Status of the Plain Chachalaca in South Texas

The Plain Chachalaca (Ortalis vetula mccalli) is the only member of the family Cracidae in the United States, where it is native to four counties in the Lower Rio Grande Valley of Texas. The species’ habitat of dense brushland and its shy, elusive nature make it difficult to observe in the wild. As a result, published information on the status of Texas chachalacas is meager. One report indicated that by 1940, severe reduction of suitable habitat, due to expanding agronomic production, and intense hunting pressure had reduced the population to 3,000 birds (Texas Game, Fish and Oyster Commission, 1945). Other reports (Blankinship, 1963; Evans, 1970; Hobson and Neikirk, 1970) have also referred to the loss of chachalaca habitat in Texas, but quantitative data have been scarce. Suitable habitat for Plain Chachalacas in the Lower Rio Grande Valley includes isolated tracts of dense brushy woodland on relatively mesic sites. Vegetation in these areas consists predominantly of woody species, including granjeno (Celtis pallida), Texas sugarberry (C. laevigata) , guayacan (PorZieria angustifolia) , and huisache (Acacia farnesiana) . Other species often found in these woodlands include Texas ebony (Pithecellobium flexicaule), cedar elm (Ulmus crassifolia) , honey mesquite (Prosopis glandulosa) , and coma (Bumelia lanuginosa). Such habitats were rather widespread in earlier days in the Lower Rio Grande Valley (Clover, 1937) and were inhabited by chachalacas in southeastern Hidalgo County, nearly all of Cameron County, southeastern Willacy County, and a narrow strip along the Rio Grande in Hidalgo, Starr, and Zapata Counties to San Ygnacio (Texas Game, Fish and Oyster Commission, 1945; Aldrich and Duvall, 1955). In view of the lack of detailed data on the species, I undertook this study, the objectives of which were: 1, to document recent reductions of suitable habitat within the natural range of chachalacas; 2, to determine the present distribution of chachalacas in Texas and compare this with the past distribution; and 3, to obtain a recent population estimate for chachalacas in Texas.