Thesis Title

Spatial Activity, Growth, and Population Characteristics of Siren Intermedia in an Intensively Managed Wetland

Date of Graduation

Spring 2000


Master of Science in Biology



Committee Chair

Alicia Mathis

Subject Categories



Most aspects of the ecology of lesser sirens (Siren intermedia) are poorly known. I conducted a mark/recapture study from March 1998-May 1999 at Mingo National Wildlife Refuge (MNWR), Stoddard County, Missouri, to examine spatial activity, growth rates, and population characteristics of lesser sirens. Density and standing crop biomass estimates were 1.4-1.7 sirens/m² and 46.6-58 g/m². Peak captures of both adults and juveniles were during the breeding season of January-March. I did not capture any individuals smaller than 120 mm TL. Adult males were significantly larger in body size (total length and mass) than adult females. Home ranges of adults overlapped considerably and were highly variable in size ranging from 1-232 m². Maximum distance between captures did not differ significantly for males vs. females, adults vs. juveniles, between size classes, or between seasons. Growth rates averaged 0.06 mm/day for all sirens and small individuals generally grew faster than larger individuals. Siren intermedia is an important part of the wetland community at MNWR and its ecology should be considered in management decisions.


© Paul William Frese