a touch of ruby in the cheek. Look at the chunky, long vibe of the bird as well. Ready to migrate! (photo by Steve Brenner, RI 2016).

Cape May warbler. Fine streaks densest at throat, bold facial pattern, and a touch of ruby in the cheek. Look at the chunky, long vibe of the bird as well. Ready to migrate! (photo by Steve Brenner, RI 2016).

Oh yeah, and black-throated blue warblers are really, really, really ridiculously good-looking.

Hatch-year Male Black-throated Blue Warbler in all of its face-melting glory (Photo by Steve Brenner, Rhode Island 2016)

Male Black-throated Blue Warbler in all of its face-melting glory (Photo by Steve Brenner, Rhode Island 2016)

Fall Empids. Buyer Beware.

Good ol’ empidonax flycatchers. These little buggars can sometime reach peep-level proportions for birders, but fortunately they sing differently enough to make spring ID manageable. Come autumn, these once chatter boxes become Trappist monks and suddenly you are staring at a tiny bird for 10 minutes wondering if you should have gone fishing instead.

I would always exercise caution when identifying silent empidonax to species. Yes, certain species level traits can be got with experience, such as primary projection and eye ring. But there is also a lot of overlap between size, wing length, bill width, eye-ring color, and even primary projection. There is a reason willow and alder flycatchers were once considered conspecific. The trickiest and often most misleading field marks are color: certainly slam-dunk yellow-bellied flycatchers can have bursting yellow throats and bellies, and certainly slam-dunk acadians will be so greenish on their top feathers you’d want to vote for Jill Stein. But a more worn and/or fresh plumaged bird can throw off all sorts of impressions at you, and lighting/viewing conditions can make a world of a difference when talking about greenish-brown backs to brownish-green backs. Best bet is to hope for a vocalization (even calls can help!) and use a combination of traits to make some judgements about a bird. Just be careful out there, and don’t worry if you can’t safely ID them all.

In the hand, most empids can be whittled down to species level using a combination of traits and morphological measurements. But even in hand there is much overlap. Here is a least flycatcher: notice the complete eye ring and plain throat. A little harder to tell from the photo is the amount of primary projection. In short, least do not have much of a primary projection. Leasts are also generally more gray and dark backed for fall empids.

Least Flycatcher. Hello eye-ring (photo by Steve Brenner, RI 2016).

Least Flycatcher. Hello eye-ring (photo by Steve Brenner, RI 2016).

Least Flycatcher side view. Grayish impression on back and head, more gradual, shorter primary projection as wings fold. (Photo by Steve Brenner, RI 2016).

Least Flycatcher side view. Grayish impression on back and head, more gradual, shorter primary projection as wings fold. (Photo by Steve Brenner, RI 2016).

Check out the empid below. Certainly a bit browner/warmer backed than the least. The eye ring is also not quite as clean and pronounced as in the least, but this is more subtle. From above, you can see how the the primaries ‘stick out’ more than the least. All that being said, this bird cannot be ID’d to species, and thus designated as ‘Traills Flycatcher’ (the old name for the willow/alder complex). Even in the hand, we can’t say what this bird is unless it was singing.

Frontal look at Traills Flycatcher. Limited, messy eyering and more dark brown look (photo by Steve Brenner, RI 2016)

Frontal look at Traills Flycatcher. Limited, messy eyering and more dark brown look (photo by Steve Brenner, RI 2016)

Topside view of the long primary projection of Traills Flycatcher and darker, brown tones on back feathers (photo by Steve Brenner, RI 2016)

Topside view of the longer primary projection of Traills Flycatcher and darker tones on back feathers (photo by Steve Brenner, RI 2016)

To drive home the point about misleading color, check out these photos of the head and back of empids taken in different lighting conditions. Depending on the light, the green tones in empids can pop versus the darker brown or gray tones in empids.

Empidonax in different light

Empidonax in different light

Empidonax in different light

Empidonax in different light

Empidonax Flycatcher in different light

Empidonax in different light

Photo 1 & 2 are actually the same individual, a least flycatcher. Photo 3 is a Traills. Even up close, lighting and viewing conditions really change impressions. In short, silent empids in the fall are like hot soup: handle with caution and be careful not to burn yourself, but after a little while they can be enjoyed quite thoroughly even if you don’t always know the exact ingredients.

Vireos

Finally, Philadelphia vs Warbling Vireos. What’s the deal with these guys? It seems like lately most eastern birders are getting better and better at looking for philly vireos. Phillys will always have the more colorful throat. Warbling vireos can certainly show some yellow in the body, but the sides will always contrast with the throat. The lores on warbling vireos is also said to be more pale than philly – to me it creates a more pale faced impression in warbling vireos. Overall, I also find philadelphia vireos to look ‘cuter’: a little darker head along with the head pattern popping out to create a distinct facial impression. Don’t worry warbling vireos, we all still love you.

Warbling vireo. Pale throat and belly with blank, pale face. (Photo by Steve Brenner, Rhode Island 2016)

Warbling vireo. Pale throat and whitish belly with some yellow sides and blank, pale face. (Photo by Steve Brenner, Rhode Island 2016)

Philadelphia Vireo. Compact, rounded face sporting dark lores. Yellow throat noticeable from the side (Photo by Steve Brenner, RI 2016)

Philadelphia Vireo. Compact, rounded, and less pale face. Yellow throat noticeable from the side (Photo by Steve Brenner, RI 2016)

Philadelphia Vireo. Look at the yellow all the way from belly to throat and how damn cute it is. (Photo by Steve Brenner, RI 2016)

Philadelphia Vireo. Look at the yellow all the way from belly to the throat and how damn cute it is. (Photo by Steve Brenner, RI 2016)

So go forth and bird the Fall like crazy my friends. You’ll probably love it.