Home-site fidelity and homing behavior of the big-headed turtle Platysternon megacephalum

Site fidelity refers to the restriction of dispersal distance of an animal and its tendency to return to a stationary site. To our knowledge, the homing ability of freshwater turtles and their fidelity is reportedly very low in Asia. We examined mark-recapture data spanning a 4-year period in Diaoluoshan National Nature Reserve, Hainan Province, China, to investigate the site fidelity and homing behavior of big-headed turtles Platysternon megacephalum. A total of 11 big-headed turtles were captured, and all individuals were used in this mark-recapture study. The site fidelity results showed that the adult big-headed turtles (n = 4) had a 71.43% recapture rate in the original site after their release at the same site, whereas the juveniles (n = 1) showed lower recapture rates (0%). Moreover, the homing behavior results showed that the adults (n = 5) had an 83.33% homing rate after displacement. Adult big-headed turtles were able to return to their initial capture sites (home) from 150 to 2,400 m away and precisely to their home sites from either upstream or downstream of their capture sites or even from other streams. However, none of the juveniles (n = 4) returned home, despite only being displaced 25-150 m away. These results indicated that the adult big-headed turtles showed high fidelity to their home site and strong homing ability. In contrast, the juvenile turtles may show an opposite trend but further research is needed.

Automated summary

The study found that adult big-headed turtles showed high fidelity to their home site and strong homing ability, with a high return rate after displacement. In contrast, juvenile turtles showed a lower return rate. Further research is needed to understand the reason behind this difference in behavior.