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Operative Environmental Temperatures and Basking Behavior of the Turtle Pseudemys Scripta
Author(s) -
Crawford Kenneth M.,
Spotila James R.,
Standora Edward A.
Publication year - 1983
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.2307/1937806
Subject(s) - thermoregulation , microclimate , turtle (robot) , degree celsius , substrate (aquarium) , operative temperature , atmospheric sciences , environmental science , air temperature , ecology , wind speed , apparent temperature , zoology , thermal , meteorology , biology , physics , humidity , thermodynamics
Operative environmental temperatures (T e , an index of the thermal environment) were measured for basking Pseudemys scripta in South Carolina. Operative environmental temperatures were good predictors of the basking behavior of P. scripta. Turtles in this study generally did not bask unless T e was 28°C (preferred body temperature) or higher. This demonstrated that basking was not a random behavior in respect to T e , and implicated thermoregulation as a major factor eliciting basking behavior. Operative environmental temperature was positively related to short—wave and total solar radition as well as to air and substrate temperature. Substrate temperature was the best single predictor of T e . A multiple regression equation (T e = 0.005R + 0.103T a — 1.16 log V + 0.932T s — 2.54, r 2 = .90, where R = total radiation in watts per square metre, T a = air temperature in degrees Celsius, V = wind speed in metres per second, and T s = substrate temperature in degrees Celsius) defines the relationship of T e to microclimate variables. Movement of the sun through the day results in spatial variation in T e 's available to turtles and influences their location and basking behavior.