calculate_Ex: Exploitation of the thermal environment

In ectotemp: Quantitative Estimates of Small Ectotherm Temperature Regulation Effectiveness

Description

This function determines the extent to which organisms exploit their thermal environment (indexed by Ex) following Christian and Weavers (1996). Ex is given by the amount of time when field body temperatures (Tb) are within the set-point range, relative to the total amount of time during which this could have been possible as indicated by operative temperatures (Te). The higher the Ex value, the more an organism exploits its thermal environment when the environment is permissive. The user-supplied vectors containing Te and Tb data are assumed to use the same time unit.

Usage

calculate_Ex(te, tb, tset_low, tset_up)

Arguments

te	A vector containing operative temperatures. These data should be in the same time unit as the tb data.
tb	A vector containing body temperature measurements.
tset_low	Lower boundary of a species or population set-point range that was determined through thermal preference trials in a temperature gradient. This may be a named double vector containing the lower boundary value, or simply the value itself.
tset_up	Upper boundary of the set-point range.

Value

Ex index, indicating thermal exploitation of the environment during a user-determined period of time.

References

Christian, K. A., & Weavers, B. W. (1996). Thermoregulation of monitor lizards in Australia: an evaluation of methods in thermal biology. Ecological monographs, 66(2), 139-157.

Examples

te <- na.omit(ichalp[,"te"])
tb <- na.omit(ichalp[,"tb"])
Ex <- calculate_Ex(te, tb, 14.44, 18.33)

ectotemp documentation built on July 16, 2020, 5:07 p.m.