Friday, August 8, 2008

Hummingbirds: Gentleman Feeders

I wondered why it is that the Hummingbirds seem to settle down and feed fairly peaceably together once the day came to an end. From early in the morning I hear their buzzing and all day they display and dive-bomb each other, each bird intent on claiming a feeder, or at least a feeder-port it seems, to himself. But at night I regularly find as many as eight or ten birds at every feeder.


I’m reading Dan True’s book Hummingbirds of North America (Thanks again BosqueBill!) and it’s all clear now. Mr True, meteorologist, pilot and bird expert, has been studying the little birds for nearly a lifetime. He tells of how a team at the Rocky Mountain Biological Laboratory, near Gothic, CO, rigged scales with a perch; scales accurate to 1/100 of a gram. All day long, the scrappy little birds were weighed each time they landed on the perch. What was discovered was that, while the hens at normally all day, the males weight increased only 1-2% during the day, but in the evenings their weights went up as much as 40% in just a few feedings!


The author, who flew a Spitfire 1 fighter plane in his military career, compares the logic of fueling planes with just enough fuel for an hour and a half of air-time, including 15 minutes of dogfight time, to exactly what the Hummingbirds are doing. Fuel is heavy and burdensome; keeping lightweight means faster acceleration and more nimble aerial combat sorties…even for birds.

During courtship a Hummingbird’s high-speed dives reach 64 MPH; the yo-yo patterned dives and pendulum swings (done facing the sun to enhance gorget colors), and zooms upward again some 20-50 feet need an athletic bird, one capable of spectacular ‘combat moves’…a light-weight bird not carrying the burden of extra fuel. The males feed only lightly following each flight to chase a rival and left serious re-fueling to the evenings. Lightness equals aerial superiority…even for the birds.


So, that’s why as evening comes the bickering quiets, the zooming settles down and everybody seems to call a truce. It’s time to eat.

From:

  • Hummingbirds of North America: Attracting, Feeding & Photographing by Dan True/University of New Mexico Press

  • Bill Calder, 1991/Rocky Mountain Biological Laboratory, Gothic, CO

11 comments:

lkw said...

Enjoyed the post! 'Our' ruby-throated hummingbird males chase each other vigorously, and I'm inspired to watch their behavior at dusk. We normally have a couple through the summer, and then the migrating hummers through mid-Oct. But ~ 5 -6 at a time has been the most we've seen, during fall migration. There are three at the moment.

What sorts of hummingbirds are these?

Beverly said...

Lisa, thank you so much. I think I'm still trying to find 'my voice' here. I appreciate your comments while I cast about and find out just what it is I want to do here.

I could not begin to tell you which birds were what in that photo, but throughout the blog I have pictures of all four of the hummers who are hanging around:
Broad-tailed (the green buzzers), Black-chinned (the tail pumpers), Rufus (beautiful chocolate brown backs), the very tiny Calliope Hummingbird with the awesome gorget. I was out tonight a bit earlier trying for a better shot; I'm quite sure there were at least 25 or 30 Hummingbirds in my yard! It's wonderful...

Bosque Bill said...

Seems to me, in a totally non-scientific study, the females are also more cooperative and focused on feeding at the end of the day. My take is that everyone wants a full tummy before settling down overnight.

Glad you are enjoying your new books.

Beverly said...

Oh, yes yes! In fact, while some might be immature males...there seems to be very few males in my nighttime photos. However, what I've noticed is that more males come even later in the evening. I was shocked to find hummers feeding outside my window quite late; long after 'dark' had set.

I recently read (somewhere) that many hummingbirds die at night; a sad thought but one that makes sense for a bird which must feed at least every few hours during the day. As you know even chickadees die in the night during foul weather if they don't get to roost with a full belly.

Some, but not all hummers go into 'torpor' while sleeping; to conserve energy. Most only do this during inclement weather but either way…it doesn’t always work. I’m happy to keep the feeders full (and clean!) for these little dynamos.

I have a question for you, if you don't mind. Will you discribe here, or on your Hummingbird Page, how and with what you took your beautiful pictures? I'm curious if you used extra lighting like True suggests?

Bosque Bill said...

My photo technique is simplicity itself. I'll describe it now and add it to my site, per your good suggestion.

1. Stand right next to feeder, as close as 12" to 18", in favorable natural light.

2. Manually focus on feeder so your autofocus won't set itself on the background.

3. Hold very still with camera pointed to where you expect the hummer to be. It will take a few minutes for the birds to become accustomed to you and ignore you completely.

4. Click when hummer is in front of your camera.

Not much of a technique is it? When I was trying to get the Calliope, which feeds only intermittently, I used a tripod just so my arms wouldn't get tired holding the camera while I waited (I kept my hands on the camera ready to snap); otherwise the technique is the same.

I found I could slowly move the camera a little bit, to aim at one side of the feeder or the other, without frightening off the birds. If you have a digital camera, you may be able to hold the shutter release partway down (you can feel the detent) which sets the exposure and makes the process of capturing the image quicker. You will get lots of out-of-focus and out-of-frame shots, so if you are digital take lots and lots of photos, then just save the good ones. I used the viewfinder, not the screen, to frame my shots as the screen is hard to see in the bright light.

Beverly said...

Yummoooo! I like simplicity!

Thanks, Bill; I love what you put on your page, too! KISS, huh? [grinz]

Chas S. Clifton said...

I had noticed the "evening truce" at the hummingbird feeder, and it's interesting to know its physiological basis.

Beverly said...

Zoe Ann, please stop trying to use my blog to hawk your wares. The information you try to leave here is inane at best, is often incorrect and is sometimes downright dangerous for the birds.

I would not recommend people purchase your book or articles regarding birds; few people would consider themselves expert after watching birds for "a year or so" and you clearly do not have a grasp on much more than how to make a dollar.

Beverly said...

[shakes head] Sorry about that… ugg.

Nice to see you here again, Chas! Yeah, Dan True’s book is full of really interesting stuff!

Hey, guess what; there’s a bird walk up in the Wet Mountains next Saturday! Apparently it’s a popular one, too; near Westcliffe. Let me know here and I’ll send you the details.

MOE said...

I live in Virginia on the Chesapeake Bay, I have 10 hummingbirds. I love them, they fight, and drink alot. I put up 8 feeders, started out with 2 hummers, and then one day the others showed up. Nature has some wonderful creatures. I can watch them for hours, I can drive down the road and hear them in the trees, cool. Enjoyed this site, thanks

Beverly said...

Why thank you Moe...thank you very much!