38 John B. Iverson 



from January 1972 through December 1976. Due to the proclivity of 

 adults and hatchlings to terrestrial activity in north Florida (Carr 1952), 

 this species is more frequently encountered on land than any other local 

 turtle. Most turtles were collected as they attempted to cross roads. Many 

 of these were dead on the road, but remained intact enough to provide 

 suitable specimens for measurement and dissection. Turtles were also ob- 

 tained by trapping, seining, and diving. In addition, specimens from 

 north Florida in the Florida State Museum (University of Florida) collec- 

 tion were included in the samples. 



Ovarian follicles, oviducal eggs, and corpora lutea were examined and 

 measured in each specimen. All straight-line measurements were taken 

 with dial calipers to the nearest 0.1 mm. Carapace length (CL) and 

 plastron length (PL) were also recorded. Measurements from preserved 

 turtles did not significantly differ from the data collected from fresh 

 specimens and were included in the analysis. 



Several clutches of shelled oviducal eggs were removed and incubated 

 to hatching at 27° to 29 °C. Data from eggs in natural nests were also 

 recorded. Most turtles were deposited in the Florida State Museum, Uni- 

 versity of Florida, but a representative series was retained by the author. 

 Means are followed by ± one standard deviation. All measurements are 

 in mm. 



SEASONAL ACTIVITY 



Striped mud turtles were collected throughout the year, both on land 

 and in water. Individuals may be found active on all but a few of the 

 coldest winter days. This species thus exhibits the longest annual activity 

 cycle of any previously studied kinosternid in the United States 

 (Christiansen and Dunham 1972). 



Annual terrestrial activity seems to be bimodal. Striped mud turtles are 

 most frequently encountered (especially on land) in March when spring 

 rains are filling the ponds and marshes, and in October as water levels 

 are dropping. Few turtles were collected during late summer when water 

 levels and temperatures are maximal, or in mid-winter (February) when 

 temperatures are minimal. Wygoda (1976) found a similar annual ac- 

 tivity pattern in K. bauni inhabiting seasonally flooded hardwood swamps 

 in central Florida. 



Since annual activity is bimodal, two (or more) epidermal scute annuli 

 are often produced by an individual turtle during any one year. Winter 

 annuli are apparently always produced and are usually more distinct 

 than those produced in the summer. This variation in annuli production 

 often makes aging turtles, based on scute annuli, difficult. 



