Blair and Lindsey (1) were the first to document bird-voiced treefrogs (Hyla avivoca Viosca) in Oklahoma. Their record was from a single location ("near where U.S. Highway [259-]70 crosses [the] Little River between Idabel and Broken Bow, McCurtain County, Oklahoma"). This discovery was also the first record west of the Mississippi River (2) and extended the known distribution 280 km west (1). All subsequent Oklahoma sightings were from this general area north of the Little River. McCarley (unpublished field notes) found calling H. avivoca on six occasions between 1964 and 1975, and Krupa et al. (3) collected specimens here again in 1984 (0.8 km north of the Little River on the east side of U.S. Highway 259-70, T7S, R24E, Sec. 13 & 14, McCurtain Co.). Smith (2) showed the Oklahoma record as an isolated population because of a lack of records from southern Arkansas and northern Louisiana. However, Fouquette and Delahoussaye (4) believed that the range was probably continuous along the Red River drainage system, which includes the Little River. This note documents additional breeding sites and updates the currently known distribution of H. avivoca in Oklahoma.
Bird-voiced treefrogs call from late April (1) until mid-July (S. Secor, pers. comm.) in McCurtain County. On four evenings in 1985 (18, 23, 24 May and 19 June), I attempted to locate breeding sites by listening for the distinctive call of the male. Accessible areas along the Little River, its tributaries, and other swampy habitats were visited between sunset and 0300 CDST. I listened for at least 15 min at each site and recorded all anuran calls with a Uher 4000 tape recorder. Locations with suitable habitat where H. avivoca were not heard during the first visit were visited again later the same evening and on future nights to confirm their absence.
Hyla avivoca were found at seven of 25 sites visited during 1600 km of travel (Fig. 1). These treefrogs were not found along the shores of rivers or streams, but in adjacent swamps and roadside ditches. No bird-voiced treefrogs were heard more than 3 km from the Little River. Trees, shrubs, and emergent and semiaquatic vegetation were characteristic of all breeding sites. Most locations where H. avivoca were absent either lacked these characteristics or were not connected to tributaries of the Little River. The westernmost record extended the range of this species 10 km. Fifty km separated this site from the Arkansas location (Fig. 1). It is probable that bird-voiced treefrogs occur in suitable areas all along this stretch of the Little River.
These observations and locality records from northcentral Louisiana (5) lend support to Fouquette and Delahoussaye's (4) contention that the range of H. avivoca
Proc. Okla. Acad. Sci. 66:37-38 (1986)
is continuous along the Red River drainage. This is despite the lack of additional records from southwestern Arkansas, which is due more to the lack of collecting in that region than to the absence of this treefrog (H. Robison, pers. comm.). Bird-voiced treefrogs may occur elsewhere in Oklahoma. Numerous records now exist along the Arkansas River Valley from the Mississippi River west to Franklin County, Arkansas, approximately 48 km east of Oklahoma (M. Nickerson, G. Turnipseed, and M. Plummer, pers. comm.). This suggests that bird-voiced treefrogs may be in Leflore and Sequoyah counties breeding in swamps closely associated with the Arkansas River.
It is probable that further field work will discover additional localities for bird-voiced treefrogs along the Red and Arkansas River drainages. This species is listed as peripherally threatened in Oklahoma (6) but is apparently not as uncommon or isolated in the state as once thought.
I thank the following: D. Fields, S. Secor, B. Ward, and G. Warren for assistance with field work; Drs. A. Blair, H. Lindsey, H. McCarley, N. Nickerson, H. Robison, W. Shepard, and G. Turnipseed for sharing information with me; and Dr. C. Carpenter, M. Paulissen, and S. Secor for their comments on this manuscript.
1. A.P. Blair and H.L. Lindsey, Jr., Southwest. Nat. 6: 202 (1961).
2. P.W. Smith, Cat. Am. Amphib. Reptiles, 28.1-28.2 (1966).
3. J.J. Krupa, S.M. Secor, and G. Sievert, Bull. Okla. Herpetol. Soc. 10: 8-10 (1985).
4. M.J. Fouquette, Jr. and A.J. Delahoussaye, Southwest. Nat. 11: 137-139 (1966).
5. B.J. Davis, Southwest. Nat. 23: 161 (1978).
6. R.E. Ashton, Jr., Soc. Study Amphib. Reptiles Herpetol., Circ. No. 5, pp. 1-65 (1976).