Tuesday, September 8, 2020

Black-crowned and Yellow-crowned Night-Herons


Who am I? (Photo: Dan Irizarry)
Night-herons are a group of waders named for their nocturnal hunting habits. There are seven extant species of night-heron, with two regularly occurring in the Americas: Black-crowned Night-Heron (Nycticorax nycticorax) and Yellow-crowned Night-Heron (Nyctanassa violacea).

While the Black-crowned has a global distribution (range map), the Yellow-crowned is restricted to the Americas (range map).  In the USA, the Yellow-crowned is found mostly in the eastern half of the country, whereas the Black-crowned can be found in some part of every state except Alaska. Both species are prone to wandering outside their core range, especially during migration and post-breeding dispersal.

These two species are unmistakable as adults, but a little trickier to identify as juveniles. Luckily, even their silhouettes are distinctive. This article discusses how to differentiate the species by their proportions and shapes, then describes three categories of plumage you may encounter: adult, juvenile, and a variable "teen" plumage. We also touch on a few other species of herons that might be confused for a night-heron.

Wednesday, December 13, 2017

Sharp-shinned and Cooper's Hawks


Fig. 1: Who am I? (Photo: Jerry McFarland)
The Sharp-shinned Hawk (Accipiter striatus) and Cooper's Hawk (Accipiter cooperii) are two closely related birds of prey, and pose an identification challenge that some ornithologists used to consider unsolvable.

These two species belong to the genus Accipiter, which contains about 50 other species worldwide. Only one other accipiter, the Northern Goshawk, is found in the USA and Canada. Accipiters' short, rounded wings and long tails are well-adapted for maneuvers in forested habitats.

In today's post we'll discuss how to differentiate this duo while perched; many of these traits can be used for in-flight ID as well. One of the most important themes in this post is that no field mark is reliable on its own. Thus, let a majority of traits lead you to an identification. If there's no majority, it's better to be uncertain than inaccurate!

Monday, October 2, 2017

Bay-breasted & Blackpoll Warblers

Fig. 1: The dynamic duo. Blackpoll (top) and Bay-breasted (bottom)
For North American birders, Blackpoll Warbler (Setophaga striata) and Bay-breasted Warbler (Setophaga castanea) are the quintessential "confusing fall warbler" pair.

A few diagnostic traits immediately separate the species. Even without seeing these field marks, a first impression of color and contrast is telling. Of course, as with any identification, it's best to observe the bird carefully, collecting as many traits as possible before making the call.

Tuesday, September 26, 2017

Welcome

Physicist Richard Feynman occasionally remembers, with frustration, his father's efforts to teach him the names of local birds. "When you know all the names, in every language, of a bird, you know nothing, absolutely nothing, about the bird. . . . Names don't constitute knowledge."

"Looks like a Homo sapiens.
That's new for the day."
We might dismiss Feynman's opinion--after all, he was no great naturalist!--if we didn't find some truth in it. Don't all seasoned birders worry that our hobby sometimes reduces these complex and awe-inspiring creatures to mere ticks on a list?

But Feynman's early skepticism proved to be an obstacle to discussing theories with his name-savvy colleagues. "What my father forgot to tell me is that knowing the names of things is useful if you want to talk to somebody else."

...or if you want to contribute to a citizen science project, or look up a topic in an encyclopedia, or take a bird to the appropriate wildlife rehabilitation center after it collides with your woefully unprotected windows.

At the very least, bird identification is an enjoyable puzzle. But I contend it is crucial to the study and conservation of our favorite things with wings. I'm constantly looking to improve my own ID skills, in hopes that they make me a better contributor to and advocate for bird conservation.
A chickadee--Black-Capped or Carolina? 
It matters more than you think

And you know what they say--the best way to learn something is to teach it!

Thus, in "Wing Tips" I share and aggregate knowledge about bird identification challenges, learning new things all the while. This blog includes tips and tricks (call them strategies) to identify North American bird species, especially those found in the northeastern US. Occasionally, it discusses bird conservation trials and triumphs.

I hope that you find this blog informative! Please leave a comment if you have a suggestion for an ID challenge to cover, or would like me to identify a bird you saw. I also welcome additions and corrections on all my posts.

Warmly,
Tessa Rhinehart