2006Notes of the NortNhOeRaTHsEteASrTnE RNN aNtAuTUraRAliLsIStT, Issue 14/2, 2103(01)7:39–42 Emergence Season and Survival in the Nest of Hatchling Turtles in Southcentral New Hampshire David M. Carroll1 and Gordon R. Ultsch1,2,* Abstract - We report the season of emergence from the nest of hatchlings of five species of freshwater turtles from a wetlands/stream/lake complex in southcentral New Hampshire from 1988–1994. Only hatchling Chrysemys picta (Painted Turtle) overwintered in the nest and emerged the following spring, although there were some cases of autumn emergence, as well as some nests with hatchlings that emerged in both seasons. In nests monitored over the winter, mortality ranged from 26–100%. Hatchlings of the other four species—Chelydra serpentina (Snapping Turtle), Glyptemys insculpta (Wood Turtle), Clemmys guttata (Spotted Turtle), and Emydoidea blandingii (Blanding’s Turtle)—emerged only in autumn. Freshwater turtles in North America range northward into the northern United States and southern Canada, where they may be numerous, but not diverse (Ultsch 2006). In spite of the cold winters in such localities, a few species have hatchlings that typically overwinter in the nest, including Chrysemys picta Schneider (Painted Turtle; Lindeman 1991, Pappas et al. 2000, Zwiefel 1989) and Graptemys geographica Le Sueur (Common Map Turtle; Baker et al. 2003, Nagle et al. 2004, Pappas et al. 2000), and are thus primarily spring emergers, although some autumn emergence does occur in both species. Other sympatric species are typically autumn emergers (here defined as emergence in the same year that the eggs are laid, rather than the following year), moving to the water to overwinter, including Apalone spinifera Le Sueur (Spiny Softshell Turtle), Sternotherus odoratus Latreille (Common Musk Turtle), Glyptemys insculpta Le Conte (Wood Turtle), Clemmys guttata Schneider (Spotted Turtle), Chelydra serpentina Linnaeus (Snapping Turtle), and Emydoidea blandingii Holbrook (Blanding’s Turtle). There are scattered reports of potential overwintering in the nest (or possibly terrestrially outside of the nest cavity) by hatchlings of some of the latter species (Ernst 1966, 1976; Pappas et al. 2000; Parren and Rice 2004; Standing et al. 1997), but almost all such evidence is indirect, usually involving the capture of one or a few hatchlings in spring, rather than an actual documentation of springtime emergence from the nest. One of us (D.M. Carroll) has been monitoring turtle behavior in southcentral New Hampshire for over 20 years. The study area was a privately owned mixture of hayfields, riparian woodlands along two streams, wetlands, and a lake (see Carroll 1991 for details). Thus there were both natural and disturbed areas available to the turtles, and field notes were taken throughout the area. Here we report on a subset of those notes: the emergence times of hatchlings for five local species from 1988– 1994. Observations were made almost daily by visits to well-known nesting areas from spring through autumn. Some nests were marked after females were observed to complete nesting and monitored for emergence of hatchlings, some nests were covered with 0.64-cm mesh screening (hardware cloth) to capture emerging hatchlings, and some observations of newly emerged hatchlings were made opportunistically during daily surveys in the nesting habitats. Painted Turtle. There were observations of 42 hatchlings, either as individuals or as entire clutches. Seven were of autumn emergence. In three cases, the observations consisted of the capture of a single hatchling (21 August 1988, 26 September 1990, and 26 September 1991). In three others, an entire known clutch emerged (between 10 and 15 August 1988, 31 August 1991, and 8 September 1993); in another clutch, six of seven 307 308 Northeastern Naturalist Vol. 14, No. 2 emerged (29 August 1992—one was dead). All remaining observations were of successful spring emergence or death during overwintering. Single hatchlings (apparently on nest-to-water journeys) were found on land on 1 and 28 May 1988, 29 April and 7 June 1991, and 15 May 1992; two were found on 10 June 1991. In some instances, nests were screened or otherwise monitored to determine emergence times, and if the young had not emerged by late spring, the nests were excavated to determine hatchling survival. Of six nests screened over the winter of 1988–89, a single hatchling emerged in autumn from one nest, and all others perished over the winter. On 23 April 1991, eight excavated nests had the following hatchlings: two alive and two dead, four alive, three alive, three alive and two dead, seven alive, five alive, one alive and three undeveloped, and four dead. All dead hatchlings were in the head-up position (vertical, facing upward). On 26 April 1991, two excavated nests yielded four undeveloped eggs in one and six welldeveloped but unpipped dead embryos in the second. On 28 April 1992, three hatchlings had emerged from under a screened nest, and three more were dead in the nest in the head-up position. On 5 May 1992, five dead hatchlings were found in the head-up position in a nest. On 9 May 1992, one nest contained three dead hatchlings and an undeveloped egg. In 1993, one nest located on 28 April had two exit holes and two dead hatchlings, suggesting partial overwintering survival; one from 1 May had five of six emerge, and one on 8 May had four dead hatchlings in the head-up position. Survival was also mixed in six nests excavated in the spring of 1994 as follows: 23 April, six emerged; one dead; 30 April, three emerged, two pipped but dead; 3 May, one emerged, four dead; 12 May, two emerged, one still alive in nest; 17 May, four dead and one alive below them; and 31 May, five dead. Wood Turtle. observations were in August and September; there was no evidence of hatchlings overwintering in the nest. For 18 nests for which the dates of emergence were known for 1990–94, hatchlings appeared from 13 August to 14 September. Within this time period, there were eight encounters of hatchlings found on land. Spotted Turtle. There were 19 observations of hatchlings from 1988 to 1994. Twelve known dates of emergence ranged from 20 August to 16 October. Hatchlings were found on land on seven occasions during this time period. There was no indication of overwintering in the nest by hatchlings. On 10 October 1991, a screened nest laid that year was excavated and found to contain three dead embryos advanced to the point of being recognizable as Spotted Turtle. Blanding’s Turtle. This species was rare in the study area. Hatchlings emerged from two nests covered with screens in 1993, 15 on 30 August, and 13 on 24–27 September. Snapping Turtle. There were 24 observations of hatchlings from 1988–94. Fourteen known dates of emergence ranged from 5–24 September. Hatchlings were encountered 10 times on their nest-to-water journeys from 6–23 September. All observed successful emergence occurred during autumn. Among Painted Turtle hatchlings, we observed autumn emergence, spring emergence, and one nest with both. Overwintering mortality was variable, and our qualitative observations suggest survival depended upon the severity of the cold and the amount of snowfall. Some screened nests were excavated in the spring to determine mortality. In 1988–89, overwintering mortality was 100% in six nests; the only potential survivor was a single autumn emerger. In contrast, of 34 hatchlings overwintering in eight nests in 1990–91, survival was 74%, with some nests having both dead and live hatchlings. Mortality over the winter of 1993–94, reckoned from known fates of hatchlings, was 53% (16 of 30) in six nests, although it is possible that a few live hatchlings may have left the nest without being counted. Other investigators have reported variable survival rates for overwintering hatchling Painted Turtles, but there is always some mortality, ranging from 18–95% 2007 Notes 309 (Breitenbach et al. 1984, DePari 1996, Lindeman 1991, MacCulloch and Secoy 1983, Nagle et al. 2000, Packard et al. 1989, St. Clair and Gregory 1990). The abundance of Painted Turtles in northern areas suggests that overwintering mortality of hatchlings is not limiting the success of populations, but nevertheless a reasonable question is why this species overwinters terrestrially when considerable mortality can occur—that is, why not leave the nest in the autumn and overwinter underwater, as do other species in the same area? Moreover, what is the fate of those hatchlings that do emerge in the autumn? Is their overwintering mortality different from that of those that remain in the nest? Only partial answers are available to date. Reese et al. (2004) found that Painted Turtle hatchlings could survive 150 days of submergence in normoxic water at 3 oC, accumulating no lactate and therefore having an entirely aerobic metabolism. However, they could only survive 40 days if the water was anoxic, which means that they would not be able to hibernate in mud if they went to water after emerging. Thus, one might conjecture that remaining in the nest eliminates a problem with hibernaculum microhabitat selection, although it subjects hatchlings to a risk of mortality due to cold, in spite of their known, but not without limits, freeze-tolerance and supercooling ability (Costanzo et al. 2004, Packard and Packard 2004). Sympatric Snapping Turtle hatchlings, however, all go to water to spend their first winter. Unlike Painted Turtle hatchlings, they are not cold- or freeze-tolerant (Packard and Packard 1990, Packard et al. 1993), so they may be forced to go to water and take their chances with potential hypoxia or anoxia. Overwintering stresses raise the possibility of a second population growth bottleneck among turtles, due to high mortality during the first winter (the first is the high mortality of eggs due to nest depredation). Further physiological studies will be needed to help elucidate why there are two very different strategies for overwintering during the first year of life among northern freshwater turtles. All hatchling Snapping Turtles, Spotted Turtles, Wood Turtles, and Blanding’s Turtles emerged in the autumn. Wood Turtles and Blanding’s Turtles have a tendency to tarry on land before entering the water, perhaps because they can feed terrestrially (C.M. Castellano, J.L. Behler, and G.R. Ultsch, unpubl. data; Standing et al. 1997, 1999; Tuttle and Carroll 2005), while Snapping Turtles and Spotted Turtles tend to move directly to water. Ultimately, they all overwinter underwater, which means that they must find an aquatic hibernaculum with sufficient dissolved oxygen to permit aerobic respiration, as hatchlings can only tolerate about one-third the duration of submergence in anoxic water as adults (Reese et al. 2004). The egg and hatchling stages are clearly critical portions of the life history of turtles. There have been many studies of hatching rates on numerous species, but none that track survival of a cohort of hatchlings outside of the nest over the first winter. Now that radiotransmitters are available that are small enough to attach to hatchlings, along with implantable identification tags that can be remotely sensed, it is possible to follow hatchlings over the first winter. Such studies will provide important information on the early life history of turtles. Acknowledgments. We are thankful to the owners of the study site for allowing unlimited access to D.M. Carroll over several decades. This research was partially supported by NSF grants IBN-9603934 and IBN 0076592 to G.R. Ultsch. Literature Cited Baker, P.J., J.P. Costanzo, J.B. Iverson, and R.E. Lee, Jr. 2003. Adaptations to terrestrial overwintering of hatchling Northern Map Turtles, Graptemys geographica. Journal of Comparative Physiology B 173:643–651. Breitenbach, G.L., J.D. Congdon, and R.C. van Loben Sels. 1984. Winter temperatures of Chrysemys picta nests in Michigan: Effects on hatchling survival. Herpetologica 40:76–81. 310 Northeastern Naturalist Vol. 14, No. 2 Carroll, D.M. 1991. The Year of the Turtle: A Natural History. Camden House, Charlotte, VT. 172 pp. Costanzo, J.P., S.A. Dinkelacker, J.B. Iverson, and R.E. Lee, Jr. 2004. Physiological ecology of overwintering in the hatchling Painted Turtle: Multiple-scale variation in response to environmental stress. Physiological and Biochemical Zoology 77:74–99. DePari, J.A. 1996. Overwintering in the nest chamber by hatchling Painted Turtles, Chrysemys picta, in northern New Jersey. Chelonian Conservation and Biology 2:5–12. Ernst, C.H. 1966. Overwintering of hatchling Chelydra serpentina in southeastern Pennsylvania. Philadelphia Herpetological Society Bulletin 14:8–9. Ernst, C.H. 1976. Ecology of the Spotted Turtle, Clemmys guttata (Reptilia, Testudines, Testudinidae), in southwestern Pennsylvania. Journal of Herpetology 10:25–33. Lindeman, P.V. 1991. Survivorship of overwintering hatchling Painted Turtles, Chrysemys picta, in northern Idaho. Canadian Field-Naturalist 105:263–266. MacCulloch, R.D., and D.M. Secoy. 1983. Demography, growth, and food of western Painted Turtles, Chrysemys picta bellii (Gray), from southern Saskatchewan. Canadian Journal of Zoology 61:1499–1509. Nagle, R.D., O.M. Kinney, J.D. Congdon, and C.W. Beck. 2000. Winter survivorship of hatchling Painted Turtles (Chrysemys picta) in Michigan. Canadian Journal of Zoology 78:226–233. Nagle, R.D., C.L. Lutz, and A.L. Pyle. 2004. Overwintering in the nest by hatchling Map Turtles (Graptemys geographica). Canadian Journal of Zoology 82:1211–1218. Packard, G.C., and M.J. Packard. 1990. Patterns of survival at subzero temperatures by hatchling Painted Turtles and Snapping Turtles. Journal of Experimental Zoology 254:233–236. Packard, G.C., and M.J. Packard. 2004. To freeze or not to freeze: Adaptations for overwintering by hatchlings of the North American Painted Turtle. Journal of Experimental Biology 207:2897–2906. Packard, G.C., M.J. Packard, P.L. McDaniel, and L.L. McDaniel. 1989. Tolerance of hatchling Painted Turtles to subzero temperatures. Canadian Journal of Zoology 67:828–830. Packard, G.C., K.A. Ruble, and M.J. Packard. 1993. Hatchling Snapping Turtles overwintering in natural nests are inoculated by ice in frozen soil. Journal of Thermal Ecology 18:185–188. Pappas, M.J., B.J. Brecke, and J.D. Congdon. 2000. The Blanding’s Turtles (Emydoidea blandingii) of Weaver Dunes, Minnesota. Chelonian Conservation and Biology 3:557–568. Parren, S.G., and M.A. Rice. 2004. Terrestrial overwintering of Hatchling Turtles in Vermont nests. Northeastern Naturalist 11:229–233. Reese, S.A., G.R. Ultsch, and D.C. Jackson. 2004. Lactate accumulation, glycogen depletion, and shell composition of hatchling turtles during simulated hibernation. Journal of Experimental Biology 207:2889–2895. St. Clair, R.C., and P.T. Gregory. 1990. Factors affecting the northern range limit of Painted Turtles (Chrysemys picta): Winter acidosis or freezing? Copeia 1990: 1083–1089. Standing, K.L., T.B. Herman, D.D. Hurlburt, and I.P. Morrison. 1997. Postemergence behaviour of neonates in a northern peripheral population of Blanding’s Turtle, Emydoidea blandingii, in Nova Scotia. Canadian Journal of Zoology 75:1387–1395. Standing, K.L., T.B. Herman, and I.P. Morrison. 1999. Nesting ecology of Blanding’s Turtle, (Emydoidea blandingii) in Nova Scotia, the northeastern limit of the species’ range. Canadian Journal of Zoology 77:1609–1614. Tuttle, S.E., and D.M. Carroll. 2005. Movements and behavior of hatchling Wood Turtles (Glyptemys insculpta). Northeastern Naturalist 12:331–248. Ultsch, G.R. 2006. The ecology of overwintering among turtles: Where turtles overwinter and its consequences. Biological Reviews. 81:339–367 Zwiefel, R.G. 1989. Long-term ecological studies on a population of Painted Turtles, Chrysemys picta, on Long Island, New York. American Museum Novitates 2952:1–55. 1Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487. 2Current address - 4324 NW 36th Street, Cape Coral, FL 33993. *Corresponding author - gultsch@bama.ua.edu.