[Tweeters] Wintering Anna's Hummingbirds... from retired
University of Oregon ornithology instructor
ucd880 at comcast.net
Sat Dec 15 08:11:30 PST 2018
Hummingbirds (probably Anna's because of the time of year) have been observed feeding on and around salmon carcasses. It was not determined if they were catching small bugs or eating something derived directly from the carcass. Just another food source they exploit when available.
ucd880 at comcast.net
> On December 14, 2018 at 11:41 PM Wild Birds Unlimited of Eugene <eugenewbu at gmail.com> wrote:
> This is part 1 of an article, written by Daniel Gleason, retired University of Oregon Field Ornithology instructor, in response to the forwarding of remarks on Tweeters that recently were published.
> Anna’s Hummingbirds: Surviving Winter…At one time, Anna’s hummingbirds ranged from northern Baja California north to the San Francisco Bay area. Over the past 100 years, their range began to expand north and east, and they are now found as far north as southern British Columbia and along the coast into southern Alaska. The eastward expansion has taken these birds into western Texas. Northern populations (Oregon and north) have slowly expanded eastward in recent years, and are now found in Boise, Idaho, in winter.
> Range Expansion: It is not known for certain all factors that prompt birds’ range expansion but it is thought that, begun, an increase of exotic plants aided the Anna’s Hummingbirds’ expansion. They were already seen year-round in California but much of the land east of California did not have supportive plants and habitat. As white settlers moved into these lands, they planted exotic plants, many which proved attractive to Anna’s Hummingbirds, both in terms of providing nectar as well as attracting insects that the birds could also eat. Much later, it people began to put out and maintain hummingbird feeders.
> Food Needed: But, all hummingbirds need more than just nectar to survive. They need proteins and other micronutrients that they get from insects, eggs on plants, and spiders, all an important part of their diet.
> People mistakenly assume that insects and spiders are not available during the cold winter months, but that is not the case. Actively flying insects are dramatically reduced during long cold periods, but many other insects can be found, and birds find over-wintering egg masses and larvae. We large humans are not good at noticing such small insects.
> Studies of captive Anna’s Hummingbirds show that they can exist on pure sugar water for 10 days, but they show significant weight loss. So more than sugar is needed and these other nutrients come from insects, spiders and their eggs throughout the year.
> Recently, in Washington, a couple of individuals have tried adding all manner of unresearched and untested products (baby formula!) to hummingbird feeders. Unless you have conclusive, scientifically-researched, proven data to support the beneficial use of such products, do not use them! If you care about hummingbirds, attempting to provide extra nutrients besides nectar is to possibly put the birds at risk!
> Why? Hummingbirds have very tiny bodies and providing even small amounts of micronutrients could be far in excess of what is needed. The quantity of such nutrients (boron, copper, etc.) would have to be measured in 10-thousandths of a gram. To weigh out such a small amount requires an analytical balance costing several thousand dollars—not something you have around home. Such small quantities are easily obtainable in a hummingbird’s daily diet, even in winter’s cold. Proteins are also obtained daily from the insects and spiders. Providing more is completely unnecessary and the excess could put the birds at risk. These products contain food ingredients humming birds would never come in contact with, and could in fact, cause poisoning to the birds due to their tiny bodies being unable to process these substances.
> Dan & Barbara Gleason
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