Kandidatuppsatser i miljövetenskap 015-2019
Campus Gotland
Disciplinary Domain of Science and Technology Uppsala University, Campus Gotland
www.uu.se
C LIMATE C HANGE , AN ADDITIONAL FACTOR FOR CONSIDERING THE THREAT LEVEL OF THE
SNOW LEOPARD (P ANTHERA UNCIA )
Adam Fast
Bachelor Thesis in Environmental Science 15 hp, 2019
Supervisor: Shannon Bower, Department of Earth Sciences Examiner: Patrik Rönnbäck, Department of Earth Sciences
The image on the front page displays: A young female snow leopard waking up after being sedated and equipped with a GPS collar in the Tost Mountains, Mongolia.
Photographer: Örjan Johansson
This thesis is the property of the author and may not be used for publication without the author’s or owner’s consent. Author name: Adam Fast
CONTENTS
ABSTRACT.………. 2
SAMMANDRAG.………. 2
INTRODUCTION.……… 3
BACKGROUND………... 5
Understanding Biodiversity in Mountains..……….. 5
Biodiversity Loss………... 6
The Assessment by ‘IUCN Red List Categories and Criteria’………. 7
IUCN Assessment of Snow Leopard, Panthera uncia...………... 8
THREATS TO THE SNOW LEOPARD………..……….8
Snow Leopard as an Apex Predator..……… 8
Home Range and Connectivity of Habitats..………. 9
Anthropogenic Stresses on Snow Leopard and their Habitat……… 9
Competition Increase Under Climate Scenarios………. 11
Maintaining a Coexistence with Snow Leopards……… 11
A Summary of the Threats to Snow Leopards……… 13
DISCUSSION………. 15
CONCLUSION………... 17
ACKNOWLEDGEMENTS……… 18
REFERENCES……… 18
SAMMANFATTNING………... 21
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CLIMATE CHANGE, AN ADDITIONAL FACTOR FOR CONSIDERING THE THREAT LEVEL OF THE SNOW LEOPARD (PANTHERA UNCIA)
Adam Fast. Independent Project in Environmental Science, 15 hp.
ABSTRACT
The snow leopard lives in the high mountains of Asia. Threats currently facing the species are being poached for its high-valued fur and being killed by herders in retaliation for livestock predation. However, climate change also has an impact on the snow leopard’s mountain habitats as tree line height and the average temperature have increased in Asian mountains.
This thesis analyzes the near-future threats from climatic changes against snow leopards and what impact human activities have on the species. Fragmentation of habitats have a huge effect on the survival of snow leopards because the connectivity routes may be reduced or lost. The general process of assessment by the IUCN was examined alongside the assessment of the snow leopard. Both anthropogenic activities and global warming lead to fragmented habitats and may isolate snow leopard populations from each other. An estimated 30 - 65 % of the snow leopard’s habitats may disappear in future scenarios. Climate change is not a threat by itself but creates new threats. Therefore, climate change needs to be taken into consideration in future assessments by IUCN due to its growing impact. The recently released IPBES report makes it apparent what destructive force human activities have on biodiversity.
SAMMANDRAG
Snöleoparden lever i Asiens höga berg. De hot som arten för närvarande står inför är tjuvjakt för dess dyrbara päls, och att dödas av hämndlystna herdar efter boskapsförluster.
Klimatförändringar påverkar även snöleopardens habitat i bergen med en växande trädlinje och ökande medeltemperaturen i de asiatiska bergen. Denna uppsats analyserar de närstående framtida hot mot snöleoparden från klimatförändringar och från mänskliga aktiviteter.
Fragmentering av habitat har stor effekt på snöleopardens överlevnad eftersom
anslutningslederna kan minskas eller förloras. IUCN: s bedömningsprocess undersöktes vid sidan av bedömningen av snöleoparden. Både antropogena aktiviteter och global
uppvärmning leder till fragmenterade habitat och kan isolera snöleopardpopulationer från varandra. Det uppskattas att 30 - 65 % av snöleopardens habitat kan försvinna i framtida scenarier. Klimatförändringar är inte ett hot i sig utan skapar nya hot. Därför måste klimatförändringar beaktas i framtida bedömningar av IUCN på grund av dess växande påverkan. Den nyligen släppta IPBES-rapporten visar tydligt på den förstörande kraft mänskliga aktiviteter har på den biologiska mångfalden.
3 INTRODUCTION
“Cats have conquered almost every corner of the planet. But now, even in the most remote places, they're feeling the impact from our way of life. [...] If cats are to survive in our
changing world, we just need to leave them some space”
- Bertie Carvel (Big Cats 2018, 49:05)
On May the 6th 2019, an IPBES (Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services) Global Assessment report was released on biodiversity and
ecosystem services. One million species have been estimated to be threatened to extinction due to human activity, which is the highest estimation in human history (IPBES 2019). One of the threatened species may be the snow leopard.
The snow leopard (Panthera uncia, previously Uncia uncia) is one of the world’s largest cats and can grow to be around 1.15 meter in length, excluding its tail which is approximately 1 meter (Snow Leopard Trust 2019a). Snow leopards live in the mountains of South and Central Asia thus their thick, dense fur and large paws tremendously adapted to the cold, snowy climate (Riordan et al. 2016, Snow Leopard Trust 2019a, Watts et al. 2019). The Asian mountains create a suitable habitat for snow leopards of 2.8 million km² in 12 countries and is occupied by an estimated population of 7446 to 7996 individuals (Khanal et al. 2018).
Snow leopards have an important role in the ecosystem as an apex predator and in
maintaining the ecosystems stability (Li et al. 2016). Their main prey consists of blue sheep, argali sheep, Asiatic ibex, Himalayan tahr and marmots, which share the alpine habitat and may also be affected by climate change (Aryal et al. 2016, Forrest et al. 2012).
Since the dawn of livestock domestication snow leopards have been threatened by humans as retaliatory killing when depredation of livestock occurs. Snow leopards can be a problem to the herders when they prey on livestock. In response to this predation, humans began hunting snow leopards with traps and guns. The fur from snow leopards has a status value for its owner which gave humans an additional reason to kill the feline (Borling & Fleischmann 2014). If the wild prey species decreases in population, snow leopards may attack domestic animals more frequently (Borling and Fleischmann 2014). Currently, domestic livestock in the mountains are increasing due to greater demand of cashmere. In Mongolia, the number of domestic goats has increased from 5 million to 14 million between 1990 to 2010, which creates competition of grazing land with their wild relatives when domestic goats migrate to higher altitude (Borling & Fleischmann 2014, Khanal et al. 2018, Watts et al. 2019).
In recent years, additional threat to snow leopard populations comes from mining activity, poaching and hunting of its prey, and climate change (Borling & Fleischmann 2014). An example of hunting of a prey species is the argali sheep (Ovis ammon). This species has been legally hunted by trophy hunters which has led to a reduced population. However, the trophy hunting has declined during the last two decades (Murdoch et al. 2017).
The main mining activity throughout Asia consist of coal extraction. China produces most coal in the world and India, Kazakhstan and Mongolia are the other top producing countries in Asia (World Energy Council 2016a, World Energy Council 2016b). In 2016, China’s government hoped to close over 1000 coal mines, though India’s government intends to increase their production of coal due to the country’s continued development (World Energy Council 2016a, World Energy Council 2016b). Mongolia is currently developing a huge coal mine in the South Gobi Desert, consisting of 7.4 billion tons of coal (World Energy Council 2016a).
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In the last 20 years, the temperature on the Tibetan Plateau has become 3℃ warmer (Snow Leopard Trust 2019b). The plateau serves as a home for over half of the wild snow leopard population and the warmer climate has an impact on the habitat, including access to water and vegetation (Snow Leopard Trust 2019b). When the temperature increases, the tree line moves further up the mountains as well (Tiwari & Jha 2018). Forrest et al. (2012) have concluded in their study that climate change could lead to a habitat loss of 30 % in the mountains of Himalayas and can threaten the snow leopards and other animals who live in the region (Forrest et al. 2012). A study by Li et al. (2016) estimates a habitat loss of 65 % in Central Asia to 2070 in a future climate scenario (RCP8.5, Li et al. 2016). World Wildlife Fund (WWF) believes that climate change is the greatest long-term threat to the species (WWF 2019).
A threatened species on the ‘Red List’ by The International Union for Conservation of Nature (IUCN) has been evaluated by an assessment of its extinction risk with the IUCN Red List Categories and Criteria (IUCN 2012). The IUCN mainly focuses on the current and previous changes, not on the future ones. Climate change is an ongoing threat that needs to be taken more seriously in the assessment due to its accelerated impact. Climate change is known to be a threat to the snow leopard, but not to which magnitude. The IUCN may change the category of a threatened species if there is new information of its population size or if the major threats have changed, decreased or increased (IUCN 2019). In late 2016, the threat category of snow leopard was down-listed from Endangered to Vulnerable due to an estimated population over 2500 but less than 10 000 mature individuals, and an estimated decline of 10 % during the three coming generations (McCarthy et al. 2017).
Purpose
Climate change is an accelerating threat to everyone and especially the species living on the edge of the world, like the mountains of South Asia. With available and relevant research of snow leopards and climate change, I will analyze how climate change may become a long- term threat to the species. Specifically, I will examine whether the down-listing of snow leopard should be reconsidered or changed if climate change is included in IUCN’s
assessment. The Snow Leopard Trust believes there is a lack of knowledge to determine the species’ threat level and that it still should be considered Endangered (Snow Leopard Trust 2017). The aim of this bachelor thesis, therefore, is to analyze the threat level of snow leopard based on the current knowledge of the species and the effects of climate change.
To accomplish this, I will narrow my focus to answering these research questions:
- What are the current threats to the snow leopard populations?
- What threats can be strengthened or created towards snow leopards due to climate change?
- What do IUCN’s criteria consider for a species to be threatened?
- What does IUCN’s decision on the decrease the snow leopard’s threat level imply for the future of the species?
The first question will be the main focus of my thesis and needs to be answered to understand the current and future threats, and for the discussion of the second question. The two
remaining questions needs to be answered to understand what information is relevant for the discussion of the threat level. My research goal is to analyze the known information of how the impact of climate change may affect snow leopards and what the conclusions can be.
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This bachelor thesis will be a literature study and information will be taken from scientific papers and trustworthy sources. To counteract bias, sources and articles with different
perspectives will be used, although most of the current studies show that climate change has a negative impact on nature. The papers and sources will be collected using the university’s library search function, from organizations working with conservation of snow leopards such as Snow Leopard Trust and World Wildlife Foundation (WWF), and from the IUCN’s Red List page. The thesis can afterwards be used as an ‘eyeopener’ for the reader to understand that climate change can be a greater threat than currently considered.
BACKGROUND
Understanding Biodiversity in Mountains
It is important to understand biodiversity in mountains before understanding the role of the snow leopard in its ecosystem. The mountainous ecosystem has a simple structure containing few species and low productivity which makes it vulnerable when one species declines (Johansson et al. 2016, Watts et al. 2019). Species richness in terrestrial biomes tend to decline in general when the elevation becomes higher (Gaston & Spicer 2004). In Nepal’s Himalayas, the temperature can change drastically in higher elevation. It has been found that temperatures drop 6.2 ºC with every 1000 m altitude rise (Aryal et al. 2016). Higher altitude, alongside decreased moisture and temperature limit the tree growth. It creates a tree line at the alpine borders (Tiwari & Jha 2018). Mountains create isolated areas with low movement between habitats compared to low altitude areas with higher connectivity to similar habitats (Gaston & Spicer 2004). This contribute to species adapting to the environment within an elevation ratio but may lead to extinction locally due to the difficulty to migrate between habitats and compromising the exchange of genes. Species in this environment may be endemic due to its adapted isolation (Gaston & Spicer 2004).
Biodiversity can be measured in various ways (Gaston & Spicer 2004). The Economics of Ecosystems and Biodiversity (TEEB 2012) explains the values as ecological-, socio-cultural- and economic value. The economic value is mostly used to describe the importance of biodiversity and can be split into use and non-use values. The use values then divide into direct- and indirect-use values, such as food production and carbon sequestration,
respectively (TEEB 2012). Today’s food production only uses a small part of biodiversity.
Humans have domesticated nearly 200 plants and 12 plants provide 75 % of the global food intake (Gaston & Spicer 2004). Different species of animals have been domesticated as well, and the global livestock was 3.39 billion animals in 1996 to 1998 (Gaston & Spicer 2004).
Currently, the world's livestock production and crop lands extend over a third of the land surface and uses three-quarters of the freshwater resources (IPBES 2019).
The non-use values have not the obvious value as the use-values but are valuable to the wellbeing of humans. These are option-, bequest- and existence value and contribute to maintaining the use of biodiversity, passing on the biodiversity to the future, and recognizing the existential value of the survival of species, respectively (Gaston & Spicer 2004, TEEB 2012). The conservation of tigers, for instance, helps the species to recover and maintain its existence, which strengthens the option value of forests being protected. Children in the future will have the experience of knowing tigers still live in the wild (as the bequest value), and even though few humans will see tigers in the wild, knowing the species exists contribute to the existence value (Gaston & Spicer 2004). Albert et al. (2018) declared the tiger
(Panthera tigris) to be the most charismatic species, as well. A charismatic species means a species with an appearance that is highly valued by humans and can increase the conservation
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of the species (Albert et al. 2018). Albert et al. (2018) used the features of ‘Dangerous’,
‘Impressive’, ‘Cute’, ‘Beautiful’, ‘Endangered’ and ‘Rare’ to identify charismatic species (Albert et al. 2018).
Biodiversity Loss
In the last 400 years, over 1000 species of animals and plants have gone extinct due to human activities (Gaston & Spicer 2004). In fact, human activities are accelerating species extinction due to five main threats: “(1) changes in land and sea use; (2) direct exploitation of
organisms; (3) climate change; (4) pollution and (5) invasive alien species” (IPBES 2019).
These threats have the highest impact globally and the consequences are devastating (IPBES 2019). All mammals and birds are threatened by 25 % and 13 % respectively, due to these major threats, and as the recent IPBES report states: one of eight million species are
threatened to extinction (IPBES 2019, Tilman et al. 2017). Anthropogenic activities have led to an increase of greenhouse gases, and today’s measured emissions are twice as high from year 1980 (IPBES 2019). The average global temperature has already increased with 0.74 ℃
± 0.2 ℃ during the last century and has been projected to rise in the future, by 1.4 to 5.8 ℃ to year 2100 (Gaire et al. 2014). Weather stations have confirmed that the temperature increase in the Himalayas is three times higher than the global average (Forrest et al. 2012). Tibetan Plateau in Central Asia has warmed twice as fast compared to the average northern
hemisphere warming rate (Li et al. 2016).
Recent studies indicate that there is a correlation between the climate and the height of the tree line. Mountainous regions are less affected by anthropogenic use and the tree line has therefore become an indicator of climate change (Forrest et al. 2012, Gaire et al. 2014, Tiwari & Jha 2018). The tree line is shifting upwards due to global warming, resulting in habitat loss and fragmentation of the alpine living species (Tiwari & Jha 2018). Increased temperature and more precipitation have been described to be the main influences of the advancing tree line (Li et al. 2016, Tiwari & Jha 2018). Alpine species are especially vulnerable to climate change due to an often conical shape of the mountains. It suppresses their natural habitat and can lead to a mountaintop extinction (Gaire et al. 2014, Tiwari & Jha 2018).
Previous mass extinctions indicate that the resilience of terrestrial and marine biotas may collapse if environmental stresses are too high and will lead to a heavy biodiversity collapse (Gaston & Spicer 2004). If one key species was to be extinct it could lead to extinction of several species in its ecosystem, or species that were dependent on it, resulting in an extinction cascade. If a population of an apex predator decrease, populations of
mesopredators, smaller predators, may increase. It would increase the predation on prey species and unbalance the ecosystem (Gaston & Spicer 2004). Lennox et al. 2018 estimates that mesopredators can be of greater threat than apex predators to the depredation of livestock (Lennox et al. 2018).
The Assessment by ‘IUCN Red List Categories and Criteria’
The International Union for Conservation of Nature (IUCN) defines species’ threat levels by the categories: Extinct (EX), Extinct in the wild (EW), Critically Endangered (CR),
Endangered (EN), Vulnerable (VU), Near Threatened (NT) and Least Concern (LC). The remaining two categories are used when there is no or to little information about the species;
Data Deficient (DD) and Not Evaluated (NE) (IUCN 2012). The categories are used to easily understand the extinction risk of species on a global scale. IUCN aims to create a framework which may be used in an objective perspective based of the current information of species’
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risk of going extinct. The Union states that it is important to know that the extinction risk, in some cases, may be estimated too high or too low (IUCN 2012).
In 1994, the ‘Red List’ was adopted by the IUCN council and is in constant development.
The evaluation of a species’ threat level goes through several processes of validation and consultation. It is used by many organizations, including non-governmental and
governmental, due to its credibility (IUCN 2012). The ‘threatened categories’ consist of CR, EN and VU, and the extinction risk increases for every category (IUCN 2012). A threatened species may be lowered from its threat category if the fulfilled criteria change during a 5- years period. But if a species is more threatened than its given category, it will be changed to a higher category immediately. The same applies to an inaccurately given threat category (IUCN 2012). There are five criteria, divided into A - E, that are evaluated before the category is given depending of which criteria that has been evaluated (IUCN 2012). The criteria to be classified as VU can be summarized as:
A. Reduced population by 50 % or more the past decade B. The range has been fragmented to 20 000 km² or less
C. The remaining population consist of less than 10 000 adults and declines with 10 % within a decade
D. A population occupy a limited area due to human activities
E. Risk of extinction within a decennium is 10 % or more (IUCN 2012) IUCN Assessment of Snow Leopard, Panthera uncia
The new assessment of snow leopard was made November 8th 2016 and lowered the threat category. Snow leopards have been classified as Endangered (EN) since the first assessment from 1986 but is currently classified as Vulnerable (VU). This decision was made due to the population being larger than 2 500 adult individuals and estimated to decrease with 10 % or more in three generations time, evaluated by the C-criteria for VU (McCarthy et al. 2017).
McCarthy et al. (2017) state that the last assessment from 2008 had errors in the estimated population size and the species’ category was overestimated. The estimated decline was changed from 20 % in two generations to 10 % because of reduced poaching and an increase in conservation programmes. Other threats such as building of roads and mines may still increase in the snow leopard's range which could affect the species’ future population. The improved information of the snow leopard population has contributed to the conservation of the species, but it remains classified as threatened (McCarthy et al. 2017).
THREATS TO THE SNOW LEOPARD
The Snow Leopard as an Apex Predator
Snow leopard, Panthera uncia, is endemic to the mountain ranges of south and central Asia (Riordan et al. 2016, Watts et al. 2019). It maintains a stable ecosystem in the alpine region as an apex predator and is considered both a keystone- and a flagship species (Li et al. 2013, Li et al. 2016, Watts et al. 2019). Forrest et al. (2012) suggest that snow leopards may also be considered as an umbrella species because of the species enormous range. It means that other species who share the same habitat may be protected by snow leopard conservation (Forrest et al. 2012). Snow leopards have an important role of controlling the population of wild ungulates which then cannot overgraze the alpine steppes, resulting in a balanced ecosystem.
This type of control, when an apex predator is controlling the ecosystem, is called a top-down control (Li et al. 2013, Lennox et al. 2018, Watts et al. 2019). Snow leopards have therefore
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adapted to the alpine regions for hunting ungulates on the steppes of the mountains (Watts et al. 2019). Blue sheep (Pseudois nayaur) is a major prey species and is important to the
maintenance of the snow leopard population (Alexander et al. 2016, Aryal et al. 2016, Forrest et al. 2012, Khanal et al. 2018, Li et al. 2016). Though in later years, depletion of natural prey species has become a severe threat to the survival of snow leopards (Forrest et al. 2012, Johansson et al. 2016, Li et al. 2013, Watts et al. 2019). Wild ungulates are competing with livestock of grazing areas and freshwater resources, putting pressure on the wild prey species (Khanal et al. 2018, Watts et al. 2019). An example of pasture competition is in Api Nampa Conservation Area in Nepal where it was estimated to withstand at least 1000 individuals of blue sheep, but data from the conservation area’s office indicate on 10 000 domestic animals grazing in the area during summer, ten times more than the wild ungulates (Khanal et al.
2018). Poaching and over-hunting of wild ungulates along with competition of pasture land and freshwater have led to a significant decline in populations (Khan et al. 2018).
Snow leopards require 600 to 900 kg of meat annually and in the absence of wild prey, they tend to predate on livestock (Khanal et al. 2018). Domestic animals can contribute up to 70 % of the snow leopard’s diet (Sharma et al. 2015). Herders often kill snow leopards in
retaliation due to their livestock loss and it has become one of the greatest threats against the species (Forrest et al. 2012, Johansson et al. 2016, Khanal et al. 2018, Li et al. 2013, Watts et al. 2019). Between 220 to 450 snow leopards are killed each year by retaliatory killing, poaching for their bones and fur, or indirectly, by traps or poison intended for wolves (Johansson et al. 2016, Khanal et al. 2018, Li et al. 2013).
Home Range and Connectivity of Habitats
Although the snow leopard habitat has been estimated to be 2.8 million km² throughout Asia, most of the protected areas are not enough to preserve the species (Khanal et al. 2018, Watts et al. 2019). Johansson et al. (2016) discovered that the home range of adult snow leopard males were twice the size of the females. This implies that the average male home range could only be sustained in 60 % of the 170 studied protected areas, and merely 5 % (eight protected areas) could sustain more than 50 females. Johansson et al. (2016) believe protected areas where humans are excluded, called land sparing, cannot alone save the species. Sustainable land sharing, coexistence, would be best way of protecting snow leopards (Johansson et al. 2016). The problem with the current protected areas could be the overexploitation by human activities such as farming and pasture, which work against the sustainable coexistence (Jamtsho & Katel 2019).
Habitat connectivity usually consists of stepping stones and natural corridors. Connectivity is important for maintaining the gene flow in the ecosystem and the diversity in the trophic levels (Riordan et al. 2016). Riordan et al. (2016) found three potentially important
movement routes in Central Asia. The routes consist of one large route and two minor ones.
The large route extends as a curve from Pamir Mountains in Tajikistan in the west, along the Western Himalayas, down to the Southwestern Tibetan Plateau and ends in the Qionglai Mountains in Central China, which connects the western and eastern population. The second route connects the northern population in the Altai Mountains, with the population around the Southern Tibetan Plateau. The model showed a low movement level between Bohoro
Mountains, south of Altai Mountains, and the northern range which may suggest on an isolation between the northern population in Altai mountains and the southern population along the Tibetan Plateau. The third presumably important connectivity route is the region of the Gobi Desert in China. Studies using GPS telemetry suggesting movement by snow leopards through the desert and it could be a second connectivity route with the northern population, though there is no evidence of its importance to the species. However, it is
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important for the species’ resilience to maintain the connectivity routes. If the corridors disappear the snow leopard becomes further isolated which may lead to inbreeding, and the risk of extinction becomes higher (Riordan et al. 2016).
Anthropogenic Stresses on Snow Leopard and their Habitat
Human activities are increasing in the mountains of Central Asia due to economic growth, including intense grazing, mining, and building of roads and dams (Alexander et al. 2016, Khanal et al. 2018). Local communities are changing their grazing systems from the nomadic continuous movement of livestock to low movement in few pasture lands and greater herds (Forrest et al. 2012, Khanal et al. 2018, Li et al. 2016). Overexploitation alongside climate change creates fragmented habitats and reduces the connectivity between them (Li et al.
2016). These events have become threats to the survival of snow leopards (Alexander et al.
2016). The anthropogenic threats are also believed to intensify in the presence of climate change (Forrest et al. 2012, Khanal et al. 2018).
When the temperature increases, several changes occur in the mountains. It reduces
permafrost, melts glaciers, exacerbate droughts in the Himalayas and changes habitats (Gaire et al. 2014, Tiwari & Jha 2018). Snow leopards have to adapt to the warmer temperatures, but they only have decades now to do so, not thousands of years as from the last glacial
maximum (Li et al. 2016). Aryal et al. (2016) found annual mean temperature to be the major influence in the habitat model with nearly 86 %, followed by annual precipitation (6 %). The results suggest that temperature could be the major factor for the distribution of the species (Aryal et al. 2016). In another study by Watts et al. (2019), annual mean temperature was negatively correlated with elevation, which was the major influence in their model. This study also suggests that temperature could be a major factor for suitable habitats due to snow leopard’s adaptation to the cold environment on higher altitudes (Li et al. 2016, Watts et al.
2019). Annual precipitation is likely to be reduced in the future and current studies indicate that it is already declining (Gaire et al. 2014). A meteorological station in Gokha, Nepal had seen a significant, negative trend in the precipitation between 1980 to 2009 by an annual decrease of 28 mm, which changed to a decrease of 55 mm/year after year 1987 (Gaire et al.
2014). Western Himalayas have also experienced negative trends in precipitation and it could be a decline of almost 20 % since the last century (Tiwari & Jha 2018).
Climate change is altering the tree line, causing the snow leopards to be squeezed between the rocky areas on higher altitude and the tree line (Aryal et al. 2016). Li et al. (2016) found that only 35 % of the species’ current home range may support the population in the future if the climatic changes continue, called climate refugia (Li et al. 2016). A habitat suitability model made by Forrest et al. (2012), by merging snow leopard distribution and vegetation dynamics with three IPCC climate scenarios, showed that 30 % of the Himalayan habitat may be lost in the future due to the growing tree line. Even with low emissions, nearly 10 % of snow leopard habitat can disappear and it may become worse with higher emissions. China and India contain the most snow leopard habitat in the Himalayas and each country would lose 25 % of their area in the highest emission scenario (Forrest et al. 2012).
Snow leopards are unlikely to survive at altitudes above 5500 m due to the limited access of oxygen, forcing the species downwards (Forrest et al. 2012). Future climatic changes may influence the niche of both snow leopards and blue sheep, its main prey species, due to both species’ niches being most influenced by temperature (Aryal et al. 2016). Currently they have the same habitat niche and Aryal et al. (2016) believe there may be a mismatch in the niche between the species in future scenarios. Their result on the mean Schoener’s D index value for current time was 0.809, which indicates a high niche overlap. Though the index value
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decreased to 0.806 and 0.764 in their future climate scenarios of year 2030 and 2050, respectively (Aryal et al. 2016). If this was to be true, snow leopards may have to adapt to a wider diet of other prey species (Aryal et al. 2016). Reduced population of prey species in combination with increased number of domestic animals may even lead to a switched diet to higher predation on livestock (Watts et al. 2019). Common leopards have attacked humans in the absence of wild prey, but snow leopards are not known to attack humans (Khan et al.
2018, Li et al. 2013).
Competition Increase under Climate Scenarios
An increasing tree line may lead to competition for prey species with the common leopard (Panthera pardus) which has been moving towards higher altitudes (Aryal et al. 2016, Forrest et al. 2012). Snow leopards currently compete for prey with Tibetan wolf (Canis lupus filchneri) but competition with common leopards could be devastating (Aryal et al.
2016, Jamtsho & Katel 2019). The common leopard has a more advanced adaptation to forest areas and is considered to be the superior species if they were to compete (Aryal et al. 2016, Forrest et al. 2012). Lovari et al. (2013) compared studies on the two leopard’s diet and found a high niche overlap with the Pianka’s Index being 0.91, where 1 is the maximum overlap. The overlap for the different taxa of prey species was wider for the common leopard and the prey species were more varied in weight. Snow leopards preferred the smaller and medium-sized prey species between 2 - 25 kg and 50 - 75 kg, respectively (Lovari et al.
2013). The common leopard hunted smaller prey species as well, and larger prey species of 75 + kg (Lovari et al. 2013).
An example of a competition between related species is between the arctic fox and the superior red fox in Sweden. Red foxes are moving northward into arctic fox habitats due to warmer climate. After nine years of studying the two foxes, Tannerfeldt et al. (2002)
concluded that arctic foxes are avoiding red foxes because they may kill juvenile arctic foxes and compete for food sources. It has forced the arctic foxes into higher altitudes with lower productivity. When the lemming population (the foxes main prey species) is low, arctic foxes move to lower altitude and the competition of prey becomes intense (Tannerfeldt et al. 2002).
Lamichhane et al. (2019) studied the coexistence between tigers (Panthera tigris) and common leopards in Chitwan National Park in Nepal. They found it to be working due to high abundance of prey species and by adapting to their own niche. The carnivores created a natural hierarchy where the tiger was the dominant species and the common leopard was the subordinate (Lamichhane et al. 2019).
Maintaining a Coexistence with Snow Leopards
Most studies conclude what areas that need to be protected and how to persuade local
communities of the value by preserving snow leopards (Aryal et al. 2016, Forrest et al. 2012, Jamtsho & Katel 2019, Watts et al. 2019). Proposed short-term solutions to reduce human- snow leopard conflicts are to improve pasture routes and compensate herders of their losses (Jamtsho & Katel 2019). Herders would be able to protect their livestock with better built enclosures and homestays for the winter, and the value of snow leopards would increase (Jamtsho & Katel 2019, Watts et al. 2019). Training local veterinarians have been proposed by Li et al. (2013) due to the heavy livestock losses by common diseases. In their study, 10 % of the livestock loss was due to snow leopards and 42 % by diseases (Li et al. 2013). If the diseases were cured, the herder’s economy would not be affected as much by the losses from snow leopards (Li et al. 2013). Sharma et al. (2015) believe it may be possible to coexist with snow leopards if livestock does not negatively affect the populations of wild prey species (Sharma et al. 2015).
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Land sharing is inevitable due to the snow leopard range of 2.8 million km2 (Johansson et al.
2016, Khanal et al. 2018). Johansson et al. (2016) propose sharing to be best suitable way of coexistence in long-term conservation but the exclusion of humans could be necessary in some areas (Johansson et al. 2016). The areas of high value to snow leopards are the ones who may withstand the rapid climatic changes, the climate refugias (Li et al. 2016). The natural corridors are also important areas to conserve to maintain a gene flow (Aryal et al.
2016, Riordan et al. 2016). Aryal et al. (2016) suggest the focus should be on extending corridors between protected areas and not on protected areas alone. The protected areas cannot secure the survival of the species due to factors such as gene exchange, prey abundance and anthropogenic activities (Aryal et al. 2016, Riordan et al. 2016).
Hanson et al. (2018) examined how local communities responded to the idea of translocation of the prey species blue sheep into the Sagarmatha National Park in Nepal to reduce the predation of livestock. The result showed a reluctance from herders, who may be those who benefit the most, because they feared damaged crops and pasture competition more than livestock losses alone (Hanson et al. 2018). In the study by Jamtsho & Katel (2019), six of the 44 interviewed herders in Wangchuck Centennial National Park in Bhutan stopped being pastoralists due to the fear of losing livestock (Jamtsho & Katel 2019). Involving the local communities in conservation is important and could reduce the human threats such as retaliatory killing (Khanal et al. 2018, Sharma et al. 2015). Cooperation between the 12 affected countries may also contribute to the survival of snow leopards and Riordan et al.
(2016) believe that global cooperation could be the greatest action for the protection of the species (Riordan et al. 2016). The religious beliefs in the local communities may contribute to conservation, as well. Sharma et al. (2015) found that in the presence of Buddhist beliefs, nearly no snow leopards were killed in retaliation or by poaching. Only one case has been reported where a snow leopard was killed during the past 15 years (Sharma et al. 2015).
Gaire et al. (2014) found Buddhism to contribute to the protection of biodiversity too (Gaire et al. 2014). In folklore around the Tibetan Plateau, snow leopards are believed to protect the mountains as guardians (Li et al. 2013).
Despite all efforts in conservation programmes and mitigation in the human-snow leopard conflict, climate change and anthropogenic activities continue to grow as threats to snow leopards (Forrest et al. 2012, Khanal et al. 2018, Li et al. 2016). Important habitats are still under climatic threats and mining is believed to increase in snow leopard habitats (Alexander et al. 2016).
A Summary of the Threats to Snow Leopards
The near-future and current threats have been summarized in direct and indirect threats (Table 1). The direct and most critical threats to snow leopards are retaliatory killing, poaching for its fur and poaching of the feline’s prey species (Table 1, Borling &
Fleischmann 2014, Forrest et al. 2012, Johansson et al. 2016, Khan et al. 2018, Khanal et al.
2018, Li et al. 2013, Watts et al. 2019). The indirect impacts from anthropogenic activities mainly lead to fragmentation of snow leopard habitat, except for traps which are placed to kill other animals such as wolves (Alexander et al. 2016, Li et al. 2013, Khanal et al. 2018).
Human activities, especially mining, may affect the connectivity routes which are important for the movement of snow leopards (Li et al. 2016). If the third route through the Gobi Desert suggested by Riordan et al. (2016) was to be important to snow leopards, Mongolia’s new mining investment may have a great impact on the species movement. Mining activity does not only lead to habitat fragmentation, it creates greenhouse gas emissions as well. Building of roads may also contribute to higher emissions because of more traffic. Higher human activity in general may contribute to more emissions, which then enhance the global
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warming. Climate change is not a threat by its own, but it creates threats to the snow leopard trough higher temperatures and an altering tree line (Table 1). The Himalayas and Tibetan Plateau are especially affected due to a higher average temperature compared to the global average (Forrest et al. 2012, Li et al. 2016, Tiwari & Jha 2018).
Temperature and precipitation were found by Aryal et al. (2016) to be the most influential factors of snow leopard habitats. The factors may become threats because they have been altered by global warming. It also applies to the growing tree line that is moving upwards and squeezes snow leopard between two biotopes which they are neither adapted to. Snow
leopards are threatened by their own ability to adapt to the rapid changes due to their slow adaptation (Li et al. 2016). Altitudes over 5500 m can be lethal due to the low amount of oxygen and if snow leopards move downwards they may have to compete with common leopards (Aryal et al. 2016, Forrest et al. 2012, Lovari et al. 2013). It is unknown if the two leopard species could coexist, but evidence suggest they will not due to overlapping diet (Aryal et al. 2016, Forrest et al. 2012, Lovari et al. 2013). The competition of prey may become even worse if blue sheep, snow leopard’s main prey, change their niche from the snow leopards’, as suggested by Aryal et al. (2016).
Table 1. Threats to snow leopard populations are divided into anthropogenic activity and climate change, and what impact they have on snow leopards, followed by the sources.
Threat Impact Source(s)
From anthropogenic activity:
Retaliatory killing Direct Forrest et al. 2012,
Johansson et al. 2016, Khanal et al. 2018, Li et al.
2013, Watts et al. 2019 Poaching for its fur Direct Borling & Fleischmann 2014, Forrest et al. 2012,
Johansson et al. 2016 Poaching of prey species Direct Forrest et al. 2012, Khan et
al. 2018
Mining activity Indirect Alexander et al. 2016,
Khanal et al. 2018
Building of roads Indirect Alexander et al. 2016,
Khanal et al. 2018
Building of dams Indirect Alexander et al. 2016,
Khanal et al. 2018
Intense grazing Indirect Alexander et al. 2016,
Borling & Fleischmann 2014 Traps for other species Indirect Khanal et al. 2018, Li et al.
2013
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Loss of connectivity routes Indirect Li et al. 2016 From climate change:
Tree line growth Indirect Aryal et al. 2016, Forrest et al. 2012, Tiwari & Jha 2018 Temperature increase Indirect Aryal et al. 2016, Forrest et al. 2012, Gaire et al. 2014,
Li et al. 2016, Snow Leopard Trust 2019b Precipitation decrease Indirect Aryal et al. 2016, Gaire et
al. 2014, Li et al. 2016, Tiwari & Jha 2018 Less time to adapt to
climatic changes
Indirect Li et al. 2016
Niche mismatch with prey species
Indirect Aryal et al. 2016
Loss of connectivity routes Indirect Li et al. 2016 Competition of prey species Indirect Aryal et al. 2016, Forrest et
al. 2012, Lovari et al. 2013 The effects of climate change become indirect threats to the snow leopard because they affect the surroundings and not the species directly. Climate change may amplify the anthropogenic threats, suggested by Forrest et al. (2012) and Khanal et al. (2018) and can eventually
become the largest contributor to the decline of snow leopards (Figure 1). For example:
climate change pushes the tree line upwards and alongside human activities, creating fragmentation. This pushes the snow leopard populations into smaller areas where it can be difficult to catch prey. Increased livestock sizes and less movement makes it easier for snow leopards to hunt domestic animals. If the predation on livestock becomes more intense, herders may eventually kill more snow leopards, the current major threat to the species (Table 1, Figure 1).
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Figure 1. How climate change affects the eventual near-future threats to snow leopards. The outer circle consists of the threats created by climatic changes, followed by the indirect threats from anthropogenic activity. The third circle represents the direct threats to snow leopards and the final in the middle represents the major threat.
DISCUSSION
Preserving the Snow Leopard
This thesis explored the topic of snow leopard conservation and whether the threats caused by climate change were sufficiently captured by international threat assessments. My research questions were:
- What are the current threats to the snow leopard populations?
- What threats can be strengthened or created towards snow leopards due to climate change?
- What do IUCN’s criteria consider for a species to be threatened?
- What does IUCN’s decision on the decrease the snow leopard’s threat level imply for the future of the species?
To answer the first research question, threats that snow leopards are currently facing are the ones with a direct impact on a population decline. The threats with an indirect impact may have begun being a threat or will be in near-future, such as mining activity and livestock grazing, due to growing economies with higher demand. Climate change strengthens the indirect ‘natural’ threats, including an increase of the average temperature and an upward- moving tree line, which answers the second research question. Both anthropogenic activities
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and climate change lead to fragmented connectivity routes which may have a direct impact on snow leopards in the future. As for the third research question, the IUCN examines species by their estimated population size and declining rate. The Union therefore changed the threat level on snow leopards due to a new population estimation. The impacts from climate change may accelerate even further in the coming 10 years, or three generations of snow leopards, which makes the estimation insufficient. The threat levels are depended on five criteria. They are developed to have the best explanation on a species’ estimated decline. The threats from climate change are difficult to estimate, but may have rapid, unexpected impacts on the nature. The potential future impacts need to be taken in consideration in all five criteria because it may have a greater impact than believed. If climate change would not be in the five criteria, it could become a sixth one due to its future strength. To expose the potential threat from climate change even further, with the greatest outcome, would be to create a new category, Threatened by Climate Change.
The snow leopard is considered to be a keystone species and a flagship species and maybe an umbrella species as well (Forrest et al. 2012, Li et al. 2013, Watts et al. 2019). The fourth research question imply on a lower awareness of snow leopards which may lead to less conservation work to secure the species for the future. It would increase the conservation work if snow leopards were more highly valued. Then the species could be considered a charismatic species. Snow leopards could be associated with every feature used by Albert et al. (2018) in their charisma determination except ‘dangerous’ since the species does not attack humans (Li et al. 2013). Snow leopards could become a symbol for both the preservation of mountainous areas and for how climate change affect mountainous living species. As seen in the tiger example, the existential value that snow leopards provide may be important to preservation due to the spiritual belief that they protect the mountains (Gaston &
Spicer 2004, Li et al. 2013). The option- and bequest values also serve roles in snow leopard conservation because they support the current and future maintenance of the mountainous biodiversity (Gaston & Spicer 2004).
As an apex predator, snow leopards have an important role of maintaining the balance in its ecosystem. If this was to be disrupted, the hole ecosystem could collapse (Li et al. 2016).
Many people are dependent of the ecosystems within the snow leopard’s range and therefore, it is important to preserve the species. The common leopard may become a competitor to snow leopards and the two species could create a natural hierarchy as it did between common leopards and tigers in the study of Lamichhane et al. (2019). If snow leopards and common leopards would have the same competition as the two fox species, it could lead to a rapid decline in the snow leopard populations. It becomes a threat and another answer to the second research question. In a worst-case scenario where the population of snow leopards would collapse, the common leopard could, if necessary, take the role as the new apex predator to maintain the balance in mountainous ecosystem. An extinction cascade may occur if the snow leopard disappears, due to the species being a keystone species, and can lead to a
mountaintop extinction. Then there is no ecosystem for the common leopards to maintain.
Conservation programmes strengthens the preservation of snow leopards which may
counteract the competition between the species and the extinctions of other mountain living species. The latest IUCN assessment on the species has contributed to the continued
conservation as well (McCarthy et al. 2017). However, conservation of snow leopards would benefit the preservation only if the emissions were to be reduced. If the emissions continue will climate change still be a threat to not just the snow leopard, but to all the mountain living species and the people who are depending on a functioning ecosystem.
16 CONCLUSION
The IUCN provides an important function by explaining how threatened many species are. It is easy to understand a species threat level by looking at the different categories and the evaluation is used by several organizations. The influence IUCN has is therefore important when discussing if climate change should be considered an additional threat or not. After the release of IPBES’ latest report on biodiversity, the effects of climate change on species worldwide have become apparent. One million species are facing extinction due to human activities, and climate change is currently the third greatest threat. Climate change can also be expected to interact with all other existing threats. The current assessment on snow leopards focus on the size of the population and in which rate it decreases. The effects from
anthropogenic activities will most likely accelerate the changes that are happening in snow leopard's range which may have a great impact on the species. The mountainous ecosystem may not have the same resilience as a species rich ecosystem. It may even collapse due to the rapid environmental changes.
Conservation programmes are reducing the threats from herders and creating awareness of snow leopards. Although, with more pressure from humans and climate change will it probably not be enough for the preservation of snow leopards. If the results from the IPBES report were to be considered alongside the IUCN’s Red List, several species would probably be classified with a higher threat level. One thing is for certain: climate change must be taken in consideration in some way, if it is in the current criteria, a new criterion or an additional category. Snow leopards are dependent on suitable habitats with an unchanged environment and as the quote by Bertie Carvel states: “[...] If cats are to survive in our changing world, we just need to leave them some space” (Big Cats 2018, 49:05).
ACKNOWLEDGMENTS
I would first like to thank Shannon Bower for being my supervisor, and believing in my thesis and all her good help. Special thanks to Örjan Johansson, for discussing my thoughts on the subject and for providing the front page picture. Thanks to Patrik Rönnbäck for approving the thesis, and to Gustaf Samelius for sending me the first articles and giving me suggestions for the thesis. Thanks to Pauline “Link” Plötz for her advice on a good way to summarize the articles and finally, thanks to Clara Schneiter for helping me with the Swedish grammar in the summary.
REFERENCES
Albert, C., Luque, G. M., Courchamp, F. 2018. The twenty most charismatic species. PLoS ONE 13(7): e0199149
Alexander, J. S., Gopalaswamy, A. M., Shi, K., Hughes, J., Riordan, P. 2016. Patterns of Snow Leopard Site use in an Increasingly Human-Dominated Landscape. PLoS ONE 11(5): e0155309
Aryal, A., Shrestha, U. B., Ji, W., Ale, S. B. Shrestha, S., Ingty, T., Maraseni, T., Cockfield, G., Raubenheimer, D. 2016. Predicting the distributions of predator (snow leopard) and prey (blue sheep) under climate change in the Himalaya. Ecology and Evolution 6: 4065- 4075
Big Cats (2018). Episode 2 [television program]. BBC one, 18 January.
https://www.bbc.co.uk/programmes/b09p26p3 (2019-04-24)
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Borling, J., Fleischmann, J. 2014. Snöleoparden. Votum & Gullers, Karlstad, Sweden.
Forrest, J. L., Wikramanayake, E., Shrestha, R., Areendran, G., Gyeltshen, K., Maheshwari, A., Mazumdar, S., Naidoo, R., Thapa, G. J., Thapa, K. 2012. Conservation and climate change: Assessing the vulnerability of snow leopard habitat to treeline shift in the Himalaya. Biological Conservation 150: 129-135
Gaston, K. J., Spicer, J. I. 2004. Biodiversity: An introduction. 2 ed. Blackwell Science Ltd, Oxford, UK.
Gaire, N. P., Bhuju, D. R., Koirala, M., Borgaonkar, H. P. 2014. Treeline dynamics with climate change at the central Nepal Himalaya. Climate of the Past 10: 1277-1290
Hanson, J. H., Schutgens, M., Lama, R. P., Aryal, A., Dhakal, M. 2018. Local attitudes to the proposed translocation of blue sheep Pseudois nayaur to Sagarmatha National Park, Nepal. Oryx 11: 1-7
International Union for Conservation of Nature (IUCN). 2012. IUCN Red List Categories and Criteria: Version 3.1. Second edition. Gland, Switzerland and Cambridge, UK: IUCN. iv + 32pp.
International Union for Conservation of Nature (IUCN). 2019. Reasons of Changing Category. https://www.iucnredlist.org/assessment/reasons-changing-category (2019-05- 10)
Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). 2019. IPBES Global Assessment Summary for Policymakers (PDF).
https://www.ipbes.net/news/ipbes-global-assessment-summary-policymakers.pdf (2019- 05-07)
Jamtsho, Y., Katel, O. 2019. Livestock depredation by snow leopard and Tibetan wolf:
Implications for herders’ livelihoods in Wangchuck Centennial National Park, Bhutan.
Pastoralism 9:1
Johansson, Ö., Rauset, G. R., Samelius, G., McCarthy, T., Andrén, H., Tumursukh, L., Mishra, C. 2016. Land sharing is essential for snow leopard conservation. Biological Conservation 203: 1-7
Khan, U., Ferretti, F., Lovari. S., Shah, S. A. 2018. Predator, prey and humans in a
mountainous area: loss of biological diversity leads to trouble. Biological Conservation 27: 2795-2813
Khanal, G., Poudyal, L. P., Devkota, B.P., Ranabhat, R., Wegge. P. 2018. Status and conservation of snow leopard Panthera uncia in Api Nampa Conservation Area, Nepal.
2018 Oryx 08: 1-8
Lamichhane, B. R., Persoon, G. A., Leirs, H., Reynaert, S., Sluydts, V., de Longh, H. H., Subedi, N., Pokheral, C. P., Dhakal, M., Oli, B. N., Poudyal, L. P., Malla, S. 2019. Factors associated with co-occurrence of large carnivores in human-dominated landscape.
Biodiversity and Conservation 28: 1473-1491
Lennox, R., Gallagher, A. J., Cooke, S. J., Ritchie, E. G. 2018. Evaluating the efficacy of predator removal in a conflict-prone world. Biological Conservation 224: 277-289 Li, J., Yin, H., Wang, D., Jiagong, Z., Lu, Z. 2013. Human-snow leopard conflicts in the
Sanjiangyuan Region of the Tibetan Plateau. Biological Conservation 166: 118-123 Li, J., McCarthy, T. M., Wang, H., Weckworth, B. V., Schaller, G. B., Mishra, C., Lu, Z.,
Beissinger, S. R. 2016. Climate refugia of snow leopards in High Asia. Biological Conservation 203: 188-196
Lovari, S., Ventimiglia, M., Minder, I. 2013. Food habits of two leopard species, competition, climate change and upper treeline: a way to the decrease of an endangered species?
Ethology Ecology & Evolution 25: 305–318
McCarthy, T., Mallon, D., Jackson, R., Zahler, P. & McCarthy, K. 2017. Panthera uncia. The IUCN Red List of Threatened Species 2017: e.T22732A50664030.
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Murdoch, J. D., Reading, R. P., Amgalanbaatar, S., Wingard, G., Lkhagvasuren, B. 2017.
Ecological interactions shape the distribution of cultural ecosystem service: Argali sheep (Ovis ammon) in the Gobi-Steppe of Mongolia. Biological Conservation 209: 315-322 Riordan, P., Cushman, S. A., Mallon, D., Shi, K., Hughes, J. 2016. Predicting global
population connectivity and targeting conservation action for snow leopard across its range. Ecography 39: 419-426
Sharma, R. K., Bhatnagar, Y. V., Mishra, C. 2015. Does livestock benefit or harm snow leopards? Biological Conservation 190: 8-13
Snow Leopard Trust. 2017. Statement on IUCN Red List Status Change of the Snow Leopard.
https://www.snowleopard.org/statement-iucn-red-list-status-change-snow-leopard/ (2019- 04-24)
Snow Leopard Trust. 2019. Key Snow Leopard Facts. https://www.snowleopard.org/snow- leopard-facts/ (2019-04-24)
Snow Leopard Trust. 2019. The threats. https://www.snowleopard.org/the-threats/ (2019-04- 24)
Tannerfeldt, M., Elmhagen, B., Angerbjörn, A. 2002. Exclusion by interference competition?
The relationship between red and arctic foxes. Oceologia 132: 213-220
Tilman, D., Clark, M., Williams, D. R., Kimmel, K., Polasky, S., Packer, C. 2017. Future threats to biodiversity and pathways to their prevention. Nature 546: 73-81
Tiwari, A., Jha, P. K. 2018. An overview of treeline response to environmental changes in Nepal Himalaya. Tropical Ecology 59: 273-285
The Economics of Ecosystems and Biodiversity: Ecological and Economic Foundations.
2012. Edited by Pushpam Kumar. Routledge, Abingdon and New York.
Watts, S. M., McCarthy, T. M., Namgail, T. 2019. Modelling potential habitat for snow leopards (Panthera uncia) in Ladakh, India. PLoS ONE 14(1): e0211509
World Energy Council. 2016. Energy resources > East Asia > Coal.
https://www.worldenergy.org/data/resources/region/east-asia/coal/ (2019-05-12) World Energy Council. 2016. Energy resources > South & East Asia > Coal.
https://www.worldenergy.org/data/resources/region/south-central-asia/coal/ (2019-05-12) World Wildlife Fund (WWF). 2019. Snow Leopard.
https://www.worldwildlife.org/species/snow-leopard (2019-04-24)
19 SAMMANFATTNING
Klimatförändringar, en riskfaktor för snöleopardens fortlevnad Introduktion
Den 6:e maj 2019 släppte IPBES en ny rapport om biologisk mångfald och
ekosystemtjänster. De uppskattade att en miljon arter kan vara utrotningshotade på grund av mänskliga aktiviteter, och snöleoparden kan vara en av dem.
Snöleoparden är ett av världens största kattdjur och är endemisk för de södra och centrala bergen i Asien. Med deras tjocka päls och breda tassar är de väl anpassade för det kalla klimatet. De asiatiska bergen skapar ett massivt habitat på 2,8 miljoner km2 i 12 länder för mellan 7446 till 7996 snöleoparder. Det förekommer att snöleoparder jagar boskap vilket har lett till att herdar skjuter kattdjuret för att inte förlora mer boskap. En annan anledning till jakt är snöleopardens dyrbara päls. Under senare år har hot mot snöleoparden utgjorts av bl.a.
gruvdrift, tjuvjakt, jakt på bytesdjur och klimatförändringar. Gruvverksamheten består mestadels av kolutvinning, där Kina och Indien är de länder med mest utvinning.
Hotade arter på IUCN:s rödlista har blivit utvärderade med IUCN Red List Categories and Criteria (IUCN:s rödlista Kategorier och Kriterier). IUCN fokuserar mestadels på dåtida och nutida förändringar men inte lika mycket på framtida förändringar. Klimatförändringar är ett framtida hot som accelererar och måste därför tas med i utvärderingen av hotade arter. Det är känt att snöleoparden påverkas av klimatförändringar men däremot inte i vilken utsträckning.
IUCN kan ändra hotstatus ifall det finns ny information som kan stärka en förflyttning mellan kategorierna. Snöleoparden blev nedflyttad från Starkt hotad (EN) till Sårbar (VU) eftersom populationen är större än 2 500 individer men mindre än 10 000, och har en uppskattad minskning på 10 % under tre kommande generationer.
Jag kommer i denna rapport att, med tillgänglig och relevant forskning, undersöka om klimatförändringar kan var ett långsiktigt hot mot snöleoparden, även om hotstatusen skulle ändras ifall klimatförändringar skulle inkluderas i IUCN:s bedömning. Syftet med detta examensarbete är att analysera snöleopardens hotnivå med tillgänglig information om arten och klimatförändringar. Fyra frågeställningar har använts:
- Vilka är de nuvarande hoten mot snöleoparden?
- Vilka hot kan stärkas eller skapas mot snöleoparden till följd av klimatförändringar?
- Vilka kriterier undersöker IUCN för att klassa en art som hotad?
- Vad innebär IUCN:s beslut om att minska snöleopardens hotnivå?
Detta examensarbete är en litteraturstudie och informationen kommer från trovärdiga artiklar och källor. Artiklarna har samlats från söktjänsten på Uppsala universitets bibliotek och från organisationer som Snow Leopard Trust och WWF.
Bakgrund
För att förstå snöleopardens roll i ekosystemet är det viktigt att först förstå biodiversitet i bergen. Ekosystem i bergen består av få arter vilket gör dem sårbara om en art försvinner.
Artrikedomen minskar generellt i högre höjder. Temperaturen sjunker också i högre höjder, och tillsammans med minskad fuktighet begränsas växandet av träd, vilket skapar en så kallad trädgräns. Berg skapar begränsade områden med låg rörelse mellan habitat, vilket leder till att arter anpassar sig till en viss höjdnivå.
Biodiversitet mäts på olika sätt och ger flera resurser som t.ex. mat. I dagens matproduktion används dock en väldigt liten del av den biodiversiteten, då tolv plantor förser världen med 75 % av allt matintag. Boskapsskötsel och odlingsmark tar upp en tredjedel av världens
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landyta. Andra värden biodiversitet ger oss är de ‘icke-användbara’ värdena i form av bevarandet av naturen för framtida generationer och det existentiella värdet av en arts överlevnad. ‘Karismatiska arter’ är ett uttryck för att beskriva en arts utseende som har högt värde för människan och ökar bevarandearbetet, som t.ex. tigern.
Biodiversitet hotas av människan och utdöenderisken för många arter accelererar. IPBES har listat de fem största hoten: (1) förändringar i mark- och havsanvändning; (2) direkt
exploatering av organismer; (3) klimatförändringar; (4) föroreningar; och (5) invasiva, främmande arter. En miljon arter riskerar att dö ut till följd av mänskliga aktiviteter.
Antropogena aktiviteter bidrar till höga utsläpp av växthusgaser, och dagens uppmätta utsläpp är en fördubbling från år 1980. Temperaturen har redan ökat med 0,74 ℃ ± 0,2 ℃ de senaste 100 åren och tros öka mellan 1,4 - 5.8 ℃ till år 2100. Flera studier visar på ett samband mellan klimat och höjden på trädgränsen, vilket därför blivit en indikator för
klimatförändringar. När trädgränsen flyttar uppåt minskas habitatet, vilket kan leda till en
‘bergstopps-utrotning’. Om en art skulle dö ut kan fler arter som är beroende av den också försvinna, vilket kan leda till en ‘utrotnings-kaskad’.
IUCN beskriver en arts hotnivå med kategorierna: Utdöd (EX), Utdöd i vilt tillstånd (EW), Akut hotad (CR), Starkt hotad (EN), Sårbar (VU), Nära hotad (NT), Livskraftig (LC), Kunskapsbrist (DD) och Ej bedömd (NE). Kategorierna används för att det ska vara lätt att förstå olika arters hotstatus. En art kan sänkas från sin nuvarande hotstatus om den inte uppfyller kraven under en 5-årsperiod. Dock kan den höjas omgående om arten är mer hotad än tidigare ansetts. Hotstatusen för snöleopard sänktes till VU för att det finns ny information om artens populationsstorlek som inte uppfyller kraven för CR.
Hot mot snöleoparden
Snöleoparden är en toppkonsument och upprätthåller en balans i de alpina ekosystemen. De håller nere bestånden av vilda hovdjur, som då inte kan intensivt beta de alpina stäpperna.
Detta kallas för top-down kontroll. Blåfår är en av snöleopardens främsta bytesdjur och är viktig för snöleopardens överlevnad. Under senare år har bytesdjurens populationer reducerats, vilket innebär ett hot mot det stora kattdjuret. Minskningen av bytesdjur beror bland annat på jakt och konkurrens om betesmarker med boskap. Vid brist på bytesdjur förekommer boskap i snöleopardens diet, upp till 70 % har uppskattats. Mellan 220 till 450 snöleoparder dödas årligen av herdar och av tjuvjakt. Fällor som är utsatta för andra rovdjur har även bidragit till dödandet av snöleopard.
Studier tyder på att de skyddade områdena i nuläget är för små för att skydda snöleoparden.
Hanar har dubbelt så stor utbredning än honor och kräver mer yta. Det har uppskattats att en hanes utbredning kunde upprätthållas av 60 % i de 170 studerade skyddsområden. Det anses att uteslutandet av människor från snöleopardens habitat såsom skyddsområden kan inte rädda arten. Samexistens anses därför vara det viktigaste för att skydda snöleoparden.
Anslutningar mellan habitat består av stenformationer och naturliga korridorer, och är viktiga att bibehålla för utbyte av gener mellan snöleoparderna. Tre potentiellt viktiga
anslutningsleder har undersökts, en stor och två mindre. Den stora leden sträcker sig från Pamirbergen i Tadjikistan i väster, längs Himalaya till Qionglai Shan i centrala Kina, och ansluter den västra populationen med den östra. De två mindre lederna ansluter den norra populationen, Altai i nordväst och Gobiöknen i nordöst, till den södra populationen. Det har visat låg rörelse mellan dessa populationer, något som tyder på en isolering. Om anslutningen mellan populationerna försvinner kan en fortsatt isolering ske och även inavel kan uppstå.
Mänskliga aktiviteter såsom intensivt bete, gruvdrift samt byggandet av vägar och dammar har ökat i bergen i Asien på grund av ekonomisk tillväxt. Ökade aktiviteter tillsammans med
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klimatförändringar har skapat fragmenterade habitat och reducerar anslutningslederna. Dessa aktiviteter har blivit hot mot snöleopardens överlevnad.
Snöleoparder måste anpassa sig till varmare klimat men tiden de har på sig har minskat från tusentals år till bara några decennier. I en studie visades det att temperatur har störst påverkan på snöleopardens habitat med 86 %. Resultatet tyder på att temperatur är den största faktorn för artens utbredning.
Klimatförändringar förflyttar trädgränsen uppåt som pressar snöleoparden mellan högre höjder och skogsområden. Mellan 30 - 65 % av det nuvarande utbredningsområdet kan försvinna på grund av högre trädgräns och varmare områden. Bara 35 % av
utbredningsområdet ansågs stå emot klimatförändringar, så kallade klimattillflykter.
Snöleoparden skulle inte klara av att leva på en höjd över 5500 m på grund av den begränsade tillgången på syre, vilket tvingar arten att röra sig nedåt.
Konkurrens kan uppstå mellan snöleopard och leopard, som rör sig mot högre altitud.
Leoparder är mer anpassade för skog och har bredare diet, vilket gör arten till en överlägsen konkurrent mot snöleoparden.
Föreslagna lösningar för att minska konflikten mellan herdar och snöleopard är att
kompensera herdar för deras förluster. Träna de lokala veterinärerna har också föreslagits. I en studie stod snöleoparden för 10 % av boskapsförlusten, medan botbara sjukdomar stod för 42 %. Anslutningslederna mellan habitat och klimatskydden anses ha störst bevarandevärde för att skydda populationen av snöleopard. Samarbete mellan de 12 berörda länderna anses också behövas för att skydda snöleoparden.
De nära-framtida och nuvarande hoten har summerats i direkta och indirekta hot. De största hoten, som även är de direkta, är hämndlystet dödande av herdar, tjuvjakt för päls och jakt på bytesdjur. Nästan alla indirekta hot, både från antropogena aktiviteter och klimatförändringar, fragmenterar snöleopardens habitat. Temperatur kan anses bli ett framtida hot eftersom den påverkas av den globala uppvärmningen. Konkurrens med leopard kan också bli ett framtida hot. Klimatförändringar är inget hot i sig, utan skapar hot och kan accelerera de nuvarande hoten.
Diskussion
De nuvarande hoten mot snöleoparden är de med direkt påverkan på populationen. Dock kan de indirekta hoten bli till direkta hot i framtiden på grund av ökade klimatförändringar som leder till fragmentering av livsviktiga habitat. IUCN analyserar en arts uppskattade
populationsstorlek samt dess minskning. Snöleopardens hotstatus ändrades för att en ny uppskattning på populationen hade gjorts. Dock har inte klimatförändringen tagits med i bedömningen, som kan ha en större påverkan på minskandet av populationen än vad IUCN har uppskattat.
Om snöleopardens värderades högre hade arten kunnat anses vara en karismatisk art. Det stora kattdjuret hade kunnat bli en symbol för bevarandet av Asiens alpina områden och för hur klimatförändringar påverkar arterna som lever där. Bevarandearbetet av snöleoparden ökar även det existentiella värdet av att arten finns kvar och stödjer det alpina ekosystemet.
Förlusten av en toppkonsument kan få hela ekosystemet att kollapsa. Många människor är beroende av samma alpina områden som snöleoparden lever i och därför är det viktigt att bevara arten. Om snöleoparden och leoparden inte kan samexistera kan leoparden kraftigt reducera populationen av snöleoparden, och i värsta fall försvinna. Om snöleoparden skulle försvinna kan ekosystemet kollapsa och leda till en ‘utrotnings-kaskad’. Bevarandet av snöleopard kan därför motverka en sådan kaskad.
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Det inflytande som IUCN har är viktigt när det diskuteras om klimatförändringen ska betraktas som ett ytterligare hot eller ej. Efter den senaste rapporten från IPBES har effekterna från klimatförändringar blivit tydliga. Klimatförändringar kan även förväntas interagera med andra befintliga hot. Bevarandeprogram reducerar hotet från herdar men med hoten från andra mänskliga aktiviteter och klimatförändringar kommer det inte att räcka för snöleopardens överlevnad. En sak är säker: klimatförändringar måste tas med i IUCN:s bedömning på något vis, om det är i de nuvarande kriterierna, ett till kriterium eller ytterligare en hotkategori.
