Marsh Wren, Douglas

[Hugh Kingery]

This morning Urling and I walked the Cherry Creek trail, north from the North Pinery parking area. Before we started we guessed at the species total: I said nine, she said fifteen. Two hours later we returned to the car with 12 species -- and then four Rock Pigeons flew over to bump the list up to 13 species.

Two observations of note: we scanned a tree on the west side of the stream that had nice-looking raptor nest in it, and noticed a Red-tailed Hawk perched on the other side of the tree. Going back, an hour and a half later, we saw the hawk perched in the same place. Protecting the nest from Great Horned Owls perhaps?

Then we listened, for 25 minutes, to a singing Marsh Wren. When we walked by the singing post at 10:30, we heard nothing. Twenty-five minutes later, the wren had launched into full gear: it sang for 25 minutes straight before we started the trek back to the car. Just before that, Urling spotted another Marsh Wren a couple of hundred yards downstream and later she encountered one upstream a quarter of a mile or more. Meanwhile our singer chattered on and on. We stood within 10 feet of the bird and never had a glimpse -- not even any movement.

Why would a Marsh Wren sing so incessantly in November? Do they set up winter territories? Do they simply feel jubilant? Did the singer want to exclude the other wrens from his bailiwick?

Hugh Kingery
Franktown, CO

[DAVID A LEATHERMAN]

Hugh et al,
In response to your question, observations reported on COBIRDS over the last few months, and my own observations, I checked the "Birds of North America" account on Marsh Wren to see what it says about autumn-early winter singing.  While not mentioning November, it did say that juveniles practice a lot of vocalizations in the autumn period ("thru October" according to the account).  Maybe that is the best guess regarding all this Marsh Wren song of late.

Dave Leatherman
Fort Collins

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Date: Sun, 15 Nov 2015 19:25:19 -0500
From: cob...@googlegroups.com
To: dougl...@googlegroups.com; cob...@googlegroups.com
Subject: [cobirds] Marsh Wren, Douglas

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[Scott Somershoe]

A friend of mine just sent me the link below about this exact topic. Food for thought. This is something I've wondered about for years. 

http://www.scilogs.com/maniraptora/why-do-songbirds-sing-in-the-autumn/

Cheers,

Scott Somershoe 

Littleton CO

Sent from my iPhone

To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/SNT148-W647DE22F5CD68DDF05F4FFC11E0%40phx.gbl.

[DAVID A LEATHERMAN]

Scott et al,
I found this discussion very interesting.  I wonder which, if any, of the three known drivers of autumn song presented in the SciLogs piece apply to Marsh Wrens?  Since the great majority of Marsh Wrens are migrants, it doesn't seem like the answer would be early selection of next spring's breeding territories (like Starlings or House Sparrows).  Since they don't hang around, at least most of them, and certainly not in flocks, maintenance of social structure doesn't seem to fit (as in photorefractory, flocking species like White-crowned Sparrows).  The production and activation of testosteronelike hormones, such as has been discovered in some species with DHEA, might be happening with Marsh Wrens.  But again, most of them are not year-'round resident individuals as in the cited case of Song Sparrows.  "Song practicing/perfecting" by birds of the year mentioned in the Marsh Wren BNA account but not mentioned in the SciLogs article seems to be a fourth possibility.  Hugh has told me about dipper adults singing to youngsters about to fledge in what seems to be singing "lessons".  Wrens and dippers, at least as currently construed, are fairly closely related.  Maybe some of the autumn Marsh Wren song we hear is adults giving lessons for the benefit of young birds prior to migration, AND young birds repeating it back prior to migration, trying to get it right months prior to their first crack at breeding next spring?

Other birds doing a lot of singing of late, some of them mentioned in various posts on COBIRDS, are Western Meadowlarks (which, similar to Marsh Wrens, mostly migrate out of Colorado), migrating American Robins, Brown Creepers freshly-arrived at low elevation from higher elevation, and certainly Townsend's Solitaires setting up winter territories.  Northern Shrikes sing a lot right after showing up at this time of year, which also seems to be a winter territory thing.  I have always wondered if there is an "exuberance" factor associated with barometric pressure and/or impending big events like migration, that triggers singing in birds.  We've all seen it - days when large numbers of birds are together but basically quiet, and days when they seem "juiced up" and hyper.  What is going on in these situations?

Probably a mixture of mechanisms at work here, especially considering all the species we hear singing in autumn, but Hugh's question and the SciLogs piece provided by Scott definitely have me inclined to pay closer attention to which species is singing where and under what conditions related to their seasonal status.  Long live COBIRDS.

Dave Leatherman
Fort Collins

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From: ssome...@gmail.com
Subject: Re: [cobirds] Marsh Wren, Douglas
Date: Sun, 15 Nov 2015 20:12:26 -0700
To: cob...@googlegroups.com

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