A Snow Challenge

On Monday and Tuesday, our Seattle weather was cold. 

During warm weather, we have two species of hummingbirds in our area. However, only one, the Anna's Hummingbird, is here during the winter. (Our native Rufous Hummingbird works hard to avoid the snow. They can migrate thousands of miles, from as far as Alaska to Mexico.)

It seems rather ironic that the migrating behavior associated with the term, Snow Bird, does not apply to the species which ends up sitting in the snow. 

Unlike Snow Geese, Snow Buntings or Snowy Owls, which have developed a significant white coloring associated with their extensive snow experience, the Anna's Hummingbirds generally seem to avoid the snow and have minimal use for white feathering. 

Their primarily green coloring seems more fitting as camouflage for a jungle bird. According to Birds of North America (BNA - citation below), the first Anna's Hummingbirds arrived in Washington state in 1964. Historically, they were primarily California birds which migrated relatively short distances e.g. up into nearby mountains during the summers.  

The expansion of exotic winter-blooming plants (like this unique hybrid of Asian Mahonia in the Arboretum's Winter Garden) and hummingbird feeders can be partially credited with attracting Anna's Hummingbirds to the Pacific Northwest. However, population growth in California may have been the underlying driving factor. 

BNA says, about the California population, 'The combination of extensive nonnative plantings, particularly eucalyptus (Eucalyptus) and tree tobacco (Nicotiana glauca), plus widespread use of feeders, has undoubtedly played a major role in expanding populations of this hummingbird.'

Curiously, the current range maps for Anna's Hummingbirds are not perfectly aligned.

Birdweb's map for Washington state implies altitudinal and maybe some longitudinal migration. It shows breeding in the Puget Trough, primarily in heavily populated areas, and the birds moving up into the Cascades or out into less populated areas of Puget Sound during the non-breeding season. 

All About Birds overlooks this level of detail in Washington state. It shows breeding throughout the western portions of Washington, Oregon, California and southwest Arizona with latitudinal migration into British Columbia and Mexico. It also implies altitudinal migration in Northern California and Southern Oregon. 

Uncertainty is evident in comments from both sites. 

Birdweb says, 'In Washington, Anna's Hummingbird appears throughout the year. It is unclear whether this is due to migration or whether the birds we see in January are the same as those we see in June.'

All About Birds says, 'Unlike most North American hummingbirds, Anna's Hummingbirds either don't migrate or else migrate a very short distance to better feeding grounds.'

Could it be that, with their recent territorial expansion, the species has not yet settled on a single optimal pattern of migration? Maybe they will and maybe they won't. Life is dynamic, spell-binding and worthy of observation and study.

In any case, the Anna's Hummingbirds appear to be quite a competitive challenge for the Rufous Hummingbirds. The Anna's arrive at most breeding territories first and they spend less energy getting there. It is clearly to their advantage, as long as they can survive the winters.

Surprisingly, for a bird originating in California, Anna's Hummingbirds can enter a state of torpor, during especially cold weather. Looking closely at the bird from our first photo we can also see some behavioral adaptions to the cold. For example, the fluffed feathers and the eyes partially closed, both of which may help to retain heat.

Regarding a scientific temperature test BNA states, 'The torpid birds were inactive, feathers fluffed, eyes closed, bill pointed upward; 90 minutes were required for an immature, injured bird to enter torpor at an ambient temperature of 2 (degrees) C...' 

During the snowstorm, our outdoor temperature was in the same range, however, I did not see any hummingbirds which appeared to be in torpor. Most likely this was because there was an adequate supply of food, which provided sufficient energy to combat the cold. I did notice one other curious potentially, cold-related behavior, e.g. the whitish accumulation of nectar near the end of the bird's bill.

Occasionally, I also saw hummingbirds with their eyes fully closed, but it was the nectar that I found most thought-provoking. I cannot remember any avian species which allows its bill to get 'dirty' and stay that way. Cleanliness is critical to the health of almost all birds.

During the snowstorm, I also saw more male hummingbirds than females. Mature males have the dark hoods which reflect brilliantly when they are at just the right angle. They also tend to be more aggressive and territorial.

In addition to the whitish spec on the bill, the color of the tail feathers on Anna's Hummingbirds are also worth observing.

Sporadic red reflective feathers about the head - where the 'hood' will ultimately develop - are generally an indicator of an immature male.

Distinguishing young males from adult females can be tricky. Females generally only have red reflective feathers on their throats, although exceptions are possible. Since young males can sometimes reflect primarily from the neck area certainty is not always possible.

One exception is during the nesting season. You can be virtually positive that a bird with neck-only reflectors while sitting on a nest, is female. Males, and especially young males, do not normally participate in brooding.

Do these tail feathers differ from those you noticed earlier? 

Mature females have progressively larger white spots on the terminal ends of their outer tail feathers. Although, even here, immature males can sometimes have somewhat similar coloring. 

This final set of photos were taken, on Thursday, after the snow melted,

In these next three photos, the hummingbird was perched on the same branch as the male bird during the snowstorm (in photos six through eight). I suspect the bird in this photo is a female. She was wiping her bill on the branch e.g. feaking.

First, she wiped one side and then the other.

The result was a perfectly clean bill. Apparently, when the weather is cold cleanliness becomes a lower priority.

However, once things warm up a bit, their eyes open wide, their feathers are less fluffed and in general...

...they have more time and energy to keep their bills clean and functional.

Have a greater day on Union Bay...where nature lives in the city!

Larry

Recommended Citation

Clark, C. J. and S. M. Russell (2012). Anna's Hummingbird (Calypte anna), version 2.0. In The Birds of North America (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.226

Going Native:

Without a well-funded Environmental Protection Agency, it falls to each of us to be ever more vigilant in protecting our local environments. Native plants and trees encourage the largest diversity of lifeforms because of their long intertwined history with our local environment and native creatures. I have been told that even the microbes in the soil are native to each local landscape. I hope we can inspire ourselves, our neighbors and local businesses to respect native flora and to support native wildlife at every opportunity. I have learned that our most logical approach to native trees and plants (in order of priority) should be to:

1) Learn and leave established native flora undisturbed.

2) Remove invasive species and then wait to see if native plants begin to grow without assistance. (If natives plants start on their own, then these plants or trees are likely the most appropriate flora for the habitat.)

3) Scatter seeds from nearby native plants in a similar habitat.

4) If you feel you must add a new plant then select a native plant while considering how the plant fits with the specific habitat and understanding the plant's logical place in the normal succession of native plants.

My intention in my weekly post is to include at least one photo each week and visually challenge us to know the difference between native and non-native lifeforms. 

What species does this bee belong to? Is it native to our area?

Scroll down for the answer.

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Black-tailed Bumble Bee: This Bombus Melanopygus was active in spite of the cold and appears to be native to most of the western half of North America. Click on the highlighted name of the bee to read more. I assume the hummingbirds leave the bees alone because of the danger from a sting. As explained in the next to last paragraph at The Hummingbird Society.

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The Email Challenge:

Over the years I have had many readers tell me that Google is no longer sending them email announcements regarding my posts. Even more frustrating when they go to 're-sign-up', hoping that will enable them to once again start receiving the announcements, they get a message which says 'Sorry, you are already signed up.' Google has not responded to my requests for help with this issue. 

My functional workaround is to set up my own email list and each week I manually send out a new post announcement. If you are experiencing the issue and would like to be added to my personal email list please send me an email requesting to be added. Thank you for your patience!

My email address is: LDHubbell@Comcast.Net