Late-season Hummingbirds in Wisconsin

Cold, snow, and ice don’t typically conjure images of hummingbirds in Wisconsin. But experts say keep an eye out for rare migrants in late fall, especially from late October through early December.

The following text was contributed by Cynthia Bridge, one of Wisconsin’s two licensed hummingbird banders.

When mid to late October arrives and a hummingbird is reported to be visiting a Wisconsin feeder many folks think “move south little bird.” The thought is often that these small birds are frail, are lingering Ruby-throated Hummingbirds, and/or are potentially in need of rescue and relocation. In most cases none of the above are true. While having a hummingbird visiting your feeder in late October through December is uncommon, it is actually the high season for observing migrating Rufous Hummingbirds in Wisconsin. In fact, if you observe a hummingbird at your feeder the last week of October through January, odds strongly favor that the species is something other than Ruby-throated, with Rufous being the most expected species.

Hatch-year female Rufous Hummingbird using feeder kept thawed by hand warmers in Fond du Lac County, 10 November 2018. Photo by Cynthia Bridge.

Rufous Hummingbirds are seen annually in Wisconsin in small numbers. Wisconsin has over fifty records of this species. They are more cold-hardy than Wisconsin’s only breeding hummingbird, the Ruby-throated. Rufous Hummingbirds breed as far north as Alaska, arriving to their high elevation breeding grounds in April when the snow still lies deep. Through banding they have been documented to survive air temperatures of -9F and wind chills of -36F.

Rufous Hummingbird Fun Facts:

  • Has the longest migration route of any U.S. hummingbird;
  • Holds the record for the longest recorded migration of any hummingbird–3,500+ miles (!);
  • Is the most widely distributed hummingbird in North America, having been recorded in every state except Hawaii,
  • Reaches the northernmost latitude of any hummingbird (61° N);
  • Breeds from southeast coastal Alaska Coastal, through Prince William Sound, south Yukon, British Columbia, Alberta, Washington,Oregon, Idaho (north panhandle to east-central), western Montana, and northern California;
  • Depends on a winter diet consisting of nectar and dormant insects gleaned from leaves, needles and bark; and
  • Is cold hardy, surviving extended periods of cold involving 10-20° F weather (based on observations and recaptures by the most experienced hummingbird banders in North America).

Rufous/Allen’s Hummingbird feeding through a snowfall in Brookfield, Waukesha County, 18 December 2012. Photo by John Newton.

Those involved with banding these rare migrant hummingbirds in late October through January refer to these birds at “winter hummingbirds.” In most cases where these winter hummingbirds are observed in Wisconsin, rescue efforts are not warranted. In fact, such measures can significantly interfere with the migration of an otherwise healthy bird. In addition, once one of these hummingbirds has found its way to a hummingbird feeder late in the season, removal of that feeder will not necessarily “force the bird to migrate” and can serve as a detriment to the bird’s survival. For a late season hummingbird that finds its way to a feeder, that feeder provides carbohydrates for an energy kick. However, protein is also an important dietary component which these winter hummingbirds find by gleaning pine trees and foliage for midges and other cold-hardy insects. A bird’s decision to migrate is multi-factorial and triggered by a variety of factors including hormones, weather, the bird’s overall condition, and food availability.

Rufous Hummingbird while being banded in Dane County, 8 November 2016. Note the calipers and eye loupe for making the detailed measurements and assessment often needed to separate this from the very similar but far rarer Allen’s Hummingbird. Photo by Cynthia Bridge.

Thus far for Wisconsin’s Winter Hummingbird 2018 season three Rufous Hummingbirds have been banded in Milwaukee, Fond du Lac and Rock counties. An additional two Selasphorus species (Rufous/Allen’s Hummingbird) were documented in Vilas and Ozaukee counties but were not conclusively identified due to the birds departing before they could be banded. Selasphorus is the genus to which Rufous and the very similar Allen’s Hummingbird belong. Birds of these two species that exhibit female and/or juvenile type plumage can often only be identified through banding and in-hand measurements. Separating these two species can sometimes come down to differences on the scale of just a few millimeters. The Ozaukee county bird appeared to be a Rufous Hummingbird. However, the Vilas county bird had a narrow and shorter appearing tail suggestive of Allen’s. Had this bird been banded and found to be an Allen’s, this would have been a first record for Wisconsin! Hence the importance and value of banding as many of these late season hummingbirds as possible.

Rufous Hummingbird just prior to its release after banding in Milwaukee County, 8 November 2018. Photo by Bonnie Resnick McLean.

Increased vigilance for late season hummingbirds, photographs of these birds, timely reporting to eBird, and participating in Wisconsin’s winter hummingbird banding program will serve to strengthen Wisconsin’s ornithological data. Winter hummingbird banding provides valuable information that increases our knowledge regarding hummingbird migration, biology, site fidelity, and longevity as well as assisting in the identification of rare hummingbird species. Despite the misconception that banding will cause a bird to leave its host location, by far most winter hummingbirds banded in Wisconsin have remained at the site they were banded anywhere from a few days to weeks following banding. Cynthia Bridge and Mickey O’Connor are Wisconsin’s two federally permitted hummingbird banders collaborating on Wisconsin’s winter hummingbird program. Please contact them with any questions regarding hummingbirds or to report an unusual hummingbird species.

Contact information
Cynthia Bridge: (608) 333-5417
Michelene (Mickey) O’Connor: (214) 980-3103