www.thefilemyrs.com > Birding > Bird Pictures > 2013 > Wintering Rufous Hummingbird
Molt on Wintering (2012-13) Female Rufous Hummingbird
Hummingbird Wing and Tail Feather Designations
primary flight feathers on a hummingbird are the ten (10) large flight
feathers closest to the end of each wing. They are numbered with the outermost
primary feather being p10 and the innermost being p1.
hummingbird has ten (10) tail feathers. These tail feathers are called
retrices and are divided into five (5) tail feathers per side. The tail
feathers are numbered from the inside out with retrix one (r1) being the
two tail feathers in the center and retrix five (r5) being each tail feather
on the outside.
are pictures of the female Rufous Hummingbird wintering in Meadowbrook,
Montgomery County, PA. These pictures are in chronological order with the
newest being at the top.
12, 2013 - (at the top) (she reappeared after bring absent for
several days) - Visitation Day #179
6, 2013 - Visitation Day #173
April 3, 2013
Visitation Day #170
Visitation Days #167
Visitation Day #166
Visitation Day #163
Visitation Day #160
22, 2013 - Visitation Day #158
Visitation Day #152
2013 - -
Visitation Day #148
10, 2013 -
Visitation Day #146
March 7, 2013
3, 2013 - Visitation Day #139
2013 - Visitation
21, 2012 - Visitation Day #67
- Visitation Day #3
Click here to see the feeder and photography setup.
Picture 27 - April 12, 2013 - There still seems to be missing primary flight feathers. Compare with Picture 1
Picture 26 - April 12, 2013 - There should be 10 flight feathers and this does not seem to be the case.
Picture 25 - April 6, 2013 - When you compare this image with the inset image taken in October it is obvious that she is missing several primary flight feathers. The relationship between the length of the primaries and the tail can be easily seen.
Picture 24 - April 6, 2013 - (Another inconclusive wing shot)
Picture 23 - April 6, 2013 - (The small amount of white showing on the right side of the tail is probably r3, r4, or r5)
22 - April 3, 2013 - (Comparing this picture with picture
20 taken 3 days ago, it appears that the r1s continue to grow. The priimary
feathers seem to be short but that may because of missing flight feathers. The
Sibley Guide to Birds states that in this species the "tail projects
slightly beyond wingtips". Obviously this is not the case in this individual
at this time.)
Scott Weidensaul comments: "The central rects have come in nicely."
21 - April 3, 2013 - (There appears to be flight feathers
that have been shed and new ones have not come in yet. I will leave it up to
experts to determine what primary feathers are there and which are missing.)
Scott Weidensaul comments: " It's hard to be sure, but it looks like she's lost p 9 and 10 - unusual to lose both at once, and impossible for me to be certain, but that's my guess."
Scott Weidensaul commented further after looking at wing pictures from 4/4: "Because she's also molting secondaries (and because on hummers there's no obvious break between pp and ss, as on many birds) I can't simply count back from the body, but I'm almost certain she's missing p 9 and 10 - the outer feathers on both sides don't have the right shape for either feather, and there are no contrast with newer feathers that was visible on p9-10 in earlier pictures."
20 - March 31, 2013 - (The tail seems to have molted
Scott Weidensaul comments: "...looks like the R1s are about finished, and have a more pronounced "nipple" than I recall seeing when I banded her"
19 - March 30, 2013 - (The primary feathers seem short.
She might have shed a couple.)
Scott Weidensaul comments: ".....hummers are almost unique in that they usually molt p10 before p9, so they have one of those two feathers in place and supporting most of the torque pressure of wingbeats (usually the new p9, because p10 is normally so worn and weakened). But she looks as though both of the outermost primaries are gone."
18 - March 24, 2013 - (Tail molt continues. A gust of
wind lifted up an uppertail cover allowing a better view of the changes in the
tail. Also notice the difference in the fresh upper body feathers as opposed
to the worn lower body feathers.)
17 - March 27, 2013 - (Wing molt conitinues)
16 - March 24, 2013 - (Tail molt continues. She seems
to have lost some back feathers.)
Scott Weidensaul comments:
"Because the latest (3/24) photos seem to show smoother white edges on the protruding tail feather, I suspect she's now lost at least R3, maybe R4."
Picture 15 - March 22, 2013 - (Tail molt continues.)
Picture 14 - March 21, 2013 - (Tail molt continues.)
13 - March 21, 2013 - (Wing molt continues.)
Scott Weidendaul comments:
"The flight photo from March 21 seems to show almost completed growth of p 7-8, though, which I think is going to be the crucial factor in when she migrates. We often see birds migrating in active body molt (some saw-whets are full of sheathed feathers) and we get hummers in fall, both RUHU and RTHU, that migrate with body molt. I'm just not sure what effect the tail molt will have on her migration schedule, but she has to be pumping a lot of energy into growing new rects, and I'd have to think that's a drain on her resources."
commented after seeing a couple of poor quality photographs which are not posted:
"She's in active primary and secondary molt, but the primaries (p8 and 7, by the looks of it) are more than half grown in, so the gap isn't as obvious. Hummers diverge from the usual molt pattern in birds, where replacement starts with p1 and goes out the wing to p10; instead they replace p7, p8, p10 and does p9 last - it's the biggest primary, and the theory is that by molting a fresh p10 first, there's less aerodynamic loss than there would be in losing p9 and depending on a very worn p10.
I'd be willing to bet she'll finish growing p7-8, then suspends molt while she migrates and finishes p10-9 on the breeding grounds…bunt we'll see. The rects are probably far less important for flight than pp and ss, so maybe she'll make the trip with them still missing.
and Scott commented further after seeing this photograph plus additional photographs.
"looks like p8 may in fact be missing, with p7 mostly grown in…and that would be s1 halfway grown (unlike most birds, there's no easily discernible distinction between primaries and secondaries, but p1 should have molted long ago, so I assume p8 is missing and the growing feather is s1). There appear to be missing innermost secondaries, too."
Picture 8 - March 14, 2013 - (Uppertail coverts continue to grow.)
7 - March 12, 2013 - (She has shed both R2s, uppertail
coverts continue to grow.)
Scott Weindensaul commented "By 3/7 she'd molted her major coverts, by 3/10 she'd molted both R1 rects, and by today she'd molted both R2s, so the only remaining tail feathers are R3-5 on both sides, all of which are tipped with white. The March 7 photo seems to show a gap in her folded primaries, as well." and also ".... most birds don't double up the physiological stress of migration and significant molt at the same time (though they often undergo body molt while migrating - saw-whets certainly do)."
Picture 6 - March 10, 2013 - (She had shed both R1s, uppertail coverts continue to grow.)
Picture 5 - March 7, 2013 - (Her new uppertail covers are growing)
Picture 4 - March 3, 2013 - (She has shed her uppertail coverts)
Picture 3 - January 23, 2013
Picture 2 - December 21, 2012 (photo by Scott Weidensaul)
Picture 1 - October 18, 2012
Setup of feeder and heat lamps (The lowest temperature this winter at the feeding station was 11 degrees F.)