An evolutionary habitat selection by the plateau pika (Ochotona
curzoniae) in relation to the niche construction of the livestock
management on the Qinghai-Tibetan plateau
Abstract
Habitat selection by animals is conventionally linked with nature
selection pressures. However, niche construction as a potent
evolutionary agent palys a crucial role for many types of evolutionary
habitat selection by species and this modifies nature selection
pressures. We used data obtained from an 11-year period to observe the
evolutionary habitat selection by the plateau pika (Ochotona curzoniae)
in relation to the niche construction of livestock management. We
hypothesized that the niche construction of local nomads affects the
evolutionary habitat selection of the plateau pika, and furthermore that
the plateau pika does not fit niche conservatism in the Kobresia
ecosystem of the Qinghai Tibetan Plateau (QTP). In order to verify the
above hypotheses, we used the distance to the nearest yak-bedding areas
and dung management as the variables that most strongly explain
variation in pika occupancy (probability) and detection probability
based on free-ranging livestock. Both pika occupancy and detection
probability decrease sharply with increasing distance to the nearest
yak-bedding area, suggesting that pika population densities are highest
closest to yak-bedding areas. There is a strong correlation between dung
cover and occupancy of the plateau pika; the more dung drying on the
ground, the more plateau pikas occupy the area. Consequently, the
plateau pika is frequently detected in damaged grass. Rangeland
dominated by Kobresia sedges on the QTP is modified by livestock grazing
and management, especially by dung management. This is the first
research suggesting that local nomads may cause expansion of the habitat
of the plateau pika. In sum, the habitat of the plateau pika is
expanding and there is strong evidence that it retains its biodiversity
on the Qinghai-Tibetan Plateau in spite of exposure to poison as control
measure. Still, the current control management of the plateau pika may
result in diminished diversity of both fauna and flora species and a
collapse of the food web on the QTP.