Date & Time: November 1, 2007. First observed by homeowner on October 28, 2007. The bird has not been reliably seen since it was banded. I arrived around 8:30 a.m. and waited only 5 minutes before the bird made an appearance. I then set up my trap at 8:45 a.m. after the bird departed The bird did not reappear until it was caught at 11:39 a.m. The bird was banded and released at 11:57 a.m. under Federal permit No. 23156, and Michigan permit No. SC 1303.

Location: At the home of Melanie Perry in Kalamazoo, Kalamazoo Co.

Observer (s): Allen Chartier, Brenda Keith, Ray Adams.

Equipment: Photographed in-hand with digital camera. 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 light was good. The bird was banded and weighed indoors and photographed outdoors.

Description: When the bird first made an appearance at the feeder, I was only able to get a look with the naked eye in poor light from about 15 feet away. I did not see any rufous coloration on the bird, but it looked very small, a fact confirmed by measurements (see below). Brenda Keith had seen the bird the evening before and was sure it had rufous "on the tail". When bird was captured for banding, 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 50% of the upper mandible on one side only. This is universally recognized as the most reliable method for age determination in hummingbirds (Ortiz-Crespo, 1972).

Sex: The extensively rufous upper tail coverts, and the extensively rufous-based central rectrix (rufous visible beyond the tips of the upper tail coverts) strongly suggested this bird was a male. The wing measurement (wing chord) of 39.80 mm was at the small extreme of the range for adult female Allen’s of the subspecies sedentarius given in Stiles (1972), (39.8-42.8), but was smaller than any wing measurements for females of nominate Allen’s or Rufous. It was also slightly below the lowest range given for immature male Rufous (40.5-43.4 mm) and within the range of both subspecies of Allen’s (38.9-41.4 mm for S. s. sasin and 39.4-43.0 mm for S. s. sedentarius). So the wing length provided strong support for the bird being male. The pattern of iridescent gorget feathers on the throat can sometimes be helpful in determining the sex of Selasphorus hummingbirds. This bird had 7 scattered around the throat (see photos). This pattern occurs most often in immature males, but the number of iridescent feathers varies considerably and is not particularly useful for supporting an age or sex determination. The bill measurement (exposed culmen) can sometimes be helpful for determining sex. This bird’s culmen of 16.69 mm was inconclusive as it falls within the range of immature male and immature female of both species, so is not helpful.

Species: Given that the bird was a hatch-year (immature) male, 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. This individual had both a notch and emargination (see photos), which would probably be possible to observe in the field. Using Stiles’ Figure 3, the shape most closely matched figure Ab. The shape of r2 alone, in this case, is conclusive for Rufous. To further support 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 8.04 mm. This is barely wider than the widest immature male for the nominate subspecies of Allen’s and near the upper end of the range for the sedentarius subspecies of Allen’s* (S. s. sasin = 6.6-8.0 mm, S. s. sedentarius = 6.8-8.2 mm), and thus does not provide support for the identification as Rufous. The width of the outer rectrix (r5) was measured as 3.02 mm. This is broader than the maximum range for immature male Allen’s (max. 2.6 mm for both subspecies) and so provides strong additional support to the identification as Rufous. Tail length measurements are often not very useful. This bird’s tail measurement of 25.8 mm is above the maximum for the nominate subspecies of Allen’s, but within the range for immature male Allen’s (S. s. sedentarius = 23.0-26.5 mm) and immature male Rufous (23.0-26.4 mm), so does not provide support for the identification as Rufous.

Molt: There was extensive body molt on the upperparts and underparts of this bird, including the throat where additional iridescent throat feathers may be growing in. The outer 6 primaries (p5-p10) were old and worn and the inner primaries (p1-p3) were full grown and contrastingly shiny black. The fourth primary was in sheath and growing in. The central rectrix (r1) appeared fresh and was likely recently replaced, and r2 – r5 were old and worn. The worn condition of these feathers almost certainly contributed to the unusually short wing chord and perhaps also to the short tail length. The bird had a fat code of 1 (0-3 scale) and weighed 3.73 grams, slightly more than is typical for an immature male planning to overwinter.

Voice: Briefly, sharp chatter 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 shape of the second rectrix, r2 (notched and emarginated), as well as width of the outer rectrix (r5) were the primary characters confirming the identification.

Experience: I have seen dozens of Rufous Hummingbirds in several states, banded 40 in Michigan, Ohio, Indiana, and Ontario, and handled 35 in Louisiana in February 2003 with Nancy Newfield. I have seen several Allen’s Hummingbirds on two trips to California, 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 November 8, 2007 based on data and photos taken during the banding process.

* 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 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, but neither were necessary to identify the bird.

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.