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Habitat selection for calving by ungulates (saiga antelope) is
an important behavioral trait because it affects neonate survival.
Generally, ungulate calving site selection varies by vulnerability
to predators, local topography, habitat quality and level of human
disturbance.
Factors that affect group sizes in large ungulates are generally
poorly understood for species from remote regions. Understanding
grouping patterns is important for effective species management,
but is lacking for the endangered Mongolian saiga (Saiga tatarica
mongolica).
We used time series data, ecological snapshots of the biomass of
native and domestic ungulates, and ecologically and behaviourally
based fieldwork to test our hypothesis. In Mongolia increases in
domestic goat production were associated with a three-fold increase
in local profits for herders co-existing with endangered saiga
(Saiga tatarica).
Factors affecting juvenile survival are poorly known in the
world's most northern antelope, the endangered saiga (Saiga
tatarica), yet these factors are fundamental for understanding what
drives population change.
Here we describe capture protocols for adult females handled
quickly and without anaesthesia. Using multiple vehicles driven at
high speed, individual saiga were isolated from groups and herded
into nets.
We report findings from the first survey for Mongolian saiga to
utilize statistically rigorous methodology, using line transect
distance sampling in 2006 and 2007 to obtain population estimates
in and around the Sharga Nature Reserve, the southern part of the
species current range.
Saiga have faced the long term threat of climate change and now
the more immediate danger of human persecution and habitat
degradation. In less than two decades, numbers have dropped 95%
from 1,000,000 to 50,000.
The current but untested hypothesis is that a combination of
unusual weather, topography and pasture improvement resulted in
fast-growing, moist and atypically composed forage, which caused a
form of metabolite toxicosis.
An analysis of assumptions underlying this hypothesis using
meteorological data and satellite imagery revealed that neither
temporal variation in weather nor highly-productive, moist forage
are likely to have been factors in the die-offs; although
significantly lower vegetation or soil moisture in die-off zones
than in the surrounding landscape indicates events were
location-dependent, and therefore precipitated by changes in
calving site selection driven by human…