A Day in the Life of a Marbled Salamander
Amphibian populations are noted for extreme year-to-year and site-to-site variation in population size and species composition. I believe the best way to understand this variation is to manipulate. Marbled salamander populations at several isolated, temporary wetlands on the Savannah River Site have been subjected to experimental manipulations in order to develop a better understanding of the primary mechanisms underlying population fluctuations: competition, predation, and hydroperiod.
Manipulations were conducted in large-scale field enclosures at Ginger's Bay, Squirrel Bay, and Bullfrog Pond from 1985 thru the mid 1990s. Experiments from 1985 to 1988 collectively demonstrated the significant effects that the number of larvae in a pond (larval density) has on important larval traits such as survival and size. Similar experiments in the 90's have addressed the impacts of invertebrate predation, timing of pond-filling, and two-species interactions. A common theme through all experiments is that conditions in the aquatic environment continue to affect individuals post-metamorphosis; i.e., in the terrestrial stage of the life cycle. The extent to which populations are influenced by conditions in the forests surrounding the wetlands is largely unknown. However, a population model based on the experimental and observational data suggests that the terrestrial habitat conditions may have stronger impacts on the population dynamics than some aquatic parameters. Because the natural history of Ambystoma opacum at Ginger's Bay has been so well-studied (including nesting behavior, reproductive behavior, and genetic structure), researchers are able to develop management plans and assess risk to the population from a strong ecological data base.
- Nunziata, SO, DE Scott, KL Jones, C Hagen, and SL Lance. 2011. Twelve novel microsatellite markers for the marbled salamander, Ambystoma opacum. Conservation Genetics Resources 3:773-775. (pdf)
- Scott, DE. 2008. Marbled salamander, Ambystoma opacum. Pages 139-141 in: Jensen, John, Carlos Camp, Whit Gibbons, and Matt Elliott (eds.), Amphibians and Reptiles of Georgia. University of Georgia Press, Athens, GA.
- Scott, DE, ED Casey, MF Donovan, and TK Lynch. 2007. Amphibian lipid levels at metamorphosis correlate to post-metamorphic terrestrial survival. Oecologia 153:521-532. (pdf)
- Croshaw, DA, and DE Scott. 2006. Marbled salamanders (Ambystoma opacum) choose nest sites at low elevations when cover availability is controlled. Amphibia Reptilia 27:359-364. (pdf)
- Taylor, BE, DE Scott, and JW Gibbons. 2006. Catastrophic reproductive failure, terrestrial survival, and persistence of the marbled salamander. Conservation Biology 20:792-801. (pdf)
- Croshaw, DA, and DE Scott. 2005. Experimental evidence that nest attendance benefits female marbled salamanders (Ambystoma opacum) by reducing egg mortality. American Midland Naturalist 154:398-411. (pdf)
- Scott, DE. 2005. Ambystoma opacum, Marbled salamander. Pp. 627-632 in: Amphibian Declines: the Conservation Status of United States Species. M. J. Lannoo (ed.), University of California Press, Berkeley, CA. (pdf)
- Boone, MD, DE Scott, and PH Niewiarowski. 2002. Effects of hatching time for larval ambystomatid salamanders. Copeia 2002: 511-517. (pdf)
- Ott, J, and DE Scott. 1999. Effects of toe-clipping and PIT tagging on growth and survival in metamorphic Ambystoma opacum. J. Herp. 33:344-348. (pdf)
- Scott, DE. 1998. A Breeding Congress. Natural History 107(8):26-28.
- Taylor, BE, and DE Scott. 1997. Effects of larval density dependence on population dynamics of Ambystoma opacum. Herpetologica 53:132-145. (pdf)
- Chazal, AC, JD Krenz, and DE Scott. 1996. Relationships of larval density and heterozygosity to growth and survival of juvenile marbled salamanders (Ambystoma opacum). Canadian Journal of Zoology 74:1122-1129. (pdf)
- Houck, LD, MT Mendonca, TK Lynch, and DE Scott. 1996. Courtship behavior and plasma levels of androgens and corticosterone in male marbled salamanders, Ambystoma opacum (Ambystomatidae). General and Comparative Endocrinology 104:243-252. (pdf)
- Scott, DE, and MR Fore. 1995. The effect of food limitation on lipid levels, growth, and reproduction in the marbled salamander, Ambystoma opacum. Herpetologica 51:462-481. (pdf)
- Scott, DE. 1994. The effect of larval density on adult demographic traits in Ambystoma opacum. Ecology 75:1383-1396. (pdf)
- Krenz, JD, and DE Scott. 1994. Terrestrial courtship affects mating location in Ambystoma opacum. Herpetologica 50:46-50. (pdf)
- Scott, DE. 1993. Timing of reproduction of paedomorphic and metamorphic Ambystoma talpoideum. American Midland Naturalist 129:397-402. (pdf)
- Scott, DE. 1990. Effects of larval density in Ambystoma opacum: an experiment in large-scale field enclosures. Ecology 71:296-306. (pdf)
- Jackson, ME, DE Scott, and RA Estes. 1989. Determinants of nest success in the marbled salamander (Ambystoma opacum). Canadian Journal of Zoology 67:2277-2281.