Evolution and Ecology

Experiencing Animal Lives

Every seed is awakened, and all animal life.–Sitting Bull

Cooper's Hawk with Pine Bark, Edith L. Moore, Houston, Texas
Cooper’s Hawk with Pine Bark for Nest, Edith L. Moore, Houston, Texas. Canon 7D/500mm f/4L IS (+1.4x TC). Natural light.

Although Sitting Bull spoke these words in the context of spring, the vitality he sensed is present throughout the year. It is this very vitality we seek through birding and nature photography.

When we can pry ourselves from the grip of work and obligation, capturing images of animals going about their business puts us back in touch with the natural world and out of touch with the annoyances of Mankind . . . .

A Blue-winged Warbler Hunts Caterpillars, Lafitte's Cove, Galveston Island, Texas
A Blue-winged Warbler Hunts Caterpillars, Lafitte’s Cove, Galveston Island, Texas. The grapevines at Lafitte’s Cove are food plants for caterpillars eagerly gobbled-up by trans-Gulf migrant songbirds returning to North America from the Tropics. Canon EOS 7D/600mm f/4L IS (+1.4x TC), High-speed synchronized fill-flash.

One of our favorite photo-birding spots is open again (yay!) after being closed due to the devastation Harvey brought. The stretch from 40-acre Lake to Elm Lake at Brazos Bend State Park seems to have weathered the storm without too much damage–certainly less than the previous round of flooding.

Even the birding wasn’t too much off from a typical day this time of year. Marsh Wrens, Swamp Sparrows, and Common Yellowthroats were abundant. Northern Harriers hunted above the rice, and the air was filled with the clatter of Belted Kingfishers and the chittering of scolding Ruby-crowned Kinglets. I apparently just missed a male Vermilion Flycatcher and a small flock of Blue-headed Vireos. All in all a nice visit to a beloved place that will likely steadily improve . . . until the next catastrophe.

Baby Alligators on Mom's Back, Pilant Lake, Brazos Bend State Park, Texas
Baby Alligators on Mom’s Back, Pilant Lake, Brazos Bend State Park, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.
Calling Moorhen, Pilant lake, Brazos Bend State Park, Texas
Brazos Bend is Back! Calling Moorhen, Pilant lake, Brazos Bend State Park, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Fishing by the Sea

There is one knows not what sweet mystery about this sea, whose gently awful stirrings seem to speak of some hidden soul beneath. –Herman Melville

Reddish Egret (White Morph) with Shrimp, East Beach, Galveston Island, Texas
Reddish Egret (White Morph) with Shrimp, back beach lagoon, East Beach, Galveston Island, Texas. Canon EOS 7DII (+1.4x TC). Natural light.

The weather last weekend was nothing short of fantastic, so off to the coast we went! A stretch of beach with a collection of lagoons and tidal channels behind (just north of the Houston Audubon Least Tern nesting sanctuary) is one of our favorite birding spots on Galveston. Here, we saw a mix of the new and the familiar.

The birds were the usual suspects for this time of year, but we caught them doing something we’d not seen before: dining on a profusion of shrimp. We saw Reddish Egrets and Lesser Yellowlegs clearly grabbing shrimp. I also suspect that Neotropic Cormorants were eating them too, but I couldn’t document the interaction photographically. I have seen Cormorants eating shrimp before, but in freshwater.

Neotropic Cormorant with Fish, East Beach, Galveston Island, Texas
Neotropic Cormorant with Fish, back beach lagoon, East Beach, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

Elisa noticed that potholes on the bottom of a lagoon–that used to be a tidal channel, now walled off from the sea by a dune–were filled wth young shrimp. These potholes appeared to be abandoned fish nests. The Lesser Yellowlegs were clearly plucking shrimp from the potholes, whereas the Reddish Egret seemed to be grabbing larger shrimp from the water column.

In addition to shrimp being taken, a variety of fish, including shad and killifish were being gobbled up by cormorants and waders. The strand line was scattered with flocks of Sanderlings. A few Ruddy Turnstones and Black-bellied Plovers were in the mix. All of these species can often be seen scavenging carcasses washed up on shore. This day was no exception: An aggressive Ruddy Turnstone repeatedly ran off a cadre of hungry Sanderlings vying for carrion.

All in all, a spectacular, winter-like day. We can only hope for many more,

Ruddy Turnstone with fish, East Beach, Galveston Island, Texas
Ruddy Turnstone with Fish Carcass, East Beach, Galveston Island, Texas. Outside the frame are a group of Sanderlings waiting for the least weakening of resolve by the Turnstone. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Keeping an Eye Out for Ross’s Geese

Life is not a spectacle or a feast; it is a predicament.–George Santayana

Sandhill Cranes, Snow and Ross's Geese, San Bernardo National Wildlife Refuge, New Mexico
Sandhill Cranes with Lesser Snow and Ross’s Geese, San Bernardo National Wildlife Refuge, New Mexico. Ross’s Geese are much smaller than Lesser Snow Geese. Can you pick out the Ross’s Geese? Hint: there is one near the center in the foreground staring back at the camera. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

Huge flocks of waterfowl are one of the great spectacles of the fall and winter. Lesser Snow Geese congregate in wetlands and agricultural fields like those in and around Anahuac National Wildlife Refuge, Texas. At Anahuac, thousands of birds can dot the land and water and form swirling clouds, but we’ve only seen them from a distance, deep in the marshes or fields. Truth be told, I assumed that all the white waterfowl we’ve seen here in the past were Lesser Snow Geese. This is probably not the case.

Last Winter, on a road trip to New Mexico, we were able to get close enough to similar flocks to identify a few of the much smaller Ross’s Geese that could easily pass unnoticed. Ross’s Geese are rare visitors to Texas and New Mexico and are far fewer in number than Snow Geese, with which they have been know to interbreed.

Ross’s Geese are small and cute, with relatively stubby beaks and round domed heads, like baby animals. As a naturalist, the first word that entered my mind when I saw Ross’s Geese was neoteny. Neotenic evolution occurs when juvenile features are retained in the adult . . . .

Ross's Geese, Bosque Del Apache National Wildlife Refuge, New Mexico
Two Ross’s Geese Surrounded by Lesser Snow Geese, Bosque del Apache National Wildlife Refuge, New Mexico. Note the bluish patch near the base of the bill on the Ross’s Geese. Also note that several of the Lesser Snow Geese are blue phase (blue geese). Blue phase Ross’s Geese are also known but are rare. Canon EOS 7DII/600mm f/4 IS (+1.4x TC). Natural light.

Ross’s Geese are Arctic breeders whose lives were poorly understood until the recent past. In the 1930’s, they were thought to only number several thousand individuals. Snow Geese were in a similar predicament a few decades earlier. In recent times, though, both species have greatly expanded their numbers and now make up sizable flocks.

The standard adaptationist explanation for herds or flocks or animals is that there is safety in numbers. The chance of any individual being taken by a predator is low. A logical extension of this strategy would be to be a rare species in a much larger group of another species. Any attack by a predator on the group would most likely result in a member of the more abundant species being taken.

Could the rarity of Ross’s Geese, coupled with looking like a juvenile (and hence receiving gentler treatment from the other geese?), be a survival strategy? Every trip to the field provides more questions than answers and ample fuel for speculation.

Snow Geese in Formation, San Bernardo National Wildlife Refuge, New Mexico
Lesser Snow Geese in Formation, San Bernardo National Wildlife Refuge, New Mexico. One of these days I’ll get a Ross’s Goose in formation with Snow Geese either in Texas or New Mexico . . . but not this day. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Catching Birds in Action

Many great actions are committed in small struggles. –Victor Hugo

A Great Egret Shades its Young, Smith Oaks, High Island, Texas
A Great Egret Shades its Young, Smith Oaks, High Island, Texas. Even in March, the brutal Texas sun can kill delicate nestlings. Mom (or dad) to the rescue! Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

As I write this, we stand on the cusp of the best month of birding on the calendar! But for the past few weeks we’ve been (mostly) photographing our more typical species (year-’rounds, wintering or summering species) going about their business, not transients flying through from somewhere to somewhere else.

Singing Male Red-winged Blackbird, Pilant Lake, Brazos Bend State Park, Texas
Singing Male Red-winged Blackbird on Rice Plant, Pilant Lake, Brazos Bend State Park, Texas. The margins of Pilant Lake were filled with Red-winged Blackbirds (and their calls) on our last visit. What a nice change: The marsh sounds as it should. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

One of the more pleasant surprises of the past few weeks is the recognition that Brazos Bend State Park (BBSP) is starting to rebound a bit from the catastrophic floods of the recent past. It is still nowhere near the mecca for observing wader action that it was before, but day by day things are improving. It will be interesting to see if songbirds return for nesting in a big way. Elisa spotted a female Northern Cardinal building a nest just above water-line on Pilant Slough, and the trilling songs of Northern Parulas are everywhere. Can Prothonotary Warblers be far behind?

The Flip, Fiorenza park, Houston, Texas
The Flip, Fiorenza park, Houston, Texas. The catfish hunt goes on! This juvenile Neotropic Cormorant is attempting to maneuver a spiny armored catfish into swallowing position. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
White Ibis in Breeding with Beak-full of Invertebrates, Pilant Slough, Brazos Bend State Park, Texas
White Ibis in Breeding with Beak Full of Arthropods, Pilant Slough, Brazos Bend State Park, Texas. This bird has (at least) a spider, a water bug, and a metallic bronze damselfly in its beak at the same time. Water hyacinth is a nasty invasive, but it’s full of nutritious bugs! Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

As noted, wader action at BBSP is still a bit down from the best of times, but the patient observer can still see a few things occasionally. Especially prominent now are the American Bitterns. Bitterns can be seen hunting all over BBSP. On our last visit, we observed one confrontation between two birds on Pilant Slough. Soon calling and confrontations should be common, only to die away by May.

In any case, starting today, we’ll shy away from BBSP for a few weeks and visit Galveston more. Hundreds of millions of songbirds have started streaming across the Gulf of Mexico, and we’re not going to miss it! With luck, we’ll capture some of these birds in action  . . . Sipping from a flower, here, or grabbing a dragonfly, there. Can’t wait!

American Bittern with Crawfish, 40-Acre Lake, Brazos Bend State park, Texas
American Bittern with Crawfish, 40-Acre Lake, Brazos Bend State Park, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Looking American Bittern, 40-Acre Lake, Brazos Bend State Park, Texas
Looking American Bittern, 40-Acre Lake, Brazos Bend State Park, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Common Loons: Into Breeding Plumage

What we achieve inwardly will change outer reality. –Plutarch

Common Loon in Pin Feathers, Offatt's Bayou, Galveston island, Texas
Common Loon in Pin Feathers, Offatt’s Bayou, Galveston island, Texas. The tips of the pin feathers on the neck and head are pigmented black. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Common Loon in Pin Feathers, Offatt's Bayou, Galveston Island, Texas
Common Loon in Pin Feathers 2, Offatt’s Bayou, Galveston Island, Texas. This is the same bird as above. Note the shagginess of the pin feathers on head and neck. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

This week on Galveston, Common Loons could be seen in many stages of transitional plumage. Every bird looked slightly different. All the birds I saw had some degree of spotting on the wings, and so lacked the brown, scalloped pattern of nonbreeding wing plumage. I saw one bird with a shaggy mane of pin feathers (Thanks to S.M. for pointing out this bird!) and one bird in almost complete breeding colors—only a stray feather here or there needed to be pigmented.

Common Loon, Offatt's Bayou, Galveston Island, Texas
Common Loon in Transitional Plumage, Offatt’s Bayou, Galveston Island, Texas. This bird appears to be in nonbreeding plumage from the neck forward. Spots on the wings show the transition to breeding colors has begun, though. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Common Loon, Offatt's Bayou, Galveston Island, Texas
Another Common Loon in Transitional Plumage, Offatt’s Bayou, Galveston Island, Texas. This bird is a little further along than the one immediately above. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

Many birds were engaged in hunting behavior much of the time. I saw fish, crabs, and a single mantis shrimp (Squilla empusa) being taken. This is clearly the time of year to be gorging and fattening up. It’s a long way back to Canada and environs for the breeding season! A good deal of preening was also going on, likely related to molting and keeping feathers in shape for the big trip ahead. Two birds had already pair-bonded and spent a significant amount of time together–another reminder that breeding in birds is often a process that unfolds in many stages over much of the year.

Common Loon in (Nearly) Breeding Colors, Offatt's Bayou, Galveston Island, Texas
Common Loon in Breeding Colors (Nearly), Offatt’s Bayou, Galveston Island, Texas. This bird was more shy than many others and had apparently already pair-bonded. Another bird in less well-developed transitional plumage kept appearing in close proximity. Could shyness toward humans and pair-bonding behaviors be related? Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Grebes: Unique Foot-propelled Divers

Feet, what do I need you for when I have wings to fly?—Frida Kahlo

Eared Grebe, Offatt's Bayou, Galveston Island, Texas
Portrait: Eared Grebe, Offatt’s Bayou, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

Among extant birds, grebes have a unique method of foot propulsion. There are other foot-propelled divers, loons, for example, but these birds have significant webbing between the toes. The birds with webbed toes push themselves forward against the drag force of water. Grebes, on the other hand, have separate toes with stiff, collapsible asymmetrical lobes on each side. The lobes on the inside are larger than those on the outside. Grebes are also unusual in that their relatively short femora (thigh bones) are oriented perpendicular to the long axis of the body, and the toes beat along a complex dorso-lateral to ventro-medial path, rather than parallel to the direction of the body’s forward motion.

Diving Eared Grebe, Offatt's Bayou, Galveston Island, Texas
Diving Eared Grebe, Offatt’s Bayou, Galveston Island, Texas. Although grebes have a unique method of foot-propulsion, they look like many other submarine hunters (e.g., loons, mergansers, cormorants) from above the water as they dive after prey. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

The traditional interpretation of how grebes paddled through the water, and the one I was taught, is that the lobes of the toes would unfold during then power stroke to provide maximum drag to push against, and fold up to reduce drag on the the recovery stroke. A more recent interpretation is that the grebe foot acts like a (slotted) hydrofoil and provides a lift force that propels the bird forward from behind (Johansson and Norberg, 2001)–physically similar to the way in which a wing allows a bird or airplane to fly. The lift hypothesis has an immediate visceral appeal to me given the asymmetrical lobes of the toes—like the vanes of a flight feather. Lift is usually explained by elementary physics textbooks as the result of the Bernoulli principle, essentially the conservation of energy for a moving fluid. This explanation is not correct quantitatively. The true explanation likely involves the most terrifying of all physics concepts . . . turbulence . . . . 

Diving Eared Grebe, Offatt's Bayou, Galveston Island, Texas
Diving Eared Grebe 2, Offatt’s Bayou, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

As a photographer on the surface, I haven’t been able to document the strange way in which grebes move through the water. Once and a while, when conditions were right, I have been treated to a glimpse of the legs in motion as in the image below. Swimming with grebes is one more activity to add to an already lengthy bucket list.

I mentioned at the opening that grebes were unique among extant birds. Hesperornithiformes, a group of toothed Cretaceous foot-propelled diving birds, are thought to have had a method of propulsion similar to grebes and to have possessed asymmetrically lobed individual toes. On a recent visit to the New Mexico Museum of Natural History in Albuquerque, I had the opportunity to study the feet of a life-sized model of Hesperornis regalis, the largest of these Cretaceous divers from the Kansas Chalk Sea. Reading the label . . . sure enough, reconstruction supervised by Dr. L. D. Martin, my late (paleo)ornithology professor, a gifted teacher with so many fascinating stories to tell about the lives of birds. . . .

Diving Eared Grebe, Offatt's Bayou, Galveston Island, Texas
Diving Eared Grebe 3, Offatt’s Bayou, Galveston Island, Texas. Offatt’s Bayou is a great place to see Eared Grebes hunting in winter. Texas City Dike is another. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

While grebe-watching, I am always interested in seeing these birds return to the surface with prey. In my experience along the Gulf Coast, Eared Grebes rarely return to the surface with prey. After dozens of dives, I have seen only one small fish clamped in a beak. This means that grebes are either remarkably unsuccessful hunters (unlikely), or that they can swallow small prey underwater (likely). Pied-billed and Least Grebes can be seen with large prey on the surface like fish, crawfish, frogs, and dragonflies. Perhaps small prey may be easily swallowed in the submarine realm, whereas large prey items may need to be manipulated into an ideal orientation in the air. In any case, grebes are certainly among the most interesting subjects for study and observation. Elisa doesn’t have to ask me twice to go grebe-watching!

Pied-billed Grebe withCrawfish, Elm Lake, Brazos Bend State Park, Texas
Juvenile Pied-billed Grebe with Crawfish, Elm Lake, Brazos Bend State Park, Texas. In the past, Brazos Bend SP was great place to see Pied-billed Grebes hunting year-round. Recent flooding has decimated the ecology of the park, and water birds are no longer abundant. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

Reference

Johansson, L.C., and Norberg, U. M. L. Norberg. 2001. Lift-based Paddling in Diving Grebe. The Journal of Experimental Biology 204: 1687-1696.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

 

Cooperative Feeding in American White Pelicans

Birds are the most popular group in the animal kingdom. We feed them and tame them and think we know them. And yet they inhabit a world which is really rather mysterious. –David Attenborough

Line of American White Pelicans, East Beach, Galveston Island, Texas
Line of American White Pelicans, East Beach, Galveston Island, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

Frankly we haven’t gotten out much lately. This is a function of terrible weather and just plain exhaustion. The prospect of fighting traffic on a gloomly, humid 85° day in February hasn’t held much charm. Spending time indoors has led to combing through the photo archives and pining for past years in which we had a proper winter.

One of the things we would have been watching for this week, had we been outdoors, is the cooperative feeding behavior of American White Pelicans. Whenever I see these birds I stand in awe, just waiting for them to so something neat. Is there anything more majestic in American birding than a string of White Pelicans paddling in formation along the shallows searching for schools of fish?

American White Pelican Feeding Frenzy, East Beach, Galveston Island, Texas
American White Pelican Feeding Frenzy, East Beach, Galveston Island, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

American White Pelicans are known to cooperatively herd fish into the shallows by beating their wings. On Galveston, a fairly common sight is a line of White Pelicans suddenly forming a circle, beaks pointed inward, and gobbling up a school of fish (presumably).

Pelican Phalanx, East Beach, Galveston Island, Texas
Pelican Phalanx, East Beach, Galveston Island, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

Once the feeding frenzy is over, the birds turn around within their circular formation and reassemble into their line and continue paddling along peacefully . . . until the next school of fish.

After fishing, East Beach, Galveston Island, Texas
Back in Line, East Beach, Galveston Island, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

The Situation on the Ground (with Squirrels)

Digging in the dirt
Stay with me I need support
I’m digging in the dirt
Find the places I got hurt . . . . —Peter Gabriel, Digging in the Dirt

Golden-mantled Ground Squirrel, Beaver Meadows, Rocky Mountain National Park, Colorado
Golden-mantled Ground Squirrel, Beaver Meadows, Rocky Mountain National Park, Colorado. This curious and charming little ground squirrel is common throughout its range in the western U.S. and southern Canada. Happily, there are no known specific threats to its continued survival. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

When  birds are not around, the bird photographer must find other critters to photograph. Often that honor falls to ground squirrels and kin! As is my usual methodology, I research the animals I encounter in the field. Just as in the case of birds, ground squirrels tell a mixed story of success and struggle in a human-dominated world.

Not surprisingly, we’ve really only seen ground squirrels that are doing pretty well (for the most part) since we haven’t yet mounted specific expeditions to see and photograph the rare and threatened ones like the Mohave, Townsend’s, or Washington ground squirrels. Make no mistake, some ground squirrels are battling for survival against many of the same menaces facing birds–habitat destruction, cats, and poisons.

Black-tailed Prairie Dog, near Roswell, New Mexico
Black-tailed Prairie Dog, near Roswell, New Mexico. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

Although technically considered a species of “least concern,” the areal extent of Black-tailed Prairie Dog colonies has fallen to about 2% of historical levels. Considered by many farmers and ranchers to be pests (Get the bazooka, Joe!), these burrowing rodents are lynchpins of their local ecology. They have many interesting ecological relationships with a variety of other organisms. Birders might be concerned about their fate given their role as prey to a variety of raptors including Red-tailed and Ferruginous Hawks and Golden Eagles. Also, Burrowing Owls will nest in prairie dog burrows (and the burrows of many other mammals, as well). In 2004, the black-tailed prairie dog was removed from consideration for endangered status based on population studies. One wonders what the level of concern would be if the range of human distribution decreased by 98% in a century and a half. I bet everyone would think everything was OK.

The rock squirrel is a suspicious fellow we see occasionally on outings in West and Central Texas and Arizona. This is a big, dark chunky squirrel that is way more timid than one would expect given its heft. Try and flush one of these characters into a pillowcase, BM! At places like Franklin Mountains State Park and Lost Maples State Natural Area, these seed-hogging marauders can often be seen emptying the bird feeders of seeds. In contrast to the prairie dog, this is not a popular squirrel among the birds—nor likely anyone maintaining a seed feeder within its range (Get the blunderbuss, Bob!).

Rock Squirrel, Arizona Sonora Desert Museum, Tucson, Arizona
Think what you will of me: I am serene (For now. As long as you stay there. And don’t move). Rock Squirrel, Arizona Sonora Desert Museum, Tucson, Arizona. This squirrel is showing me his hands so I know that he is unarmed. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

Although relatively little is known about its ecology, the Uinta ground squirrel is easy to spot at Yellowstone National Park. There are no known threats to its survival, especially since a big chunk of its limited range falls within that park in Idaho, Montana, and Wyoming. These critters are considered by some farmers to be agricultural pests (Arm photon torpedoes, Scotty!) because of their unforgivable tendency to dig and root up plants.

Now that we’ve seen quite a few species of squirrel, tree and ground, I have started paying more attention to them. When in a strange place, I’ve stopped assuming every squirrel I’ve seen is a common species (or subspecies) I’ve seen a hundred times before. For example, turns out a patch of habitat we bird occasionally (Cave Creek, Arizona) is home to the Mexican fox squirrel. Maybe next time I’ll capture a nice image of this cheeky critter!

Uinta Ground Squirrel, Yellowstone National Park, Wyoming
“Get yer finger offa the trigger, amigo! I’m keepin’ my hands where you can see ’em!” Uinta Ground Squirrel, Yellowstone National Park, Wyoming. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Birding the First Pleasant Weekend of Fall

It’s very far away,
It takes about half a day,
To get there, if we travel by my, uh . . . dragonfly—Jimi Hendrix, “Spanish Castle Magic”

Gray Catbird, Lafitte's Cove, Galveston Island, Texas
Portrait: Bathing Gray Catbird, Lafitte’s Cove, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

Well, it finally happened. After five brutal months, the first cool front of fall 2016 arrived. And we returned to the field. In just a few weeks’ time, I found that my photography skills had atrophied a bit, but in an hour or two I was getting some nice shots again. On Saturday, I visited Lafitte’s Cove and found Prothonotary, Palm, and Magnolia Warblers, a lot of Gray Catbirds, Brown Thrashers, and mosquitos without number.

Golden silk orb-weaver spider cutting leaf free from web, PIlant Lake, Brazos Bend State Park, Texas
Golden Silk Orb-weaver Spider (Nephila clavipes) Cutting Leaf Free from Web, Tower Trail, Brazos Bend State Park, Texas. A moment later the leaf tumbled to the ground. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

On Sunday, we visited Brazos Bend State Park and observed a flood-disrupted ecosystem. Major portions of 40-acre, Pilant, and Elm Lakes were covered with invasive water hyacinth, and hunting waders, the birds we love to see most at the park, were nearly absent. Here and there, large patches of dead hyacinth revealed where park employees had sprayed herbicide. At both Lafitte’s Cove and BBSP, the real story was about arthropods, though, and at BBSP we spent an extended visit with naturalist friend and park volunteer R.D., from whom we learned more about spiders and dragonflies.

Golden silk orb-weaver with moth and dewdrop spider, Pilant Lake, Brazos Bend State Park, Texas
Spiderweb as Micro-habitat: Golden silk orb-weaver with moth and dewdrop spider (Argyrodes sp.), Tower Trail, Brazos Bend State Park, Texas. Every so often the smaller spider would run down and touch the moth—only to run away before the monster could strike. Canon EOS 7DII/600mm f/4L IS (+1.4x TC).

Along the tower trail at BBSP we saw many golden silk orb-weaver spiderwebs. In many webs, entrapped prey and fallen leaves could be seen. We observed several instances of spiders cutting leaves free from their webs. Perhaps the most interesting phenomenon we observed was dewdrop spiders stealing food from the web of their host. Dewdrop spiders are kleptoparasites of the Genus Argyrodes. Although some researchers have questioned whether or not dewdrop spiders were harmful to the orb-weavers (and therefore not parasites), recent studies have documented that the host spiders suffer nutritionally and must repair damage to webs caused by the small spiders as they remove entangled prey. Apparently spiders take better care of webs that they themselves spin!

Anax junius caught in orb-weaver web, Pilant Lake, Brazos Bend State Park, Texas
Anax junius Caught in Golden Silk Orb-weaver Web, Tower Trail, Brazos Bend State Park, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

The green darner (Anax junius) migration was in full swing, the air filled with millions of these large dragonflies, many mating. Lots of other dragonfly species were zipping around, too. Black saddlebags (Tramea lacerata), many also coupling, even seemed to predominate at Lafitte’s Cove. Dragonflies are an important food source for birds, and I have seen several species of waders (Snowy and Cattle egrets, and Little Blue and Green Herons) and one species of warbler (Prothonotary) eat them at BBSP.

Although dragonflies seem to be a favorite food among birds, orb-weaver spiders seem not to be. Big, juicy spiders sit right out in the open while predatory birds typically operate all around them. The orb-weavers would certainly be easier to catch than a dragonfly. Perhaps the arachnids taste bad. I have heard anecdotally, though, that during drought years the orb-weavers essentially disappear from the park. Does this mean that birds will eat them if they get hungry enough? Other possibilities do exist (like humidity-sensitive fungal infections of spiders or eggs), but the report is certainly food for thought.

Little Blue Heron wiht Anax junius, Brazos Bend State Park, Texas
Little Blue Heron with Male Anax junius Dragonfly, Pilant Lake, Brazos Bend State Park, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

©2016 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Birding the Past

Remembrance of things past is not necessarily the remembrance of things as they were.―Marcel Proust

Pileated Woodpecker, Pilant Slough, Brazos Bend State Park, Texas
Pileated Woodpecker in Nest Cavity, Pilant Slough, Brazos Bend State Park, Texas. In a pinch, with a little imagination and a suspension of disbelief, the Pileated Woodpecker could pass for the extinct Ivory-billed Woodpecker . . . Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

The world is old. The world is new . . . .

Over the past few weeks we’ve made a few tepid efforts to get back into the field, mostly binocular birding. After an hour or so, I was dragging along on my heels, round-shouldered, and dripping with sweat. But the first hint that fall might arrive someday is in the air in the early, early morning hours. The sky and clouds may have just a hint more peach and pink. It’s not quite so broiling, at least for a few of these early hours.

Down at Bryan Beach we did see a few things of note. Horned Larks were hunting insects among the beach flotsam. A Ruddy Turnstone was engaged in a life-and-death battle with a large buprestid beetle. This year’s crop of young Wilson’s Plovers were everywhere. In a previous post I remarked about how much this area reminded me of the the great Western Interior Sea of the Cretaceous Period . . . .

Redwood Forest, southwest Oregon
Redwood Forest, Oregon Redwoods Trail, Siskiyou National Forest, southwest Oregon. This could be a scene from the Jurassic Period. The understory is mostly ferns, and the trees are conifers, Coastal Redwoods (Sequoia sempervirens) and Douglas fir. Sequoia conifers date back to the Late Jurassic Epoch. Mosses and ferns are far more ancient. The dark giant shapes slipping through the trees are sauropods. Canon EOS 7DII/Tokina 11-16mm f/2.8. Natural light.

Like Billy Pilgrim, I sometimes find myself free of the confines of a particular time. Growing up on a land shaped by glaciers–moraines, eskers, and potholes–and half the year covered in drifting snow, whipped up into sparkling wisps, it was easy for a kid to stare squinting into a world that dissolved into Clovis hunters in fox and ermine parkas, perhaps, like Eskimos, sporting stylish ivory sunglasses, pursuing herds of mammoths and musk oxen across the ice-pack.

From time to time, I find myself in haunted places that make such time travel easy.

Gray Jay, Hoh Rainforest, Olympic National Park, Washington
Spirit Guide: A Friendly Gray Jay, Hoh Rainforest, Olympic National Park, Washington. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

The Hoh Rainforest of the Olympic Peninsula is one such place. Russell Cave is another. The Hoh Rainforest is a misty woods, its mightly conifers draped in moss, and the forest floor covered in ferns. In such forests 150 million years ago the proto-birder could likely have heard the squawking of Archaeopteryx or Microraptor in the canopy as they waited for a stegosaur to lumber past. But steer clear of the giant bison hunters of Russell Cave. They’re a rough lot.

Russell Cave National Monument, Alabama
Russell Cave National Monument, Alabama. Human habitation began in Russell Cave during the Archaic Period, around 10,000 years ago. Archaeologists think these Native Americans occupied the cave mostly during winter. Canon EOS 7D/Tokina 11-16mm f/2.8. Natural light.

For a minor creative project I’m working on, we took a trip to Mercer Arboretum and Botanical Garden. I was interested in taking a few images of primitive plants in the Prehistoric Garden. In the garden are a number of types of plants representing groups that date back to the Mesozoic Era, and in a few cases even the Paleozoic Era. We saw the maidenhair tree (Gingko biloba), ferns, tree ferns, cycads, dawn redwood (Metasequoia glyptostroboides), and several strangely wonderful Araucaria conifers (including the Moreton Bay pine, A. cunninghami, and the bunya-bunya, A. bidwillii).

Spinkled throughout the gardens we saw other plants of nearly equal antiquity. Magnolia and sycamore, for example, date back to the Early Cretaceous Epoch. On this trip we even saw a tyrannosaur eat a guy! I swear!

Cycad, Prehistoric Garden, Mercer Botanical Garden, Humble, Texas
Cycad Fronds, Prehistoric Garden, Mercer Botanical Garden, Humble, Texas. Stare into a cycad understory today with impunity. Were it the Jurassic or Cretaceous Period, you might not like what was staring back! Canon EOS 7DII/50mm f/1.4. Natural light.

©2016 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Color Variation in Breeding Male Orange Bishops

I have called this principle, by which each slight variation, if useful, is preserved, by the term of Natural Selection. –Charles Darwin

Male Orange Bishop, Buffalo Run Park, Missouri City, Texas
Male Orange Bishop, Buffalo Run Park, Missouri City, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Photo taken July 13, 2016. Natural light.

On our most recent visit to Buffalo Run Park in Missouri City (8/6/16) it seemed that some of the Orange Bishops (Euplectes franciscanus) were a different color than during previous visits. In mid-July, I thought that all the males were orange and black (with a muddy orange-brown mantle) and a hint of red in the throat.

The redness of the throat was heightened when the birds went into display mode as you can see in the images immediately above and below. The red color could be structural (due to the physical optics of the feather), a result of pigmentation, or both. It seems likely that this red color could be in part structural, like the colors of a hummingbird gorget, but for reasons discussed below it seems unlikely that the red is due to this alone.

Displaying Male Orange Bishop, Buffalo Run Park, Missouri City, Texas
Male Orange Bishop in Display Mode, Buffalo Run Park, Missouri City, Texas. This is the same bird as at the top of the post. This bird was displaying into the sun. Coincidence? Note the red in the throat and upper chest. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

On August 6, I saw a number of birds that were clearly more red than orange. Because the difference was so striking, I wondered if these redder birds were actually a different species, namely the Southern Red Bishop (Euplectes orix). Some quick research revealed that the Southern Red Bishop is not kept as a pet for some reason and thus not likely to be found in pet shops, the ancestral source of the Buffalo Run birds. Also, although very similar in general appearance to the Orange Bishop (aka, Northern Red Bishop), the black face mask of the southern species extends around the bottom of the lower bill into the throat. The birds at Buffalo Run Park, then, are clearly the northern species.

Color in birds is a fascinating and complex subject involving some rather difficult physics and biochemistry. Color can be a function of both pigmentation and physical optics (interference and diffraction) of light as it passes through the feathers. Reflection from lighter feathers beneath the outer feathers is also implicated in some avian colors. Interestingly, the color of birds can be affected by diet, especially in the case of yellows, reds, and oranges which are derived from ingested carotenoid compounds.

As a test of whether the red color in the redder Orange Bishops was structural, I was sure to capture images of the birds facing into and away from the sun (below). I would expect differences in appearance if the color was structural, much as a hummingbird looks different when illuminated from different angles. I noticed no change in color due to direction of light in the case of the redder bishops. Likewise the orange Orange Bishops appeared very similar facing into and away from the sun, with the exception of the throat. The two birds above are facing into the sun, and the bird in an earlier post was facing away from the sun.

For these reasons, I suspect that pigmentation is involved in the red of these birds. But this begs a number of other interesting questions. If carotenoid pigments are often involved in the warm colors, and these compounds are found in the diet of birds, how is it that bishops look the same in Africa as Texas? Surely they are not eating exactly the same plants. Or are they? Is it natural for bishops to redden into a deeper red later in the breeding season? If so, is this due to diet or genetics or both? Are the red versus orange birds simply a matter of individual variation, the stuff of natural selection? A few hours chasing African birds around on a sweltering Texas morning has provided more questions than answers.

Redder Male Orange Bishop, Buffalo Run Park, Missouri City, Texas
Redder Male Orange Bishop, Buffalo Run Park, Missouri City, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Photo taken on August 6, 2016. The camera was facing north. Natural light.
Redder Male Orange Bishop, Buffalo Run Park, Missouri City, Texas
Redder Male Orange Bishop, Buffalo Run Park, Missouri City, Texas. Canon EOS 7DII/600mm f/4L (+1.4x TC). Photo taken on August 6, 2016. This is the same bird as the previous image. The camera was facing north. Natural light.

Finally, although the females are very sparrow-like in appearance and much more shy and difficult to photograph than the males, I made several attempts to maneuver close to them for an image. I would note that, ultimately, color in breeding male birds is all about female breeding preference. Buffalo Run Park could be natural laboratory for the study of how invasive species adapt to a new environment, specifically breeding in a new context. I foresee a master’s thesis for some budding young ornithologist.

Female Orange Bishop, Buffalo Run Park, Missouri City, Texas
Female Orange Bishop, Buffalo Run Park, Missouri City, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

©2016 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Avian Happenings, East End, Galveston Island, Texas

Those who live by the sea can hardly form a single thought of which the sea would not be part. –Hermann Broch

Laughing Gull with White Shrimp, East End, Galveston Island, Texas
Laughing Gull with White Shrimp (Litopenaeus setiferus), East End, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

Over the past week or so, I’ve made several dawn and dusk visits (once with Elisa) to the East End/East Beach area to observe and photograph summer shorebird behavior—which abounds at this time of year. Unfortunately by 8 am the area has been a blazing inferno, making photography a challenge.

In an earlier post I mentioned the appearance of a new tidal channel near the East End Lagoon Preserve. This week I took a look-see to find out the status of the new channel and the impact it might be having on the wildlife of the area. As I expected, the channel has expanded: it is now about twenty yards wide at the mouth during high tide. A Reddish Egret patrolled the channel mouth while Laughing Gulls, Royal and Sandwich Terns, and the odd Willet mostly stood around while I photographed them. They were taking some interesting prey, though.

Laughing Gull with Cutlassfish, East End, Galveston Island, Texas
Laughing Gull with Atlantic Cutlassfish (Trichiurus lepturus), East End, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

During the warm months, a strange, eel-like fish, the Atlantic cutlassfish (aka ribbonfish), is abundant in the bays and channels along the Texas Gulf Coast. Laughing Gulls and Royal Terns were having a field day eating them this week. Although the birds consumed them enthusiastically, both species seemed to have difficulty swallowing the fish’s long, thread-like tail. Some birds were walking around with a silver thread trailing out of their beaks!

Mating Royal Terns, East End, Galveston Island, Texas
Mating Royal Terns, East End, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Male Least Tern with Nuptial Gift, East End, Galveston Island, Texas
Male Least Tern with Nuptial Gift, East Beach, Galveston Island, Texas. The Least Tern is an endangered species and nests in scrapes on supratidal areas on Galveston’s East Beach. These nesting areas are protected by the Houston Audubon Society. Please adhere strictly to posted warnings. All beach-nesting birds have taken a terrible beating in recent decades because of recreational use of beaches—especially motorized vehicles that crush eggs and nestlings. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

The real story at this time of year on Texas beaches and barrier islands is, of course, breeding. The Royal Terns, Least Terns, and to a lesser extent, the Sandwich Terns, clearly had mating on their minds. Royal and Sandwich Terns were doing some dancing. Male Royal Terns and Least Terns were presenting females with a nuptial gift of small fish. A few Least Terns were nest-sitting. Some Royal Terns were copulating right out in public. Gracious! What will the drunken fishermen think?

Plovers, too, were everywhere on the East End of Galveston. Wilson’s Plovers were breeding along with Least Terns in the protected areas. Snowy Plovers were running around everywhere, but likely not nesting—their coastal nesting areas are further south in Texas. A few Black-bellied and Semipalmated Plovers were standing around trying to look innocent—as if we didn’t know that they are tardy for an appointment in the high-Arctic. Or perhaps they are among those rare birds that reside in Texas during the summer but do not breed?

Semipalmated Plover, East Beach, Galveston Island, Texas
Semipalmated Plover, East Beach, Galveston Island, Texas. These birds breed in the high-Arctic, not Texas. Photographed in mid-June, is this bird really late for the spring migration, really early for the fall migration, or a “rare summer visitor?” Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Male Wilson's Plover, East Beach, Galveston Island, Texas
Male Wilson’s Plover in the Weird Light of a Supratidal Mudflat at the Crack of Dawn, East Beach, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Female Wilson's Plover, East Beach, Galveston Island, Texas
Banded Female Wilson’s Plover at Dawn, East Beach, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

Finally, lending a splash of color to the seascape were American Avocets in breeding colors. These birds are either very late spring migration stragglers or belong to scattered clusters of birds, rare summer residents, that inhabit the Texas Coast. Whatever their story, it’s nice to be able to see shorebirds in breeding (summer) and non-breeding (winter) plumage at the same locale.

American Avocet in Breeding Color, East Beach, Galveston Island, Texas
American Avocet in Breeding Color, East Beach, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

©2016 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.