Teachers’ Lounge

Bird Vocalization of the Month: Allen’s Hummingbird

by ocarmi on Feb. 26th, 2009 2 Comments

February species: Allen’s Hummingbird
Scientific name: Selasphorus sasin
Sounds: Anna’s song, Rufous’s buzz, Anna’s wing whirr
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Male Allen's Hummingbird
Male Allen’s Hummingbird, Selasphorus sasin

Photo credit: Sgrace

It is misleading to refer to this month’s blog entry as “Bird Vocalization of the Month.” The sounds I will focus on this month aren’t exclusively vocalizations. To add to that, it is probably unfair of me to refer to just one bird, because I will be discussing three!

I was walking across campus the other day, when I was stopped by a familiar sound I had not heard in a while—the buzz of a Selasphorus hummingbird.

Selasphorus (pronounced “sell-LASS-for-riss”) is a genus of hummingbirds, of which two species occur in the Bay Area. Birdwatchers use the term Selasphorus because the two species, Allen’s and Rufous Hummingbirds, are difficult to tell apart.

The reason I had not heard the buzz in a while is that Selasphorus Hummingbirds do not occur in the Bay Area year round. Allen’s Hummingbirds (Selasphorus sasin) breed in the Bay Area, and arrive by late January/early February. By late July they’ve all left for the “winter.” Rufous Hummingbirds (Selasphorus rufus) breed as far north as Alaska(!), and only migrate through the Bay Area. The first Rufous Hummingbirds to migrate north through the Bay Area do not appear until April or so, and on their move south, young birds (the last to migrate) do not start appearing here until the Allen’s Hummingbirds are all but gone. Thus, given the date, the Selasphorus hummingbird I encountered on campus was probably an Allen’s Hummingbird.

Male Rufous Hummingbird
Male Rufous Hummingbird, Selasphorus rufus

Photo credit: Rick Leche

A third species of hummingbird common in the Bay Area—the Anna’s Hummingbird (Calypte anna) —is found here in great abundance year-round.  Anna’s and Selasphorus hummingbirds look very different. Male Anna’s Hummingbirds, as shown below, are mostly green with an iridescent rose-red gorget and crown. Females are green, without the rose-red. Selasphorus hummingbirds, as shown above, are mostly green and rufous, and males have a brilliant orange-red gorget.

It was fun for me to learn to recognize the sounds produced by our local hummingbirds, because when I first heard them, I found them to be quite bizarre! For example, the song of the Anna’s Hummingbird sounds to me like a squeaky bike. The Cornell Laboratory of Ornithology’s All About Birds site links to a recording of an Anna’s Hummingbird song.

anna's hummer
Male Anna’s Hummingbird, Calypte anna

Photo credit: Len Blumin

The song of the Anna’s Hummingbird, and similar vocalizations of other hummingbirds, are produced in the syrinx—the vocal organ of birds. However, hummingbirds don’t produce sounds only by vocalizing. The buzz I heard while walking across campus was produced by the wings of the Allen’s hummingbird I encountered—males of Selasphorus hummingbirds have modified wing feathers that make this sound possible. Different species of hummingbirds have distinctive buzzes. For instance, check out a recording of the buzz of an Rufous Hummingbird, and compare it with the wing whirr of an Anna’s hummingbird (both recordings copyright NatureSongs 1997-2008).

The buzz or whirr caused by the wings of a hummingbird is a useful first cue that a hummingbird is present. If you hear a hummingbird buzzing, it is well-worth stopping and trying to spot it, because it is possible you may then be treated to a display dive! Display dives are used by males to attract females, or to ward off competing males from their fiercely protected feeding territories.

Each species of hummingbird has a distinctive dive pattern, which can be used to identify it. The display dive of an Allen’s Hummingbird consists of a series of swings, each one accompanied by an eerie, wheezy sound, followed by a high dive accompanied by a louder wheezy sound. The display dive of an Anna’s Hummingbird consists of a bout of singing in mid air, followed by a vertical rise and a fast J-shaped dive. There is a loud “pink” at the bottom of the dive. This entire display is then repeated multiple times. Researchers have long debated whether the beep (the “pink”) at the bottom of the dive is a vocalization or whether it is produced mechanically. Two researchers from the University of California, Berkeley, Dr. Christopher Clark and Teresa Feo, recently showed definitively through the use of a high-speed camera and some elegant experiments that this sound is produced by the tail of the hummingbird!

Your homework assignment: Listen to the recordings of these hummingbirds—especially to the wing buzzes and whirrs. See if you can notice these buzzes while spending time out of doors—you may be treated to an unsolicited hummingbird sighting!

2 Comments So Far

  1. Daniel Kreeger and Mom on May. 24th, 2009 at 7:31 AM

    We saw the most extraordinary hummingbird this morning. I had never seen it, but my kindergartner said he was very close to one in Sacramento…(he says “I was so close and it was so cool”) it was completely black, but for a bright red head. Anyone know what we saw? Thanks!

  2. ocarmi on May. 29th, 2009 at 1:00 AM

    Dear Daniel Kreeger and Mom!

    Thank you for your observant comment. I’ve replied in a new blog entry.

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