Our directory of things of interest

University Directory

Solving the suspicious saiga silencing

Solving the suspicious saiga silencing
17 Jan
2018
Warm and humid conditions are found to be the trigger for a mysterious die-off of saiga antelopes

The Central Asian steppe, in which saiga antelopes inhabit, is renowned for being an extreme part of the world in which to live, with temperature swinging wildly from below -40°C in winter to above 40°C in summer. Add in the risks posed by hungry wolves, insecure food supplies, disease, and – of course – the ever-present threat of humans (through poaching and sprawling development), and the saiga’s continued survival, even with a growing population, is admirable. Nevertheless, their ranking of ‘critically endangered’ on the IUCN Red List is a constant reminder of the precariousness of their existence.

Yet even this harsh lifestyle had scientists unprepared for the scale of the 2015 sudden die-off of saiga antelopes, a so-called ‘Mass Mortality Event’ (MME). In only a few weeks, just as the animals were calving, over 200,000 saiga in Kazakhstan simultaneously succumbed to a lethal infection. More than 60 per cent of the global population was wiped out in a matter of days.

The culprit: the bacteria Pasteurella multocida. With an over 80 per cent mortality rate among even healthy infected individuals, the pathogen tore through entire herds, causing haemorrhagic septicaemia (blood poisoning) and imminent death.

saiga2

However, researchers reviewing the tragic incident pondered why the bacteria had taken hold and caused the MME, when it had previously been living harmlessly in the saiga’s tonsils with no signs of outbreak. What had caused the bacteria to suddenly invade the bloodstream, ruthlessly killing off entire herds?

‘The recent die-offs among saiga populations are unprecedented in large terrestrial mammals,’ reflects Richard Kock, professor in emerging diseases and lead researcher at the Royal Veterinary College. ‘The 2015 Mass Mortality Event provided the first opportunity for in-depth study, and a multidisciplinary approach has enabled great advances to be made.’

Working alongside a team of experts from a wide range of international institutions, Kock et al. identified a particular combination of climatic factors which they believe aligned to create ideal conditions for Pasteurella multocida to unleash in this way. In particular, increased humidity and raised air temperatures indicated that such phenomenons are most likely to occur when the weather is humid and warm, as happened prior to the 2015 MME.

These results suggest that previous saiga antelope MMEs, such as during the 1980s, may have been triggered by similar conditions. The perilous existence of the saiga means these MMEs are continually making the species more vulnerable to extinction (the current population is a shadow of the estimated 1,250,000 during the 1970s).

saiga4

‘The use of data from vets, biologists, botanists, ecologists and laboratory scientists is helping improve our understanding of the risk factors leading to MMEs – which was beneficial when another MME occurred, this time in Mongolia in 2017,’ explains Kock. ‘Improved knowledge of disease in saiga, in the context of climate change, livestock interactions and landscape changes, is vital to planning conservation measures for the species’ long-term survival.’

‘MMEs are a major threat for the saiga antelope and can wipe out many years of conservation work and saiga population growth in just a few days,’ adds Steffen Zuther, project manager for Kazakhstan at the Frankfurt Zoological Society and Association for the Conservation of Biodiversity of Kazakhstan. ‘Therefore, understanding these MMEs, what triggers them and what can be done to combat them is extremely important to develop effective saiga conservation strategies. The triggering of such MMEs in saiga through weather conditions shows that not much can be done to prevent them occurring, and therefore how important it is to maintain saiga populations of sufficient size for the species to survive such catastrophes.’

geo line break v3

Free eBooks - Geographical Newsletter

Get the best of Geographical delivered straight to your inbox by signing up to our weekly newsletter and get a free collection of eBooks!

geo line break v3

Related items

Subscribe to Geographical!

geo line break v3

Free eBooks - Geographical Newsletter

Sign up for our weekly newsletter today and get a FREE eBook collection!

geo line break v3

University of Winchester

geo line break v3

EDUCATION PARTNERS

Aberystwyth University University of Greenwich The University of Derby

TRAVEL PARTNERS

Ponant

Silversea

Travel the Unknown

DOSSIERS

Like longer reads? Try our in-depth dossiers that provide a comprehensive view of each topic

  • Natural Capital: Putting a price on nature
    Natural capital is a way to quantify the value of the world that nature provides for us – the air, soils, water, even recreational activity. Advocat...
    The human game – tackling football’s ‘slave trade’
    Few would argue with football’s position as the world’s number one sport. But as Mark Rowe discovers, this global popularity is masking a sinister...
    Essential oil?
    Palm oil is omnipresent in global consumption. But in many circles it is considered the scourge of the natural world, for the deforestation and habita...
    The Money Trail
    Remittance payments are a fundamental, yet often overlooked, part of the global economy. But the impact on nations receiving the money isn’t just a ...
    Alien views
    The tabloids would have us believe that immigrants are taking our houses, our jobs, our school places and our hospital beds. But a close reading of th...

MORE DOSSIERS

NEVER MISS A STORY - Follow Geographical on Social

Want to stay up to date with breaking Geographical stories? Join the thousands following us on Twitter, Facebook and Instagram and stay informed about the world.

More articles in NATURE...

Wildlife

Exciting news for wildlife and photography enthusiasts alike – the…

Wildlife

A new system of robotic aerial vehicles is revolutionising the…

Wildlife

Technology used in creating safe urban environments is now being…

Climate

Brazil’s shift to the right of the political spectrum could…

Wildlife

Laura Cole travels to Orkney to find out why numbers…

Wildlife

The unprecedented frequency of winter tick epidemics have resulted in…

Oceans

Ocean debris, mostly composed of plastic, reaches remote Atlantic islands…

Geophoto

With motion detectors becoming ever more sophisticated, and clearer, crisper…

Nature

Natural capital is a way to quantify the value of…

Tectonics

The reason for the unusual location of Mount St Helens…

Climate

Most plants thicken their leaves in response to higher carbon…

Climate

Not just the preserve of flatulent cows, methane is causing…

Climate

As the United States’ Supreme Court delays a landmark climate…

Geophoto

Of Britain's 15 national parks, the New Forest is probably…

Energy

The Treasury has announced that it is considering imposing a…

Tectonics

Major earthquakes are triggering seismic activity half the world away

Climate

Marco Magrini finds that a warming world also means a…

Wildlife

Unchecked tourism is potentially reducing the number of cheetah cubs that…

Oceans

A relocated military base in Okinawa, Japan will cause ‘irreversible’…

Climate

The ongoing recovery of the planet’s ozone layer is being…