Carl H. Ernst

Ecology of the Spotted Turtle, Clemmys guttata (Reptilia, Testudines, Testudinidae), in Southeastern Pennsylvania

Daily and annual activity cycles, reproductive potential, population dynamics and social relationships of the turtle Clemmys guttata in southeastern Pennsylvania are presented with observations on food, feeding, movements, predation, parasites, algal relationships and shell abnormalities. Comparisons are made with Chrysemys picta, the other populous turtle in the study area.

Ecology of the Turtle, Sternotherus odoratus, in Southeastern Pennsylvania

The common musk turtle, Sternotherus odoratus, was studied in Lancaster County, Pennsylvania from 1965 to 1983. During spring and fall, activity was confined to the morning hours, but in the summer (June-August) activity occurred during the morning and early evening hours. Diurnal trapping never produced S. odoratus, while nocturnal trapping did, probably indicating more nocturnal or crepuscular activity than revealed by visual inspection. The turtles were active from April to October, approximately 200 days per year. Cloacal temperatures of active turtles ranged from 14-30?C (J = 21.7); 67% of these temperatures fell between 16-24?C. Feeding did not take place at water temperatures below 18?C. The earliest date of feeding was 18 April 1967 and the latest 14 September 1966, a maximum observed annual feeding period of 150 days. In Pennsylvania S. odoratus were omnivorous. Growth ranges were calculated, and the oldest individuals, based on known age at initial capture, were 27 and 28 years old. Mating was observed in April and May, nesting during early evening in June. The mean number of eggs per clutch was 3.25 and the realized reproductive potential 0.5 young per clutch. The population density was 24 per hectare. The adult male to female ratio was 1.34/1.00, and the juvenile to adult ratio was 0.40/1.00. The average distance moved between captures was 93.6 m (males 117.3 m, females 89.5 m, juveniles 79.4 m). Home ranges were shifted after a pond, the primary habitat, was drained. Notes are also presented on the extent of predation, injuries, leech parasitism and carapacial algae. The common musk turtle, Sternothe- rus odoratus (Testudines, Kinosternidae) ranges from Maine and southern On- tario southward to Florida in the East and Texas in the West (Reynolds and Seidel, 1982). Although this turtle has been studied in some parts of its range, no extensive study has been published on its ecology in the northeastern United States. This paper summarizes an 18 year study on this turtle in south- eastern Pennsylvania, and makes com- parisons with other studies from other parts of its range. Ecological studies on S. odoratus have been previously con- ducted in Michigan (Risley, 1933), Oklahoma (Mahmoud, 1969), and Flor- ida (Berry, 1975; Bancroft et al., 1983); of these, those of Mahmoud and Ban-

Population Dynamics and Activity Cycles of Chrysemys picta in Southeastern Pennsylvania

The daily and annual activity cycles, reproductive potential, population dynamics, and social relationships of the painted turtle, Chrysemys picta, in southeastern Pennsylvania are presented and comparisons with other population studies on this species and other turtles are made. Chrysemys picta was active only during the daylight hours, foraging for food during the late morning and late afternoon hours and basking at other times. The turtles were active as long as the water temperature remained above 10 C. Most were dormant from late October through March, but always some were active. Mating occurred from late April to mid-June, and nesting occurred during June and July. The mean number of eggs per clutch was 4.73 and the realized reproductive potential was 2.6 young per clutch. The density of turtles was estimated at 239 per acre. The adult sex ration was 1:1 and the juvenile to adult ratio 1:4. The rate of turnover in the population was estimated to be approximately 51 per cent with most mortality occurring in the smaller size-

Temperature-Activity Relationship in the Painted Turtle, Chrysemys picta

Cloacal temperatures of 519 adult Chrysemys picta from southeastern Pennsylvania were recorded during various phases of their normal annual activities: basking, feeding, moving in water, moving on land, and dormant in water at high and low temperatures. The optimum activity temperature was calculated as approximately 20.5 C and the normal active range 8-26.8 C. The critical thermal maximum was approximately 41.5 C. Hibernating C. picta apparently maintain cloacal temperatures slightly above that of the surrounding hibernating medium (sand or mud). Catheterized individuals lost 8.2-11.0% of their body weight through evaporative water loss at a gradient of 0.15-0.29 gm/hr when exposed to summer temperatures of 10-29 C and relative humidities of 45-95%.

Environmental Temperatures and Activities in the Wood Turtle, Clemmys insculpta

Cloacal and environmental temperatures of 205 wild wood turtles, Clemmys insculp- ta, from Lancaster County, Pennsylvania were recorded during various phases of their normal activities: basking, feeding, moving in water or on land, dormant in water or on land at both high and low temperatures, and courtship, mating, and nesting. The mean cloacal temperature for activity was calculated at 21.01?C and the normal activity range 7.5-30.0?C. Cloacal temperatures were closely correlated with those of the environment during all activities. Clemmys insculpta basked less frequently than its two sympatric congeners C. guttata and C muhlenbergii. C insculpta was also more terrestrially active and more active during midday than the other two Clemmys. Its ability to withstand warmer field temperatures than either C guttata or C. muhlenbergii is probably correlated with its larger body size. Reproductive activity and brumation are aquatic. Wood turtles do not aestivate and are predom- inately terrestrial during June-August, entering shaded forms or mud puddles to escape the heat.

Geographic Variation in Growth and Sexual Size Dimorphism of Bog Turtles (Clemmys muhlenbergii)

Abstract We examined sexual size dimorphism (SSD) and growth rates in samples of bog turtles (Clemmys muhlenbergii) from North Carolina, Pennsylvania and New Jersey. Mean carapace length (CL) of males was significantly greater than mean CL of females in all three states. However, the degree of SSD varied significantly among states. Specimens from North Carolina had the greatest SSD, the largest mean adult CL, and the largest mean hatchling CL. Growth rates were rapid until about age 6 and a CL of 80 mm. Males grew faster than females thereafter. A comparison of the three parameters estimated from von Bertalanffy growth equations showed significant differences for asymptotes between sexes and states for the North Carolina and Pennsylvania samples, but not for the growth rate constant (parameter k). Geographic variation in SSD appears to be a result of differences in growth related to the timing of maturity and the approach to asymptotic body size caused by indeterminate growth, or both. We suggest that male-biased SSD in this species is ultimately a consequence of the advantage conferred to larger males in male-male interactions and during mating.

Environmental Temperatures and Activities in Wild Spotted Turtles, Clemmys guttata

Cloacal and environmental temperatures of 512 wild spotted turtles, Clemmys gut- tata, from southeastern Pennsylvania were recorded during various phases of their normal activities: basking, feeding, moving in water or on land, dormant in water of both high and low temperatures, and courtship, mating and nesting. The mean cloacal temperature for activity was calculated as approximately 20.16?C and the normal activity range 3-32?C. Cloacal temperatures were closely correlated to those of the environment during all activities. Males fed and were otherwise more active than females in waters of cooler temperatures (P < 0.05), but this was probably due to females remaining active longer into the warmer parts of the annual cycle. Clemmys guttata are often active at water temperatures of about 5?C in early spring. They become dormant when water temperatures reach about 30?C in June, and also shift their diel activity cycle from afternoon to morning as summer approaches. Feeding begins when water temperatures reach 14?C. Reproductive activity may occur at cloacal temperatures as low as 8?C in water of 8.5?C. Clemmys guttata behaviorally thermoregulate by basking in cooler weather, and by burrowing into the soft bottom of a waterway or entering muskrat burrows and lodges to avoid extreme hot and cold conditions.

Growth of the Spotted Turtle, Clemmys guttata

Growth of the spotted turtle, Clemmys guttata, was studied in southeastern Pennsylvania. Growth is more rapid in juveniles and slows once maturity is reached, but is not as affected by the attainment of maturity as in Chrysemys picta and Chrysemys scripta. Growth in the first season depends on the date of hatching; hatchlings which overwintered in the nest and emerged the following spring grew larger due to a longer season. The usual growth period in southeastern Pennsylvania is from 1 April to 30 June, or 91 days, and is most limited by water temperature. The growth period is compared to that of Chrysemys picta from the same locality.

Geographic Variation in the Neotropical Turtle, Platemys platycephala

Difference in carapacial and bridge patterns, and in mensural and meristic data indi- cates that the populations of Platemys platycephala from the rios Cenepa and Santiago, Peru and the rios Napa and Curaray, Ecuador represent an undescribed dark subspecies. The Quaternary rainforest refuge theory is discussed in view of the origin and subsequent zoogeography of the new subspecies. The Neotropical sideneck turtle, Pla- temys platycephala, has an extensive range in northern South America. It oc- curs throughout most of the Amazon

Geographic Variation in the Asiatic Turtle Chinemys reevesii (Gray) and the Status of Geoclemys grangeri Schmidt

The Chinese coin turtle Chinemys reevesii is widely distributed in eastern Asia from Japan to southern China. Within its range, three taxa have been described which are similar to C. reevesii except for minor differences (Geoclemys grangeri, Geoclemys paracaretta, and Damonia unicolor). Although these variants have been synonymized by some authors, no quantitative studies have been conducted to support or reject their validity. The present study examined 31 characters of specimens throughout the range. Analysis indicates that all variants are within the diagnostic extremes observed in this species. Low interpopulational variation in C. reevesii is due in part to several millennia of human disturbance.