In structural complexity, adaptation to all sorts of environments, and development of a remarkable social organization among some, the arthropods are judged to represent the peak of evolutionary advancement attained by invertebrates.—Moore, Lalicker, and Fischer, Invertebrate Fossils (1952)
It’s almost time to get back into one of our spring birding habits: A road trip to the Smith Oaks Rookery on High Island in the afternoon (for the best light), followed by the night in Winnie, and a trip down the Bolivar Peninsula the next morning. The highlight of Bolivar is usually Frenchtown Road, where shorebirds and waders can often be seen hunting for invertebrates, especially arthropods, on the tidal flats, in the shallow tidal channels, and from among the exposed oyster patch reefs.
Another spring tradition is travel to Bryan Beach (or Surfside Jetty Park or Quintana Neotropical Bird Sanctuary), followed by a trip up Follett’s Island, across to Galveston Island, ending at Lafitte’s Cove. These trips have the best of both worlds, littoral marine habitats and songbird migrant traps among mighty hardwoods.
This time of year reminds the birder of the fact that birds are governed by the never-ending search for food. As avian migrants follow the sun’s energy north, they are mostly following the the exploding biomass of terrestrial invertebrates, primarily arthropods. Birds lucky enough to be able the tap the perennial invertebrate bounty of the sea can overwinter along the coast. Those dependent on terrestrial and aquatic arthropods like insects must wait for the inevitable return of the summer swelter.
Dans les champs de l’observation le hasard ne favorise que les esprits préparés.—Louis Pasteur
Pasteur’s brilliant and famous expression above (“Chance favors the prepared mind” in streamlined English translation) is undoubtably one of life’s great truths. Ultimately, seeing a particular bird species or avian behavior is a matter of chance. In all the singular sightings of difficult-to-see species (Tropical Parula, Red-faced Warbler, Clay-colored Robin, Black Rail, etc) that I’ve made, I realize that had I been looking in a slightly different direction for a fraction of a second, I would have missed the bird entirely. But being in the right place at the right time to even have a possibility of making the observation in the first place is decidedly a matter of preparation (and effort), not chance.
Photographing birds is even more subject to the vagaries of chance than simply seeing birds. A passing cloud, a wind gust, a stray blade of grass in front of the subject, stepping in a hole or ant nest, or getting stung in face by a nasty bug at the precise moment a shutter should have been activated can all doom a photo that, a fraction of a second before, held great promise. The fact that rare, unpredictable natural events can be captured at all is sometimes a matter of some amazement to me given the difficulty of the problem. I think, for example, that after thousands of hours of photo-birding I’ve seen birds eating walkingsticks a total of three times in my life, and, incredibly, I was able to photograph it each time! On the other hand, I’ve never captured a single decent image of some species of birds I’ve seen dozens of times!
From time-to-time, I talk with photographers who have quit trying to photograph birds, or are at least considering quitting. They cite the difficulty and not getting any good results. What they seem to be hoping for is serendipity, or at least great good fortune. But after slogging through swamps and jungles, being pelted by rain and blasted by the sun from deserts to plains and mountain-tops, and shooting tens of thousands of images, I’ve started to doubt that serendipity or even good luck is much of a factor in photo-birding. I think that there are only drive and statistics. If you want some bird photos, then clear your calendar, break out the sunscreen and bug repellent, and get out there and photograph some birds (and enjoy the process)!
After months of want and hunger, we suddenly found ourselves able to have meals fit for the gods, and with appetites the gods might have envied.–Ernest Shackleton
The current seasonal transition got me thinking about the life struggles of birds. As a birder, I look forward to the coming spring and summer with a mixture of anticipation and apprehension. Yes, there will be be many interesting sights and sounds to experience. But the return to the sweltering heat, blistering sun, and the ubiquitous biting insects (Zika, anyone? Chikungunya?) can and will put a damper on many a trip. The loveliness of the Texas winter for the birder disguises the fact that for birds, these are hard times. Food is in short supply and a hard freeze out of the blue can spell death subtropical species that wander just a little too far north.
Birds that would prefer a juicy arthropod, may now have settle to settle for a dried out seed or two. But change is coming! Buds are appearing, and flowers are starting to buzz with insects. Once the spring really gets rolling and winter moves out, the birds here in North America now will have a brief stretch of time to dine with little competition. Soon, though, hundreds of millions of hungry avian Neotropical migrant mouths will arrive, and the hardscrabble competition for food will begin again!
Until I know this sure uncertainty, I’ll entertain the offered fallacy.–William Shakespeare, The Comedy of Errors
Birding is something I do alone, with Elisa, or with very small groups of people—so the impact and embarrassment of personal screw-ups has been limited. Field blunders have ranged from the minor (like calling a female Orchard Oriole a Prothonotary Warbler in front of the late Steve Gross) to silly, like hustling out the woods in grizzly country feeling like I was being hunted only to decide that it was all in my head! Probably.
In the imagination-getting-the-better-of-oneself scenario, a week or so ago I was on the levee between 40-acre and Pilant Lake when I heard a loud rustling coming from the rice on the edge of Pilant Lake. Whatever it was sounded big—and it sounded like there were several somethings. Would I see a row of feral pigs? Otters? Raccoons? Otters would be great! This could be exciting! A similar thing had happened before and a bobcat had poked its head out less than five yards in front of me!
So I fiddled with my gear in eager anticipation . . . when who popped out? A group of the noisiest grackles on the planet emerged from the vegetation, and they had nesting materials in their beaks. At least I got a few shots of that, I thought disappointedly. Later, while reviewing the images, I realized that it was not nesting materials that they had, but straw-colored katydids! The birds must have been in a line to flush out the insects. Without knowing it, I had likely observed avian cooperative hunting. I have seen Cattle Egrets doing much the same thing. So much for otters.
In the not-knowing-what-you’re-looking-at scenario, last week I was watching American Goldfinches chiseling into stems of an unidentified plant and plucking out tiny somethings. That’s weird, I thought, what could these birds be getting out of stems? Later, I brought up the question to a naturalist friend, and he quickly offered that insects had possibly infested the stems and the birds were simply fishing them out. But later while reviewing the images trying to identify the “insects,” I realized that the stems were not stems at all, but rather dried-out elongated seed pods, and the birds were (unsurprisingly) simply eating seeds! The whole conversation about insects in stems was like the Peanuts episode when Lucy and Linus wonder about how potato chips could migrate from Brazil (after misidentifying a potato chip as a beautiful yellow butterfly).
In my own defense, once in a while I see something unusual enough that I don’t feel silly when I misinterpret it. I remember photographing the Yellow-crowned Night-Heron below and feeling sorry that the poor animal had a growth on its lower bill. A few years later, while sifting through the archives I noted that it was not a growth, but rather a gar tooth that was protruding from the bill. The bird must have been hunting in the water when a gar bit it through the lower jaw. In the ensuing struggle, the tooth must have broken off.
Finally, this post reminds me of a question I often pose to myself: Do I see more when I am out photographing or when I am binocular birding? I’m pretty sure that I see more with binoculars alone because I’m not worrying about light, perspective, and so on. But then again, without images to check what I’ve been seeing, how do I really know that what I’ve been looking at it is what I thought I was looking at?
If the earth should cease to attract its waters to itself all the waters of the sea would be raised and would flow to the body of the moon.—Johannes Kepler, Astronomia nova (1609)
Among all the great men who have philosophized about this remarkable effect, I am more astonished at Kepler than at any other. Despite his open and acute mind, and though he has at his fingertips the motions attributed to the earth, he nevertheless lent his ear and his assent to the moon’s dominion over the waters, to occult properties, and to such puerilities.–Galileo Galilei, Dialogue Concerning the Two Chief World Systems (1632)
Last weekend offered up the most spectacular weather imaginable, and we headed to East Beach, Galveston and Frenchtown Road, Bolivar. Arriving at low tide, our timing was perfect. Both these localities present exceptional naturalist experiences, especially at low tide. Where else is there evident a more elegant connection between the astrophysical, geological, and biological worlds than in an intertidal zone?
At East Beach we watched Greater and Lesser Yellowlegs hunt among the ripple marks, tidal channels, and pools abandoned by the retreating tides. Vast flocks of Black Skimmers whirled overhead and large numbers of gulls, terns, and American White Pelicans gathered on emergent sand bars.
Near Frenchtown Road, low tide means that oyster patch reefs are exposed, and Red-breasted Mergansers, cormorants, and waders fished in the tidal channels between the reefs. Shorebirds like American Avocets, Willets, and dowitchers hunted among the exposed clusters of oysters. Forster’s Terns were plucking small fish from the surface waters of the channels. I was surprised to observe the Willet below catching fish in the shallows between patch reefs—usually these birds are grabbing crabs from among the oysters.
Frustratingly, I realized that (being a landlubber from Minnesota) I do not know my Gulf Coast tidal zone fishes, so I could not identify any of the birds’ menu items. To remedy this situation, this week I ordered a copy of Fishes of the Gulf of Mexico: Texas, Louisiana, and Adjacent Waters by Hoese and Moore. It will sit next to my Peterson Field Guide to Freshwater Fishes of North America North of Mexico—so soon I’ll at least have a shot at identifying piscine prey, no matter the salinity.
Shall I not have intelligence with the earth? Am I not partly leaves and vegetable mould myself.–Henry David Thoreau
Frequent readers of this blog may know that I prize images of birds struggling with prey above all others. But sometimes the birds and mammals of the marsh and forest, either through preference or requirement, dine on plant foods—especially during the colder part of the year when insects and other arthropods are less abundant.
It’s sometimes a challenge to identify animal prey items seized by birds and other animals. Plant foods are often even more of a challenge—unless the meal is something easy like hackberries, tallow seeds, privet fruits, maple seeds, and so on. Sometimes birds are munching seeds or buds of what I (as no botanist) consider fairly nondescript, difficult to identify plants. The fact that there are so many invasive species around these days only complicates the task. I will often make attempts at identification, but these are often frustrated by constraints of time and available references—but it’s fun to try!
Charm is an intangible. Chutzpah, charm, charisma, that kind of thing, you can’t buy it. You either have it or you don’t.–Colm Feore
Among the most charming of the small songbirds are the titmice. Along the Upper Texas Gulf Coast, Tufted Titmice are common year-round. And they are a delight to encounter in the woods, as they peer back with those curious, yet suspicious eyes!
Tufted Titmice seem to prefer arthropod prey (including spiders and their egg cases), but will eat nuts, seeds, and fruit during the winter. They will also visit seed and suet feeders during the lean months, but to my eye, they never seem completely at ease in doing so, being true wild creatures of the forest.
Small super-active songbirds like the titmice may be the supreme challenge for the bird photographer—especially under completely natural conditions (i.e., not baited and not near a feeder). Take a look at Elisa’s beautiful image of a singing Black-crested Titmouse from Lost Maples. We often see Bridled Titmice on our frequent trips to southeast Arizona, but I have yet to capture any really nice images (These birds are fast!).
We have seen all but two species of North American titmice: The Oak Titmouse (California), and the Juniper Titmouse (Southwest U.S., west of Texas). I have no doubt they will be just as challenging and charming as their Gulf-Coast kin!
The acrid scents of autumn,
Reminiscent of slinking beasts, make me fear.–D. H. Lawrence, Dolor of Autumn, 1916
Elisa and I made the most of last weekend’s gorgeous weather and birded Brazos Bend State Park, both Saturday and Sunday. On the way back home Sunday, we saw a massive flock of blackbirds and Starlings in an agricultural field. Shortly thereafter, tapping some primal anxiety in the face of crops being stripped to the ground, I assume, Elisa brought up Genesis 1: 26, a verse we have both lamented and puzzled over . . .
And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth.
Could its sentiment be in response to an alternative viewpoint or movement, one that emphasized Man’s place in nature, rather than his supposed dominion over it? Was a reference to God’s will intended as an argument-ender—much as the Israelite claim on the very land of Canaan itself?
The putative author of Genesis is, of course, Moses. Tradition has it that this book was written around the 15th century B.C., during the Bronze Age. Agriculture was not new at this time. Surely some had noticed the impacts agriculture had upon the land, even in antiquity. Perhaps these hypothetical romantics turned their eyes back to a more ancient lifestyle, the way of the hunter-gatherer, a way that is now all but extinct. You will search in vain for a more succinctly articulated statement of mainstream Man’s attitude toward nature, or a more impactful one, than Genesis 1:26. Over the millennia, it has certainly proved the winning position . . . .
In any case, at Brazos Bend, the sights and sounds were typical for the season. Yellow-rumped Warblers, Tufted Titmice, Carolina Chickadees, and Carolina Wrens were everywhere in the hackberry, willow, and Chinese tallow trees that line the paths surrounding 40-acre, Pilant, and Elm Lakes.
But I can only report one new observation from these days at BBSP: A Great Egret hunted Green Treefrogs (Hyla cinerea) among the tall vegetation (mostly rice) along the southern margin of Pilant Lake (between the tower and the bridge). I have seen Little Blue Herons, Tricolored Herons, and American Bitterns hunting treefrogs in this area on previous occasions, but this is the first time I’ve seen a Great Egret doing it.
All four species have a similar hunting technique: rather than keeping their eyes down on the ground in search of fish, crawfish and other invertebrates, and other frog species, the birds carefully inspect the stalks of vegetation from top to bottom, and around all sides, and occasionally pick off the treefrogs. The treefrog hunting behavior is also quite different from when the waders are looking for dragonflies. Dragonfly hunting can involve snatching the insects from the air, or picking them off the very top of eye-height or shorter vegetation. As always, while hunting treefrogs these birds slide their heads back and forth like Hindu dancers apparently to use their stereoscopic vision to judge the exact distance for a strike.
It seems that Brazos Bend will often reward the vigilant observer with new sights, no matter how often one visits.
By the pricking of my thumbs,
Something wicked this way comes.
Whoever knocks.—William Shakespeare, Macbeth (Act 4, Scene 1)
During the dreary, rain-spoilt part of last weekend, in bitter anticipation of the next monster rain storm (Monday into Tuesday), I perused our photo archives in search of interesting tidbits to brighten my mood. Some nice shots I’d forgotten about did resurface, like the hawk above.
But birds do often lead a more hardscrabble life than we sometimes think. Not surprisingly, close re-inspection of images sometimes yields evidence of disease or parasites. The Bay-breasted Warbler below–that frustratingly stayed in the shadows of a thicket–turned out to have a tick above the left eye, for example. Birds are subject to infestation by a variety of disease-causing ticks, and some researchers worry about the introduction of diseases into North America by migrating Neotropical birds.
In addition to evidence of parasitism and disease, I sometimes find physical injury to birds when I return to the archives and really scrutinize the images. In the field I didn’t notice the spine-like projection under the lower jaw in the Lesser Yellowlegs below. At first, I thought the spine might really be a spine—as in a fin-spine that pierced the floor of the lower jaw, perhaps when the bird attempted to swallow a fish. But clearly a fish with a fin spin that large would be too large to attempt to swallow. On closer inspection, it appears (based on color and texture) that the spine is a shard of the lower jaw that continued to grow, perhaps after being fractured. If any readers know more about the origin of such injuries, I would be interested in hearing about it.
The result of these sorts of searches serve to remind that nature, like the world of Man, can be a harsh place. Birds face a gauntlet of challenges, and I often regret not being able to do more to preserve them and their world.
We climb a ridge, and a shout of surprise involuntary arises from our lips as we find the waters replete with strange animals, and the sun above us darkened by the wings of great flying dragons . . . . —Charles H. Sternberg (Popular Science News, December, 1898)
Last Sunday we took an excursion to Bryan Beach and the lagoons behind. On this day, the seas were rough, and I watched in awe as Brown Pelicans sailed through the troughs of a churning waterscape. I couldn’t help but think of the spectacular scenes of the Late Cretaceous Epoch painted by Charles R. Knight (at the absolute height of his powers) for the Field Museum of Natural History in Chicago in the late 1920’s—especially the oft-reprinted breaching mosasaur and turtle with Pteranodon skimming the giant swells in “turquoise, gray, and rose” (Knight’s words).
I like to imagine that places like Bryan Beach and environs are not unlike much of what Midcontinent North America was like when the Western Interior Seaway connected the Gulf of Mexico with the Arctic. But of course there are tremendous differences: Texas Gulf Coast bays, for example, typically have only about 15 cm of tidal variation in sea-level, but mathematical models of the Western Interior Seaway suggest that it was subject to around 0.5-1.0 m of tidal variation along the southern boundary (e.g., Erickson and Slingerland, 1990).
To my imagination, this suggests vast areas of tidal channels, mudflats, and marshes dotted with countless millions of birds hunting, fishing, and probing for prey. But except for birds like Hesperornis (and kin) and Ichthyornis what these birds were like remains largely a mystery as only fragmentary remains assigned to around twenty or so genera are known.
The main reason I frequent the shallow lagoons behind Bryan Beach (other than reverie) is that this area is a reliable spot to see Reddish Egrets, both dark and white morphs. On this trip, we saw both color phases. I was especially excited to see Reddish Egrets hunting alone and in mixed flocks of waders and shorebirds. At one point, a large group of White Ibises, Snowy Egrets, Lesser Yellowlegs, and Dowitchers encountered a school of small fish and swept across the lagoon together in a communal fishing “drive.” Sometimes the Reddish Egrets broke off from the flock and fished alone—although sometimes a few Snowy Egrets, Lesser Yellowlegs, or Dowitchers shadowed them.
With a little imagination it’s easy to envision such scenes occurring along the tidal mudflats and lagoons of the Western Interior Seaway. Squinting at the above scene, it might be easy to believe that you are seeing the Cretaceous cousins of today’s birds. But sorting out the taxonomic nightmare of what you are seeing would have been a bit dicier in the Late Cretaceous than it is today. Feathers, it seems, were widely distributed among dinosaurs, so many of those little feathered bipeds hunting and fishing across those mudflats were not close modern bird relatives at all, but rather dinosaurs, or perhaps even more likely, members of the strictly Mesozoic avian groups that perished at the end of the Cretaceous Period.
Finally, sometimes lost in my imaginary Cretaceous, I have to remind myself that I can stray to the waters’ edge—no fear in our time of being confused with a small dinosaur . . . and a mosasaur bolting from the shallows and dragging me kicking and screaming into the surf.
Erickson, M.C. and Slingerland, R. 1990. Numerical simulations of tidal and wind-driven circulation in the Cretaceous Interior Seaway of North America. Geological Society of America Bulletin102(11): 1499-1516.
He was born when I was six and was, from the outset, a disappointment.―James Hurst, The Scarlet Ibis: The Collection of Wonder
After a photo-birder friend (LM) told me about the White Ibises nesting on the the south edge of Pilant Lake, I recently spent a few hours trying to photograph nestlings. Only one nest can currently be photographed (above), but there are many others back in the swamp—and the air is filled with the weird gurgling noises ibises make.
The one nest that can be seen is still rather difficult to photograph given its distance from the trail and the profusion of vegetation. But I could see that the nest contains two nestlings, one much larger than the other. Likely the smaller chick simply hatched later, the size disparity exacerbated by the bigger chick receiving more than its fair share of food along the way. Such a disparity in nestling size often spells doom for the littlest birds. In this case, though, the little bird is a real fighter and chased mom’s beak around relentlessly hoping for a morsel or two of regurgitated crawfish. I hope it makes it, although the odds may be against.
The long, curved beak of ibises is used to probe into burrows and crevices occupied by a variety of prey. The rapid up-and-down motion of the beak reminds me of a sewing machine. At BBSP, it’s common to see White and White-faced Ibises grabbing a variety of aquatic arthropods including predaceous diving beetles (larval and adult) and crawfish. Frogs and small fish are taken, too, as are the bulbs of some aquatic plants.
Spoonbills and ibises constitute the Family Threskiornithidae, the former being close relatives of the Old World Ibises. I tend to think of spoonbills simply as ibises with a specialized feeding strategy: Typically the bill is waved back and forth through the water to capture prey, vertebrate and invertebrate, which is then flipped up into the air and ingested (below).
We have seen all U.S. species of ibises, including the Scarlet Ibis, an exotic South American and Caribbean native that was introduced into Florida in 1961. We saw this species on Sanibel Island at the J.N. Ding Darling National Wildlife Refuge on the the west coast of Florida about seven years ago. A small group of these birds was walking along the strand line of this famously shelly beach. This sighting, dear reader, was before we were serious photo-birders, so you’ll just have to take my word that it occurred! We hope to return one day and document the behavior of these spectacular, brilliantly-colored Tropical birds.
From time to time, I’ll be going through old images when I suddenly discover something I overlooked or misinterpreted in the field. For example, I remember photographing the scruffy young Eastern Bluebird above because I had a hard time figuring out what the heck it was (until I saw another one in better plumage!).
I also remember being perplexed about why it was gathering nesting materials in November—normally that sort of thing should end around July or August. I probably just scratched my head and chalked it up to Texas and our subtropical climate. Birds here in the swelter zone can sometimes breed outside their usual temperate region breeding seasons.
But upon re-inspection of the image (I’m sure I chimped my settings in the field!) all is revealed: There are no nesting materials, but rather a twiggy-looking meal, namely a praying mantis! This has happened a few times now with mantids and phasmids, so it’s something to watch out for. Sometimes birds with sticks (apparently) actually have walking sticks!
Having images to study hours or months later allows for testing your notions of what you saw in the field and to even make brand new discoveries ex post facto. The Clapper Rail above, for example, was hunting along the margin of the water at ANWR last winter. I could tell that the bird was grabbing small fish and what looked like leeches. I have seen and photographed waders and other water birds eating leeches. Upon closer inspection of the images, though, it looks like this Clapper Rail has a big juicy planarian its beak—a first sighting for me.
On the other hand, I know that I see less overall in the field in the first place when I am photo-birding, rather than binocular birding. Just like the old joke where the guy is looking under the street light for his lost keys because this is where the light is best, it’s sometimes tempting to photo-bird only where the light is good. I have caught myself ignoring movement in gloomy or brushy areas simply because I knew that I couldn’t get a decent shot. So, in this case, contrary to the quote above, photography can help birders not to see.
On a final note, Brazos Bend State Park re-opened July 8, and I was among the first members of the public to return post-flood. During the first half-hour there, I could feel the stress of life melt away. My general impression, though, is that there were not as many birds around as usual. I suspect that ground-nesting species of birds were drowned out. On the other hand, the mosquito and gnat populations were certainly healthy, as was the frog population. Perhaps the waders will rediscover the park and its bonanza of amphibians.
Most interesting to me was that the Prairie Trail looked different from usual as regards summer wildflowers. A few regulars were around like widow’s tears, but what struck really me was the profusion of partridge-pea (Chamaecrista fasciculata). This common legume is native to most of the eastern U.S. and is known to thrive in disturbed areas, such as those recently burned, and apparently recently flooded. It will be interesting to document how quickly the park returns to its former glory.