Location Code: OH-32
Ohio Rare Bird Report
Species: Rufous Hummingbird (Selasphorus rufus), adult female
Date & Time:October 20, 2009. First observed by homeowner on October12, 2009 and was last observed by the homeowner on November 5, 2009. I arrived around 8:30 a.m. (E.S.T.) and set up my trap at 8:45 a.m. The bird soon made an appearance, and went into the trap, at 8:48 a.m. The bird was banded and released at 9:06 a.m. under Federal permit No. 23156, and Ohio permit No. 11-21. The bird returned to the feeder around 10:30 a.m.
Location: At the home of Tim Sage in Green Twp., Ashland Co.
Observer (s): Allen Chartier. Tim Sage (homeowner), Don Plant, and Su Snyder.
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 partly cloudy and the light conditions were excellent. The bird was banded, measured, weighed, and photographed outdoors.
Description: When the bird first made an appearance at the feeder and trap, it was not examined very closely in order that it could be captured quickly. Once the bird was in-hand 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: 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 less than 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 characters support that this bird was a female.
The wing measurement of 43.59 mm was in the middle of the range for adult female Rufous given in Stiles (1972), and also within the range for adult female Allenís of the non-migratory subspecies (sedentarius). So, the wing length was also useful for determining the sex of this bird.
The bill measurement (exposed culmen) can sometimes be helpful for determining sex as indicated in Table 1 in Stiles (1972). This birdís exposed culmen measurement of 17.65 mm was in the mid-range for females (adult and immature) and above the range given for immature males, so was also useful for determining the sex of this bird.
The pattern of iridescent gorget feathers on the throat can sometimes be helpful in determining the sex of Selasphorus hummingbirds, but is often ambiguous. This bird had 19 iridescent gorget feathers in the lower part of the throat.
Species: Given that the bird was an after hatch-year (adult) female, using Stiles we can determine whether this bird was a Rufous or Allenís 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 Ac.
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 8.18 mm. This is very slightly wider than adult females of both the nominate subspecies and the sedentarius subspecies of Allenís Hummingbird given in Stiles (1972), and so strongly supports the identification as Rufous. The width of the outer rectrix (r5) was measured as 3.12 mm. This is broader than the maximum range for adult female Allenís (max. 2.7 for sasin and 3.0 mm for sedentarius as 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 birdís tail measurement of 29.0 mm is above the maximum for adult females of both subspecies of Allenís (Stiles 1972) and is even slightly above 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 3 primaries (p8-p10) were old and worn, and the inner primaries (p1-p7) were recently replaced and contrastingly shiny black. All the tail feathers appeared to be fresh and unworn.
Fat/Weight: The bird had a fat code of 1 (0-3 scale) and weighed 3.73 grams, a little above average for an adult female planning to overwinter (typically 3.4-3.6 in my experience).
Voice: None heard.
Similar Species: Allenís Hummingbird is the species most similar to Rufous Hummingbird. On this bird, the diagnostic "notched and emarginated" second rectrix (r2) and the measured widths of the outer (r5) and central (r1) rectrices were the primary characters confirming the identification.
Experience: I have seen dozens of Rufous Hummingbirds in several states, banded more than 50 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 2006 helping other banders. I have seen several Allenís Hummingbirds on two trips to California and once recently in Arizona (2006), 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.
When report was written: This report was written on November 25, 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.
* 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.
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.