The Species-Abundance Distribution of Snakes in a Bottomland Hardwood Forest of the Southern United States

• Published in: Journal of herpetology Vol. 41; no. 3; pp. 385 - 393
• Main Authors: Ford, Neil B, Lancaster, Debra L
• Format: Journal Article
• Language: English
• Published: P.O. Box 58517, Salt Lake City, Utah 84158, USA Society for the Study of Amphibians and Reptiles 01-09-2007
• Subjects: Agkistrodon piscivorus; Amphibians; Animal ecology; Ecological genetics; ECOLOGY; Fish; Floods; Forest ecology; Nerodia erythrogaster; Snakes; Species; Species diversity; Synecology; Thamnophis proximus
• ISSN: 0022-1511; 1937-2418
• DOI: 10.1670/0022-1511(2007)41[385:TSDOSI]2.0.CO;2

Species-abundance distributions often form a log series curve with a few common species and a large proportion of rare species. Niche apportionment and random processes such as dispersal and local extinction are reflected in the structuring of abundance ranks among species within a community. Bottomland hardwood forests of the southern United States have high biotic production because of flood pulses that bring in nutrients. The assemblage of snakes in these environments is diverse both in terms of diet and morphology. In this habitat, the high levels of some resources should be involved in the abundance ranks of the most common species, but other factors (e.g., body size) may be important in the abundance ranks of the less common species. We examined the abundances of snakes in a 2300-ha bottomland deciduous forest in northeastern Texas. Fourteen total species were recorded, but only in one year were all species collected. Three semiaquatic species, Thamnophis proximus, Nerodia erythrogaster, and Agkistrodon piscivorus were the most common. These three species eat fish and amphibians that are concentrated in ephemeral pools, but their foraging methods differ. Several other species had intermediate abundances and a wide variety of diets. Smaller and heavier species did not have lower abundances, and we suggest that, although poor dispersal ability may be involved in the rarity of some species, there are likely several factors involved. We hypothesize that both niche characteristics and random processes are involved in producing the stair-step appearance of the abundance ranks of these snakes.