TY - JOUR
T1 - Iridescent ultraviolet signal in the orange sulphur butterfly (Colias eurytheme)
T2 - Spatial, temporal and spectral properties
AU - Rutowski, Ronald L.
AU - Macedonia, Joseph M.
AU - Merry, Justin W.
AU - Morehouse, Nathan I.
AU - Yturralde, Kasey
AU - Taylor-Taft, Laura
AU - Gaalema, Diann
AU - Kemp, Darrell J.
AU - Papke, Randi S.
PY - 2007/2
Y1 - 2007/2
N2 - Many of nature's most striking animal colours are iridescent, exhibiting a high degree of spectral purity and strong angular dependence of intensity and hue. Although a growing number of studies have detailed the intricate mechanisms responsible for producing iridescent colours, few attempts have been made to describe their dynamic appearance in ecologically and behaviourally realistic contexts. We suggest that the optical properties unique to iridescent structural colours are important for understanding how they function as signals during behavioural interactions. Using males of the orange sulphur butterfly, Colias eurytheme, which exhibit an iridescent ultraviolet (UV) reflectance on their dorsal wing surfaces, we develop a holistic framework for inferring the appearance of this signal to conspecifics under field conditions that incorporate data on their spectral sensitivity. We show that, during flight, the UV signal is brightest within a wing beat cycle when viewed from directly above the male. Spectral properties of the signal under natural lighting indicate that male wing colour should be readily perceived and distinguished from that of females and from the dark green visual background of UV-absorbing vegetation. Finally, our analyses permit predictions regarding how signal senders and receivers should orientate themselves for maximal transmission and reception of this ultraviolet iridescent signal.
AB - Many of nature's most striking animal colours are iridescent, exhibiting a high degree of spectral purity and strong angular dependence of intensity and hue. Although a growing number of studies have detailed the intricate mechanisms responsible for producing iridescent colours, few attempts have been made to describe their dynamic appearance in ecologically and behaviourally realistic contexts. We suggest that the optical properties unique to iridescent structural colours are important for understanding how they function as signals during behavioural interactions. Using males of the orange sulphur butterfly, Colias eurytheme, which exhibit an iridescent ultraviolet (UV) reflectance on their dorsal wing surfaces, we develop a holistic framework for inferring the appearance of this signal to conspecifics under field conditions that incorporate data on their spectral sensitivity. We show that, during flight, the UV signal is brightest within a wing beat cycle when viewed from directly above the male. Spectral properties of the signal under natural lighting indicate that male wing colour should be readily perceived and distinguished from that of females and from the dark green visual background of UV-absorbing vegetation. Finally, our analyses permit predictions regarding how signal senders and receivers should orientate themselves for maximal transmission and reception of this ultraviolet iridescent signal.
KW - Colour signal
KW - Iridescence
KW - Lepidoptera
KW - Pieridae
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U2 - 10.1111/j.1095-8312.2007.00749.x
DO - 10.1111/j.1095-8312.2007.00749.x
M3 - Article
AN - SCOPUS:33846680919
SN - 0024-4066
VL - 90
SP - 349
EP - 364
JO - Biological Journal of the Linnean Society
JF - Biological Journal of the Linnean Society
IS - 2
ER -