A Song for August 10

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The Wrentit is said to be the most sedentary bird in North America. For evidence in favor of that conjecture, map all eBird sightings of the species and zoom in on the mouth of the Columbia River. The Wrentit is thick on the Oregon side, absent on the Washington side. Apparently this bird is unwilling or unable to fly across the Columbia River. But, its range has expanded in the past century. It's one of the suite of California species that have made Oregon their home, along with the Black Phoebe and Red-shouldered Hawk. It has done this with the small relocations of natal dispersal, whereby fledged young leave home, but settle as close by as availability of suitable habitat allows.

A mated pair of Wrentits defend territories year round, but I always noted an uptick in vocalizing in late summer on our place outside Eugene, Oregon. That's easy to do, because most species go silent in August. I hypothesize that August is when dispersing young are moving through, looking for a place to settle. Vocalizing is a good way to let intruders know a patch of ground is taken. Wrentits have an accelerating song, which carries well, and then they have this ratchet call. It's about the "driest" bird sound I know. I love to hear it though. Wrentits are seldom seen. Not being a wrentit looking for a place to settle, I am always happy to be reminded they are there.


In writing the commentary for these posts I have made extensive use of the invaluable bioacoustic resources listed below. For phylogenetic information, I often start with a web search of "Phylogeny of x," where x is an avian genus, family, or order. That is a hit-or-miss proposition. A recently-released resource that makes phylogenetic queries more systematic is the Birds of the World website from the Cornell Lab of Ornithology. If you follow the link and type the name of an avian family into the search box, you will be able to visit a home page for that family that presents the number of genera and species, and an illustration for each genus. If you subscribe, you will get more information. Also available to subscribers is the Birds of the World species accounts. Rolled out in 2020, this is currently an amalgam of the Birds of North America series, that was initiated by the American Ornithologists' Union around 1990, a recently-initiated online equivalent for Neotropical Birds, and the Handbook of Birds of the World series that was produced by Lynx Edicions, also beginning in the 90s. BNA has been hosted by the Lab of O for some time, and they recently added HBW to their portfolio. Especially useful for my purposes is the Systematics History subsection of the BNA accounts. EBird still has its separate species pages for all the birds of the world. These feature photos, recordings, range maps, and numerical eBird statistics, but little text. Overall, the abundance and availability of resources is astounding. Never has so much been available to so many for so little.

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Email: web at archmcallum.com

Nathan D. Pieplow. 2017. Peterson Field Guide to Bird Sounds of Eastern North America. Houghton Mifflin Harcourt.
Nathan D. Pieplow. 2019. Peterson Field Guide to Bird Sounds of Western North America. Houghton Mifflin Harcourt.
Donald Kroodsma. 2005. The Singing Life of Birds. Houghton Mifflin.