Mornings in the backyard

I’ve spent the last few (early) mornings sitting in a blind or a chair watching Ruby-throated Hummingbirds feed on the flowers in the backyard garden. Occasionally a male visits, but he is wary, hiding behind flowers where he is obscured from view. Two other female or juvenile hummers are bolder and will hover in full view on flowers about 20 feet away. Here are a few of my attempts to capture the action:

Oops, right search image, but wrong flower — a gladiola not open yet.

The reluctant male that couldn’t seem to face toward me to show off his gorgeous magenta bib.

I always thought Cardinal flower was the favorite target of hummers, but it turns out they like Salvia better.

Manuevering between closely spaced flowers gives you an appreciation of their aerodynamic capabilities.

Even by just entering part way into the flower, a hummingbird can tell whether there is a nectar reward there or not using taste receptors at the tip of their long tongue. This visit lasted less than a second.

To be effective at pollinating a flower, the hummingbird must insert its beak all the way in so that the flower’s reproductive parts, particularly the pollen on the anthers, will rub off on its head, as seen below.

Hummer is getting dusted with pollen on the top of its head; that pollen will rub off on the protruding female stigma of an adjacent flower the bird visits.

Ruby-throated Hummers have glittering green feathers on their back, which blends in well with the vegetation. So, at rest, they can be hard to spot.

Below is some HD video I took of one hummer.  You might not be able to see the video if you are reading the blog from your email, so go the blog post itself by clicking on the title of the blog in the email.  In the bottom right corner of the video are three icons. Click on HD to enable that view (recommended), or on the icon that looks like a speedometer to slow the action to 0.5 real time (also recommended). Click on the right-most icon to view in full screen mode (best view). It’s difficult to appreciate the incredible control these hummers have over their position in space until you slow it down. Click on the X in the top left corner after the video finishes to return to the blog post.

To learn more about the coevolution of cardinal flower and hummingbird pollinators, click here: https://bybio.wordpress.com/2013/08/17/a-perfect-fit/

it’s all in the tongue

Have you ever wondered how hummingbirds manage to slurp up the nectar in a flower so quickly?  Rarely do they pause at one flower for longer than a second or two before moving on.

ruby-throated-hummingbird-on-cardinal-flower

Female Ruby-throated Hummingbird feeding on Cardinal Flower in my wildflower garden

Occasionally we get a glimpse of a long tongue protruding from their bill when they exit the fake flower on a feeder.

hummingbird-sticky-her-tongue-out-tj-baccari

Female or juvenile Ruby-throated Hummingbird (Photo by TJ Baccari)

But how does that tongue work to enable them to sip so quickly?  Initially, it was thought that the tongue was merely a long capillary tube that drew the nectar up through cohesive action of fluid droplets.  But that is much too slow a process.

High-speed videography by researchers at the University of Connecticut has revealed that a hummingbird’s tongue expands rapidly from a flattened ribbon inside the bill to a forked pair of open tubes as the tongue is protruded into a feeding tube or flower nectary.  The tongue moves in and out of the bill 15 times a second, expanding and compressing as it moves in and out of the bill, and that pumping action is what delivers the nectar to the mouth so rapidly.

hummingbird tongue-1

You can see the expanded tongue segments immersed in the nectar in this screen capture from a high-speed video taken by the University of Connecticut researchers who made this discovery.  Science Daily, August 19,, 2015.

A short video illustrates this much better than I can explain it.

https://static01.nyt.com/video/players/offsite/index.html?videoId=100000003892113

ruby-throated-hummingbird-approaching-cardinal-flower

I never tire of learning about the wonders of nature.

Shooting under

Under what?  Under challenging light conditions, underneath your subject, under-exposed? All of the above?  I learned an important lesson in how to use my equipment that made a big difference in the outcome.  What I discovered about light metering and exposure values might not be news to seasoned photographers, but it might save some frustration for other beginners out there.

Let’s say you want to take a decent photo of a Ruby-throated Hummingbird, sitting up high on a plant in a brightly lit environment.

ruby-throated hummingbird

The bird is very pale, with its white belly and throat and pale green back. In fact, it’s the brightest thing in the well-lit environment. You have four choices on most SLRs for metering the light in this scene. Here’s what happens when you set the light metering mode to evaluative metering (the default mode that measures light across the whole frame).

ruby-throated hummingbird-overexposed; scene exposed with evaluative metering mode

All the details in the bright white subject are lost, and frankly the focus is not as sharp as it should be because the edges are washed out. The background looks nice though.  Evaluative metering would be a better choice for a landscape.

The most appropriate metering mode for this type of shot (small, bright object in the middle of a darker field) is spot metering, which measures the light intensity just in the circular area around the spot on which you focus (i.e., the head or other high contrast area on the bird).  The result looks more like the first photo — better contrast and better detail.

Pushing this focus on the light intensity of just the bird a little further, I decreased the exposure compensation by one stop (i.e., underexposed), and I like the result even better.  The details are much sharper in an underexposed photo, and the black background kind of makes the bird just pop out of the photo.

ruby-throated hummingbird-underexposed-using spot metering

For even more dramatic contrast, even more underexposure produces something like this.

ruby-throated hummingbird-underexposed

I am 20 feet below the bird, so the background is very dark.  Spot metering is necessary, and undexexposure helps highlight the subject.  The bird is sticking its tongue out at me.

The Digital Camera World website has some excellent discussions of subjects like this – here’s a link to one on Metering Modes that explains all four light metering modes very clearly.

From the blind…

The hummingbirds have been quite active lately in the wildflower garden, so I set up the blind this morning to see if I could capture some of the action.

a blind for wildlife photography

I don’t normally keep so much of the window space open — just enough to poke my telephoto through the open space toward the garden.  The blind is about 10-20 feet from the plants the hummers prefer.

There seem to be four hummingbirds buzzing around the cardinal flowers and the nectar feeder — one very shy but aggressive male, and three female-looking birds that could be a female and her two juvenile offspring.

Ruby-throated Hummingbird on cardinal flower

Lots of bees in this photo as well as the hummer probing the red cardinal flower

Ruby-throated Hummingbird

Every now and then, one would perch on the tomato cages in the vegetable garden, about 10 feet away.

My goal was to get some photos of the very shy (or wary) male Ruby-throated Hummingbird who dashes in to drink from the nectar feeder, but rarely goes to the flowers.

Ruby-throated Hummingbird male

He seems bigger than the others and has a darker throat, so he is easy to spot, but very difficult to photograph.

Ruby-throated Hummingbird male

He even hides behind the nectar feeder, giving an obstructed view of his ruby throat.

Ruby-throated Hummingbird male

At last, one quick shot of him next to (instead of in back of) the Cardinal Flowers.  Those wings beat 53 times a second while they hover, so cranking up the shutter speed is required.

The hummingbirds are probably feeding voraciously now, stockpiling calories to store as fat for their long migratory journey south to wintering areas in Mexico and Central America.  Apparently a particular hummingbird follows the same route each year, but they don’t migrate in a flock, nor do young hummers necessarily follow their parents.  They just know the way south.

Bees, birds, and butterflies

The wildflower garden was really “humming” with activity this morning. Perfect weather combined with maximum bloom of the wildflowers has drawn a variety of wildlife in.

wildflower garden

The scene on a mid-August (feels like fall) morning.  You can’t see them in this photo, but there are dozens of bees, mostly bumblebees, working the flowers.

tiger swallowtail butterfly on obedient plant

At least two and possibly three Tiger Swallowtail butterflies roam the various flowers looking for the best nectar supplies.  This one seemed to enjoy the Obedient plant nectar.

ruby throated hummingbird on cardinal flower

Ruby-throated Hummingbirds are back, just as the Cardinal flower has reached maximum bloom. They actually seem to prefer the flower nectar over the sugar water in the HB feeder.

goldfinch-male-and-female-pair on cup plant

And of course, the Goldfinches are everywhere, picking off the seeds from all the flowerheads.

goldfinch-on-gray-headed-coneflower

They don’t like the Black-eyed Susan as much as the Cup Plant (above), but any composite flower will do for these guys.

A perfect fit

Ruby-throated Hummingbirds love red flowers.  In my garden, they particularly like the Cardinal Flower, which sends up 4 foot tall stalks with a bright red plume of flowers that develop sequentially from bottom to top of the stalk over a 4-6 week period. Apparently, it produces some really good nectar too, because it is the first flower they visit in the morning.

Here I come -- bring out the nectar.

Here I come — bring out the nectar.  This little female Ruby-throated Hummingbird was extremely cooperative, foraging for several minutes on a clump of cardinal flowers, while I sat in a very hot blind about 15 feet away.

Sometimes the probing is just a test to see what might be there, as the bird tastes with the tip of its tongue.

In this shot, her bill is inserted only part way into the flower, and her head is completely clear of the flower structures.

In this shot, her bill is inserted only part way into the flower, and her head is completely clear of the flower structures.  This foraging position won’t accomplish what the plant intended the bird to do in return for a nectar reward.

When there is sufficient nectar at the base of the flower, hummingbirds hover for several seconds in place while they mop up every drop.  In this case, the bird’s head almost disappears into the flower as it inserts the bill all the way in.

It looks like the hummingbird is getting a pat on the head from the flower.  In this case, the bird is indeed performing a vital service for the plant -- moving pollen from one flower to another.

It looks like the hummingbird is getting a pat on the head from the flower. In this case, the bird is indeed performing a vital service for the plant — moving pollen from one flower to another.

The bill of the Ruby-throated Hummingbird is the perfect size and shape for this flower.  When it dips its bill deep into the base of the flower, the top of its head brushes a fringe of anthers which deposit pollen on the surface of its head feathers.  Later when it visits a different flower, perhaps on a different plant, the pollen will be rubbed against that flower’s stigma, adhering to the sticky surface.  If it is the right type of pollen, it will germinate and a pollen tube will grow down the stalk supporting the stigma (the style) into the ovary. Sperm can then leave the pollen grain, swim down the tube, and fertilize the ova to begin the process of seed production.

The contact between the stigma of the flower and the

The contact between the stigma of the flower and the hummingbird’s head is more obvious in this close-up.

Hummingbirds don’t care which flowers deposit pollen on their head, but the plants want to ensure that a particular flower receives pollen from a different individual (i.e., avoid self-pollination).  To maximize the potential for out-crossing, Cardinal flowers develop the male parts first — promoting pollen donation, and after a few days, the style and stigma emerge to protrude beyond the anthers — promoting pollen reception.

The anthers look like a white fuzzy fringe on the stalk that sits above the petals and the opening of the flower.

The anthers look like a white fuzzy fringe on the end of a gray stalk that sits above the petals and the opening of the flower.  The flower on the left shows the pink stigma just beginning to grow beyond the level of the anthers.  The flower on the right is newer and does not yet have female reproductive parts showing.

A mature Cardinal flower, with the stigma (and style) protruding beyond the anthers.  This stigma could easily pick up pollen from the back of a hummingbird's head.

A mature Cardinal flower, with the stigma (and style) protruding beyond the anthers. This stigma could easily pick up pollen from the back of a hummingbird’s head.

Coevolution of cardinal flower structure and Ruby-throated Hummingbird sugar appetite has made this system a perfect fit for both.

The End.

The End.

Mighty mite

The summer blooms are at peak color in the garden, and there is a bouquet of red, pink, purple, yellow, orange, and white right now.  They are a month late, but finally we are seeing quite a few bees of all sorts and a few butterflies in the garden.  For the past week, another tiny visitor has been making the rounds of the red and orange flowers.

It's hard to believe that these Butterflyweed flowers have enough nectar in them to make them worthwhile to a hummingbird, but the bird keeps coming back for more.

It’s hard to believe that these Butterfly weed flowers have enough nectar in them to make them worthwhile to this female Ruby-throated hummingbird, but she keeps coming back for more.

She sampled the flowers of the cup plant, but those were really duds, as were the bee balm, and the coneflowers.  But red cardinal flowers were promising, although only a few were open.

She sampled the flowers of the cup plant, but those were really duds as far as nectar is concerned, as were the bee balm and the coneflowers. But red cardinal flowers were promising, although only a few were open.

Of course the fall-back is to tank up on the sugar water in the feeder.

Of course the fall-back is to tank up on the sugar water in the feeder.

Ah, that's better.

Ah, that’s better.

After all that feeding, it’s time for a rest, to process some of that liquid so she doesn’t have to carry it around.

You don't often see hummingbirds perch, but if they are, chances are there will be some voiding of excess liquid occurring.  Best not to stand under the tree where they perch.

You don’t often see hummingbirds perch, but if they do, chances are there will be some voiding of excess liquid occurring. Best not to stand under the tree where they perch.

Ruby-throated Hummingbirds weigh less than 4 grams, but can store up to 1 ml of nectar in their digestive tract while they process the nutrients in the nectar.  If we assume that 1 ml weighs about 1 gram (as plain water would), then the bird has just gained 25% of its body mass during its feeding bout, and it doesn’t make sense energetically to try to fly with all that extra weight.  The Hummingbird gut is specially adapted to absorb sugar and other nutrients in nectar across the lining very quickly and efficiently, removing more than 90% of the calories in the nectar on its first pass through.  Then the excess liquid in their diet can simply be excreted in just a few minutes.

Doesn’t that give them a sugar-high?  I suppose it does, but hummingbirds can also quickly metabolize that sugar and turn it into body fat, which they will use to keep them warm overnight.  Altogether an amazing metabolic marvel, the mighty mite.

Good Question! — Hummingbird courtship revisited

One of the great things about blogs is that people from all over everywhere find your blog and ask good questions in their comments that then stimulate me try to find an answer.

Hummingbirds seem to engender a lot of comments from readers, one of whom asked whether Anna’s Hummingbirds were the only ones that made such death-defying courtship flights.  As it happens, Ruby-throated Hummingbirds, those tiny little flying machines that manage to migrate from eastern North America over the entire Gulf of Mexico without stopping, also engage in the same “bullet falling from the sky” courtship behavior.  They don’t go as high, but they swoop down from about 45-50 feet, pull up, and fly up again in a U-shaped pattern, which they repeat over and over.

(photo from Wikipedia:  http://en.wikipedia.org/wiki/Ruby-throated_Hummingbird)

To answer the question of how much stress there is on a male hummingbird during his courtship flight, I found a report in the New Scientist on exactly that subject.  Chris Clark (biologist at UC Berkeley) found that male Anna’s hummingbirds travel a distance of 400 times their body length per second during their head-long dive.  That is almost twice as fast as a stooping Peregrine Falcon! As they pull out of their dive, the male hummingbird’s body undergoes centripetal acceleration of 10Xg forces, which is enough to make blood drain from your head to your toes and cause a human to faint dead away.  Even trained jet fighter pilots will pass out above 7Xg acceleration.

Male Anna’s Hummingbird display dive compiled from high speed video (from UC Berkeley News, January 30, 2008).