. Recent studies have shown that acoustic signals play an important role in turtle social behavior and reproduction. We recorded embryos and hatchlings of Lepidochelys kempii inside the nest and underwater in June 2016 in Playa Santander, Veracruz, Mexico, and detected 189 sounds that were classified into 6 types according to their aural and spectral characteristics. Our results show that acoustic communication appears to be widely used in all species of sea turtles in aquatic environments, probably because of the high efficiency of this signaling modality in water compared with air.

. Recordings were made in nests of Eretmochelys imbricata and 107 samples of 10-min recordings revealed 575 sounds that were classified manually into 4 categories. Our results show that hawksbill turtles vocalize within the nest, especially during and after eclosion, which suggests vocalizations are important for communication among hatchlings to synchronize emergence from the nest.

There are only a few studies documenting acoustic communication in chelonians; here we provide additional evidence that sound plays an important role in the interchange of information in this group. We recorded 12 nests of Dermochelys coriacea during March 2012 at Barra de la Cruz Beach, Oaxaca, Mexico. Four types of sounds were identified from recordings of nests after 51 d of incubation; our results reinforce the idea that sounds are important to coordinate group behavior in turtles.