Banding Data

Location Code:  SAG3
Location Desc.: MICHIGAN, Saginaw Co., Shields
Latitude:  N 43° 25'
Longitude:  W 084° 03'
Hummer Host: Bernie Coleman

Total banded to date: 1

Date Band No. Age Sex Comments
17-Nov-08 Hx1137 AHY F Rufous Hummingbird!
First observed: 12-Nov-08.
Last Observed: 05-Dec-08.

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Description

Michigan Rare Bird Report

Species:   Rufous Hummingbird (Selasphorus rufus), adult female

Date & Time: November 17, 2008.  First observed by homeowner on 12 November 2008 and last observed on 5 December 2008. I arrived around 9:00 a.m. and waited about 15 minutes before the bird made an appearance.  I then set up my trap at 9:30 a.m. and caught the bird at 9:33 a.m.  The bird was banded and released at 9:42 a.m. under Federal permit No. 23156, and Michigan permit No. SC 1303.  The bird had returned to the feeder at 10:10 a.m.

Location: At the home of Bernie Coleman in Shields, Saginaw Co.

Observer (s):  Allen Chartier

Equipment: Photographed in-hand with digital camera (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 overcast and the light diffuse. The bird was banded, measured, 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 my 10x Swarovski binoculars from a distance of about 30-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 after hatch-year (adult) based on the absence of shallow groovings or corrugations on 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 rectrix (r1) was restricted to about the basal 25%, and was completely covered by the green upper tail coverts. As the bill corrugations indicated the bird was adult, plumage alone is enough to confirm the bird was a female, but these additional plumage characters support that this bird was a female.

The wing measurement of 42.93 mm was at the short end of the range given for adult and immature female Rufous given in Stiles (1972). It is also near the large end of the range for immature males, so the wing chord measurement weakly supports the sex of this bird as female.

The bill measurement (exposed culmen) can sometimes be helpful for determining sex as indicated in Table 1 in Stiles (1972). This bird’s exposed culmen measurement of 17.05 mm was near the middle of the range given for adult and immature females Rufous. It is also near the large end of the range for immature males, so the exposed culmen measurement supports the sex of this bird 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).  This pattern is more indicative of females than males, though the number of iridescent feathers varies considerably and is not particularly useful for supporting an age determination. 

Species:  Given that the bird was an after hatch-year (adult) female, using Stiles 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, and is considered diagnostic. This individual had noticeable notching and emargination on both webs of the second rectrix (see photos), which confirms that this bird was a Rufous Hummingbird.  Using Figure 3 in Stiles (1972), the shape most closely matched figure Aa.

As additional support for the identification, the widths of two other tail feathers, the central rectrix (r1) and the outermost rectrix (r5) were measured. The width of the central rectrix (r1) was measured as 7.67 mm. This is at the narrow end of the range for adult female Rufous and at the wide end of the range for both subspecies of Allen’s Hummingbird* given in Stiles (1972) so is only suggestive of Rufous.

The width of the outer rectrix (r5) was measured as 3.48 mm.  This is broader than the maximum range for immature female Allen’s (max. 3.3 mm for both subspecies given in Stiles 1972) and so provides additional conclusive and diagnostic support to the identification as Rufous.

Tail measurements are often not very useful.  This bird’s tail measurement of 28.5 mm is above the maximum for adult females of both subspecies of Allen’s (Stiles 1972) and is at the upper end of the range for adult female Rufous. So tail length is somewhat useful in this case.

Molt: There was no body molt evident on this bird.  The outer 4 primaries (p7-p10) were old and worn, and the inner primaries (p1-p6) were recently replaced and contrastingly shiny black. Rectrices 3 and 4 were worn while r1, r2, and r5 were fresh and probably recently replaced.

Fat/Weight: The bird had a fat code of 1 (0-3 scale) and weighed 3.41 grams, about average for an adult female planning an extended stay.

Voice: Brief, sharp chip note when the bird was released. More strident than Ruby-throated gives.

Similar Species:  Allen’s Hummingbird is the species most similar to Rufous Hummingbird. On this bird, the diagnostic “notched and emarginated” second rectrix (r2), measured width of the outer (r5) rectrices were the primary characters confirming the identification, with tail length and to a lesser extent the width of the central (r1) rectrix supporting the identification.

Experience: I have seen dozens of Rufous Hummingbirds in several states, banded more than 50 in Michigan, Ohio, Indiana, and Ontario since 2001, handled ~35 in Louisiana in February 2003 with Nancy Newfield, and handled about a dozen in Arizona in 2006 helping other banders.  I have seen several Allen’s Hummingbirds on two trips to California and once recently in Arizona , and handled 3 in Louisiana in February 2003.  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 19, 2008 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-COrtiz-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, FStiles, F.G.  1972.  Age and Sex Determination in Rufous and Allen Hummingbirds.  The Condor 74: 25-32.

 

Photos