Location Code:  KAL17
Location Desc.: MICHIGAN, Kalamazoo Co., Richland Twp.
Latitude:  N 42° 23'
Longitude:  W 085° 30'
Hummer Host: Cindy & Ken Van Den Berg

Total banded to date: 1

Click here to view written description.

Michigan Rare Bird Report

Species:      Rufous Hummingbird (Selasphorus rufus), immature female

Date & Time: November 20, 2011.  First observed by homeowners (Cindy and Ken Van Den Berg) in early October 2011 and last observed on December 10, 2011. I arrived around 9:00 a.m., and met Rich and Brenda Keith who had made the initial contact with the homeowner about this bird.  We waited only a few minutes before the bird made an appearance, and it was obviously a Selasphorus based on the peach color evident on the bird’s flanks.  I set up my trap (with the bird hovering near my head!) at 9:15 a.m. and caught the bird at 9:16 a.m. The bird was banded and released at 9:29 a.m. under Federal Bird Banding Permit No. 23156, and Michigan Scientific Collectors Permit No. SC 1303.

Location: At the home of Cindy and Ken Van Den Berg in Richland Twp., Kalamazoo County . They declined to allow birders to visit their home to view the bird as observing would be difficult without being inside the house.

Observer (s):  All data and observations in this report were made by Allen Chartier. Also present were the homeowners (Cindy and Ken Van Den Berg), Nancy Chartier, and Rich and Brenda Keith.

Equipment: Photographed in-hand with digital camera (photos attached to this document).  All measurements were made using digital calipers.  Bill corrugations were determined by viewing through a 10x loupe, as they are impossible to accurately determine any other way.

Viewing conditions: The sky was partly cloudy and the temperature was 43 degrees. The bird was banded, weighed, and photographed outdoors.

Description:    When the bird first made an appearance at the feeder, it was apparent that it was a Rufous or Allen’s Hummingbird, based on peach-rufous on the flanks, and an irregular blotch of iridescent throat feathers This observation was made with the naked eye from a distance of about 10-feet. The bird was then captured for banding, and it was aged, sexed, and identified in that order.  The proper use of Stiles (1972) for banders requires that an individual Rufous/Allen’s Hummingbird in-hand be correctly aged and sexed before a species determination can be made (B. Sargent and N. Newfield, pers. comm.).

Age:  The bird was aged as hatch-year (immature) based on the presence of shallow groovings or corrugations on about 70% of the upper mandible. This is universally recognized as the most reliable method for age determination in hummingbirds (Ortiz-Crespo, 1972).

Sex:  The upper tail coverts and rump were entirely green. The rufous on the base of the central rectrices (r1) was restricted to about the basal 25%, and was completely covered by the green upper tail coverts. These characters suggested this bird was a female. The wing measurement of 44.41 mm was longer than any age of male Rufous or Allen’s given in Stiles (1972), so this measurement is a very strong indication that the bird was female. The bill measurement (exposed culmen) can sometimes be helpful for determining sex. This bird’s exposed culmen measurement of 18.08 mm was longer than adult and immature males of nominate (S. s. sasin) Allen’s Hummingbird, but within range of immature males of the sedentarius subspecies* of Allen’s and shorter than the range of adult females of sedentarius. So, the bill measurement somewhat supports the sex as female. The pattern of iridescent gorget feathers on the throat can sometimes be helpful in determining the sex of Selasphorus hummingbirds. This bird had 17 clustered together in the center of the throat (see photos), which is more frequent in females than males. There is a tendency for immature males and immature females to have fewer iridescent feathers, but this is extremely variable, so this bird’s throat pattern cannot really be used to support aging the bird.

Species:  Given that the bird was a hatch-year (immature) female, using Stiles (1972) we can determine whether this bird was a Rufous or Allen’s Hummingbird using several additional measurements and observations.  The presence of notching and/or emargination on the second rectrix from the center (r2) is one feature that can often be observed in the field to confirm Rufous.  The r2’s of this individual did show both emargination and notching (see photos), which is diagnostic for Rufous. Using Figure 3 in Stiles (1972), the shape most closely matched figure Ab for Rufous, which would be possible to see in photos of the free living bird, provided it spread its tail which they rarely do unless defending food sources from other hummingbirds. Additional support for the identification can be obtained by measurements of the widths of two other tail feathers. In cased where r2 shows no notching or emagination, the measured widths of the central rectrix (r1) and the outermost rectrix (r5) are the primary means to confirm identification. One central tail feather (r1) was measured as 8.58 mm. This is around the mid-range for immature female Rufous (7.8-9.5 mm) given in Stiles (1972), and above the upper end of the range for immature female of nominate (S. s. sasin) Allen’s (6.9-8.2 mm). It is also above the range for immature females of the sedentarius subspecies of Allen’s (7.3-8.4 mm). So, the width of the central rectrix provides conclusive and diagnostic support to the identification as Rufous Hummingbird. One outer rectrix (r5) was measured as 4.30 mm. This is near the mid-range for immature female Rufous (3.2-4.7 mm) and broader than the maximum range for immature female Allen’s (max. 3.3 mm) for both subspecies, and so provides conclusive and diagnostic support to the identification as Rufous. Tail measurements are often not very useful.  This bird’s tail measurement of 28.0 mm is above the maximum for immature females of the nominate subspecies of Allen’s (Stiles gives no corresponding measurement for immature female S. s. sedentarius), and even slightly above the maximum given for immature female Rufous. So tail length is also useful in this case. Also, the wing measurement of 44.41 mm is above the maximum for immature females of nominate Allen’s, but is within the range for immature females of the sedentarius subspecies of Allen’s (42.1-45.0 mm), so weakly supports the identification as Rufous Hummingbird.

Molt: There was no body molt evident on this bird.  The outer 3 primaries (p8-p10) were old and worn and the inner primaries (p1-p7) were recently replaced and contrasting shiny black. All the rectrices, except r3, were fresh and unworn.

Fat/Weight: The bird had a fat code of 1 (0-3 scale) and weighed 3.64 grams, about average for an immature female planning to overwinter.

Voice: Brief, sharp chatter when the bird was released. More strident than Ruby-throated gives. A clear sharp chip note when the bird was hovering nearby waiting for me to hang up the trap.

Similar Species:  Allen’s Hummingbird is the species most similar to Rufous Hummingbird. On this bird, the emargination and notching of the second rectrix provided confirmation of the identification as Rufous. The widths of both the central (r1) and outer (r5) rectrices provided additional diagnostic and conclusive support for the identification as Rufous. Both wing and tail measurements also provided additional support for the identification.

Experience: I have seen hundreds of Rufous Hummingbirds in several states, banded nearly 60 in Michigan, Ohio, Indiana, and Ontario, and handled ~35 in Louisiana in February 2003 with Nancy Newfield, and handled about a dozen in Arizona in July 2006 helping other banders.  I have seen several Allen’s Hummingbirds on two trips to California and once recently in Arizona , handled 3 in Louisiana in February 2003, and banded Ohio ’s first Allen’s Hummingbird in December 2009.  As a trained, licensed hummingbird bander, I am familiar with all pertinent in-hand criteria for distinguishing Rufous from Allen’s Hummingbird, in addition to known field criteria for separating these species.

When report was written:  This report was written on December 14, 2011 based on data and photos taken during the banding process.

References consulted:  None were consulted while observing the bird in the field, nor were any used to write notes in the field or to write this report.  Stiles (1972) and Pyle (1997) were available during the banding of the bird.

*    There are two subspecies of Allen's Hummingbird.  One is the widespread and migratory nominate subspecies (Selasphorus sasin sasin) breeding from coastal northern California to coastal southern California and mainly migrating southward into Baja California , Mexico .  The other is a more range-restricted and generally non-migratory subspecies (S. s. sedentarius), breeding on California 's Channel Islands and the adjacent mainland (around Los Angeles ). But sedentarius presents some problems, because it is intermediate between S. s. sasin and Rufous in some characters.  And, while sasin has a shorter bill than Rufous, sedentarius has a longer bill!  If sedentarius were entirely sedentary, this would not be an issue.  But, I've been told (N. Newfield, pers. comm.) that the first specimen of Allen's Hummingbird collected in Louisiana actually fits sedentarius!  So, however remote the possibility, sedentarius must also be considered.

References:

Ortiz-Crespo, F.I.  1972.  A new method to separate immature and adult hummingbirds. Auk 89: 851-857.

Pyle, P.  1997.  Identification Guide to North American Birds: Part 1.  Slate Creek Press, CA.

Stiles, F.G.  1972.  Age and Sex Determination in Rufous and Allen Hummingbirds. The Condor 74: 25-32.