Leon,
The bird in Jim's interesting photo appears to be using the icicle as access to the feeder. Whatever works.
Another twist on this theme is using icicles, especially those that form from the underside of tree branches, as a source of sugar-fortified water. In late winter particularly, I have seen icicles in maple trees being used as a source of nutrition by many birds and fox squirrels. These maple icicles, which I call "sapcicles", are usually darkest at the tip and have the hue of low-grade maple syrup. As sap rises in trees in winter and early spring, it tends to leak from bark cracks caused by winter freeze-thaw cycles and around swelling flower buds. When the temperatures are warm enough to cause leakage, followed by nightly freezing, sapcicles form.
Another source of sugary icicles is snow that melts from branches in trees chronically infested with aphids and other insects with sucking mouthparts like scales. These insects withdraw sap, utilize nitrogenous compounds in it, and secrete the rest which tends to be high in carbohydrates (aka sugars). This sugary excretion is called "honeydew". It falls and tends to coat the upper surfaces of anything below: branches, flared trunks or your car windshield. Snow deposits atop the honeydew. When it melts it becomes another source of sugary water that under the right conditions forms icicles.
Black-capped Chickadee is the species I have seen sipping from the tip of sap and honeydew enriched icicles most often, but probably many species do so.
Dave Leatherman
Fort Collins
Sent: Thursday, January 19, 2017 11:37 AM
To: Cobirds
Subject: [cobirds] House Finch perched on icicle - Otero county
COBirders-- Today Jim Thompson of La Junta sent me the photo below. My memory is undependable so when I say I haven’t seen a bird perched for any length of time on an icicle, I’m asking whether this is as rare as I think it is.
Leon Bright, Pueblo
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