POPULATION NUMBERS AND TRENDS 



Populations of Houston toads in Harris County 

 have decreased markedly since the late 1940's, but 

 the rate has not been documented. John Wottring, 

 the naturalist responsible for recognition of the 

 Houston toad as a distinct species, reported collect- 

 ing 66 from a single chorus in 1949, and "quite a 

 lot" in 1953 (from his field notes). Brown (1967, 

 1971) found only three during the breeding sea- 

 sons in 1965, 1966, and 1967. Extensive surveys 

 in 1974, 1975, and 1976 revealed the presence of 

 two Houston toads in southeastern Houston (R. 

 Thomas unpublished data). Surveys in 1978 failed 

 to locate any Houston toads in Harris County 

 (Jameson and Handerstein unpublished). 



Populations in Bastrop and Burleson Counties 

 have apparently remained stable during the past 

 10 years, estimated at a maximum of 300 indivi- 

 duals (Brown 1975). 



Thomas and Potter (1975) estimate the total 

 population to be near 1,500 individuals. Mark-re- 

 capture studies have not been attempted. 



REPRODUCTION 



Breeding is initiated by heavy rains from Feb- 

 ruary to June and lasts only a few nights (Kenne- 

 dy 1962). One female laid 728 eggs (Kennedy 

 1962). Hybridization with Woodhouse's toads 

 (fertile hybrids) and Gulf Coast toads (infertile 

 hybrids) has been documented (Brown 1971). 



MANAGEMENT AND CONSERVATION 



A Recovery Team was appointed in January 

 1978 to develop a plan for removal of this species 

 from endangered status. Critical Habitat has been 

 designated (43 FR 4022, 31 January 1978). Areas 

 of land, water, and airspace in two counties were 

 designated: (1) Bastrop County, from the junc- 

 tion of line corresponding to 30°12'00"N and 

 Texas State Highway 95 east along a line corres- 

 ponding to 30°12'00"N, to where it intersects a 

 line corresponding to 97°17'30"W, to where it 

 intersects the Colorado River, west and northwest 

 along the north bank of the Colorado River to 

 the due southward extension of Texas State High- 

 way 95, and north along the extension and Texas 

 State Highway 95 to where it intersects a line 

 corresponding to 3O°12'00"N; (2) Burleson Coun- 

 ty: a circular area with a 1.6-km radius, the center 

 being the north entrance to Lake Woodrow from 

 Texas FM 2000. 



About 285 ha at Buescher State Science Park 

 are reportedly being maintained in a condition 

 as favorable for Houston toads as possible (F. Pot- 

 ter personal communication). 



The endangered Houston toad has received 

 considerable publicity and most local land owners 

 are aware of the problem. 



Houston toads were reared at the Houston 

 Zoo in 1978 and 1979. The first project involved 

 collecting eggs in the wild and then releasing over 

 1,000 tadpoles back into the wild. In 1979, eggs 

 from Houston toads were spawned at the zoo and 

 at the time this report was prepared (May 1979), 

 tadpoles were being raised for subsequent release. 



AUTHORITIES 



Lauren E. Brown (Recovery Team) 

 Department of Biological Sciences 

 Illinois State University 

 Normal, IL 61761 



William L. McClure (Recovery Team) 

 Houston Urban Project 

 P.O.Box 187 

 Houston, TX 77001 



Floyd E. Potter (Recovery Team) 

 Texas Parks and Wildlife Department 

 4200 Smith School Road 

 Austin, TX 78744 



Norman J. Scott, Jr. (Recovery Team) 

 US FWS 



Natl. Fish & Wildl. Lab. 

 Albuquerque, NM 



Robert A. Thomas (Recovery Team) 

 Louisiana Nature Center 

 4100 One Shell Square 

 New Orleans, LA 70139 



Okla W. Thornton 

 5525 4th Street No. 99 

 Lubbock, TX 79416 



PREPARER'S COMMENTS 



There is an obvious paucity of base-line eco- 

 logical information about the Houston toad. Pro- 

 per management of the species will require such 

 data. 



LITERATURE CITED/SELECTED 

 REFERENCES 



Altig, R. 1970. A key to the tadpoles of the Con- 

 tinental United States and Canada. Herpetolo- 

 gica26(2):180-207. 



Blair, W. F. 1956. Call difference as an isolation 

 mechanism in southwestern toads (genus 

 Bufo). Texas J. Sci. 8:87-106. 



. 1958. Distributional patterns of verte- 

 brates in the southern United States in rela- 



