Trapping success and population analysis of Siren lacertina and Amphiuma means.
Masters thesis, University of Florida.
Siren and Amphiuma are two poorly known genera of aquatic salamanders that
occur in the Southeastern United States. A primarily bottom-dwelling existence makes
these salamanders difficult to detect with conventional sampling methodologies.
Therefore, the current status of their populations is unknown. I compared the capture
success of modified crayfish traps and plastic minnow traps in capturing these
salamanders. 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) from
August 2001 until September 2002.
Crayfish traps were much more successful than minnow traps in catching siren
and amphiuma. Crayfish traps yielded 270 captures for an overall capture success of
16%, whereas minnow traps yielded only 13 captures for an overall success rate of
0.05%. 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. lacertina
and A. means.
Several variables were found to have significant effects on capture rates of
salamanders. A. means were most often captured in summer and the number of captures
was positively correlated with water temperature, water level, and rainfall. S. lacertina
were most often captured during winter and spring. Number of captures was negatively
correlated with water temperature, while no relationship was found with water level or
rainfall. Trap day and baiting had no significant effect on number of A. means or S.
Recapture probabilities of both species were low, 0.025-0.03 for S. lacertina and
0.08-0.11 for A. means. Monthly survival rates were high, 0.77-0.97 for A. means and
0.88-1.00 for S. lacertina. Density estimates of 1.3 salamanders/m2 (S. lacertina) and
0.28 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 many
other wetland species. Thus, more attention must be focused on evaluating and
monitoring their populations.
||Trapping success and population analysis of Siren lacertina and Amphiuma means
|Number of Pages:
||Wildlife Ecology and Conservation
||University of Florida
||Florida Cooperative Fish and Wildlife Research Unit
||aquatic salamanders; Okefenokee National Wildlife Refuge; Katherine Ordway Preserve; Georgia; Florida; trapping; mark-recapture; surveys; Siren lacertina; Amphiuma means; Greater siren; Two-toed amphiuma
||01 Jun 2011 13:56
||29 Sep 2011 14:46
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