Notes from a birding trip through Mexico by Jim Conrad
Pickup trucks provide taxi service through the Sierra Mazateca foothills. If you want a ride, you hold out your arm, ask the price to the next town, and hop into the back. Sometimes you stand with others, holding onto the sideboards, and sometimes there are board seats and a tarp cover. Some pickups run on schedule but others run just when the driver is in the mood. Some drivers are friendly and businesslike, others are surly, giving the impression that they're offended having to stop. I'm deposited in Tuxtepec where regular bus service begins for the lowlands.
I leave the state of Oaxaca and enter the state of Veracruz. Now the flat land between villages and cities is occupied by banana and sugarcane plantations, and weedy pastures with Zebu cattle attended by lots of Cattle Egrets. Every inch of the landscape is occupied by settlements, intensively cultivated plantations, pasture, or rampant weediness. People are everywhere, some working, some lazing, many walking where there seems no place to go. I cross the Veracruz lowland in a fugitive mood, hoping that by nightfall I can be someplace where I can peg a tent.
Bus connections aren't so good so I take a series of slow local buses from Tuxtepec to Cosamaloapan, then Tlacotalpan, then briefly quite near the Gulf of Mexico to San Andrés Tuxtla, and, finally, late in the afternoon on a bus so broken down and slow that it's really fun to lean back and gawk from the open windows, to Catemaco, population 45,000. Catemaco is a tourist town on the edge of Laguna Catemaco; "Laguna" means "Lake."
Especially in golden, late-afternoon sunlight it's a pretty region with steep-sided, raggedly vegetated mountains, the Tuxtlas, rising beside the large lake, which is roughly circular, and about 15 kms across (nine miles). I remember twenty years ago having taken a gravel road along the lake's northern shore and now I want to revisit that road, for I recall how wild it was, and I need to escape the tourist zone. On the outskirts of town a cooperative of pickup-truck operators provides fairly regular service along that road now. I hop into the back of a truck and ask the driver to drop me someplace near the lake where I can camp.
At dusk I'm deposited in the village of Coyame, built at the crossroad of the gravel road and a dirt road in pretty bad repair. The lake is a five minute walk below town. Coconut Palms grace the shore and there are dry sand rises perfect for a tent, with fantastic views across the lake. Among the populace standing around looking at me I choose the most friendly looking, a woman shopkeeper closing up her store. I ask if there's someplace where I might pitch a tent. She suggests the very spot I've eyed. Since a dozen or so onlookers surround us all agree that it's a good spot and that there's no problem with my staying there, I thank everyone and go down to the palms, with maybe fifteen kids trailing and asking questions. Now the community considers itself something of my guardian. Sometimes the opposite of secretness is the best security, even when camping.
Approaching the lakeside I see the picture below, a Guiana Chestnut out in the water near my tent site, with herons preparing to spend the night there.
In dusk's final glow I'm barely able to see where the tent goes. The children leave when their mothers call. I enter the tent and zip up the door, leaving a cloud of mosquitoes outside. Inside, I lie feeling the day's heat in the sand beneath the tent's floor, listening to waves lap at the water's edge, still intoxicated by the view of the heron-filled Guiana Chestnut, hardly able to wait until I awaken the next morning, maybe with wild ducks right beside me.
At dawn it's not ducks but duck-like American Coots, thousands of them fairly evenly spaced over the big lake's surface. Coots are "duck-like" and not actually ducks, even though they float on the water and almost look like ducks, because they're not in the Duck Family, the Anatidae. Coots, being members of the Rallidae, are more closely related to cranes and rails. Coots have lobed, not webbed toes, and their beaks are narrow, not flat, like a duck's.
A floating mat of non-flowering Water Hyacinth carpets about thirty feet of water next to shore and a unique but absolutely-to-be-expected bird walks upon the hyacinth mat, pecking here and there, looking for snails, aquatic insects and larvae, and an occasional small fish. It's the Northern Jacana, the only Mexican member of its family, sometimes appearing as far north as extreme southern Texas.
The special thing about the jacana is its feet, as you can see at the right. These toes make sense, of course, because they distribute the bird's weight evenly over a large surface area so as the bird forages atop floating vegetation, such as waterlily pads, it's less likely to sink. Sometimes jacanas are called "lily-trotters," or "lotus-birds." Here, despite their wonderful toes, as they move across the water-hyacinth mat, as soon as they step on a plant the plant begins sinking, so the bird is obliged to keep moving from one sinking plant to the next.
The jacanas aren't alone. A small flock of glossy-black Great-tailed Grackles also treads atop the Water Hyacinths but, since they're far lighter, they're not sinking. Neither are they as graceful as the jacanas. On level ground grackles walk, not hop, but the water-hyacinth platforms are too irregular for walking so the grackles clamber, jabbing their black, chisel-like beaks at snails wedged between bulbous Water Hyacinth stems. The plants don't sink beneath the grackles' weight but they do twist in the water, throwing the grackles off balance and causing them to continually and ingloriously hold their wings and ample tails at the oddest angles.
Along shore a Green Heron catches a slender, silvery fish, then flies with it in its beak to a pole emerging from the water. The heron jerks its head to manipulate the writhing fish into swallowing position, then the fish simply slides down the heron's throat. The heron is left looking somewhat smug and the fish, just an instant ago full of life and silvery brightness, is simply gone.
Men also are fishing at this break of dawn, their small, shallow boats like the coots evenly spaced over the lake's surface, all at respectful distances from one another, though from time to time they call across the water saying that the fishing is no good today. The men stand in their boats casting large, circular nets. The nets bear weights at their sides so they rapidly sink, then when the man pulls on the line attached to the net's center the net closes like a hand.
One boat enters the lake late and makes its way along shore beside me. A great mass of coots escape from the Water Hyacinths into deeper water. As they take off, while flapping furiously they run for a distance atop the water, suggesting that their bodies are too heavy for such pudgy wings to lift them into the air. The birds land a long stone-throw's out, forming a dark, diffuse cloud of birds there. When the boat passes, the birds make their way back into the hyacinths.
For every 20 coots out there maybe there's one Pied-billed Grebe. Though these two species share the lake's surface they're clearly foraging for different foods, and thus their niches are not overlapping. In fact, coots mainly eat aquatic vegetation, while grebes are almost entirely carnivorous, mainly eating crustaceans such as crayfish, as well as small fish, mollusks, and aquatic insects.
When coots dive they soon bob back to the surface near where they disappeared but grebes remain submerged for 45 seconds and longer, usually resurfacing surprisingly far from where they dove.
Though the coot's food obviously has much less nutritional value than the grebe's high-energy carnivorous diet, my impression is that the coots spend less time feeding than do the grebes As I scan Lake Catemaco's surface, every Pied-billed Grebe seems hard at work alternating long dives with brief periods of catching breath, while a large percentage of the coots are bathing, standing on Water Hyacinth rafts sunning themselves, or just idly floating, looking around.
A Pied-billed Grebe pops to the surface and as it catches its breath a Green Heron comes flying very low over the water with its legs stretched forward, giving the appearance of being about to land atop the grebe. Neither I nor the grebe can imagine what's on the heron's mind. The grebe submerges just long enough for the heron to pass, then surfaces again, looks over its back, and I swear there's an expression in its face, saying, "You fool!"
And how exquisitely grebes are adapted for their life in water. As with coots, their toes are "lobed" with a series of flaps, so as they push their feet backward against the water the flaps open up like oars, propelling the bird forward. Then when the feet are drawn forward the flaps collapse and the water offers little resistance. Grebe's toenails are even flattened, like little paddles, something very rare among birds.
Moreover, a grebe's legs arise far back along its body. This makes it hard for grebes to move on land but, in accordance with the laws of physics, it enables the birds to harness a powerful forward thrust when diving. Like many birds highly adapted to diving, grebes have difficulty lifting themselves from the water's surface. With rapidly beating wings they taxi across the surface with their running legs frantically providing extra propulsion below them, before becoming airborne.
I'm surprised to find so few ducks here -- just a few Lesser Scaups. My field guide's distribution maps indicated that several species are to be expected here. Maybe other species arrived but saw all the coots and just kept going.
One reason I've been wanting to see ducks is that before my trip I was reading Paul A. Johnsgard's Handbook of Waterfowl Behavior. Therefore, now the Lesser Scaup before me throws back its head in a curious way and I recall that Johnsgard dignifies this blur of action with the name of "head-throw display." He says that it lasts approximately 1/20th to 1/30th of a second, and that the bill is thrown back less than 45 degrees, even though it appears to reach almost the vertical. Head-throws are displayed by males to focus the female's attention and convey the message that he's interested in her. Since it's such a brief event it's always preceded by special "head shakes" conveying the message "Pay attention, now, for I'm about to head-throw... "
Head-throws very similar to the Lesser Scaup's and with the same message attached also appear among Greater Scaups, Canvasbacks, Redheads, and Ring-necked Ducks -- all species so closely related to our Lesser Scaup that on occasion they hybridize with them in the wild. Johnsgard makes the point that head-throws in Greater Scaups are slower than in Lesser Scaups -- about 1/6th of a second instead of the Lesser Scaup's 1/20th to 1/30th of a second.
Toward noon the lake becomes a broad, shallow saucer of placid, shining quicksilver. The thousands of coots that earlier were dispersed across the lake's surface have gradually coagulated into groups closer to shore and as time passes the gatherings condense until finally they form tight knots keeping in sheltered bays. Having them closer at hand I'm astonished at how much they eat -- swallowing entire sprigs of an aquatic plant similar to the Elodea grown in home aquaria.
One coot latches onto a six-inch sprig too large to swallow and, although all the coots in that group float in a morass of the plant, a neighboring coot covets the large prize and rushes to rob it from the owner. A small contest erupts, drawing attention of other coots, who rush to join the fray. In the end the sprig breaks into several segments and no coot gets more than a modest snack.
Here's the Official List for birds seen on the lake, including atop rafts of vegetation floating along its margins.
MEXICO: Veracruz; Laguna Catemaco, freshwater lake and shore in vicinity of Coyame about 10 kms east of town of Catemaco, on north shore; elevation about sea level and about 25 kms inland
In this list there's not a single bird not also appearing in the US.
Now I pack my tent into my backpack and begin working farther along shore. In the afternoon I come to another Guiana Chestnut at the water's edge. About 35 feet high, the tree's trunk is equipped with buttresses jutting from its base like foot-thick, seven-foot-high rocket fins. The buttresses give the tree better footing in soft mud.
This tree, like the one sketched in the lake where Great Blue Herons and Great Egrets gathered, is nothing less that an airborne garden. Up close I can see how the big herons and egrets can stand atop the trees' canopies as if they were on solid platforms: Outermost twigs are thick and strong enough to make solid perches for big birds.
Inside the tree these coarse twigs are encrusted with the following:
Deep within the Guiana Chestnut's shadowy interior I spot White-eyed Vireos and Black-and-white Warblers. I'm accustomed to seeing the warblers in northern forests where they glean tiny arthropods from the bark of tree trunks and branches rather like nuthatches. Here they do the same thing, but inside the big tree they glean aroid stems, and the stipes of long, cascading ferns.
The tree bears abundant chestnut-brown, spherical fruits nearly the size of basketballs. I wonder what caused these fruits to evolve to be spherical and so large. Here the fruits fall into the mud, the thin brown rind splits and several lemon-size seeds are released.. At first the seeds are encased in whitish, cellophane-like membranes. These tear away leaving the seeds looking like bright green gobs of partially melted plastic with deep furrows in the shape of stars with four slender arms.
More often than not the seeds pile up at the water's edge, germinating in soggy, wind-heaped-up piles of decaying Water Hyacinth and other aquatic vegetation. All or nearly all of the seedlings must die, for I find no saplings in the area.
Much impressed by this tree, though the place strikes me as being particularly snaky, I peg my tent inside an angle formed by two of the tree's flaring buttresses.
At dusk, behind the netting of my tent door and thus safe from the hoards of mosquitoes, it's a cozy nest with a view of the setting sun. Two Northern Waterthrushes come sauntering along the water's edge, flipping wet leaves, bobbing their tails, and teetering together as two waterthrushes should. A little later a pair of Plain Chachalacas glides into the dense tangle of branches not twenty feet above me. As they move toward one another after landing I hear them purring like big cats, and see their archaeopteryx-like silhouettes stealthily coming together.
All night I sleep with waves breaking so nearby that they splatter my tent.
Here's the Official List for the next day's birds seen as I hike the gravel road skirting the lake and headed eastward.
MEXICO: Veracruz; Laguna Catemaco, along 10 kms of gravel road east of Coyame, which is about 10 kms east of the town of Catemaco; this is the northern shore; roadside, woods and pastures; elevation about sea level and about 25 kms inland
One of the most exotic birds in the above list is the Blue-crowned Motmot, pictured above. Notice how the long tails are missing barbs along part of their lower lengths. This is typical of most motmot species. Blue-crowned Motmots are fairly common in Mexico's humid Gulf lowlands, sometimes not very shy of humans. They might appear in one's garden, or even at an overgrown trellis at a porch's corner.
For me, the list's most striking feature is that nearly a third of the species are warblers and vireos from the north, spending their winter here.
Still, even in this weedy, much disturbed environment there are wonderful things northern birders never see, such as the Yellow-throated Euphonia at the right. Euphonias are closely related to tanagers. This species occurs in wet tropical forests and their borders, plantations and gardens from Mexico's northern Gulf lowlands to Panama. It's a common species, but always nice to see.