Hello Tweeters,

All of the postings about the Golden-crowned Kinglet (GCKI) have been
fascinating and at the prompting of Bruce's posting, I decided to seek some scientific information, which I have
posted below. I searched The Birds of
America Online at the Cornell Lab of Ornithology, which I have found to be an
invaluable resource in helping me write the Bird of the Month column for the
Eastside Audubon newsletter The Corvid
Crier. For a small annual fee you
can have complete access to an incredible amount of information about birds. If
you join Project Feederwatch and send in reports from your feeders, you get a
benefit of free access to The Birds of America Online. Everyone gets 3-4 visits at no charge.

I copied out part of the section on Food Habits. It seems we are seeing some normal winter feeding behavior, but the Morse study indicates other species may play a role in where GCKI forage.


Andy McCormick, Bellevue, WA


The Birds of America Online



Golden-crowned Kinglet Regulus
satrapa

Authors: Ingold, James L., and
Robert Galati



Food Habits

Feeding

Main Foods Taken

In winter: small, soft-bodied arthropods (insects, mites,
and spiders) and their eggs; small amount of vegetable matter. In breeding
season: same as in winter, but probably no vegetable matter.

Microhabitat For Foraging

Gathers food from tips of branches, under bark, tufts of
conifer needles, and trunks of spruce, fir, and pine trees; may also forage on
ground. Hovers and gleans in canopy from 2 to >8 m (Sabo and Holmes 1983). In winter, uses branches
and dead leaves in brush, understory, and tall trees in branches from tip to
trunk (Lewke 1982, LaGory et al. 1984). High niche overlap with
Black-capped Chickadee (Parus atricapillus) and Ruby-crowned Kinglet (LaGory et al. 1984).

Food Capture And Consumption

?Sabo (1980) analyzed 14 niche variables for individuals
foraging in subalpine forests in New Hampshire. Leaf-gleaning, leaf-hawking,
and twig-gleaning were the 3 most common maneuvers used; individuals foraged
equally near trunk and on perimeter of tree; most foraged in coniferous
foliage, occasionally on broadleaf trees and forest floor; individuals never
foraged in herb layer; foraged equally in midstory (2?5 m) and midcanopy (5?8
m), occasionally in upper canopy (>8 m), but rarely in understory (0.1?2 m).
? In w. Sierra Nevada, CA, individuals foraged mostly in foliage of white fir
and sugar pine (Pinus lambertiana) by gleaning, less commonly by lunging
or hovering (mostly at height of 5 m), showing high niche overlap with
Chestnut-backed Chickadee (Parus rufescens; Airola and Barrett 1985).

Foraging sites may be affected by presence of other
species?e.g., Tufted Titmouse (Parus bicolor)?which force this species
to forage lower in deciduous forests and, while in mixed forests, to move out
of conifers and into deciduous trees (Morse 1970). In presence of large numbers of
Carolina Chickadees (Parus carolinensis), this species moves to tips of
foliage and feeds mainly by hovering (Morse 1970).


From: BBPaige at nikola.com
To: tweeters at u.washington.edu
Date: Fri, 14 Jan 2011 19:59:54 -0800
Subject: [Tweeters] Golden-crowned kinglet behavior.

I've seen the described tame, intent, ground-feeding behavior dozens of times this winter since November,
in many different situations and conditions, cold, wet, windy, calm, sunny, morning, afternoon, late evening,
and have observed the kinglets actively picking tid bits (insects?) out of the grass and off leaf litter,
plus making aerial forays from the ground up for short distances.
I also tend to think these small birds are benefiting from some very small, abundant food items that are an
important winter food source. Is there something somewhere in research data or literature about this behavior?

Bruce Paige
Sequim