ML289560271

Age and sex

Juvenile Male - 1

Media notes

Perched field photo with tail spread

Observation details

I had received poor quality cell photos of a Selasphorus hummingbird coming to a feeder 35 minutes from my home. Homeowner Pam Lehnherr reports the bird was at least present the day before Thanksgiving. She confirmed she had photos on phone dating back to Dec 6. Reports she had limited storage and had deleted the earlier photos. I expected to find a Rufous which is the most common late season hummingbird in Wisconsin. Fairly quickly I ascertained when seeing the bird upon arrival that this was a HY male Rufous/Allen's. We caught the bird for banding within 5 minutes of Peter Bridge setting up the trap. Once in hand I was immediately struck by the narrow appearance of the outer two rectrices. Secondly I did not observe a notch on the outer vane of R2 which I expected should be more salient if this was a HY male Rufous. Note the appearance of R2 can be quite variable. R2 did not appear exceptionally narrow. But both Kelly Bryan and Sheri Williamson concur that the shape of R2 is within the variation for Allen's. Third, I was struck by the short tail measurement. Measurements are as follows: Wing 40.89 mm, Tail 23.6 mm, Culmen 17.06 mm, weight 3.93 g. R5 which is a difficult measurement to obtain without removal of the feather from the bird was measured by two methods. Measurement by laying the feather on the ruler came in just under 2mm, estimated at 1.9 mm. Measurement of r5 with the calipers which is more difficult to do with the feather on the bird was 2.12mm. I consider this second R5 width measurement to be over-generous to the true width of that feather. Regardless both measurements are in range and point to Allen's Hummingbird (1.6-2.5 mm Pyle, Stiles) versus RUHU (2.7-3.7 mm Pyle, 2.7-3.6 Stiles). Size index (SI), a combination of wing+tail+culmen, developed by Kelly B. Bryan from his West Texas Data set to improve separation of of similar species with statistical significance also points to this bird being comfortably in range for HY male Allen's at an SI of 81.55. SI mean for Allen's is 80,45, range 75.11-83.49; SI mean for HY male Rufous is 85.25, range 80.69-90.28. Fat on this bird was scored as 1. No pin feathers or sheathing were noted on its wing, tail or body feathers. The inner primaries 1-5 were fresh and recently grown in as were some of the wing coverts. The tail had moderate wear on the tips. The bird was released in good health. He continued to feed and remained in the banding area while we watched him and packed the banding gear.

Technical information

Model

Canon EOS 7D Mark II

Lens

EF100-400mm f/4.5-5.6L IS II USM

ISO

1000

Focal length

400 mm

Flash

Flash did not fire

f-stop

f/5.6

Shutter speed

1/1600 sec

Dimensions

1625 pixels x 1300 pixels

Original file size

1.38 MB