the color Purple

As I look around at flower gardens in my backyard and in my neighborhood, I see a lot of purple.  Where the first flowers of spring seemed to be largely pink in color, the first flowers of summer seem to be mostly purple, a color that is not all that common in plants.  Why so much purple, and why now?

The intensely violet color of spiderwort flowers is on one end of the purple spectrum.

False Indigo flowers are another example of intensely dark purple color.

Purple is for the bees, and especially the solitary bees which are the most abundant and hearty pollinators we see in cool spring and early summer weather, before honeybees and butterflies have become active.  Bee eyes can detect light wavelengths in the ultraviolet part of the spectrum, and it seems that plants have adapted their floral displays to guide the bees right to the places on the flower where their search for nectar or pollen will do the flower the most good (i.e., pollination).

Streaks on the landing platform petal of the iris are probably visible to bees in the ultra-violet range.

One study with bumblebees in Germany showed that naive bees were highly attracted to flowers in the ultra-violet to blue range of wavelengths, and those flowers tended to produce more nectar or nectar with higher sugar concentrations than flowers of other colors.  Purple flowers that attract solitary bees tend to have the highest sugar concentration in their nectar (20-50% sugar), compared to yellow and red hummingbird and butterfly flowers that average around 20-22% sugar in the nectar.

The bell flower petals look homogeneously lilac to our eyes, but what do they look like to bees?

The variation in “purple-ness” of early summer flowers is due to the proportion of anthocyanin pigment in the flower in response to the pH of the soil environment.  In the presence of acid (or hydrogen ion), the pigment is red (or pink), whereas in the presence of nitrogen base the pigment is blue, and in the presence of aluminum, it is violet.   So, you can change the colors of your hydrangea or forget-me-nots by what you put in their soil.

Magenta-colored clematis flowers are the result of a redder expression of anthocyanin in a more acid cellular environment.

Flowers of this penstemon are pink-purple, based on the reaction of the anthocyanin in a more acid pH.

Bachelor’s Buttons, native of Europe, grows best in basic soils, which accounts for its deep blue color, and the bees seem to love it.

Purple is a coveted color in the garden, because of its rarity, and the ephemeral nature of purple flowers.  Looking back in our own history, we find that limited resources and the labor-intensive process used to create the color purple made it an expensive luxury, indulged in only by the most wealthy or by royalty.  Regardless of expense, its calming (blue overtones), yet energizing (red hues) make purple a favorite color.

Back in April

The great migration of songbirds is mostly over, and the “pretty birds” have moved on to their northern breeding grounds.  Several people have commented on what an amazing spring it was this year, with so many migrants congregating in backyards everywhere.

Swainson’s Thrush was almost a common backyard bird as they stopped off to search through the fallen leaf litter for something to eat.

Apparently the extreme cold weather and snow we had back in April stalled the migration, with birds piling up just south of us, waiting for better weather and northerly winds.  Elsewhere the migration stalled where extreme flooding occurred in Iowa, Missouri, and Nebraska.

As we returned north from Texas through the Plaines states in late April, we just missed the massive concentration of waterfowl that had briefly taken up residence in Loess Bluffs wildlife refuge in northwestern Missouri.  It wasn’t easy to get to the refuge because there was flooding with road closures all around it.  The refuge itself was also flooded, but we could still drive part way around it.

Redbuds were in bloom. Flooded pools that were full of migratory waterfowl two weeks earlier in the background.

Extensive wetlands attract a variety of waterfowl, especially Snow Geese.

May Apples were just about to bloom in the forests on the Loess Hills.

A month earlier, the refuge had an enormous population of Snow Geese stopover for refueling on their northward migration.  The Kansas City Star newspaper reported that on March 5, there were about 20 Snow Geese on the refuge, and a week later there were 1.3 MIllion!  Imagine the mess 1.3 million Geese would leave behind.  Maybe it’s a good thing the water levels were so high.

The scene on the refuge on March 15, 2019. Photo from the Kansas City Star.

There were still quite a few Snow Geese on the refuge (far away across the water in the background) in late April.  But what is of interest in this shot is the horde of Tree Swallows (small black dots on the cattails in the middle of the pond) spending a few nights in the marshes fattening up on insects.

We made a sunset drive through the refuge and spotted a few of the residents.

Lots of Great Blue Herons

Another GBH

Another GBH, in a scene looking like abstract art.

A pair of Sandhill Cranes moseying along the bank.

Turkey Vultures were congregated at the outlet of this large pond, where there was a bunch of stinky, dead fish.  The last golden rays of the setting sun almost made this bird attractive…

After reveling in the spring weather of northern Missouri, we headed home to MN, where the leaves were still in buds on the trees.

Breakfast toad

Filet of toad, a delicacy for a Red-Shouldered Hawk, was on the menu for one hawk that swooped down about 30 feet from me while I was photographing a couple of Redstarts (featured in the last post).

I saw the bird land silently and immediately spread its wings over its prey. This “mantling” behavior is done to conceal their kill from the eyes of others.

I thought the bird might have a mouse in its beak.  This is a juvenile bird, probably from last year’s brood.  You can just barely see the red shoulder patch, but it hasn’t acquired all of the adult’s distinctive barred striping on the breast.

Red-shouldered Hawks are forest or forest-edge birds, unlike their more open country counterparts, the Red-tailed Hawks.  These are usually the birds that we hear screaming at roosting owls in the forest in the daytime — owls that are likely to nab one of the hawk’s chicks right out of its nest.

Cropping in a little tighter, the supposed mouse does look like an amphibian with its webbed feet, most likely a toad, since frogs don’t usually venture this far from water.

Red-shouldered Hawks have a varied diet of small mammals, amphibians, snakes, as well as nestling birds.  They typically sit quietly in a tree just below the forest canopy, near water, and wait until something moves that looks edible, and then pounce, just as this bird did. Their phenomenal eyesight helps them detect the smallest quiver of grass or leaves that indicates a prey item.

The click of my camera’s shutter must have alerted the bird to my presence, because it suddenly turned, looked straight at me, and took off, flying straight toward my head and then over it.  I was too stunned to raise the camera and get a photo of it coming at me though.

I wonder if this was one of the offspring from the pair of Red-shouldered Hawks I photographed in my neighbor’s backyard last year, as they were being mobbed by crows.

The pair settling in to their nesting territory in early spring last year.

Later in the summer, I photographed the pair again, when they were defending their nest (and chicks) perhaps from an owl perched nearby.

Warblers in the woods

What a week it has been!  Rain, wind, cold weather, all combined to keep the migratory warblers hunting low in the vegetation.  And they were so frantic to find something to eat, they pretty much ignored the photographer stalking them.  Here are a few of the ones I saw in the back yard this week.

Dozens of female Redstarts flitted through the vegetation, barely pausing for a second to pose.  The yellow spots on the tail that are flicked often as the bird moves, makes her easy to spot.

Probably the most common birds seen in the backyard this week, male and female American Redstarts.

The second-most common Warbler in the backyard this week, the Chestnut-sided Warbler has a bright gold cap, and chestnut sides! They were everywhere, including the front lawn.

Chestnut-sided Warbler perched on a twig on the lawn, on the lookout for insects.

American Redstarts and Chestnut-sided Warblers may stay around this area to breed, or might move north to southern Canada, nesting in the deciduous forests in northern and northeastern U.S.

But others will be on the move much farther north. And since the early bird gets the best nesting spot, they will have to fuel up quickly on this stopover and continue north soon. Magnolia Warblers and Canada Warblers, like the Tennessee Warblers in the last post, migrate to the coniferous forests in northern Canada to nest.

It was really challenging to photograph this Magnolia Warbler who was on a mission to find something to eat, darting from branch to branch, in and out of the sun, never stopping.

Taking time out to sing, the Canada Warbler looks somewhat like a Magnolia Warbler but has a necklace of black without stripes down its breast and a beautiful yellow eye ring.

Wilson’s Warblers prefer the stream and forest edges in far northern Canada or mountainous areas of the U.S. and nest in low vegetation, unlike most of their warbler cousins. They are so ubiquitous across northern Canada in the summer that they are probably viewed migrating through almost all of the lower 48 states.

Wilson’s Warbler has a black cap on its yellow head, and moves much more slowly than Magnolia!

The great migration is about over, and spring wildflowers are finally on the way in greater numbers.  It’s been a cold start to the summer this year.

I wanted a photo of yellow birds on the yellow violets in the back yard, but it was not to be…

the nectar thief

Each year, the Ohio Buckeye tree outside my porch window puts out a prodigious number of flower spikes, which reliably attract a few pollinators and one clever nectar thief.

Pollination of these flowers is sufficient for the tree to produce copious quantities of nuts, which are harvested by the squirrels in the fall.

Hummingbirds, bumblebees, and orioles visit the Buckeye tree in the spring, along with a horde of Tennessee warblers.

Tennessee Warblers arrive just as the Buckeye tree is in full flower. How do they manage to time it just right?

Tennessee Warblers really have nothing to do with the state of Tennessee, but do migrate through there, where they were first seen and named way back in 1811.  Like many small insectivores they spend the winter in the tropics, eating insects and nectar, and breed in the Canadian spruce forests where they specialize on spruce budworm and are critical to controlling outbreaks of the moth there.

Though they do visit flowers to consume nectar, they do not perform much of a pollination service for the plants, because they use their sharp beaks to pierce the flower at its base to get at the nectar at the bottom of the flower tube, thus avoiding the pollen on the anthers sticking far out of the flower.

Note where the beak is positioned to the side of the flower at its base. Pollen might inadvertently stick to the bird’s head or breast as it bumps into the anthers, but it might be hit or miss in depositing the pollen on the stigma of another flower.

Their beak is slightly open as if they are biting the flower to open a small hole in its base.

They only visit for a few days each spring, so I guess this must be the peak of their migration through MN this year.  You can see a light dusting of pollen on this bird’s neck and breast.

The sugars in the nectar will be metabolized and stored as fat and should provide these tiny little birds (about 2/3 the size of a chickadee) with the fuel they need to get to the Canadian spruce forest to breed.

(these photos shot with the Sony RX10 iii bridge camera through my porch window — what an amazing little camera!)

A weekend of birds and flowers

We drove to Lincoln, Nebraska for a wedding, and on the way we stopped to census the bird life with a few other birders at Weaver Dunes Nature Conservancy preserve in southeastern Minnesota: the day’s total was 77 species, and among them 14 species of warblers!  This was part of the Nature Conservancy’s one-day state chapter competition.  Last year MN came in second, and the pressure was on to beat Texas this year.

It took six people to find a Blue-headed Vireo in a tree.

Female Downy Woodpecker working on a nest hole — one of the 77 species we saw.

A rustic looking barn on a farm across the road from the preserve.

Prairie Violets covered the ground on some of the dune slopes, the first spring flowers blooming here.

Even the lichen were “blooming”: British Soldiers lichen with their bright red fruiting caps on gray-green stems, usually found on rotting stumps like this one.

I had a Sony RX 10 camera I was trying out on this trip, so before the wedding, we headed over to the Sunken Garden in Lincoln to see what was blooming.

Lots of mosquitos on the water lilies, but no frogs to enjoy them.

I don’t know what these trees were, but their new leaves were brilliant salmon red and pink.  The red pigment in new leaves protects them from sun damage before the leaves have synthesized their chlorophyll pigment.

 

Black and white tulips — that’s a little different.

Spiderwort growing by a waterfall made a nice contrast.  The camera has a wide range of shutter speeds for special effects, like silky water,

Quite a camera this Sony RX10, with its fixed 24-600 mm lens. And it weighs about 1/10 of what Big Bertha (my SLR and telephoto combo) does.  Something to consider when you need a multipurpose, lightweight travel camera.

A busy day at the rookery

April and May are busy months at Smith Oaks Audubon Sanctuary on High Island, east of Houston.  Great Egrets and a variety of other long-legged waders nest in high density on an island in the middle of a rather large pond.

Some nests are almost within pecking distance of each other. Great Egrets and Roseate Spoonbills are among the earliest nesters here.

The Island is surrounded by water, patrolled by alligators, which keeps potential coyote and raccoon predators from predating the chicks.

Great Egrets are still sporting their breeding plumes, which flair out with the wind,  and are used to attract a mate with an elaborate display.  Unfortunately, thousands of these birds used to be shot each year to collect the decorative plumes to adorn ladies’ hats.

Great Egrets are the symbol of the National Audubon Society, which was initially founded to protect birds from being killed for their feathers.

It looks like this pair are incubating eggs, which have to be turned in the nest every so often to ensure optimal development of the embryos.

The Great Egrets are well into their nesting phase, with some birds standing over their half-grown chicks and others still sitting on eggs.  Males build a large nest platform that may be as much as 3 feet across.  Once he attracts a mate to his nest site, the couple work together to finish the nest, adding a foot-thick layer of sticks to make the nest cup.

There are at least two, very vigorous chicks in this nest, which were beating up in each other until one parent interceded.

These birds typically lay more than 2 eggs, but begin incubating right away. This means the last egg laid in a clutch of 4, for example, hatches four days after the first egg laid, and the youngest chick will be a a great disadvantage in trying to compete with its larger nest mates.  In years when there is plenty of food, it might survive, but its larger siblings might steal its food or pick at it with their sharp beaks, and often this runt doesn’t survive.

Typical sibling rivalry…

A royal courtship

The East Beach of Galveston Island seems to be an attractive hangout for shorebirds trying to fatten up on the easily caught fish in the shallow bays.  But there was more than eating on the minds of the Royal Terns congregating there among the Brown Pelicans, Laughing Gulls, Skimmers, and other small shorebirds.

What is going on with those crown feathers that look like mohawks on the two Terns on the right? Is that just wind, or some kind of social signal to other Terns?

There are definitely some preliminaries to courtship going on between the three terns in the foreground.

Terns doing a sort of funky high-step dance…

Now this is getting a little more serious, with a presumed male offering a freshly caught fish to a presumed female.

She is going to make him work for it, as she walks off, exhibiting her lack of interest in him, or the fish. Perhaps she just ate?

Courtship feeding is common in many bird species and is supposed to demonstrate to the female what a great hunter and provider the male is.  In some cases, it may provide females with the extra protein and fat they need to produce a clutch of eggs after the energy drain of migration.  However, in this case it may be that many suitors and many fish equals a disinterested partner.

[Note added:  In cases where females have refused a fish, it was because it was too small!]

The objective of the ritual of courtship is to attract a compliant female to accept his gift of sperm. But not to attract a crowd of onlookers, like Laughing Gulls.

And so another foraging trip, to pick up another fish, as the Royal (Tern) courtship proceeds.

Shooting at eye (or foot) level

Most of the time I have photographed birds that were above or below my head, and it’s hard to get an accurate representation of their body shape and they way they move in their environment that way.  In photographing some shorebirds in our bird photography workshop we tried to get down at their eye level, sitting low or lying on our stomach.

This Clapper Rail, usually a secretive bird hidden in tall marsh grass, was lured over to a speaker playing rail calls on the side of the road.

Patience, grasshopper, the bird will eventually come out of the marsh grass.

Some of us could get lower than others.  The danger in getting too low is that the bird’s feet might be hidden from view. I (on the right) opted to sit higher and shoot with the camera in a lower position using the flip screen and live view on my camera.

Down on the gulf shore, we sat in the sand and photographed shorebirds coming to some bait left on the beach.

Sanderlings were uninterested in the bait, and never paused while probing in the sand continuously for small invertebrates buried just below the surface.

A Ruddy Turnstone, however, picked up some of the shrimp left on the beach.

A Willet walked over to a crab left on the beach but was put off by the Turnstone’s defensive posture.

But then a couple of herons realized there was free food available and wandered over, coming within 20 feet of where we sat in the sand.

What a pose! And what enormous feet.

And here came the Black-crowned Night Heron to check out the bait.  Sitting low really paid off getting a shot of the feet on the bird’s approach.

Do you think this bird has seen bait buckets before?

Yes, it has.

Stalking a Kildeer nest

“Would you like to see (and photograph) a Kildeer on its nest?” our fearless leader and master bird photographer, Alan Murphy, said one morning during our photography workshop in Galveston. And thus began the nest stalk and another learning experience about how to approach birds for close-up photography.

One of the Kildeer pair guarding its nest (somewhere in this little path of gravel in a residential lawn), and wary of our approach.

Using our collapsed tripods like a walker and creeping forward on our knees, with faces hidden behind the camera, we slowly narrowed the distance between us and the bird.  And then waited…and waited…until finally the bird relaxed and settled back down on the nest.

The bird approached this spot from one direction, then ran back, then approached from a different direction, and repeated this several times before standing over the nest and gradually hunkering down over it.  But despite our low angle kneeling in the grass, we can’t see the nest, just the bird sitting.

So, we moved ever so slowly, doing the tripod “walker” creep to one side of the nest where there was a clearer view.  That of course flushed the bird off the nest, and we began another waiting period of knee agony.

One of the pair calls to the other to come to the nest, perhaps for defense?

And off they ran, into the lawn, to lead us away from the nest.

But we’re waiting, kneeling behind our tripods and cameras, letting the birds get used to the foreign, hopefully non-threatening, objects near their nest.  And patience pays off, as one of the pair returns to settle on the eggs.

I didn’t see the eggs until the bird actually approached and stood over them. Their camouflage in the gravel is really good.

Slowly fluffing out the breast feathers to surround the eggs and allowing the eggs to come into contact with bare skin, the bird slowly settles over its nest.

And now we leave this pair alone, to continue their parental duties of incubating their developing chicks.

Kildeer eggs in the nest

The Kildeer nest is simply a scrape in the gravel, where the eggs lie with pointed ends toward the center (usually). Their irregular shape ensures that they will roll in a circle near the nest, not away from it. And the splotchy pattern on the shell blends in nicely with the dirt and gravel. (Photo by Debbie Reynolds)

i would never have thought we could approach a nesting bird like this and get this close.  But patience, and some knowledge of what a particular bird will tolerate pays off in the end.  A good learning experience.