Wednesday 27 December 2017

[cobirds] More chasing sites

I chased the Red-breasted Sapsucker near the Broadmoor Hotel expertly discovered by Mr. Tonnessen (thank you) on Christmas Day.  What a gorgeous bird in its northern race finery.  It appeared to me the bird had active sap wells (some chipped out right before our eyes) in ponderosa (the private residence e of Mirada), Siberian elm (private residence and along the fence of the golf course) and Scots pine (golf course).  The ones in ponderosa seemed to be its favorites (i.e. most productive) by far.  This was the first time I have ever watched a sapsucker chip out a new well and then see the golden resin appear down in this hole when the bird excavated deep enough into the phloem and outer xylem wood below the bark.  Doug Faulkner was the first to point out the long bill this bird has, 10% longer than we could remember other sapsucker species having.  This may be a fluke of this individual.  But if not, my first thought was this might have something to do with this species living in the Pacific Northwest where the trees can be huge and the bark might be thicker (that is, requiring a longer tool to get thru).


On Christmas at the Doubletree Motel pond near I-25 and the Lake/Circle Drive Exit in Colorado Springs (besides a Great White-fronted Goose) was a Yellow-rumped Warbler in pines near the lake.  The pines were full of aphids, probably Eulachnus rileyi (same species as was at the Twin Lakes phenomenon (Tennessee Warbler, Yellow-rumped Warbler, Nashville Warbler, Hammond's Flycatcher) in northeast Boulder, and probably the same aphid in pines utilized by the Black-throated Green Warbler found by Nick Moore in Boulder near Baseline/Broadway).


On 26 December I checked out the One Belmar Place apartments in JeffCo off Center south of Alameda where Prairie, Yellow-throated and Yellow-rumped Warblers have been reported in December.  Lots of the same aphid in the pines all around the pond in the apartment courtyard.  Some of these were collected yesterday - only a few mature aphid cadavers, mostly overwintering eggs lined up on the needles.  I saw no warblers yesterday but they could still be around.


Also at the same One Belmar Place apartments pond were several Redheads constantly diving for salad (and a non-diving Mallard hoping for kleptoscraps).  The greens are a species of pondweed (Potomogeton sp.) chronicled in "The Hungry Bird" column in "Colorado Birds" (issue 47(2) which was April 2013).  The ducks were definitely chowing down on the plant which might have been garnished by tiny amphipods called scud.  I notice Chris Wood also reported Greater Scaup here recently, which also might well have been eating the same items.


                                                                     


Key to the Pine Warblers in Loveland and Smokey Hill Village (Arapahoe County) of late seem to be suet feeders near pine trees (infested with aphids?). 


The Laporte Palm Warbler in mid-December is a dilemma.  What could it have been doing on the ground under a Russian-olive thicket and under kochia weeds in a field near the thicket feeding with juncos (on more than one day)?  My guess for the field would be cutworm larvae (aka miller moth caterpillars), and either freeze-softened olives or arthropods in the leaf litter for under the olive trees.


Prairie Warbler, Yellow-rumped Warbler, and Chestnut-sided Warblers in Pueblo (plus Blue-gray Gnatcatcher, Ruby-crowned Kinglet, Song and White-crowned Sparrows, not sure about the Varied Thrush) were definitely eating chironomid midges that emerged from the open water of the Arkansas River and roosted in good numbers on willows, other vegetation and park cars near the river bank.  One Bewick's Wren at Brandon's Prairie Warbler site was seen repeatedly inspecting vehicles.  At first I thought this was about the normal "grilled" insects on radiators favored by House Sparrows and others in summer.  But when I checked, midges were all over the end of these vehicles closest to the river.  These same midges were no doubt the secret to the successful, first-ever overwintering of White-throated Swifts near Pueblo Dam a few winters ago.


It has been a remarkable December in Colorado for rare birds, somewhat traceable to the reluctant retreat of warm weather and resultant presence of conspicuous insects in active stages other than those in which they normally overwinter.  How many more warblers are out there eating aphids in pine trees in business parks and apartment complexes, especially those with the safety net of feeders and open water in aerated ponds?  Would it be possible for one person to get 5 or more warbler species on 1 January 2018?  If so, would that be cause for happiness or alarm, or both?


Dave Leatherman

Fort Collins





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