-Range extensions for the eastern hognose snake, Heterodon platirhinos, are compared to known and new data from eastern New England: Rhode Island, Massachusetts east of the Worcester County line, and New Hampshire. The species is unknown from coastal islands; reasons are suggested. The disjunct New Hampshire population occupies inland sandy habitats dominated by white pine (Pinus strobus). Albino and melanistic specimens occur. Eastern New England, including New Hampshire, Rhode Island, and Massachusetts east of the Worcester County line, is regarded as part of the peripheral range of Heterodon platirhinos, where the species is rare or only locally common in semi-isolated (Platt, 1969). The only previous evidence we can find for occurrence of this species in New Hampshire, for example, is the photograph of an albino and the letter published by Newton (1940). The species is not, however, listed by the state of Massachusetts for special consideration (Blodget and Cardoza, 1983). New Hampshire has no state listings at present. One of us (JDL) has extensive experience with this species in the southern region of eastern New England, and the other (MCM) in the northern portion. Our field experience overlapped for many years in the centrally located suburban Boston area. Because Edgren (1961) examined no New Hampshire specimens, and saw only 25 from Massachusetts, we believe a range and population analysis is warranted at this time. Aspects of geographic distribution are shown in Fig. 1. Little (1971) plots eight major environmental variables of climate and physiographic features. None corresponds closely with the limits of hognose snake distribution. Only the ranges of two tree species, swamp white oak, Quercus bicolor, and Atlantic white cedar, Chamaecyparis thyoides, show some correspondence (Little, 1971). Both of these trees are characteristic of wet areas in typical southern New England pine barrens, preferred by the hognose snake in much of its range, where adjacent drier areas are dominated by pitch pine, Pinus rigida. Our records from southern New Hampshire (Hillsborough and Merrimack counties) show good correspondence to inland soils derived from sandy outwash material (Goldthwait et al., 1951), but not with the sandy coastal plain soils utilized by these snakes from Long Island southward (Conant, 1975). We have previously (Lazell and Michener, 1976) suggested that three factors control hognose snake distribution in the sandy soils of this region: 1. Heterodon platirhinos is a southern form, whose range has only recently moved north; therefore, the species arrived in New England after sea levels had risen significantly since the Wurm (ca. 10,000 yr BP), and the species has not colonized across sea water. 2. These snakes must have an abundance of toads (Bufo spp.) as prey to sustain adult populations. 3. They must have a supply of small amphibians, either salamanders, Plethodon cinereus, or peepers, Hyla crucifer, to sustain hatchlings and young until they are big enough to eat toads. Small toads alone cannot supply the young snakes' diet, because these amphibians do not metamorphose into the terrestrial form until well into the summer of each year. Hognose snakes are thus able to colonize peninsular habitats where soils are loose enough to permit burrowing and the habitats can supply needs two and three above. Hognose snakes seem to be absent from all of the islands in Rhode Island (Table 1). Similarly, hognose snakes are absent from all of the Massachusetts coastal islands including Monomoy, which has been connected to the mainland and which does support toads. Monomoy lacks both woodland salamanders and peepers (Lazell and Michener, 1976). Two peninsular barrier systems support good populations of hognose snakes: Sandy Neck and the Provincelands, in Barnstable County, Massachusetts. Details of their physiography are given in Lazell (1979). A mark recapture survey has been begun on Sandy Neck; preliminary results indicate approximately one hognose snake per three hectares of land, excluding salt marsh. Hognose snakes are abundant north of Provincetown in Provincelands, where at old This content downloaded from 157.55.39.251 on Fri, 13 May 2016 07:23:39 UTC All use subject to http://about.jstor.org/terms M. C. MICHENER AND J. D. LAZELL FIG. 1. Distribution of the hognose snake in eastern New England. Black circles are museum specimens, open circles photographs; the number of individuals in each case is indicated if more than one. Sight records are indicated by X. Urban areas are stippled. dump sites one may find more than one per hectare. Both of these peninsulas supply all three range requirements noted above. We are convinced that Heterodon platirhinos, albeit more or less common, is fairly continuously distributed south of Conant's (1975) line, given minor adjustments (Fig. 1). Because this snake does well in edificarian habitats, and is most common in the pine barrens ecosystem TABLE 1. The major islands of Rhode Island. None is known to support hognose snakes. Habitat characteristics are more fully described in text. Habitat prerequisites