698 Northeastern Naturalist Vol. 19, No. 4 698 Identification of Terrestrial Wintering Habitat of Acris crepitans (Northern Cricket Frog) Gregg Kenney1,*, Kelly McKean1, Jason Martin2, and Cory Stearns1 Abstract - We describe the winter hibernacula of three individual Acris crepitans (Northern Cricket Frogs) around Glenmere Lake in southeastern New York. Frogs were tracked by following fluorescent powder trails of treated Northern Cricket Frogs in late fall 2010. Three frogs were tracked to two subterranean burrows that were 87 m and 140 m from the nearest aquatic habitat. To determine if frogs survived until spring, the burrows were covered by small enclosures in late winter 2011. Northern Cricket Frogs emerged into both enclosures: one frog in one enclosure on 17 March and two frogs into the other enclosure on 10 April. This report confirms the use of subterranean terrestrial habitat distant from water as wintering habitat of Northern Cricket Frogs. Acris crepitans Baird (Northern Cricket Frog) occupies most of the eastern United States, but populations are declining in as many as 17 states and may be extirpated from many areas (Conant and Collins 1998, Gray and Brown 2005). In New York State, the historic distribution of Northern Cricket Frogs, a state-listed endangered species, was limited to the lower Hudson Valley, Long Island, and Staten Island. Northern Cricket Frogs were extirpated from Long Island by the 1930s and from Staten Island by the 1970s (Gibbs et al. 2007). Overall, this species has been extirpated from at least 20 historically occupied sites in New York since around 1900 (New York Natural Heritage Program 2011). The reasons for these declines are not known (Beasley et al. 2005), and many aspects of the life history of the Northern Cricket Frog are poorly understood. The utilization and importance of terrestrial habitat around breeding areas are particularly opaque. Some studies of the species in other portions of their range suggest that they do not move very far from their breeding areas (Burkett 1984, O’Neil 2001). However, other work suggests that Northern Cricket Frogs and Acris gryllus LeConte (Southern Cricket Frog) may actually move considerable distances from their breeding habitat and that these movements may be essential to metapopulation dynamics (Gray 1983, Micancin 2010). Hecht et al. (2008) observed Northern Cricket Frogs in upland habitat in New York as far as 400 m from the closest known breeding ponds, with movements away from ponds in the fall and toward the ponds in the spring. These upland movements would be important to Northern Cricket Frog ecology if they represent movements to wintering areas. Microhabitats used by this species for winter habitat have not been identified in the northeastern portion of their range, but lab and field experiments in Ohio suggest that they move upland in the fall to find appropriate wintering habitat that is moist but does not freeze (Irwin et al. 1999). The wintering habitats that have been identified have all been found in close proximity to water: crayfish burrows (Irwin 1999), cracks in the mud (Gray 1971, Irwin et al. 1999), or streambanks (Swanson and Burdick 2010). From September through November 2010, we conducted a pilot study in the uplands adjacent to Glenmere Lake, Orange County, NY. Glenmere Lake is a 328-acre reservoir largely surrounded by undeveloped municipal parkland. The movements of 53 Northern 1New York State Department of Environmental Conservation, 21 South Putt Corners Road, New Paltz, NY 12561. 2Cornell Lab of Ornithology, 159 Sapsucker Woods Road, Ithaca, NY 14850. *Corresponding author - ghkenney@gw.dec.state.ny.us. Notes of the Northeastern Naturalist, Issue 19/4, 2012 2012 Northeastern Naturalist Notes 699 Cricket Frogs were tracked using fluorescent powder (ZQ-17 Saturn yellow and ZQ-11 Aurora pink; Dayglo Color Corporation, Cleveland, OH). Frogs were captured by hand in terrestrial habitats as they emigrated from the lake, and powder was applied to their hindquarters (see Rittenhouse et al. 2006). The movements of the powdered frogs were then tracked on 2 consecutive nights with the use of an ultraviolet flashlight (VI light, Northwest Marine Technology, Shaw Island, WA). Forty-two of the 53 powdered individuals were tracked for 2 consecutive nights after capture, and nightly movements ranged from 0.25–47.6 m. The majority of relocated frogs (80%) were observed using microhabitat features that afforded them some sort of cover (i.e., in thick grass, under leaves, under woody debris). Interestingly, 3 frogs entered subterranean burrows in terrestrial habitat. One individual was tracked into a burrow on 28 October. The hole was approximately 6 cm in diameter, and use of a small video camera (VideoStik, VOscope, Wynnewood, OK) determined its depth to be >1.5 m. It appeared to be a rodent burrow, but this was not confirmed. This “deep burrow” was 140 m from the nearest known aquatic habitat. Two other individual frogs were tracked to a large flat rock on 25 October. Both frogs were observed utilizing 2 separate holes under the rock. These 2 holes were each about 20 mm in diameter, about 5 cm deep, and were connected underground. It is possible that these holes were originally excavated by an Ambystoma maculatum Shaw (Spotted Salamander) that was repeatedly observed in the vicinity. This “shallow burrow” was 87 m from the nearest aquatic habitat . In late winter of 2011, both burrows were covered by 0.16-m3 enclosures that allowed ambient temperatures and moisture inside the enclosure, but did not allow frogs to leave. These areas were selected because not only did we observe cricket frogs use them, but we also felt that they may provide the conditions necessary for winter survival. Additionally, we could precisely locate where the frogs would emerge if they used this habitat feature for overwintering. The enclosures were made of a plastic tub that had the bottom replaced with a fine wire mesh. The open portion of the tub was placed on top of the burrow and the edges were covered with soil. Enclosures were checked once a day when nighttime temperatures remained above freezing from 15 March until a cricket frog emerged. One individual was located in the “shallow burrow” enclosure on 17 March and 2 individuals were located in the “deep burrow” enclosure on 10 April. Enclosures were removed once a frog was observed. Our observations confirm that Northern Cricket Frogs use terrestrial habitats distant from water for overwintering. These areas likely represent core habitat needed to complete the overwintering component of the species’ life cycle. Loss of terrestrial habitats that provide wintering habitat may be an important threat to Northern Cricket Frog populations (Lehtinen 2002). Terrestrial habitats adjacent to wetlands are important to many herpetofauna and are typically not protected through local land-use ordinances (Semlitsch and Bodie 2003). For the species to continue to persist in New York State, particular attention should be paid to the conservation of terrestrial areas that represent core habitat for the Northern Cricket Frog. Acknowledgments. Partial funding for this project was through New York State Wildlife Grant T-12 in cooperation with the US Fish and Wildlife Service Division of Wildlife and Sport Fish Restoration. Thanks to Lora Smith and Jennifer Howze for helpful comments with this manuscript. 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