Date: Fri, 31 Aug 2001 15:33:21 +0000
From: "Nancy L. Newfield" <colibri@GS.VERIO.NET>
Reply-To: BB for Hummingbirds and Gardening for them in the Southeast
<HUMNET-L@listserv.lsu.edu>
To: HUMNET-L@listserv.lsu.edu
Subject: Re: [HUMNET-L] Black-chinned: T.vs. C.

At 10:16 AM 8/31/01 -0500, Dennis Demcheck wrote:

>Regarding the club-shaped tips of the primaries of the Black-chinned:
>
>Two years ago I hosted a wintering Black-chinned. it was a classic
>trap-liner, but I was always able to see it briefly in the morning, and at
>least once more during the day.
>It took about 10 days of observing (about 25 quick looks) before I saw
>without any doubt the club-shaped primaries. This was during a grooming
>session. In my opinion, this field mark is good for your own yard on a
>regular visitor. However, it can really lead you astray if you only get
>one or two looks, no matter how perfect the lighting and angle is for those
>two looks.

I think you are correct on that, unless the bird perches on a feeder inches
from your window and permits a very close inspection. And, it is not
particularly useful on immature females. It is certainly good on adult
males [when you don't need it], on adult females, and on immature males, but
the distinction is not all that clear on immature females.

Nancy L. Newfield

+++++++++++++++++++++++++++++++++++++++++++++++++++++

Date: Fri, 31 Aug 2001 10:38:01 -0500
From: Van Remsen <najames@unix1.sncc.lsu.edu>
Reply-To: BB for Hummingbirds and Gardening for them in the Southeast
<HUMNET-L@listserv.lsu.edu>
To: HUMNET-L@listserv.lsu.edu
Subject: Re: [HUMNET-L] tail-pumping in Black-chinned

On Fri, 31 Aug 2001, Nancy L. Newfield wrote:

> Laurie Binford and [I think] Mike Seymour were looking at the actual manner
> in which Black-chinneds and Ruby-throateds move their tails. If the bird
> pumps its tail on arrival at the feeder or flower, but then holds the tail
> still while actually feeding, then it is usually a Ruby-throated. If the
> bird pumps the tail while actually feeding [while hovering], then it usually
> is a Black-chinned. I have watched a lot of hummers with this in mind and
> think they might be on to something. Of course, if the bird perches to
> feed, . . .

Nancy/HUMNET: there is chronic confusion on the use of tail-pumping as a
field ID character for Ruby-throated and Black-chinned. Here's the
problem. Ruby-throated, like all hummers, pumps its tail while maneuvering into
position -- hey, that's part of the reason WHY they have tails ... to
maneuver. But once the bird sticks that bill into the feeder or flower,
THEN Ruby-throated holds its tail steady (maybe an occasional nervous
jerk), but Black-chinned pumps virtually continuously, several times per
second. This is noticeble to the naked eye as far away as you can see the
bird. With an N of about 20 Black-chinneds at my place, this has worked
100% of the time (using other characters for independent ID as
Black-chinned). As for Ruby-throated, my N for feeding observations must
be in the 10,000 range, with ZERO cases of steady tail-pumping
while-drinking. Cardiff concurs from his observations down the street.

Although the tail-pumping observation was reported decades ago, I haven't
seen it explained correctly in print. Bottom-line = don't pay any
attention to tail-pumping UNTIL hovering bird inserts bill into
feeder/flower.

#################################

Van Remsen,
LSU Museum of Natural Science,
najames@unix1.sncc.lsu.edu

===================================================

Date: Sat, 15 Dec 2001 23:47:10 -0600
From: Nancy L Newfield <colibri@GS.VERIO.NET>
Reply-To: BB for Hummingbirds and Gardening for them in the Southeast
<HUMNET-L@listserv.lsu.edu>
To: HUMNET-L@listserv.lsu.edu
Subject: [HUMNET-L] Some Interesting Hummer Behaviors

Today, Gene and Edna Street and I watched an immature male Black-chinned
feeding at flowers at their LaPlace home. Occasionally, he "pumped" his
tail in the typical Black-chinned manner, but more often, this bird
"pumped" only a little as he approached the flower, then held still while
feeding - just like the way Van talks about Ruby-throateds doing.

Didn't catch the bird, but did see a couple of purple feathers on his throat.

NLN
*************************
Nancy L Newfield
Casa Colibrí

===================================

From: BB for Hummingbirds and Gardening for them in the Southeast <HUMNET-L@LISTSERV.LSU.EDU>
Subject: Re: [HUMNET-L] Rufous & Black-chinned in Temecula

In parts of Texas where the ranges of Rubythroateds and Blackchins overlap,
"wing buzz" can be quite valuable in separating male RTHU's from BCHU's --
especially in low light situations where the gorget color is not easily
viewed. As was discussed last year on Humnet, BCHU's have a discernible
wing buzz when they accelerate their wings to hover or zoom off (RTHU's
don't). It's not nearly as noticeable as the rattle from Broadtails, but
it's definitely there. You can listen to the wing buzz of a male BCHU on
enature.com (with a variety of other hummer sounds). The first half of the
recording has the typical 'humming' and foraging sounds while the latter
half has that distinct "a few bb's in a small metal can being shaken very
fast" type of sound. By the way, Sheri Williamson mentions the Blackchin's
wing buzz during her vaunted radio interview with the BBC.

Howard Williams
Dallas, Texas