Abstract

Freshwater megafauna populations, which are declining worldwide, are well known but often overlooked and understudied compared with marine and terrestrial megafauna. One species of freshwater megafauna is the Suwannee alligator snapping turtle (Macrochelys suwanniensis), which is endemic to the Suwannee River drainage in Georgia and Florida. Several trapping studies have examined M. suwanniensis distribution, body size, and population structure, but little information exists regarding its population status. The objectives of our study were to 1) estimate population size, 2) estimate apparent survival, and 3) model population growth rates (k) by conducting a capture–mark–recapture study of M. suwanniensis in the Suwannee River in Florida. From 2011 to 2013, we repeatedly sampled 12 randomly selected 5-km sites along the Suwannee River for M. suwanniensis using baited hoop-net traps. We captured 126 individuals and had 29 recaptures. Both adult males and adult females had very high apparent survival (0.99), whereas juveniles had lower apparent survival (0.32). We estimated a population density of 6.6 turtles/river km, indicating a population of 1709 (95% CI, 1205–2694) M. suwanniensis from the town of White Springs to the upper limit of the estuary in the main stem of the Suwannee River (approximately 259 river km). We constructed 2 postbreeding census matrix population models for M. suwanniensis and incorporated parameters from this study and from the literature. Both matrix population models suggested a slightly decreasing population (k = 0.99), but because of the uncertainty around our estimates, we consider the population trend to be unclear. Elasticity analysis revealed that k was most sensitive to changes in adult survival compared with other model components. This is a conservation concern because adult M. suwanniensis may be incidentally killed by fishing gear. Our study was short-term, and our analyses had limitations; therefore, we recommend future areas of research, including long-term population monitoring.

Abstract

The Khorat snail-eating turtle (Malayemys khoratensis) is a recently described (2016), poorly studied freshwater turtle known from the Khorat Plateau in Thailand and a small area near Vientiane, Lao People's Democratic Republic. We investigated the occurrence and natural history of M. khoratensis during field surveys of Xe Champhone Ramsar Site (XCRS) and Nong Louang Wetland Complex (NLWC) in Savannakhet Province, and also examined museum specimens and published and unpublished photographs of Malayemys spp. from Lao. Our field surveys confirmed the occurrence of M. khoratensis in the XCRS and NLWC, where populations remain subject to harvest at levels unlikely to be sustainable. We examined 7 museum specimens from Vientiane, Savannakhet, Khammouan, and Champasak provinces. Museum specimens from Vientiane, Savannakhet, and Khammouan provinces were referable to M. khoratensis. Published photographs confirm the occurrence of M. khoratensis in Vientiane Province, and Malayemys subtrijuga in Champasak Province. Collectively, our records extend the geographic distribution of K. khoratensis by > 300 km from previously reported localities. We posit the existence of a biogeographic barrier in southern Lao and adjacent Thailand that separates the allopatrically occurring M. khoratensis and M. subtrijuga.

Abstract

Immature hawksbill turtles were studied in Jardines de la Reina Archipelago, the principal area of distribution for this species in Cuban waters. Hawksbill areas of occurrence, size composition, scope of movement range, and somatic growth rates are presented. A total of 496 individuals were caught while diving or with nets at depths of 0.5–2.5 m. Differences in size distribution were observed among survey areas within the Jardines de la Reina Archipelago. Mean curved carapace lengths were 35.6 ± 9.6 cm and 59.6 ± 7.7 cm for hawksbills captured in the external and internal cays, respectively. Forty-two individuals were recaptured between 1 and 4 times at intervals averaging 554.9 d. For recaptured turtles, 91% were encountered within < 1 km of their original capture location. Our findings indicate that the benthic habitats of Jardines de la Reina Archipelago are favorable for the recruitment of juvenile hawksbill turtles transitioning from pelagic habitats. The data also show that hawksbills are distributed throughout the Jardines de la Reina Archipelago study region, and that coastal foraging areas within this region host small, postpelagic juveniles as well as larger immature hawksbills that have been resident for extended periods.

Editorial Introduction. — This section is devoted to poetry involving turtles, representing either reprinted previously published or new unpublished material. We encourage our readers to submit poetry or songs for consideration, either their own material or work by other authors. Poems may be submitted to Anders G.J. Rhodin, Chelonian Research Foundation, E-mail: RhodinCRF@aol.com.

Our desire is to share with our readers the beauty and wonder of turtles as expressed through the art of the poem or song. In the sense that the relationship between man and turtles is multifaceted, so too is turtle poetry. The poems we publish here