. Marine turtles often conduct extensive migrations from foraging to breeding habitats. Turtles may spend several months in these breeding habitats, while periodically taking brief excursions onto terrestrial environments to nest. Identification and protection of these breeding habitats over the duration of the reproductive season is therefore vital for the conservation of sea turtles. Here, we used satellite telemetry to investigate the internesting behavior of East Pacific green turtles from 2 nesting beaches: Nombre de Jesús and Playa Cabuyal, located 50 km apart on the Pacific coast of Costa Rica. A total of 21 satellite transmitters were deployed at Nombre de Jesús ( n = 8) between 2007 and 2009 and at Cabuyal ( n = 13) between 2012 and 2015. We found that turtle movements and dive behaviors were notably different between the 2 beaches. Specifically, the turtles from Cabuyal engaged in deeper dives (10 ±3 m vs. 6.5 ±2 m [mean ±SD]), presumably because they had access to deeper waters, and had larger minimum convex polygon area (606.5 ± 1150.5 km 2 vs. 16 ± 11 km 2 ) than turtles from Nombre De Jesús. Turtles from Nombre de Jesús also engaged in shorter dives (6.68 ± 4.5 min), compared with Cabuyal, where a majority of dives lasted between 10 and 30 min (18.75 ± 5.6 min). Finally, turtles at Nombre de Jesús dove significantly deeper during the day compared with the night, a pattern that was not present at Cabuyal. We conclude that internesting behaviors can be different even between beaches within the same geographical area. As such, internesting habitat management plans should pay specific attention to potential site-specific variation in internesting behaviors.

Adult North American tortoises ( Gopherus spp.) engage in aggressive interactions with conspecifics when competing for mates and burrows. However, aggressive interactions have not been widely reported in hatchling and juvenile tortoises. We describe aggressive interactions between wild hatchling and juvenile gopher tortoises ( Gopherus polyphemus ) based on video recordings collected at tortoise burrows. Immature tortoises usually inhabited burrows alone but occasionally shared them. Presence of multiple individuals inside burrows hindered tortoise movements in burrows. Hatchlings or juveniles exhibited overt aggression toward similar aged/sized conspecifics in at least 6 of 13 (46%) encounters, and cameras may have failed to detect aggression occurring inside burrows. Hatchlings and juveniles also exhibited aggressive responses to foreign objects that were similar in appearance to small tortoises. Aggressive behaviors resembled those of adults and included repeated ramming, pushing, biting, and flipping. Young tortoises may respond aggressively to conspecifics at burrows because the presence of additional individuals constrains thermoregulatory and antipredator movements within these important microhabitats. Social interactions appear to play a greater role in the ecology of hatchling and juvenile gopher tortoises than previously recognized.

The olive ridley sea turtle ( Lepidochelys olivacea ), a species listed by the International Union for Conservation of Nature as vulnerable, is characterized by its mass-nesting behavior, also known as arribada. For decades, this phenomenon has facilitated the utilization of this species by coastal communities, much of it illegally. At Ostional beach, Costa Rica, a community-based egg-harvest program operates legally to generate important income for the community while promoting the protection of the ridley nesting assemblage. However, to date, no analysis exists that indicates the long-term viability of the egg harvest program as a sound management tool. To address this void, we generated baseline abundance data of the major arribada events that occurred in the period 2006–2010, as well as egg harvest data, along with preliminary hatching success. Arribadas ranged between 3564 and 476,550 egg-laying females, which indicated a large variability in the magnitude of the mass nesting events. Estimated mean egg harvest was 4746.4 and ranged from 1527 to 8138 total clutches. In relation to the estimated number of clutches laid, the estimated mean of clutches harvested was 21.2%, ranging from 1.5% to 102.4%. Estimated monthly mean hatching rates ranged from 0.0% to 32.6%. It is not clear whether arribadas underwent a significant change in abundance during the study period, although the number of years covered is too short to establish a long-term trend. However, when compared with historical data, the population appears to have declined. Based on our data, we present various management recommendations aimed at increasing hatching rates.

The high probability of being depredated on the crawl to the water may have influenced the evolutionary processes of hatchling sea turtles on the beach. During this time hatchlings must locate water and move as quickly as possible in order to reduce the time spent on the beach. Hatchling leatherback turtles ( Dermochelys coriacea ) at Playa Grande, Parque Nacional Marino Las Baulas, Costa Rica, spent on average 34 minutes visible on the beach, covered a distance of 46.8 m, and moved at a rate of 3.11 m/min. During the time on the beach, 12% of hatchlings were eaten by predators, 83% reached the water, and 5% were determined as potential mortalities (hatchlings were stuck on debris, vegetation, or upside down). The main predators of hatchling leatherbacks at Playa Grande were ghost crabs ( Ocypode occidentalis ), great blue herons ( Ardea herodias ), and yellow-crowned night herons ( Nycticorax violaceus ) during the night, and crested caracaras ( Caracara plancus ) during the day. Tracks left by the hatchlings on the sand were straighter as they approached the water. Dispersion (distance between the 2 outermost tracks coming from a nest) was correlated with number of hatchlings crawling. Hatchling leatherback turtles at Playa Grande are threatened by predation by domestic animals. Hatchling mortality due to human-related activities is likely to increase in the future due to increasing pressure from tourism at Parque Nacional Marino Las Baulas.

ABSTRACT The number of leatherback turtles ( Dermochelys coriacea ) nesting at Parque Marino Las Baulas declined precipitously in the 15 years that we monitored the population (1988–1989 to 2003–2004). We estimate that the annual survival rate of adults was 0.78 (95% CI: 0.75–0.80) and that mortality rates for juveniles and subadults in the ocean appear to be double those of a stable population. The proportion of hatchlings produced from deposited eggs increased since the park was established as a result of conservation practices. Because the number of nesting females decreased, the overall production of hatchlings per season declined but was much greater than would be expected without protection efforts. There were similar numbers of hatchlings leaving the beaches of Las Baulas in 1998–2003, with 68 to 188 nesting females under the current conservation regime as there were in 1988–1989 with ca. 1500 nesting females and no park. Female leatherback turtles that nest at Las Baulas have a high level of exchange between nesting beaches; thus, protection of both Playa Grande and Playa Langosta is critical for the survival of the population. Despite current protection efforts, the population at Las Baulas is still threatened by mortality at sea and development on and behind the nesting beaches.