San Ygnacio Professional Review and Guide
"For many years, birders visiting the Lower Rio Grande Valley have made the drive upriver to this small town, about 55 miles northwest of Roma, to look for one special bird: White-collared Seedeater, a tiny sparrowlike species that’s common in Mexico and Central America but that appears sporadically in an extremely limited range north of the U.S. border. The seedeater is almost always found in dense vegetation near the Rio Grande, and San Ygnacio has long been the most reliable spot.
The property along the river is privately owned, and a fee is required to enter. The owner has been using the money in part to stock feeders and watering stations and create butterfly gardens in the area. Some luck is needed to find a seedeater; early morning and late afternoon are usually best. In spring, males sometimes perch atop a tall reed and sing their sweet whistled song, but often the birds skulk in the thick vegetation. Be patient and enjoy looking for other birds including Red-billed Pigeon (rare), Green Kingfisher, Great Kiskadee, Green Jay, and other typical Valley species."