TITLE:
Effects of Inhabiting and Life Patterns on the UV Spectral Properties of Small Mammalian Herbivores’ Urine
AUTHORS:
Junnian Li
KEYWORDS:
Rodents Urine, Ultraviolet (UV) Light, Fluorescence
JOURNAL NAME:
Open Journal of Forestry,
Vol.13 No.1,
December
9,
2022
ABSTRACT: It is well known that avian predators can use prey excretions such as
urine and feces to track their prey, and the urine and feces of small mammalian
herbivores can reflect ultraviolet (UV) light and emit fluorescent light. There are still some debates as to whether UV visibility of small mammalian herbivores’ urine
is used as a hunting cue by avian raptors. Some studies in Europe have
demonstrated that diurnal raptors are capable of utilizing these cues to target
key prey species. However, researchers in Australia have argued that raptors do not use the UV visibility of urine
while hunting. To our knowledge, there are no reports from Asia
concerning the ultraviolet spectral characteristics of small mammal herbivores’ urine.
This study examined the UV spectral properties of urine from 6 small mammal
herbivores species by comparing the UV reflectance and fluorescence spectra of
urine from small mammalian herbivores living in plateau meadows, plateau
shrubs, open marshland, farmland, and semi-desert grassland in China. In
addition, we compared the UV spectral properties of urine from ground-dwelling
species of rodents and subterranean species
to determine whether ultraviolet visibility of small mammal herbivores’ urine
could be used as a visual signal by Asian vole-eating raptors. The results
showed that: 1) the SC370 values of urine from four small mammal herbivores species were ordered as plateau pika (plateau
meadow) > root voles (plateau bush) > reed voles (swampland) >
Brandt’s vole (desert grassland); and 2) UV
fluorescence peak intensity and the wavelengths of urine from ground-dwelling species (such as the
root vole, plateau pika, or Brandt’s vole) were significantly higher
than those of subterranean-dwelling species
(mandarin vole and plateau zokor). These results indicate that UV visibility
of small mammal herbivores’ urine may act as a visual cue for raptors.