Reptiles and amphibians are two important groups of vertebrate wildlife that largely have been ignored by natural resource professionals. A few naturalists and herpetologists working before 1950 helped identify most of the species in North America and provided the first range maps that approximated known distributions. In New York, for example, Bishop (1941) wrote the first definitive monograph on the salamanders. Until recently, amphibians and reptiles have received little other systematic attention. The present decade however, has seen a renaissance of herpetological field work that includes a compendium of standard monitoring methods for amphibians (Heyer 1994), and development of the North American Amphibian Monitoring Program (NAAMP), (Schmieder 1996). A few updated field guides, such as the work by Conant and Collins (1991), and the standardization of names (Collins 1990) as recommended by the Society for the Study of Amphibians and Reptiles, have added to this resurgence of interest. Also in 1990, the Endangered Species Unit of the New York State Department of Environmental Conservation (NYSDEC) began an ambystomid salamander survey which was successfully transformed into the New York Amphibian and Reptile Atlas Project. The goal of the Atlas Project is to document the occurrences and distributions of all species of herptofauna living wild in New York by 1999.
In 1993, the New York Cooperative Fish and Wildlife Research Unit began research aimed at identifying areas of the state that were rich in vertebrate species and that heretofore were either unrecognized and/or unprotected by legal statutes. This research project has developed in concert with efforts in other states into a national Gap Analysis Program, which in essence seeks to characterize and link vegetative habitat as determined from Thematic Mapper (TM) satellite imagery to all of the extant vertebrate life in North America. Using geographic information system (GIS) techniques, areas of high species richness can be evaluated as to their size, disjunct nature, and degree of legal protection afforded by current statute and land ownership.
The New York Endangered Species Unit has collaborated extensively with the Cooperative Research Unit in the NY Gap Analysis effort and has provided approximately 21,000 reported individual observations of reptiles and amphibians for use in completion of the Gap effort. The purpose of this poster is to recognize this collaboration and to display and discuss this dataset in light of different mapping methods, mapping units, and species aggregates. Linking species to identifiable habitat derived from TM imagery in order to map predicted distributions is a subsequent step to be treated later.
The NY State Herpetological Atlas Project is a cooperative venture that systematically collects data on all species of herptofauna statewide. Data collection emphasizes standard atlasing techniques to record occurrences of species on a latitude and longitude grid pattern, with each grid cell equivalent to a USGS 7.5' quadrangle. Each grid cell is referred to as an atlas block. Project volunteers throughout New York include professional biologists, naturalists, educators, and other contributors. All records of species occurrence are validated by professionals. Data management and retrieval and display uses FoxPro, MapInfo, Access and ArcInfo. To date, about 840 volunteers have contributed over 21,000 species observations to the Atlas database. Thirty-two species of amphibians and 35 species of reptiles, including three introduced species, have been reported. Five marine sea turtles found off coastal Long Island are omitted from this dataset. At least one species of herptofauna has been reported in 849 of the 985 atlas blocks, (86%) of the state, and at least ten species are known from 340 of the blocks (34%). The most diverse block to date has 38 species; five blocks in the lower Hudson River Valley have more than 30 species, while another 15 blocks in this same drainage basin have more than 23 species.
Maps A, B, and C represent herptofauna distribution by county, township, and topographic quadrangle respectively. Maps A and B are based upon fixed political boundaries which vary in size and shape and offer little to the investigator's efforts to assess species richness and distribution in a uniform way. Nevertheless, such information can be valuable in situations where governmental units may wish to take action to protect or enhance a particular assemblage of species within their jurisdiction. As the appreciation of biodiversity grows, it will likely be recognized first by individuals and then by political entities, such as counties, townships, or local action groups.
Map C, based upon a standard grid with cells of nearly equal area, improves the investigator's ability to compare species richness and distribution across the entire state. Also, it better represents the actual species distribution in areas such as northern New York where townships are quite large, thereby suggesting a higher species diversity than may actually exist. This map highlights what appears to be a reporting bias which plagues most datasets drawn from non-systematic surveys used in mapping vertebrate distributions. Central New York, extending from the Pennsylvania border northward to the eastern shore of Lake Ontario, shows a higher number of species compared to the areas immediately east or west of the region. Reporting rates in this region benefit from the presence of two large universities, three state universities and six other colleges in the region. Also, NYSDEC biologists working in this region have taken a lead role in participating in and promoting the reporting of herptofaunal records. While a systematic survey may indeed show the Central Region to have somewhat higher species diversity, expert opinion of the authors hold that we are seeing a reporting bias for this more intensively surveyed area. Indeed, Map D confirms this reporting bias and points out the need for more survey effort in other areas. The positive side of this observation is that we now expect species gains in the remaining blocks awaiting systematic survey. Also, we know where to target future survey efforts. The higher species richness in the lower Hudson River Valley, where there are five blocks with more than 32 species, is likely accounted for in two ways. Both survey data and historical knowledge indicate that the observed higher species richness is appropriate for this region.
Sixty-four species of amphibians and reptiles can be found living wild in New York, not including marine turtles, established exotics, and important subspecies/hybrid complexes. With the exception of the Plymouth Redbelly Turtle, known only from eastern Massachusetts and Rhode Island, New York has all of the herptofauna species found in New England.
New York State is the northern range limit for several species found in the eastern United States, including the Eastern Hellbender, Marbled Salamander, Eastern Tiger Salamander, Northern Red Salamander, Long-tailed Salamander, Wehrle's Salamander, Eastern Spadefoot, Northern Cricket Frog, Southern Leopard Frog, Eastern Mud Turtle, Bog Turtle, Eastern Box Turtle, Northern Fence Lizard, and the Northern Copperhead. The occurrence of several of these species at their northern range limit contributes to the high species richness of Southeastern New York. The Eastern Tiger Salamander, Eastern Massasauga, Queen Snake, Blanding's Turtle, Midland Painted Turtle, and Western Chorus Frog appear to have spread into the state from regions west and south of New York where all have centers of abundance and a wider distribution (Schmidt 1938). The Mink Frog with a center of abundance in Canada reaches its southern range limit in Northern New York.
In general, a large number of species are rather uniformly distributed across the entire state. These include the Spotted Salamander, Redback Salamander, Northern Two-lined Salamander, Red Spotted Newt, Bullfrog, Northern Gray Treefrog, Northern Spring Peeper, Green Frog, Wood Frog, Pickerel Frog, Common Snapping Turtle, Painted Turtle, Common Garter Snake, Northern Water Snake, and Eastern Milk Snake. The American Toad is also found throughout the state, except on Long Island.
New York State has a diverse and widespread herptofauna. Species representation includes most species present in New England and several additional species from adjacent northern, southern and western regions. The New York State Amphibian and Reptile Atlas Project has made great strides in characterizing and drawing attention to this important group. Current Gap Analysis research is adding to the effort to further delineate and display this rich heritage of amphibians and reptiles in New York.