Breeding Migration of Ambystoma cingulatum in Florida

Abstract

-The movement of Ambystoma cingulatum was monitored at a 0.8 ha breeding site in Okaloosa County, Florida with a drift fence and funnel traps for two consecutive breeding seasons (1993-1995). In 1993-1994,198 salamanders were captured, 76% in the months of October and November; yearlings comprised 66% of the catch. A total of 59 salamanders was captured in 1994-1995, only 10% of which were yearlings. Differences in number of yearlings captured between years may be the result of annual variation in either the amount and distribution of rainfall or recruitment of juveniles in previous years. Salamander movement was positively correlated with precipitation and minimum air temperature. The sex ratio was female-biased in 1993-1994, but no different than parity in 1994-1995. In 1993-1994, salamanders that entered and exited the breeding site only once remained in the basin for an average of 38 days, and exited within an average of 44 m from the point of entry. More salamanders immigrated from mesic longleaf/ slash pine flatwoods than from xeric longleaf/sand pine flatwoods. Reported declines of reptile and amphibian populations have increased in recent years (Petranka et al., 1993; Blaustein and Wake, 1995). In the Coastal Plain of the southeastern United States, declines of herpetofaunal populations have been attributed to the drastic reduction and fragmentation of the longleaf pine ecosystem (Auffenberg and Franz, 1982; Moler, 1992; Dodd and LaClaire, 1995). The flatwoods salamander (Ambystoma cingulatum), which is restricted to the southeastern Coastal Plain (Conant and Collins, 1991), is believed to have undergone a rangewide population decline as a result of habitat conversion (Bury et al., 1980; Means, 1986; Means et al., 1996). It is considered rare in Georgia (L. LaClaire, pers. comm.), Florida (Ashton, 1992), and Alabama (Means, 1986); endangered in South Carolina (S. Bennett, pers. comm.); and is a candidate for federal listing (U. S. Fish and Wildlife Service, 1994). Anderson and Williamson (1976) noted that 'Present Address: 529 N Main Street, Jonesboro, Illinois 62952, USA. e declines of reptile and amphib an l ions have increased in recent years a et al., 19 3; Blaustein and Wake, 1995). less is known of the life history of the flatwoods alamander than any other species of Ambystoma. Little new information regarding the natural history of this secretive species has surfaced in recent years. Most recent literature regarding A. cingulatum has addressed its endangerment status while summarizing what is already known of its biology (Bury et al., 1980; Means, 1986; Ashton, 1992; Palis, 1996). Palis (1995) described larval growth, development and metamorphosis for two Florida populations. Means et al. (1996) reported the decline of a population du ing a 22 yr period apparently as a result of habitat alteration associated with plantation forestry. Recent surveys in Alabama (J. Godwin, pers. comm.), Florida (Palis, unpubl. data), Georgia (L. LaClaire, pers. comm.) and South Carolina (S. Bennett, pers. comm.) have failed to detect A. cingulatum at many historic locations. Information regarding the timing of reproduction, environmental factors influencing migration, and size and structure of breeding populations is necessary to make management and conservation decisions. To this end, I studied a popues is known of the life history of the flatwoods alamander than any other species of Ambysoma. Little n w information regarding the natual history of this secretive species has surfaced recent years. Most recent lit ra ure regarding . cingulatum has addressed it ndangerment tatus while summarizing what is already nown of its biology (Bury et al., 1980; Means, 986; Ashton, 1992; Palis, 1996). Palis (1995) decribed larval growth, development and me aorphosis for two Florida populations. Means t al. (1996) reported the decline of a population uring a 22 yr period apparently as a result of abitat alteration associated wi h plantation for71 This content downloaded from 157.55.39.239 on Thu, 15 Sep 2016 05:29:32 UTC All use subject to http://about.jstor.org/terms