[Tweeters] Part 2, Wintering Anna's Hummingbirds... from retired University of Oregon ornithology instructor

Wild Birds Unlimited of Eugene eugenewbu at gmail.com
Fri Dec 14 23:45:19 PST 2018


Part 2 of Dan Gleason's article:

*Anna's Hummingbirds' Movements: *Anna’s Hummingbirds are the only
hummingbirds north of Mexico that do not migrate latitudinally: north to
south. Since they are in various places within their range all year long,
it is easy to assume that the birds at your feeders during the spring and
summer are the same birds you see in the winter. Many studies now show that
that may not be the case: many birds may move about during different parts
of the year. There is much about Anna’s Hummingbirds and their movements
that we still do not know, but it is clear that many populations do have
annual movements, which may vary from population to population. There are
Anna’s Hummingbirds in southern California that move eastward into the
mountains after breeding. Some populations in the central portions of
California may be sedentary, but others may wander to unknown areas.
Migratory movements of birds north of California are largely not
understood; some appear to move eastward and it’s thought that some move to
coastal areas. Aside from whole populations moving, individuals are known
to move to different locations from season to season. So don’t assume that
if the number of hummingbirds at your feeders diminishes over the course of
the winter that it means some birds have died. It is much more likely that
individuals have simply flown off to a different location.



*Activity Changes: *After breeding and after juveniles have fledged, many
people see a decrease in activity at their feeders. From mid to late
summer, this may be in part because there remains an abundance of flowers
and insects available and feeders are less important. But, it could also be
because some of the birds have left your area and moved to a different
location. Birds returning in late summer to fall may actually have bred
elsewhere and have only recently found your feeding station. They may stay
through the winter or they may move elsewhere later.



*Erroneous Assumptions? *Additionally, assuming that cold weather has
killed many Anna’s Hummingbirds is likely an erroneous assumption in most
cases. These are very hardy birds that are able to survive very cold
weather remarkably well. Not many years ago, there was a period of
prolonged sub-freezing temperatures in Eugene, Oregon. There was fear that
many hummingbirds would die from the cold and decreased food supply.
However, just a couple of weeks after the bitter cold ceased, the annual
local Christmas Count found a record number of Anna’s Hummingbirds. So
these birds survived quite well. During cold weather, hummingbirds may
depend on feeders more than at warmer times, but other foods are still
found and relatively few birds are lost.



If you keep your feeder up, fresh with nectar, making sure it does not
freeze in extremely cold weather may be important at that time. Such
conditions are hard for the birds to survive for long periods of time.
Using a heated feeder that keeps the nectar from freezing is often a good
idea in really cold weather. Other ways to be sure your nectar doesn't
freeze include having two feeders on hand then swapping them before dawn
works, thawing nectar each morning and replacing it before putting a thawed
feeder out, putting a heating device near the feeder, like a shop light or
Christmas lights, are all known strategies for making sure the nectar
doesn't freeze. There is even a hummingbird feeder heater called the *Hummer
Hearth*, designed and made by a retired Northwest engineer that keeps the
nectar from freezing.



Enjoy the hummingbirds that come to your yard, but do not mistakenly think
your knowledge or ideas are superior to Mother Nature’s, when she has made
sure that hummingbirds have expanded their range without much help from
well-meaning but misguided humans.



Dan & Barbara Gleason

eugenewbu at gmail.com
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