Trapping success and population analysis of Siren lacertina and Amphiuma means
Siren and Amphiuma are two poorly known genera of aquatic salamanders thatoccur in the Southeastern United States. A primarily bottom-dwelling existence makesthese salamanders difficult to detect with conventional sampling methodologies.Therefore, the current status of their populations is unknown. I compared the capturesuccess of modified crayfish traps and plastic minnow traps in capturing thesesalamanders. In addition, a mark-recapture study of S. lacertina (Greater siren) and A.means (Two-toed amphiuma) was conducted at Okefenokee National Wildlife Refuge(southern Georgia) and at Katharine Ordway Preserve (north-central Florida) fromAugust 2001 until September 2002.Crayfish traps were much more successful than minnow traps in catching sirenand amphiuma. Crayfish traps yielded 270 captures for an overall capture success of16%, whereas minnow traps yielded only 13 captures for an overall success rate of0.05%. In addition, several marking techniques were evaluated, and of these, only passive integrated transponder (PIT) tags were retained for the duration of the study.Therefore, I recommend this marking technique for long-term monitoring of S. lacertinaand A. means.Several variables were found to have significant effects on capture rates ofsalamanders. A. means were most often captured in summer and the number of captureswas positively correlated with water temperature, water level, and rainfall. S. lacertinawere most often captured during winter and spring. Number of captures was negativelycorrelated with water temperature, while no relationship was found with water level orrainfall. Trap day and baiting had no significant effect on number of A. means or S.lacertina captured.Recapture probabilities of both species were low, 0.025-0.03 for S. lacertina and0.08-0.11 for A. means. Monthly survival rates were high, 0.77-0.97 for A. means and0.88-1.00 for S. lacertina. Density estimates of 1.3 salamanders/m2 (S. lacertina) and0.28 salamanders/m2 (A. means) were obtained for Lake Suggs using Jolly-Seber models.Siren and amphiuma make up a substantial part of wetland biomass and can impact manyother wetland species. Thus, more attention must be focused on evaluating andmonitoring their populations.
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| Format: | thesis biblioteca |
| Language: | English |
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University of Florida, Wildlife Ecology and Conservation
2003
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| Subjects: | Biology, aquatic salamanders, Okefenokee National Wildlife Refuge, Katherine Ordway Preserve, Georgia, Florida, trapping, mark-recapture, surveys, Siren lacertina, Amphiuma means, Greater siren, Two-toed amphiuma, |
| Online Access: | http://hdl.handle.net/1834/23059 |
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