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.

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!

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.