Location Code: OH-34
Ohio Rare Bird Report
Species: Allen's Hummingbird (Selasphorus sasin), immature male
Date & Time:December 11, 2009. First observed by homeowner in late September or early October 2009, and last observed on December 27, 2009. I arrived just before 9:00 a.m. and the bird was present, sitting on the hook above the feeder. I then set up my trap at 9:15 a.m. and caught the bird at 9:30 a.m. The bird was banded and released at 9:45 a.m. under Federal permit No. 23156, and Ohio state permit No. 11-21. The bird returned to the feeder at 10:00 a.m.
Location: At the home of Mae Miller in southeastern Walnut Creek Township, Holmes Co.
Observer (s): Allen Chartier, Nancy Chartier, Mae Miller (homeowner), Bruce Glick, Ed Schlabach.
Equipment: Photographed in-hand with digital camera. Only 4 photos were taken by me, as the bird was showing moderate signs of stress after being in-hand for 15-minutes, so it was released since diagnostic photos had been obtained as well as all necessary measurements. 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 clear 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, it was apparent that it was a Rufous or Allenís Hummingbird, based on peach-rufous on the flanks, and a rufous tinge on the upperparts, including exensively on the upper tail coverts and on the tail, indicating it was an immature male. This observation was made with 10x Swarovski EL binoculars 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/Allenís Hummingbird in-hand be correctly aged and sexed before a species determination can be made (B. Sargent and N. Newfield, pers. comm.).
Age & Sex: The bird was aged as hatch-year (immature). Normally this would be based on the presence 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). But this individual showed very little (5%), suggesting that it was either an adult, or an immature that had hatched very early as the corrugations "fade" as these birds age. All but one of this birdís tail feathers were adult male type. The single white-tipped left outer rectrix (r5) along with the lack of a complete iridescent gorget confirms the age as hatch-year. There were 7 iridescent orange feathers scattered around the perimeter of the throat, a frequent pattern in hatch-year male Selasphorus hummingbirds, but this character was not well photographed. The pointed, orange and black-tipped tail feathers lacking white tips (except one) confirmed that it was a male.
Species: Given that the bird was a hatch-year (immature) male, using Stiles we can determine whether this bird was a Rufous or Allenís Hummingbird using several additional measurements and observations. The width of the outer rectrix (r5) is a diagnostic character for both species. This bird had both an adult-type and a hatch-year type outer rectrix, so both were measured. Referring to Figure 4 in Stiles (1972), the pattern and shape of this white-tipped hatch-year r5 was most similar to figure Bg (Allenís). The width of this hatch-year r5 was measured as 1.81 mm. According to Stiles (1972) this confirms the species as Allenís Hummingbird as the range given for Rufous is 2.7-3.6mm and the range given for Allenís is 2.7-2.6mm. The width of the adult-type r5 was measured as 1.17 mm. Stiles does not provide measurements for this feather for adult males, but another reference (McKenzie and Robbins 1999) does, with a sample size of 28 adult male Allenís and 123 adult male Rufous. This birdís r5 falls clearly within the range, in fact slightly narrower, given for Allenís (1.50-1.90mm), and is clearly outside their range given for Rufous (2.35-2.93). The narrower than expected width could easily be due to wear, which is evident in the photos, and suggests this bird has had some of these adult tail feathers for some time. Thus the measured widths of both outer rectrices of this bird are sufficient alone to confirm the species as an Allenís Hummingbird.
In most cases, the width of the central rectrix (r1) is also diagnostic, but neither Stiles (1972) nor McKenzie and Robbins (1999) provides measurements for adult male type r1 feathers. In any case, this bird only had 8 rectrices,. Which tail feathers were missing was very difficult to determine. Examining the bird when in-hand did not provide a clear answer as to which two feathers were missing, so the photos had to be examined in detail at home, and is the main reason that outside expert opinion was sought (see below), not for confirmation of the species ID, which is well confirmed by the widths of both r5 as noted above.
Sargent suggests that the missing feathers are r1, but did not provide measurements from adult male r1 on Allenís, though his rationale that r1 is often missing is something Iíve experienced with Rufous. In another e-mail, not copied here, Newfield suggested that this was too narrow to be the r1 on an Allenís (r1 is the widest tail feather on both Rufous and Allenís), but also did not provide a rationale or measurements. Pattonís rationale on molt sequence is exactly what Iíve experienced with Rufous, and his photo of a male Allenís with an adult tails is very instructive. In his photo (see below), the r4 is nearly as narrow as the r5. The Ohio bird does not show this, which strongly suggests to me that it is the r4 tail feathers that are missing, and that the hatch-year r5 will be the last one to be shed after the r4 feathers start growing in. The measured width of the centermost feather on this bird was 5.84 mm, but since no reference is available for adult males no conclusions can be reached, though this is notably narrower than any adult male Rufous Iíve personally banded (n=12, range 7.21-8.52).
The second rectrix (r2) is very noticeably notched and emarginated in adult male Rufous Hummingbirds (Williamson 2000, and see my adult male Rufous Hummingbird tail photo below for comparison), often appearing like a bite was taken out of it. If Patton is correct, and I believe he is, the Ohio birdís r2 feathers were definitely not notched in any way, but rather were very gradually tapered to a point with only a slight suggestion of tapering, as well as being very narrow, which is diagnostic for Allenís Hummingbird. If Sargent and Newfield are correct and the centermost feathers on the Ohio bird are actually r2, the same applies as there is no notching as would be found in a Rufous, and this feather is evenly tapered. Thus the shape and apparent narrowness of this birdís r2 is additional, diagnostic support for the identification as an Allenís Hummingbird.
The wing measurement of this bird was 40.36mm. This is very slightly below the minimum given for Rufous in Stiles, but is in the mid-range for both subspecies of Allenís Hummingbird (sasin and sedentarius)* so provides additional support for the identification as Allenís. The bill measurement (exposed culmen) of this bird was 16.24mm. This is near the midrange for immature male Rufous and Allenís (sasin) but very near the low end of the range for Allenís (sedentarius). The tail measurement may have been based on an incomplete tail (if Newfield and Sargent are correct) so would not be a valid measurment, and in any case tail length is rarely useful for identification purposes in these species.
The upperparts of this bird were all green, from crown to rump, with absolutely no rufous feathers as would be expected on a Rufous Hummingbird, so favors Allenís. The upper tail coverts were solid rufous in color, which is characteristic of an immature male of either species.
Molt: There was extensive body molt on the upperparts and underparts of this bird. During processing, this bird dropped several body feathers, which were collected (allowed under my permits) and will be submitted to an appropriate bird collection in Ohio, probably Ohio State University. As they are all body feathers, there is nothing diagnostic about the feathers, but perhaps some future researcher may wish to extract DNA from these feathers. The outer two primaries (p9 and p10) were old and worn (duller) and the remaining primaries were fairly fresh and blackish. All the rectrices were adult and somewhat worn, except for the left outer r5 which was a retained hatch-year feather. Incoming r3 and r4 would be the last to grow in, and it appears that this bird lacks r4 feathers. This tail pattern suggests a fairly advanced stage of molt.
Fat/Weight: The bird had a fat code of 1 (0-3 scale) and weighed 3.58 grams.
Voice: Briefly, a single sweet "chip" repeated when the bird was released.
Similar Species: Rufous Hummingbird is the species most similar to Allenís Hummingbird. On this bird, the diagnostic shape of the second rectrix (r2 not notched or emarginated), as well as the very narrow width of the outer rectrix (r5) were the primary characters confirming the identification as these characters are considered diagnostic. Both the lack of shallow groovings on the bill and the nearly complete adult tail are characteristics Iíve never encountered in hatch-year male Rufous Hummingbirds in the fall, and suggests a more advanced stage of development of this bird. Allenís Hummingbirds nest from December-February in California. An Allenís fledging in February or March would be expected to show little or no corrugations on the bill by December, so thus this is also suggestive of the identification as Allenís and not Rufous, which does not begin nesting until April or May. In general, Allenís (sedentarius) has longer wings, tail, and bill than Allenís (sasin). Nearly all characteristics fall in the mid-ranges and do not provide clear evidence of one subspecies over the other, not allowing a determination to be made. So it is best not to assign this individual to either subspecies of Allenís Hummingbird.
Experience: I have seen dozens of Rufous Hummingbirds in several states, banded nearly 60 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 Allenís 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 Allenís Hummingbird, in addition to known field criteria for separating these species.
Outside expert opinion: Given that this bird had some unusual characteristics of tail molt, I sought additional opinions from two hummingbird experts who I happen to know quite well, Bob Sargent and Nancy Newfield. Both were sent my photos attached here (not Bruceís), as well as the measurement data provided above. Additionally, after posting photos of this bird to my blog (where I present slightly different information than is included here), Dave Patton also volunteered his opinion and helpful photos based on his viewing my blog posting which contains preliminary information, some different than that contained in this more thoughtful report. I realize that the committee may or may not seek additional outside opinion, but I feel that since these opinions are available, it makes sense to include them in this report. Here are their comments, copied from their emails to me:
When report was written: This report was completed on December 20 2009 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, but neither was necessary to identify the bird.
Ortiz-Crespo, F.I. 1972. A new method to separate immature and adult hummingbirds. Auk 89: 851-857.
McKenzie, P.M. and M.B. Robbins. 1999. Identification of adult male Rufous and Allenís hummingbirds, with specific comments on dorsal coloration. Western Birds 30: 86-93.
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.
Williamson, S.L. 2000. Hummingbirds of North America. Houghton Mifflin Co., New York, NY.