The function estimates body temperatures (C, operative environmental temperatures) of a butterfly based on Kingsolver (1983) and Buckley and Kingsolver (2012) . The function is designed for butterflies that bask with closed wings such as Colias.

Tb_butterfly(
  T_a,
  T_g,
  T_sh,
  u,
  H_sdir,
  H_sdif,
  z,
  D,
  delta,
  alpha,
  r_g = 0.3,
  shade = FALSE
)

Arguments

T_a

numeric air temperature (C).

T_g

numeric surface temperature (C) in the sunlight.

T_sh

numeric surface temperature (C) in the shade.

u

numeric wind speed (m s-1).

H_sdir

numeric direct solar radiation flux (W m-2).

H_sdif

numeric diffuse solar radiation flux (W m-2).

z

numeric solar zenith angle (degrees).

D

numeric thoracic diameter (cm).

delta

numeric thoracic fur thickness (mm).

alpha

numeric wing solar absorptivity (proportion). The range for Colias butterflies is 0.4 to 0.7.

r_g

numeric substrate solar reflectivity (proportion). See Kingsolver (1983) .

shade

logical whether body temperature should be calculated in sun (FALSE) or shade (TRUE).

Value

numeric predicted body (operative environmental) temperature (C).

Details

Thermal radiative flux is calculated following Gates (1980) based on Swinbank (1960) . Kingsolver (1983) estimates using the Brunt equation with black body sky temperature from Swinbank (1963) .

References

Buckley LB, Kingsolver JG (2012). “The demographic impacts of shifts in climate means and extremes on alpine butterflies.” Functional Ecology, 26(4), 969-977. doi:10.1111/j.1365-2435.2012.01969.x .

Gates DM (1980). Biophysical Ecology. Springer-Verlag, New York, NY, USA.

Kingsolver JG (1983). “Thermoregulation and Flight in Colias Butterflies: Elevational Patterns and Mechanistic Limitations.” Ecology, 64(3), 534-545. doi:10.2307/1939973 .

Swinbank WC (1960). “Wind profile in thermally stratified flow.” Nature, 186, 463-464.

Swinbank WC (1963). “Long-wave radiation from clear skies.” Quarterly Journal of the Royal Meteorological Society, 89, 339-348.

Examples

  Tb_butterfly(T_a    = 25, 
               T_g    = 25, 
               T_sh   = 20, 
               u      = 0.4, 
               H_sdir = 300, 
               H_sdif = 100, 
               z      = 30, 
               D      = 0.36, 
               delta  = 1.46, 
               alpha  = 0.6, 
               r_g    = 0.3)
#> [1] 29.16499