At the Santa Ana National Wildlife Refuge we heard this bird long before we saw it. Texans often call it the “Mexican tree pheasant.” The bird that has come to define the Lower Rio Grande Valley for me is more commonly known as the Plain Chachalaca (Ortalis vetula). It is a raucous, ungainly bird with a range that now extends from the Lower Rio Grande Valley to the Nicoya Peninsula of Costa Rica though its ancestors are found in the fossil record as far north as Nebraska. It is an ancient bird: in the fossil record it goes back to the Mesozoic Era. Visually the bird is not particularly impressive. It looks like a pheasant with an abnormally large and stiff tail. The upper parts are brownish olive, the head and neck almost grey. The underparts are paler, and the long tail much darker. The young look like pitiful newly-hatched chickens. Our Texan subspecies is O. vetula mccalli. Other subspecies become progressively darker as you move southwards from the Rio Grande Valley to Central America. The ones from Costa Rica are dark enough to seem like a different species.
Plain Chachalaca populations are all believed to be non-migratory. By and large it is an arboreal bird though sometimes a bunch of them are seen roosting heavily, side by side, on power lines. Monogamous pairs and family units tend to roost together. On trees it is often seen scurrying along branches like a clumsy over-sized squirrel. Flight is at best awkward, and rarely sustained for any length of time. According to Timothy Brush, in his recent account of the birds of the Lower Rio Grande Valley, it “acts . . . like a cross between a roadrunner and a monkey [1, 55].” Where it occurs you’d be hard pressed not to notice it. The nests are supposed to be flimsy structures on trees—we found none though it is perhaps a little too early in the year and, in any case, we didn’t have time to search carefully. Mexico has other species of Chachalaca; we have only one. And it’s unlike any other bird found in the US.
The bird gets its name from its loud cha-cha-lac-a call. A flock calling together produces an ear-splitting chorus, particularly in the early morning. In the 1970s at least one ornithologist found the sound so distressing as to compare the call to that of a howler monkey (Alouatta sp.) . The Chachalaca’s call is the defining sound of the Rio Grande valley for me, particularly Santa Ana, ever since we first found the birds last Saturday. Besides the call, what’s particularly engaging is the Chachalaca’s habit of pecking at ripe fruit upside down, looking particularly precarious because of its bulk and rather uncertain flying ability. But they know what they’re doing—you hardly ever see one lose its foothold.
Plain Chachalacas are still fairly abundant at isolated sites in the Lower Rio Grande Valley. Much of its historical habitat has disappeared because of the industrial and agricultural transformation of the land on the Texas side of the river, and what remains is highly fragmented. Credible anecdotal evidence suggests that the subspecies is doing well in Mexico, otherwise there would be reason for concern. (Some subspecies, such as one found in Honduras [O. v. deschauenseei] are in much worse shape and listed as endangered.) Strangely, much of what is known about the bird is all based on anecdotal reports. Recent detailed studies of its behavior have been confined to the Lower Rio Grande Valley in Texas, at the northern edge of its range and, therefore, possibly unrepresentative of the species as a whole . There was an earlier thorough Teutonic study of a population in Chiapas, Mexico, but that is now more than fifty years old . Well, here’s an opportunity for an aspiring ornithologist, and a new study with modern methods won’t go entirely unnoticed. . . .
We went to Santa Ana from Laguna Atascosa last Saturday. Our intention was to follow Route 281 which tracks the Rio Grande about fifteen kilometers north of the Mexican border. We wanted to experience the Lower Rio Grande habitat, or at least what’s left of it. But a chemical spill had closed the road and forced a detour inland, a reminder of the extent to which polluting industries are concentrated on the US-Mexican border, especially around Brownsville. The fight for environmental justice here must go hand in hand with efforts at biodiversity conservation for ethical as well as purely prudential reasons: the poor along this border, often of Mexican descent, probably have less political clout than any other group in this state. Yet, without their historical stewardship the biota that exists would neither have survived till now nor can make it into the future. The chemical spill last week was just west of one of the new units of the Lower Rio Grande Valley National Wildlife Refuge (as yet inaccessible to the public)—it goes to show how fragile even protected areas are in this troubled landscape.
What makes the spill even more worrisome is that less than 5 per cent of the original habitat remains on the US side of the Lower Rio Grande Valley. Not only do polluting industries abound, but this is one of the most heavily cultivated areas in Texas, if not the US. Luckily, the other side of the river is faring somewhat better, with much of the landscape remaining comparatively much less transformed. Moreover, Mexico is now creating an ecological reserve almost 1000 km long along the south bank of the Rio Grande. Though sometimes only about 10 m wide, the reserve will connect some much larger conservation areas. Two of these are already in place, and a third, Ocampo, is supposed to be created later this year. The hope is that roadless areas will deter illegal emigration and drug trafficking into the US, a far more sensible alternative to the walls and “smart” fences proposed by Republicans in the US Congress who have very accurately been accused of continued racism towards Mexicans. What remains to be seen is whether the Mexican reserves remain paper parks or are actually implemented in the field with adequate management resources—given the history of conservation in Mexico, there’s ample room for caution.
At 2 088 acres, Santa Ana is tiny compared to Laguna Atascosa, only about 5 per cent the size of the latter. Yet, nearly 400 bird species have been recorded here, only slightly less than the number at Laguna Atascosa. There is thus probably some justification for regarding Santa Ana as the birding capital of the US but, for birding at least, I prefer the open vistas of Laguna Atascosa. Much of the habitat at Santa Ana is forest with dense undergrowth, making birds hard to find. But not all of it. Given its tiny size, Santa Ana is remarkable for the diversity of its habitat, ranging from grassland to wetland to thick forest. We meandered through large fields of Sunflower (Helianthus annuus). There were several ponds though reserve staff told us that it has been so dry that the only wetlands remaining are those that are being artificially maintained with infusions of water. Amphibians have been rare this spring and summer. (The lower Rio Grande occasionally dries up due to droughts, most recently in the early 2000s .) The forest, however, was sometimes spectacular, with Spanish moss dripping from the trees. But it was also dark and dense, with a low canopy filtering the light and creating a brooding tropical atmosphere rarely found in the continental US.
Because it is summer, private cars were permitted on the circular Wildlife Drive, about 11 km in length, and well worth doing in the early morning. (It would probably be even more rewarding in the late evening but, strangely, the Drive closes as early as 3.30 p.m.) Cotton-tailed rabbits and white-deer were easy to see, though not as plentiful as at Laguna Atascosa. But the Texas tortoise was ubiquitous, basking in the sun besides ponds and puddles of water. Lizards were everywhere. There are over 20 km of walking trails, perhaps pleasant in the winter, but hot and humid now besides being frequented by some of the largest swarms of mosquitoes I have seen in Texas. But our walks were rewarded with a plenitude of birds, most notably, a Ladder-backed Woodpecker (Picoides borealis) and, especially, a dainty Cactus Wren (Campylorhynchus brunneicapillus), a species which I had previously only known from Arizona.
By the typical standards of our Refuges in Texas, Santa Ana has been around for a long time, since 1943. It was originally protected as a sanctuary for migratory birds. Santa Ana is often called an island but this is inappropriate, once we take the Mexican context into account. The area south, which you can see from those trails that follow the Rio Grande itself, has many patches of fairly intact habitat left and the Refuge is less of an island than a peninsula jutting into the US. The contiguity with relatively good biological habitat in Mexico is almost certainly why the species diversity at Santa Ana is high as it is. Within the US, areas such as Laguna Atascosa and Santa Ana have become isolated patches though the new Lower Rio Grande Valley National Wildlife Refuge (LGVNWR), with several units distributed across the region, will supposedly help re-establish connectivity between the protected areas from Falcon Dam State Park, about 50 km to the west, and Laguna Atascosa, about the same distance to the east. For the biodiversity of the Lower Rio Grande Valley, this will not be enough: much of the intervening areas have deteriorated to such an extent that they are useless as habitat for many native species. An active plan for ecological restoration is in order, perhaps creating a Biosphere Reserve for the entire region. But the creation of the LGVNWR is at least a good beginning. What we need is some immediate political planning, as well as a systematic spatially referenced biodiversity assessment of the region, something that has never been attempted.
Santa Ana is worth visiting, even in summer, and the Lower Rio Grande Valley, as a whole, is as biologically diverse and interesting, as any other region in Texas. Be warned, though, that camping is not easy in the region. Bentsen Rio Grande State Park only has “primitive” camping which means that you have to carry your equipment about a kilometer from your car to the campsite. The best bet is to look for private RV parks near the State Park, some of which welcome “tenters” while others resolutely refuse to tolerate them. We stayed at “Americana: The Birding Center RV Resort” a few kilometers from the State Park and were rewarded with a White-tipped Dove (Leptoptila verreauxi) in the morning. These are supposedly spreading northward and are unusually tame around the Park where they once used to be fed . (With friendly welcoming owners and clean bathrooms this “resort” is to be recommended to campers though, next to a busy road, it’s far from quiet.)
 Brush, T. 2005. Nesting Birds of a Tropical Frontier: The Lower Rio Grande Valley of Texas. College Station: Texas A & M Press.
 Oberholser, H. C. 1974. The Bird Life of Texas. Vol. 1. Austin: University of Texas Press.
 Peterson, M. J. 2000. “Plain Chachalaca.” Birds of North America 550: 1 -23.