The Houston toad is generally considered a 

 post-Pleistocene relict of the more northerly dis- 

 tributed American toad (B. americanus) (Blair 

 1958, 1965) and may be ill-adapted to southern 

 environments (Brown 1971). If true, this may ex- 

 plain the species' apparent failure to adapt to 

 habitat alterations. 



PRIORITY INDEX 



Not assigned. 



DESCRIPTION 



A small toad, the Houston toad is similar to 

 the American toad, but with heavier cranial crests, 

 especially behind the eyes. Males have a 49- to 

 66-mm snout-to-vent length; females meaure 57 

 to 80 mm. The dorsum is light brown to cream 

 with a variable number of dark brown to black 

 spots, each with one or more warts. The venter is 

 cream, usually heavily mottled. A hght mid-dorsjd 

 stripe is usually present. Tadpoles are virtually 

 indistinguishable from American toad larvae 

 (Altig 1970). The mating call consists of a long 

 (7- to 22-sec), high-pitched (1,646- to 2,300-Hz) 

 trill with 14 to 16 pulses per second (Brown 

 1973). 



Photographs appear in Sanders (1953), Blair 

 (1959, 1972), Kennedy (1962), Brown (1971), 

 Thomas (1975), Thomas and Potter (1975), Eh- 

 renfield (1976), and Hardy (1977). Audio- 

 spectrograms of the mating call are given in 

 Brown (1971, 1973). 



RANGE 



The species' historical range included the fol- 

 lowing localities: northwest and southeast Hous- 

 ton, Harris County; Lake Woodrow, Burleson 

 County; 6 miles south of Liberty, Liberty Coun- 

 ty; Austin County; and 6 and 12.6 miles east of 

 Columbus, Colorado County (Sanders 1953). 

 Brown (1971) also reported populations 2 miles 

 west of Fresno in Fort Bend County and in the 

 vicinity of Bastrop and Buescher State Parks in 

 Bastrop County. 



The species has not been found in Liberty, 

 Austin, Colorado, or Fort Bend counties since 

 originally reported. It is now known to exist only 

 in the vicinity of Bastrop and Buescher State 

 Parks, Bastrop County; Lake Woodrow, Burleson 

 County; and possibly southeast Houston, Harris 

 County. 



RANGE MAP 



Historic localities are designated on the follow- 

 ing map by triangles; present known localities are 

 indicated by dots. Critical Habitat as designated 

 in 43 FR 4022, 31 January 1978, is shown on a 

 separate map. 



STATES/COUNTIES 



Texas: Austin,' Bastrop, Burleson, Colora- 



do,* Fort Bend,' Harris, Liberty.' 



HABITAT 



Houston toads are restricted to areas charac- 

 terized by sandy soils. Localities in Bastrop and 

 Burleson Counties are heavily wooded with lob- 

 lolly pine {Pinus taeda) and/or mixed deciduous 

 forest, interspersed with open grassy areas. The 

 southeast Houston locality is residential with 

 open, grassy fields. 



Breeding habitats include roadside ditches, 

 temporary ponds in residential areas and pastures, 

 and other seasonally flooded low spots. Houston 

 toads also breed in Lake Woodrow and nearby 

 permanent ponds. 



FOODS AND FORAGING BEHAVIOR 



Bragg (1960) reported captives feeding on va- 

 rious insects and smaller toads. Thomas (unpub- 

 lished data) examined 17 specimens and found 

 unidentified red ants in one and beetle remains in 

 another. 



SHELTER REQUIREMENTS 



Apparently requires sandy loamy soils for 

 burrowing. 



NESTING OR BEDDING 



The species breeds in temporary rain pools, 

 flooded fields, and permanent ponds. 



RITUAL REQUIREMENTS 



Males call from small mounds of soil or grass 

 surrounded by water, or from shallow water. 



OTHER CRITICAL ENVIRONMENTAL 

 REQUIREMENTS 



Not known. 



' Believed extirpated in these counties. 



