Subject: [Tweeters] Woodpecker feeding roles
Date: Jul 8 18:59:35 2010
From: Jeff Kozma - jcr_5105 at charter.net


To add to Steve's great comment, from my observations of nestling feeding by Hairy and White-headed Woodpeckers, it appears that adult's don't alternate feeding (male, female, male, female, etc.) as I had expected. Mostly I have recorded that one sex will make multiple visits over say 30-40 minutes, and then the other adult comes with food and the one feeding leaves with the just arriving adult then making multiple visits. I believe that this allows the other bird to go off and forage for itself as feeding nestlings for multiple trips can get be quite demanding. Only when there are 3 or more chicks in the nest do both adults seem to return more often to the nest with food, with less individual time away, probably because of the increased demands of multiple beaks to feed.

Another thing I have found interesting is that I expected Hairy Woodpeckers to bring back substantially more wood boring beetle grubs (Cerambycidae) than White-headed Woodpeckers, as Hairy's are more adapted to excavating these tasty (I'm guessing) morsels from beneath bark. But, (although I have not analyzed my data yet), it appears that White-headeds bring back wood boring grubs with nearly equal frequency as Hairy's. Watching White-headeds bring back food has been enlightening and they actually have quite a varied diet. One male was particularly adept at bringing back moths for its young. Other interesting prey items have been crickets (Jerusalem brown type), mayflies, large flies (some with a large flesh colored abdomen), cicadas, caterpillars, spiders, beetles, and even a wasp. Interestingly, most birds I have witnessed capturing moths or butterflies remove the wings, but the woodpeckers bring it all back and just shove it in! The most frequently brought back prey item by both species is ants. It will be interesting to analyze my data this fall to see what the 2 years of feeding rate data completely reveal.

I also want to point out that male woodpeckers are really good Dads! They do most of the incubation (alternating by day and completely at night), alternate brooding young during the day and entirely at night, appear to do a greater portion of the nest sanitizing (removing fecal material), and do their fair share of feeding.

Jeff Kozma

Yakima

jcr underscore 5105 at charter dot net
----- Original Message -----
From: Stephen Shunk
To: tweeters at u.washington.edu
Sent: Thursday, July 08, 2010 10:51 AM
Subject: [Tweeters] Woodpecker feeding roles


Hello Tweeters,
I'd like to add one thing to Wayne's comments on Brenda's inquiry about Williamson's Sapsuckers feeding young.


Some woodpecker parents of nearly all N. Am. species will often split their foraging niches when feeding young (or all year). In some cases, this means one adult will collect food for nestlings close to the nest, collect fewer morsels per outing, and deliver more often, while the other adult collects larger beaksful farther from the nest, making fewer visits. This may be why you did not see the female but saw the male multiple times.


In other cases, the adults might split the canopy horizontally, with one feeding higher and one lower. Still another scenario is for the adults to split the size of the feeding substrate, i.e. one adult on the branches and one on the trunks. This has been particularly well documented in Downy Woodpeckers, both in and out of the breeding season.


For those of you who like scientific jargon, this is called sexual niche partitioning!


Happy woodpeckering,
Steve Shunk


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Message: 12
Date: Tue, 6 Jul 2010 07:46:52 -0700
From: Brenda Burnett <beaknbird at hotmail.com>
Subject: [Tweeters] Williamson's Sapsucker question
To: <tweeters at u.washington.edu>
Message-ID: <BAY149-w94231BD04661393A7302AB1B20 at phx.gbl>
Content-Type: text/plain; charset="iso-8859-1"


Hi Tweeters!

Yesterday on a hike to Bean Creek Basin, we got to watch what looked like a male Williamson's Sapsucker coming and going to a nest hole in a snag, feeding a very noisy brood. Would the male be doing this? I can't think what species' female would look like that: roughly the size of a Hairy Woodpecker, solid black back and tail, white horizontal marks on head/face, big solid white patch along each side. Didn't get a good look at the front throat/belly. We watched it when we went up the trail and again when we went down. Didn't see a female at all, tho' she might've been in there with the babes (?). So that's my question...would a male Williamson's be doing the busy feeding job?

Also seen:
dozens of Western Tanagers (one almost mistook me for a perchable tree branch)
American Dippers
flycatchers galore (unfortunately silent)
Yellow-Rumped Warblers in full breeding plumage
Chipping Sparrows (many!)
Hermit Thrushes
Cassin's Finch
Black Swifts
Lincoln's Sparrows
Mountain Chickadee
Golden-Crowned Kinglet
Lazuli Bunting (I think...)


Brenda Burnett

Seattle

beaknbird at hotmail dot com

--
Stephen Shunk
Paradise Birding
Sisters, OR USA
www.paradisebirding.com
541-408-1753



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