UNUSUAL HUMMINGBIRD FOR IDAHO

ANNA'S HUMMINGBIRD -- Calypte anna

20-27 September 2004, Mtn Home, Elmore County

While not an unheard of hummingbird in Idaho, Anna's certainly is deserving of attention in this state. On the official Birds of Idaho Field Checklist, Anna's Hummingbird is listed as rare and local statewide during migration. There are typically at most two or three reports per year (and I personally suspect a much larger number that goes unreported). The origin of these birds is uncertain, but it is thought that fall sightings may be wanderers from breeding sites in the Pacific Northwest, perhaps Seattle, WA or Vancouver, BC.

On 20 September I went to the home of Ethel and Doyle Wilson in Mtn Home in an effort to band a few more Black-chinneds before the season ended. The second bird caught turned out to be a tail-less Anna's Hummingbird. No bill corrugations were visible and therefore I initially considered this bird an AHY (After Hatch Year; adult) female. However, in retrospect this species nests very early in the year and I wonder if it is conceivable that corrugations would be greatly reduced or absent by this time of year. The throat contained two noticeable pinkish gorget feathers, and several additional throat feathers that had light pinkish tips only. These were only visible in good light and at a very specific angle. There were no colored feathers on the crown. Based on this, I determined this bird to be a probable female, but the age (even sans corrugations) is still problematic. However, the shape of the secondaries (See Figure 6 below) provides evidence that this is indeed a young bird ("Hatch Year").

My leaning now is that this is a hatch year female Anna's, but without details in the retrices this question is still somewhat troubling. In fact, there may be some indication that the bird is even best left unsexed without tail features available. I seek comments from those having more experience with this species. If you have information that may help me determine the age and sex of this bird conclusively from these photos, please let me know. Also please indicate if I have your permission to reproduce your conclusions / reasons / comments in the section of this webpage below for the education of other readers. Thanks!

UPDATE: This bird was still present through the evening of 26 September, and maybe later. Jay Carlisle reports the bird was growing tail feathers (about 1/3 in by then) and the homeowners reported two hummingbirds still present for a couple more days, but they weren't sure if one was the Annas.

Many thanks to Doyle and Ethel Wilson for allowing me to study their hummingbirds, and for being gracious hosts to several people who wanted to observe this bird during it's stay.

MEASUREMENTS in hand: Exposed culmen: 18.02 mm. Wing cord: 48.59 mm. Tail length: (missing all feathers). Mass: 4.8 grams. Fat score: 2 on scale of 0-4.

PHOTOS (all © 2004 Stacy Jon Peterson; taken with Nikon Coolpix 4500, macro setting; contrast enhanced / sharpened, etc., on MS Picture It! Photo version 7.0)

Figure 1. The dusky throat feathers shown here appeared pretty much the same color in real life. Two feathers were noticeably pinkish in hue, and many of the other dusky throat feathers had light pinkish tips. but all this was only visible in good light and at specific angles. Would this suggest HY, or can AHY-F show this feature, too? Or would AHY-F show more distinct gorgets after a single year of life?	Figure 2. The dorsal surface of this bird was fairly bronze-green as shown. The crown was dingy grayish without any trace of irridescent rose-colored feathering. Note all tail feathers are missing, with no sign of pinfeathers. I suspect they were lost adventitiously for the most part -- and probably fairly recently at that.
Figure 3. The side view shows the typical Anna's face pattern and more green feathers on the flanks. The band is also visible on the left leg. However, some Black-chinneds (and other species?) can show incredibly large greenish gorget feathers, so caution is warranted.	Figure 4. Note the green flanks extending down onto the belly and the large dusky throat feathers, all good features of Anna's.
Figure 5. The open wing shows significant wing molt. Both p9 & 10 are brownish (old), which contrast in color with darker, new inner primaries (see also Figure 6). p8 is about 80% completely grown in, partially hidden by p7 in this photo, and retains the feather sheath. p5 was broken on this wing (but present and complete on the opposite wing), leaving the gap in the wing. Calypte hummingbirds are the only common ones in North America that are in active wing and tail molt during the summer. This bird was also in heavy primary & secondary covert molt, as well as body molt on the belly.	Figure 6. The old outer primaries (p9 & p10), the incomplete p8, new p7-2, and p1 (not visible but appeared to be in pinfeather still) are shown here. Note here that the top secondary is dark, new, and double concave (much more easily discerned when viewed in original high resolution photograph) and contrasts with the tan, round-tipped secondaries below it. This double-concave shape is indicative of AHY secondaries, while the round-tipped secondaries are features of HY birds. This suggests to me the bird is molting into AHY plumage. Right?

Comments From Members of the Hummingbird Research Community
(used by permission)

• Female ANHUs are indeed very difficult to age in fall and early winter, and "age = unknown" is sometimes the only reasonable option. However, age-related differences in molt timing may be helpful through early fall. I've noticed that females in primary molt this late in the season also tend to have dull gorgets with little or no red iridescence while those with fully fresh remiges also tend to have considerable gorget iridescence. Since this is consistent with the molt timing we see in males, I feel confident in aging females based on the presence/progression of primary molt. Once the molt is complete in HYs, things get much trickier, though gorget iridescence may still provide a clue. Based on this, I'd concur with Stacy's assessment of this bird as HY. As Stacy alluded, Anna's begin breeding much earlier than most species - by December over much of their range and as early as October here in SE AZ. This means that many juvenile-plumaged ANHUs are actually SYs, and even the genuine HYs are up to 9 months old by now. Strong bill corrugations are a nice age indicator if present, but in this species I don't think I'd rely on them for aging after June. Correlating age with molt progression and bill maturation is something that desperately needs doing in Anna's, preferably in a locale where individuals are year-round residents and can be studied intensively over months/years.
  -- Sheri Williamson, humbander, Bisbee, AZ
• We see very few HY ANHUs this time of year with corrugations and since molt is well underway, most of the birds are noted as age unknown.
  -- Barbara Robinson, humbander, Mariposa, CA
• I had HY ANHU without bill corrugations by the end of July, [determined to be] HY by rounded secondaries and males with incomplete gorgets. I have a word of caution about using the rounded ss [(secondaries)] to age ANHU: I find that the inner 3 frequently are rounded to some degree even in AHY birds. It is the outer 3 ss (1,2,3) that are the most useful. I also see ss that I call slightly rounded (not strikingly round) in both immatures and AHY females and thus not helpful to age. ... During our last two banding sessions (September), HY males had at the minimum 20% throat iridescence in centralized, dense area and some head iridescence. HY females (recaps) had scattered throat iridescence from approximately 0 to 30 individual feathers.
  -- Rita Colwell, humbander, Los Altos, CA
• ANHU rarely show corrugations at more than about 30% of the bill on the HY birds that I trap this time of year. I also see a growing number of HY birds with adult rectrices so they aren't always a help even if they're present. However, I'd lean toward a HY female [for this bird] for a couple of reasons (neither of which is really definitive). First of all, ANHU breed so early (possibly beginning in January even up here in the cold and rainy PNW) that they begin to molt surprisingly early -- I had an AHY male in body molt in early June. AHY birds around here now have pretty much completed flight feather molt while HY birds are showing the whole range from just beginning body molt to molting gorget feathers. I've even had one HY male already in full adult plumage minus a couple of crown feathers (I trapped it earlier this Spring/Summer so I'm sure of the age). Secondly, I rarely see an AHY female with no iridescent feathers on the throat while this isn't uncommon for HY birds.
  -- Dan Harville, humbander, Seattle, WA

If you have information to share regarding the identification of ths bird, I'm very interested in how you reached your conclusions. Please write your thoughts to: SJPeterson@aol.com. I would like to reproduce your comments above for the education of other viewers of this weg page. Please indicate your willingness in that regard.