Eastern and Western Blue-gray Gnatcatchers

The Blue-gray Gnatcatcher sounds different in the West than it does in the East. However, the differences in song are not well understood by most birders, nor particularly well described in most field guides. [Read more]

Fox Sparrow, Part 2: Alarm & Contact Calls

In my last post I promised a discussion of Fox Sparrow alarm and contact calls, and it’s time to deliver on that promise. [Read more]

Fox Sparrow, Part 1: Flight Calls

Several recent genetic studies have provided evidence that four groups of Fox Sparrows have separate evolutionary histories and may deserve species rank. Some differences in call notes between the groups may have bearing on their identification and taxonomy. [Read more]

The Next Junco

A paper that I wrote with Clint Francis, published this month in the Wilson Journal of Ornithology, shows that one isolated population of Yellow-eyed Juncos sings quite differently from its relatives in mainland Mexico. [Read more]

More Than Just Snap, Crackle, and Pop

When it comes to sounds, the White-crowned Manakin (Pipra pipra) isn’t the most interesting of the family. Its displays are mundane compared to, say, Long-tailed Manakin. And the mechanical sounds made are limited and mostly simple. But it does appear to have a plethora of distinct vocal types that may well correspond to different species, despite the fact that they all look nearly or completely identical to each other in plumage. [Read more]

Sage Sparrow Subspecies

Guest post today by Walter Szeliga, who is starting to turn his audio recorder on some very interesting problems of identification and taxonomy. [Read more]

The “Western” Flycatcher Problem

In 1989, the American Ornithologists’ Union split the Western Flycatcher into two species: Pacific-slope Flycatcher and Cordilleran Flycatcher. The conventional wisdom is that they are impossible to identify by plumage or structure, even in the hand. Voice is the only field mark. However, the situation with their vocalizations is quite messy, and worthy of an in-depth examination. [Read more]

A Pygmy-Owl Challenge

Many people think that what we call “Northern Pygmy-Owl” may contain somewhere between two and four species, based on regional differences in vocalizations. Nobody knows exactly where the changes between these songtypes occur, or how abrupt they are, because we just don’t have enough data. Now, my friend Arch McCallum is setting out to get to the bottom of this tricky situation — and you can help. [Read more]

How Many Tuftedcheeks?

Recently, on a trip to Costa Rica, I was able to record the song of nominate Buffy Tuftedcheek. I was completely unprepared for how different it sounded from Pacific Tuftedcheek. I’ve posted a few cuts I got in Costa Rica on xeno-canto, and written a feature comparing them. [Read more]

Splitting Mountain Chickadee

The AOU’s North American Checklist Committee has posted a set of proposals currently under consideration. The biggest surprise is a proposed split of Mountain Chickadee into two new species, partly on the basis of vocalizations — but I’m rather skeptical of the reported differences. [Read more]