Background: Most spectral data for the amphibian integument are limited to the visible spectrum of light and have been
collected using point measurements with low spatial resolution. In the present study a dual camera setup consisting of two
push broom hyperspectral imaging systems was employed, which produces reflectance images between 400 and 2500 nm
with high spectral and spatial resolution and a high dynamic range.
Methodology/Principal Findings: We briefly introduce the system and document the high efficiency of this technique
analyzing exemplarily the spectral reflectivity of the integument of three arboreal anuran species (Litoria caerulea,
Agalychnis callidryas and Hyla arborea), all of which appear green to the human eye. The imaging setup generates a high
number of spectral bands within seconds and allows non-invasive characterization of spectral characteristics with relatively
high working distance. Despite the comparatively uniform coloration, spectral reflectivity between 700 and 1100 nm
differed markedly among the species. In contrast to H. arborea, L. caerulea and A. callidryas showed reflection in this range.
For all three species, reflectivity above 1100 nm is primarily defined by water absorption. Furthermore, the high resolution
allowed examining even small structures such as fingers and toes, which in A. callidryas showed an increased reflectivity in
the near infrared part of the spectrum.
Conclusion/Significance: Hyperspectral imaging was found to be a very useful alternative technique combining the
spectral resolution of spectrometric measurements with a higher spatial resolution. In addition, we used Digital Infrared/
Red-Edge Photography as new simple method to roughly determine the near infrared reflectivity of frog specimens in field,
where hyperspectral imaging is typically difficult.