Two hundred alligator snapping turtles were trapped at an average rate of 0.057 turtles per trap-night in all but 1 of 33 sites in southeastern Louisiana. Trap rate varied between sites, by harvest pressure levels at sites, and by season, but not by hydrology. Perceived trap rate differences under different harvest regimes appeared to be a function of seasonal differences in trap rate. No differences in sex ratio or percentage of immature turtles were detected between sites, harvest regimes, seasons, or water-body types. Turtle weight varied between harvest regimes and hydrology. Weight–length relations for turtles was highly correlated and similar between sexes, except that males continued to grow to larger sizes than females (males averaged 150% female weight and 118% female carapace length). Sex ratio was 1:1, and immature turtles made up 48% of the total. Average sizes of turtles were very similar between Louisiana and turtles from surveys in several other states. Population structure differed between surveys, with Louisiana having a higher percentage of immature turtles and lower trap rate than elsewhere. Population differences could not entirely be explained by differences in harvest regimes between states. Large-scale turtle butchering operations in southern Louisiana have closed, as has commercial harvest. Anecdotal reports that alligator snappers were nearly extirpated from a heavily harvested site proved erroneous. Resurvey of sites to determine current population trends is recommended.

Two Turkish populations of Mauremys caspica and Mauremys rivulata were compared morphologically, serologically, and ecologically. Morphometric differences were noted among sexes and populations. Electrophoretic patterns demonstrated significant differences between the taxa and supported their status as distinct species.

We studied the linear home range and seasonal movements of Podocnemis sextuberculata from September 1996 to December 1998 in the Mamirauá Sustainable Development Reserve located in the middle Solimões River, near Tefé, Amazonas, Brazil. We collected data on turtle movements and home range through mark and recapture and radiotelemetry, focusing on seasonal differences between periods of high and low water levels. Based on radiotelemetry of 6 females in the Jarauá River system, linear home range varied from 16.52 to 44.5 km. Nesting migrations from the Jarauá to the beaches of the Japurá River averaged 18.04 km. Males did not move significantly between captures. For conservation purposes, it is of critical importance to protect both the canals that the turtles use to travel between the lakes and the river as well as the deep holes in the river where mature turtles congregate during the dry season.

The diet of the Texas map turtle (Graptemys versa) in the Colorado River drainage was studied using 1) stomach flushing and collection of feces in 1998–1999 and 2) dissection of museum specimens collected in 1949 prior to invasion of their habitats by exotic Asian clams (Corbicula spp.). Feces were found to be better indicators of dietary diversity based on log–log comparisons of sample volume with turtle size and the fact that Corbicula were absent in stomach flushes of small female specimens that yielded abundant shell fragments in their feces. Adult males fed most heavily on aquatic insect larvae (primarily trichopterans and ephemeropterans) and showed little change in diet over 5 decades. Small females that overlapped adult males in body size had wider heads and alveolar surfaces of the jaws than did males and fed predominantly on Corbicula, snails, insect larvae, and algae. Females that were larger than males in body size showed a change from a diverse diet in 1949 that included sphaeriid clams, trichopteran larvae, sponges, bryozoans, and algae, to nearly exclusive feeding on the invasive mollusk Corbicula 5 decades later. Based on the present report and previous studies, it appears that 1 result of the invasion of rivers in North America by Corbicula is greatly decreased diversity of diet in adult female Graptemys of moderate head width (mesocephaly).

We determined characteristics of the sand, level and frequency of tidal inundation, and hatching success at loggerhead sea turtle (Caretta caretta) nest sites on 8 low-relief mangrove islands in the northern half of the Ten Thousand Islands in southwest Florida. The sand was generally composed of larger particles and tended to be wetter, more porous, and more saline than on other loggerhead nesting beaches. More than one-third (38.9%) of the nest sites experienced tidal inundation. The mean salinity of inundating water was 26.9‰ (± 9.3, range = 0–40). The water content and salinity of the sand water at nest sites increased with increasing frequency of inundations. The mean particle diameter and total porosity of the sand were negatively related to sand water salinity, perhaps indicating that in the largest-grained, most porous sands, salt was more effectively washed out by rainfall. Hatching success decreased as inundations, sand water content, and sand water salinity increased. However, at nest sites that did not experience inundation, the sand water content and sand water salinity were not related to hatching success. Loggerhead clutches can tolerate a wide range of incubation environments, including a certain amount of inundation. Clutches that are deposited in low-beach areas (close to the water and more prone to inundation) can produce hatchlings. Because the characteristics of loggerhead hatchlings are influenced by the incubation environment, conservation strategies that involve moving all clutches from low-beach areas to high-beach areas may reduce the variety of incubation environments, thus reducing hatchling variability and possibly preventing the expression of characteristics that promote hatchling survival or otherwise increase the reproductive success of females.

We studied a population of wood turtles (Glyptemys insculpta) along 42 km of a river in a national forest in northern Michigan. For each of 3 summers (1998–2000), 9 or 10 turtles were radiotelemetered and relocated 3–6 times per week; during one winter (2000–2001) 5 turtles were radiotelemetered and relocated once per month. Mean summer home range estimates using 95% adaptive kernel were 40.6 ha (range 0.4–354 ha); using the minimum convex polygon method, summer home ranges averaged 30.2 ha (range 0.2–390 ha). No statistical relationships were found between size of summer home ranges and turtle age, size, or sex. Summer home ranges in 2000 were significantly larger than those in previous years. Because 2 of the study years were unusually dry, we calculated drought indices for each year of the study. We report larger summer home ranges for wood turtles than have been reported in previous studies, including those that report annual home ranges, which may indicate poorer habitat quality in our study area or drought effects.

Home range, habitat use, and seasonal behavior of the Central African forest-dwelling hingeback tortoises Kinixys erosa and K. homeana were quantified by radio tracking 3 translocated and 6 resident individuals for up to 2.3 years in southwestern Cameroon where the two species are sympatric. Individuals of both species varied widely in total and seasonal minimum convex polygon home range estimates (1.1–47.8 ha). Harmonic surface area home range estimates, however, show that most of each tortoise's locations occurred within a relatively small core area representing 5%–25% of an individual's total range. Males of both species had the largest home ranges, and specimens tracked for more than one year showed a decrease in yearly home range size estimates. Considerable overlap of total home ranges but little overlap of core areas exist among individuals of species. Kinixys homeana was located more frequently in forest gaps than was K. erosa, but substantial overlap occurred of habitats and microhabitats used between species. Tortoises tended to gain weight at the beginning and end of the rainy season, and lost weight through the middle of each season.

Testudo werneri is one of the smallest tortoise species in the Mediterranean region, with a historical distribution in northeastern Egypt, Sinai, and parts of the Negev desert in Israel. Populations in Egypt are already practically extinct due to anthropogenic factors affecting the habitat and collection for the pet trade. Currently, T. werneri has a national Israel Red List status of Endangered (EN, A2cd, B). The species' primary habitat, desert sands, is degrading rapidly because of a multitude of human induced factors. Other threats include unnatural predators attracted by human settlements, and collecting for food and pet trade. According to present estimates, the global population has declined by around 95% in less than three generations. The remaining T. werneri population is essentially restricted to an area of around 700 km² or less in northwestern Negev, Israel. Ten individuals are known from Zaranik in northern Sinai of Egypt. The present population size is estimated at between 2520 and 3150 individuals depending on parameters used, of which around 1890 to 2360 tortoises would be adults. True figures may be considerably less, however. Testudo werneri is clearly threatened by extinction, potentially within decades, but more data are needed for an accurate estimate. The establishment of new nature reserves in the sands of northwestern Negev in conjunction with effective management would enhance the survival prospects of the species, assuming that most of the known threat factors can be addressed. Testudo werneri qualifies globally for listing as Critically Endangered (CR, A2abcde 3de) under current IUCN Red List Criteria; this was recommended and accepted by the IUCN in 2003.

Gonads and accessory ducts of 140 live, captive-raised juvenile Erymnochelys madagascariensis (72–375 g body mass) of 1–3 years of age as well as those of some wild, larger turtles were investigated by endoscopy. The gonads of all examined turtles could be visualized by endoscopy and unambiguously identified as testes or ovaries. Of the captive-raised juveniles, 75% were females and 25% males. One-year-old females have small, thin, transparent ovaries with transparent, whitish follicles and thin oviducts. Follicles in 2-year-old females increase in number and appear as transparent, whitish flat discs and the oviducts become broader and transparent-whitish to whitish. Three-year-old females have yellowish-whitish follicles and whitish oviducts. Juvenile females over 0.5 kg body mass have yellow follicles and white oviducts. A 1-year-old male and 2 small 2-year-old males show testes of rose pink-whitish color and transparent epididymes. Other 2-year-old males have yellowish-orange testes and in males > 130 g body mass, the epididymes turn transparent-whitish. Three-year-old males have yellow-orange testes that are thicker and rounder, and whitish epididymes with meandering ducti epididymides. The developmental changes of juvenile reproductive tracts seem to depend more on age than on size.

In this paper, we describe a new species of freshwater turtle from the Burnett River of coastal Queensland. It is a large, predominantly herbivorous species previously regarded to belong to the widespread species Elseya dentata. It is most closely related to Elseya irwini, E. lavarackorum, an undescribed taxon from the Johnstone River of northern Queensland, and possibly E. branderhorsti from New Guinea. It can be distinguished from the above species by the combination of a robust skull that acutely narrows across the pterygoids behind the processus pterygoideus externus, a deeply furrowed head shield and underlying bone, very prominent alveolar and lingual ridges on the triturating surfaces, a serrated margin to the carapace (prominent in juveniles and persisting into early adulthood), an anterior plastron that is broad, not oval in outline, and notable irregular white or cream markings on the lateral and ventral surfaces of the head and neck of adult females, often extending down the forelimbs. The new species inhabits the coastal Mary, Burnett, Fitzroy-Dawson, and associated smaller drainages of southeastern Queensland.

We measured 140 stripe-necked terrapins (Mauremys leprosa) from the center of the Iberian Peninsula, Spain. Female body size exceeded that of males, and female shells were wider and more domed than those of males in relation to carapace length. Plastron length was also greater in females, but preanal tail length was greater in males. Tail length showed similar values in both sexes. Morphological aspects related to sexual selection processes and those related to the fecundity of females are discussed as possible explanations of the sexually dimorphic traits in this species.

Since 1991, Projeto TAMAR-IBAMA, the Brazilian sea turtle conservation program, has maintained a station in Ubatuba, State of São Paulo, southeastern Brazil, a feeding area for sea turtles where incidental capture in coastal fisheries occurs. We present an overview of the local fishing methods, explain the conservation approach and field methods employed by TAMAR in the region, present biological data collected between 1991 and 1998, and provide an assessment of the conservation status of sea turtles in the Ubatuba region. During the study period, 2,515 captures of sea turtles were recorded, comprising four species: green turtles (Chelonia mydas, 98.4% of total captures, generally juveniles), loggerheads (Caretta caretta), hawksbills (Eretmochelys imbricata), and leatherbacks (Dermochelys coriacea). Most of the data come from turtles incidentally captured in fishing gear, mainly by artisanal methods. The available data suggest that Ubatuba is a developmental habitat for juvenile green turtles.

Subsurface temperature variation suggests that the thermal environment of giant Amazon river turtle (Podocnemis expansa) nests is influenced by the proximity of the water table and by the nest depth. The difference between vertical temperature gradients along fluvial beaches indicates that nest placement can exert a significant influence on substrate temperature. Temperatures decrease significantly with depth where P. expansa nest on the beach, but do not change with depth in lower beach areas where P. unifilis nest. Daily temperature variation decreases with depth along the entire beach.

The yellow mud turtle (Kinosternon flavescens) is a xerothermic relict partially distributed among several disjunct populations on sand prairies along the former Prairie Peninsula in Illinois, Iowa, and Missouri. In Illinois, where the species is listed as endangered, the largest known population occurs at the northeastern extent of the species' range in Henry County. A major portion of the site is in private ownership, and the Illinois Department of Natural Resources seeks to acquire additional mud turtle habitat to supplement a 1998 acquisition that was designated as a preserve. To determine additional preserve acquisition area, identify critical habitat, and recommend management techniques, data regarding the range, habitat use, and seasonal activity of turtles at this location were collected through radiotelemetry, aquatic trapping, and drift fence captures. Eleven adult mud turtles (6 males, 5 females) were fitted with radiotransmitters and tracked between 12 May 1992 and 6 June 1993. Radiotagged turtles occupied ephemeral ponds between mid-April and late May, and aestivated in sand dunes in June and July. Some emerged for a second aquatic activity period in the ponds in July and August. Hibernation occurred in sand dunes from September through mid-April. Aquatic trapping and drift fence captures of adults and juveniles confirmed similar schedules of activity, aestivation, and hibernation observed in the telemetered individuals. Drift fence captures of hatchlings indicated emergence from nest locations from early May through June. A lack of hatchling captures in mid-summer suggests that hatchlings remained in ponds or dried pond beds through the summer. Important aquatic habitat identified during the study included shallow ponds with soft, muddy substrates and dense emergent vegetation; important terrestrial habitat included sand dunes with an elevation of at least 15 feet above the ponds. Telemetered adult mud turtles burrowed into sand dunes at locations of up to 90 m from pond edges. Females oviposited at nest locations up to 70 m from pond edges. Nest predators included coyotes (Canis latrans), striped skunk, (Mephitis mephitis), and western hognose snake (Heterodon nasicus). The recommended area for the preserve addition includes a buffer of terrestrial habitat to a distance of 90 m from maximum pond level edges. Additional preserve design recommendations include constructing a bridge or culvert under a road that bisects the site so that turtles can move between aquatic and terrestrial habitats on each side of the road, and encouraging native shortgrass prairie vegetation in acquired areas. Other recommendations include periodic introductions of hatchling mud turtles from a nearby, appropriately identified population, predator management techniques that encourage hatchling recruitment, and conducting habitat management activities with the potential to disturb soils between November and March.

Seasonal habitat utilization, refugia selection, and sheltering behavior by the leopard tortoise (Geochelone pardalis) was investigated over a 24-month period (September 1990–September 1992) in the Franklin Nature Reserve, South Africa. The study area was located on Naval Hill, a dolerite and shale mesa which provided diverse topographical and vegetation aspects from which the tortoises could select habitats and refugia. Results showed that considerable shifts occurred in habitat and shelter selection between summer days, summer nights, and winter, with tortoises predominantly utilizing the plateau area. This was ascribed to the availability of shelter, exposure to solar radiation, accessibility, food resources, and the presence of water. Shelters were selected to meet specific needs governed by environmental conditions at the time, with 64.6% of shelters being exclusively utilized within one of the three periods monitored. Thirty-three plant species were utilized as shelters. Tortoises selected dense shelter cover during summer days, light shelter cover or none at all for summer nights, and light shelter cover for winter. Of the latter category, 67.4% of tortoises selected < 50% cover. Day and night shelter orientation was completely random in summer. The orientation of winter shelters was predominantly westerly with light cover shelters, and within which 67.4% of tortoises remained throughout winter. Under the cold conditions encountered on Naval Hill this appeared to be the best-suited survival strategy and provided the best conditions for tortoises to build up and retain sufficient heat during the day in order for them to maintain a temperature above that of ambient through most of the night.

The IUCN Red List status of Kinixys homeana is reassessed using interviews, field surveys, recent and old literature, and extrapolation of local trends (mainly in Nigeria). Available data indicate that numbers have declined drastically in recent years due primarily to habitat loss, hunting, and export for the pet trade. All these threats are still current and probably increasing, and we recommend change in status from Data Deficient to a minimum of Vulnerable A2cd.

Lepidochelys olivacea was the most frequent sea turtle documented in the Gulf of Mannar during 2000–2001, whereas during the 1970s it was Chelonia mydas. Reduction in overall proportions of C. mydas and its size classes is attributed to exploitation of eggs, turtles, and incidental catch in fishing gear.

Digestive tract contents of stranded green turtles (Chelonia mydas) from Ra's Al Hadd area, Oman, were examined. In decreasing order of importance, the food items (dry weight) comprised 19 taxa of algae (49%), 22 taxa of animal matter (26%), 2 seagrasses (15%), litter (7%), and substrate (3%).

The calcium content of flatback (Natator depressus), loggerhead (Caretta caretta), hawksbill (Eretmochelys imbricata), and green (Chelonia mydas) sea turtle eggshells are not significantly different. Green turtle eggs with external fungal invasion by Fusarium solani had significantly reduced calcium content of the outer, inorganic portion of the eggshell.

Feeding in the wild of the tortoise Homopus signatus signatus in South Africa was recorded and the diet compared to previously reported fecal analysis. Several new plant species were identified in the diet, and analyses differed by ca. 24% in terms of species present. Tortoises did not feed on all plant species or parts to the same extent, indicating selective feeding.

Strandings of juvenile green turtles, Chelonia mydas, at Samandağ beach, southeastern Turkey near Syria, suggest the area may represent a juvenile developmental habitat for the species.

Population structure of Malaclemys terrapin terrapin in an unaltered creek in southern New Jersey was compared to data collected 12–13 years earlier. I found significantly lower average carapace size of terrapins and lower frequency of adult females compared to the earlier survey, and speculate that road mortality of nesting females may be responsible for these trends.

Allometric growth and sexual dimorphism of the shell is evident in Malayemys macrocephala from the Chao Phraya River Basin of central Thailand. Differences in allometric growth between males and females produce sexually dimorphic adults. Adult females exhibit larger sizes and have relatively wider and higher shells and longer plastra than males.

A 20-year record of captive breeding of a female Heosemys grandis revealed a tradeoff between egg size and clutch size across the years when she produced 2 clutches per breeding season. First clutches had few large eggs and second clutches had a large number of smaller eggs. Four F1 progeny from this founder female began their reproductive years with much smaller eggs; however, their eggs increased in size over successive years until they were the same size as those of the long-term breeder.