For the saiga,
persecution by hunters has seen their global population reduced by 95 per cent
in less than 25 years, a catastrophic decline accelerated by the fall of the
Soviet Union and the opening up of previously closed borders. This decline has
now reached crisis point after the sudden and inexplicable mass die off that
occurred a couple of years ago ! The
saiga antelope (Saiga tatarica) is a critically endangered antelope that
originally inhabited a vast area of the Eurasian steppezone from the foothills
of the Carpathian Mountains and Caucasus into Dzungaria and Mongolia.
On the remote
steppes of central Kazakhstan, a truly extraordinary – and tragic – event
unfolded in May 2015. Female saigas gathered in huge numbers to give birth on
the open plain over a period of just 10 days – and a BBC camera crew and the
research team they were with watched them die in their hundreds of thousands in
the space of just a fortnight. The animals wre captured in an episode of BBC nature
documentary Planet Earth II.
But why did this
mass death happen? By gathering like this, for as short a time as possible, the
saigas swamp their main predator, wolves, with food so that each individual
calf is less likely to be eaten. The calves are born large and well-developed –
in fact, saigas have the largest proportional birth weight of any wild ungulate
– so that they can outrun a predator within just a few days. They also need to
give birth in a short time in order to coincide with the peak of lush grass
before the summer heat of this harsh continental plain dries the vegetation.
An example of this
incredible spectacle was filmed by another BBC camera crew for their pioneering
programme about nature in the former Soviet Union, Realms of the Russian Bear,
shown in 1994. But much were to happen in the interim. The saiga was poached to
near-extinction in the early 2000s for their horns and meat as the Soviet Union
collapsed, and was listed as Critically Endangered on the IUCN Red List in
2001. However, by 2015, conservation
work by governments, scientists and NGOs was paying dividends; overall numbers
had risen from its nadir of an estimated 50,000 in the early 2000s to around
300,000 in early 2015. One central Kazakhstan population, in particular, was
responsible for the vast majority of this increase – and this is where the
Planet Earth II camera crew headed for their shots of the calving spectacle in
2015 but ended up seeing mass dying !
Later analysis
revealed that the proximate cause of death was toxicity from infection by
opportunistic bacteria found naturally in the animals’ respiratory tract –
Pasteurella multocida. The next Q was why did these usually harmless bacteria become
virulent? What was the environmental or internal trigger, either reducing the
animals’ immunity to these bacteria or triggering virulence in the bacteria, or
both? In exploring these questions, BBC research was a Russian doll; they went back to old field notes from the Institute of
Zoology in Kazakhstan for 1988 when a similar mass mortality occurred; reviewed
research on mass deaths in other species; looked for differences in the
vegetation composition between the 2015 die-off and in other years; and built
statistical models to explore changes in temperature and rainfall over a range
of different temporal and spatial scales.
Before the results
could be out, there were wild theories including the involvement of aliens ! UFO Sightsing Daily, posted: "This
Antelope mass death was an experiment by aliens. It is well known to the
Kazakhstan Government that aliens are making use of an underwater base in the
Caspian Sea which Kazakhstan boarders."
Man could
find reasons for the mass die-off, but when will they realize that their
cruelty and greed is pushing Saiga and many other animals towards extinction !
With regards – S.
Sampathkumar
27th Sept. 2017
