MAMMALS do not normally visually perceive infrared
(IR) or ultra-violet (UV) light that exists on either
side of the visual spectrum from 390 to 760
nanometers (nm) (Wolken 1975). There is no
evidence to suggest that nocturnal mammals have
become more sensitive to long wavelength light as an
adaptive response (Lythgoe 1979), although some
reptiles can sense longer wavelength, thermal IR
radiation (Barrett et al. 1970). Because it is not
perceived, and is unlikely to affect animal behaviour,
IR observation can be an invaluable tool for wildlife
researchers. This paper describes the construction
and use of simple IR radiation sources that can be
used for non-invasive behavioural observations of
captive and free-ranging mammals.
Hybrid thermal Yagi-Uda nanoantennas for directional and narrow band long-wavelength IR radiation sources