Plain Chachalaca: a subtropical species found in chaparral thickets along the Rio Grande River. Photo: Lynn Bieber-Weir
South Texas is blessed with the most distinctive avifauna in the contiguous United States; no fewer than 30 species are restricted to the region. In addition, early April brings a wide array of northbound migrant passerines, raptors, and shorebirds resulting in a bird diversity that is truly staggering. The lower Rio Grande Valley is also well known for its butterfly, dragonfly, and reptile diversity and we’ll spend time with these groups as well. Indeed, there are more species of butterflies in the Valley than have been recorded in all of North America east of the Mississippi River!
We’ll have a full week to explore a range of faunal regions, from the broad coastal plain with its shallow lagoons and grasslands, to the scrubby mesquite/cactus forests of the drier uplands, and finally to the dense stands of sabal palm, huisache, Texas ebony, and Montezuma bald cypress that line the river itself.
Day 1: The tour begins at 6:00 pm in Corpus Christi. If the weather conditions permit we’ll visit a local park for an hour’s birding before dinner. Night in Corpus Christi.
Day 2: We’ll spend at least part of the morning birding in the Corpus Christi area. There are some excellent areas for landbird migrants, plus a wide array of shorebirds around Aransas Bay. If there’s been a flight we may spend the entire morning here. When we depart Corpus Christi, we’ll route through the vast King and Kenedy Ranches on our way to the lower Rio Grande Valley. We’ll stop in oak woodland and mesquite grassland, where we’ll get our first look at South Texas specialities including Great Kiskadee, Green Jay, and Long-billed Thrasher. Raptors should be common on the roadsides, and we’ll look especially for Crested Caracara and White-tailed, and Harris’s Hawks. In the afternoon we’ll visit the Valley Nature Center Thicket in Weslaco, which often harbours migrants and parrots and has a small colony of breeding Yellow-crowned Night-Herons. Afterward’s we’ll continue to McAllen and visit a nearby Green Parakeet roost. Night in McAllen.
Day 3: We’ll depart early for the densely vegetated Frontera Audubon Thicket, a small but lovely park near downtown Weslaco. Here we should encounter Golden-fronted Woodpecker and observe Buff-bellied Hummingbird as it attends the flowerbeds. In recent years Frontera has been very productive for vagrants and localized species such as Groove-billed Ani and roosting Common Pauraque. We’ll also visit the McAllen Sewage Ponds and Anzalduas County Park, where we hope to encounter some mixed flocks and perhaps the charming Northern Beardless-Tyrannulet. Our last birding stop for the day will be along the Rio Grande itself at the Roma Bluffs. Here we’ll have our first prolonged look at the river, scanning from the banks for a passing Muscovy Duck or Red-billed Pigeon and exploring a small trail that runs downstream from the road. Night in Zapata.
Day 4: Today we’ll visit Salineno, just downstream from Falcon Dam, where we’ll spend the morning investigating riparian forest for some of the harder-to-find South Texas specialities such as Audubon’s Oriole, Ringed and Green Kingfishers, Red-billed Pigeon, and Muscovy Duck. The riparian vegetation downstream from the Falcon Dam spillway is particularly lush with older native hardwoods such as Texas ebony and huisache. Once we’ve finished at Salineno, we’ll venture upstream to the desert chaparral of Falcon State Park. Here among the cactus and scrubby mesquites we’ll look for a variety of desert birds not easily found in the lower valley, such as Scaled Quail, Black-tailed Gnatcatcher, and Lark, Clay-colored, and Black-throated Sparrows. Close study of the ground is often worthwhile as well, since the area around Falcon Dam is home to a number of lizard species otherwise found only in Mexico. Night in Zapata.
Day 5: We’ll devote most of the morning to searching for White-collared Seedeater, a very local resident of the upper Rio Grande Valley that is closely tied to thick riparian grasses. We’ll look in several consistently productive areas near Zapata and San Ignacio, where thick grasses also support large numbers of migrant sparrows, and we’ll spend some time teasing out the field marks of the local species. We’ll then drive to McAllen, with stops along the river to search for any of the specialities we might have missed. Night in McAllen.
Day 6: Today we’ll head to the coast to explore the migration hot spot of South Padre Island. The southern part of the island is quite developed, but some small sanctuaries, several with permanent water, and a number of well-vegetated and little-travelled residential streets can attract literally thousands of brightly coloured migrant warblers, tanagers, orioles, and grosbeaks. Such ‘fallouts’ require the right weather conditions, of course, but if we are lucky enough to be there when one occurs, the spectacle is simply astonishing. We’ll also seek out waders and terns, possibly including American Avocet, Marbled Godwit, Gull-billed and Sandwich Terns and will have plenty of time to sort through the pertinent field marks of each species present. After a seafood dinner on the island we’ll venture out to a nearby marsh at sunset to watch for emerging rails and, with some luck, perhaps a Purple Gallinule or Least Bittern. Night in Harlingen.
Day 7: This morning we’ll visit the National Audubon Society’s Sabal Palm Sanctuary, the largest extant native palm forest in the lower Rio Grande Valley. In addition to the palms, the sanctuary’s numerous ponds, grasslands, and Rio Grande riparian forest support large numbers of area specialties including Green Jay, Great Kiskadee, and White-tipped Dove, and one never knows what rarities might occur. If Tamaulipas Crows are present this year, we’ll visit another of the valley’s famous birding locations, the scenic, if fragrant, Brownsville dump. A number of rare gulls have also been found here, but even if there are none, we should get fine views of migrant Franklin’s Gulls, at this season especially lovely with their rosy breasts. In the afternoon we’ll venture out to the long sand beaches of Boca Chica, where the Rio Grande empties into the Gulf of Mexico. On the way we’ll pass through Texas coastal plain where we hope to encounter White-tailed Hawk, Aplomado Falcon, and a host of gulls, shorebirds, and wading birds. Night in Harlingen.
Day 8: Today we’ll return to South Padre, or if migration is light, we’ll visit Laguna Atascosa National Wildlife Refuge and explore the long loop road that passes bays, beaches, mudflats, and grasslands. Flocks of Roseate Spoonbills and White-faced Ibis are regular, and the grassy scrub holds White-tailed Kite, Botteri’s Sparrow, and some of the largest Western Diamondback Rattlesnakes in Texas. Night in Harlingen.
Day 9: Our final morning will be flexible, allowing us to look for any local rarities or species we might have missed, or to return to the coast in the hope of a fallout on South Padre Island. If the weather is not conducive for fallout, we’ll visit Santa Ana NWR. This incredible refuge boasts the second largest birdlist of any refuge (after Laguna Atascosa) and can prove productive for Tropical Parula, Clay-colored Thrush, and waterbirds. We’ll then make the drive back up to Corpus Christi. Night in Corpus Christi.
Day 10: The tour concludes this morning in Corpus Christi.
Updated: 17 November 2020