[cobirds] Re: recent observations related to food

Forgot to add the photos.  Sorry,

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From: DAVID A LEATHERMAN
Sent: Tuesday, March 14, 2023 12:43 PM
To: COBIRDS <cobirds@googlegroups.com>
Subject: recent observations related to food

 

COBIRDERS,

1) We have seen a rather remarkable influx of Cassin's finches to the lower elevations of the Front Range just east of the foothills this winter.  Almost all the individuals I have seen, and this is backed up by reports on COBIRDS and eBird, involve brown-striped females or immatures.  I believe the resource initially attracting/supporting this phenomenon last fall is a heavier-than-normal green ash seed crop.  Of late I have noticed finches continuing to exploit the still-plentiful ash seed crop, but many are now also feeding on the bulging flower buds of both Siberian and American elm.

2) In spring the sap rises in deciduous trees.  Maples are the poster child for this.  In Colorado two common species of maple, silver maple (Acer saccharinum) and boxelder (A. negundo) are common.  Silver maple is a non-native that was heavily planted because it is fast-growing but that is now generally not highly regarded by tree people because it is weak, prone to breakage and short-lived.  Boxelder is a native but on the "banned" list for planting in some towns because it attracts boxelder bugs that can be a nuisance when they invade homes to overwinter.  Drawbacks aside, both trees tend to leak sugary sap from branch crotches and bark cracks at this time of year and birds partake.  Of late I have seen one neglected, decidedly unattractive sapling silver maple provide sweet liquid to juncos, house finches, Cassin's finches, black-capped chickadees and bushtits.  Oh yes, and fox squirrels.  The photo below shows a bushtit getting sap oozing from wounds a squirrel made to enhance the flow.  It reminds me of what we see with hummingbirds and a whole host of other animals from flies and butterflies to bobcats drinking from the faucet provided by the three sapsucker species.  Location is Frey Avenue just east of Grandview Cemetery, Fort Collins.

  

3) I share a rather sad situation that involves avian flu and lawn fertilizer.  The photo below shows a Canada goose showing the glazed-over eyes (and staggering gait not apparant in the photo) of waterfowl succumbing to the flu, but it also shows a fertilizer pellet on the beak acquired by this goose during what might have been its last supper.  Location is Fort Collins City Park.

  

4) I am curious as to whether anybody has seen the yellow-throated warbler presently being seen along Bear Creek in Denver feed on the roof, walls or other areas apart from feeders of the apartment complex frequently mentioned in reports.  Also, if that bird is visiting feeders, does anybody know what is in the feeders?  I am assuming suet or suet cakes enhanced with seeds, with suet being the real attraction.  The situation sounds very similar to one we had here in Fort Collins a few winters ago when the combo sustaining the yellow-throated warbler thru the winter was both suet and arthropods it was getting from the roofs and walls of houses near the feeding operation.

5) Lastly, has anybody seen Bohemian waxwings during the current invasion eat anything other than juniper berries, buckthorn berries, Russian-olives and crabapples?  The list of potential fruits this bird eats is large but every report and photo I've looked at only involves these four things.  

Thanks.

Dave Leatherman

Fort Collins