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Declines in amphibian populations have been noted since at least the 1970s (Gibbs et al., 1971; Hayes and Jennings, 1986; Tyler, 1991; Pounds and Crump, 1994; Bradford et al., 1994a; Drost and Fellers, 1996; Green, 1997b; Lannoo, 1998b; Bury, 1999; Campbell, 1999). In 1989 at the World Congress of Herpetology , informal conversations among scientists led to a concern that amphibian declines were more than local phenomena and may be a global issue (Wake and Morowitz, 1991; see also K. Phillips, 1994). In 1991, out of this concern, scientists and resource managers established the Declining Amphibian Populations Task Force (DAPTF) and formed regional working groups. In 1994, the Midwestern Working Group of the DAPTF met with biologists from around the United States at the Indiana Dunes National Lakeshore; the group discussed monitoring needs and set a goal of establishing a continent-wide monitoring program. Specifically, the group wished to provide a statistically defensible program to monitor the distributions and relative abundance of amphibian populations in North America, with applicability at state, provincial, eco-regional, and continental scales. The Indiana Dunes meeting led to the formation of the North American Amphibian Monitoring Program (NAAMP), a partnership among state, provincial, academic, and nonprofit groups working regionally to gather monitoring data on amphibian populations. The NAAMP framework and protocols were developed during subsequent meetings held at the Canada Centre for Inland Waters in 1995, over the Internet in 1996, and in subsequent discussions. Personnel of the U.S. Geological Survey at the USGS Patuxent Wildlife Research Center in Laurel, Maryland, agreed to administer and coordinate the central database and Internet Web site. Across North America, amphibians have variable life history and natural history features. Therefore, the original goal of the NAAMP effort was to employ several survey approaches and protocols to ensure that all species could be monitored. The first NAAMP protocol to be implemented was a roadside calling survey, with the goal of monitoring anuran (frog and toad) species that make distinctive vocalizations during courtship. This roadside calling survey is now the sole focus of NAAMP. Roadside calling surveys are most useful in regions of North America where all (or most) of the anuran species in an assemblage vocalize in a relatively predictable manner. This protocol can be used in the eastern half of North America (eastward from the Great Plains states and provinces) and to a lesser extent in the remaining Canadian provinces and Pacific Coast region. Due to its usefulness over a large geographic scale, its non-invasive nature, and the success of auditory surveys such as the Wisconsin Frog and Toad Survey and the Breeding Bird Survey, a volunteer-based program for this protocol appeared feasible. Some regions of North America began to monitor anurans with calling surveys prior to the creation of NAAMP. In 1981, the Wisconsin Frog and Toad Survey was the first to begin (Mossman and Hine, 1984; Mossman et al., 1998). Modeled after the successful long-term North American Breeding Bird Survey (BBS; e.g., Peterjohn et al., 1995), the Wisconsin survey is based on permanent routes, each consisting of 10 roadside listening stations. Routes and listening stations were subjectively selected. At each station, observers listen for 5 minutes and record the species heard (within an unlimited detection radius ) and a rough index of abundance (calling index) for each species. Each route is completed once during three prescribed seasonal periods calculated to cover the breeding periods of all Wisconsin anurans. The Wisconsin program has served as the model for programs initiated in other states and provinces, such as Iowa in 1991 (Hemesath, 1998); Ontario in 1992 (Bishop et al., 1997); Minnesota, which started a pilot program in 1993 and expanded in 1996 (Moriarty, 1998); and Michigan in 1996 (L. G. Sargent, personal communication). Some of these programs modified the Wisconsin protocols (e.g., using a three-minute listening period or selecting routes in a more objective manner). Provinces and states where roadside calling surveys have been attempted for amphibian monitoring are listed in Appendix 45-A. The first NAAMP calling survey field season was held in 1997, and it included both new and previously established regional programs. The 1997 NAAMP protocol was based on the experience gained by the regional surveys, the results of a technique -validation study (Shirose et al., 1997), preliminary power and trend analyses of the Wisconsin data set (e.g., Mossman et al., 1998), and experience from the BBS, which provided a useful framework for constructing a large-scale monitoring program . The...

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