Leech removal is not the primary driver of basking behavior in a freshwater turtle

Leaving the water to bask (usually in sun) is a common behavior for many freshwater turtles, with some species also engaging “nocturnal basking.” Ectoparasite removal an obvious hypothesis explain nocturnal basking and has been proposed as key driver of diurnal basking. However, efficacy basking, day or night, remove leeches not experimentally tested. Therefore, we examined number that were removed from Krefft's river turtles (Emydura macquarii krefftii) after making at range times day, durations, temperatures. Turtles had high initial leech loads, mean 32.1 per turtle. Diurnal under heat lamp 3 hr ~28°C significantly reduced numbers relative controls. In trials, 90.9% lost (mean loss 7.1 turtle), whereas 30 min same conditions was effective (no leeches, all still visibly wet). Similarly, basking” ~23°C removing leeches. Only 18% (one turtle one another four leeches). outdoors direct sunlight 20 temp = 34.5°C) resulted small reduction 50% losing average 0.7 These results indicate can if temperatures are durations long. it only unusually long this system. Our data showed even 20-min period longer than 70.1% natural events, which took place cooler does appear be purpose majority events.