The falling out man and the wild - a review of influential factors, causes, impacts, and strategies for minimizing human-wildlife conflict

Human-Wildlife Conflict (HWC) is negatively acting on both humans and wildlife equally alike as it affects the co-existence of natural resources leading to loss, fragmentation, and degradations of wildlife habitats. Apart from this, direct and indirect effects result on both humans and wildlife; loss of lives is the major direct impact affecting both counterparts. This paper is reviewing the reasons for arising of HWC, causes of HWC, major impacts on HWC, and different preventive and mitigatory measures practiced in different parts of the world.


INTRODUCTION
With the evolution of human beings on earth, positive or negative interactions with wildlife have risen as humans acquired wild habitats and resources. In fact, human-wildlife problem date back to the prehistoric time (Zedrosser et al. 2011). Archaeological evidence revealed a fossilized skull of Taung Child (Australopithecus africanus) with a bite mark of a predatory bird -Crown hawk-eagle (Berger and McGraw 2007;Lee-Thorp et al. 2000;Berger and Clarke 1995;Dart 1925;Berger 1987). It is considered as the first recorded case of Human-wildlife conflict (HWC) during the prehistoric period before 5 million years ago, the last ages of the Miocene Epoch. Through the fossil records of the Woolly Mammoth and Woolly Rhinoceros, it has also been proven that HWC has led to the extinction of those animals within the late Pleistocene of the Glacial period (110,000 -11,650 years ago) (Surovell et al. 2016). As explained by Guthrie (2005) and Somadewa et al. (2019), cave and rock paintings in different parts of the world are the other historical evidence that re-

THE FALLING OUT MAN AND THE WILD -A REVIEW OF INFLUENTIAL FACTORS, CAUSES, IMPACTS, AND STRATEGIES FOR MINIMIZING HUMAN-WILDLIFE CONFLICT
veals the close association of humans and wildlife. Gordon (2009) states, these types of evidence have been recorded from the soil context of 10,000 years ago in the Neolithic period due to crop and livestock depredations.
The conservationists describe the HWC as interactions between wild animals and people (Monney et al. 2010). Messmer (2009) described HWC as a negative interaction between humans and wildlife. Adams and Hutton (2007) defined by as any interaction between humans and wildlife which leads to negative impacts on the social, economic or cultural life of the human. Walpole et al. (2003), Baruch-Mordo et al. (2011), Davison et al. (2001), Hoffman and O'Riaia (2012), Dickman (2010), and Okello (2005) have stated that present HWC is occurring in several parts of the world among several different animal taxa and human beings. This happens due to the sympatric nature and co-existence of both humans and wildlife in the same geographic area, using the same resources (Hockings and Humle 2009;Pisa and Katsande 2021;IUCN 2005). Thus, HWC occurs when the needs and behavior of wildlife  Packer et al. (2005a) has stated that HWC leads to the occurrence of several consequences such as damage and destruction to crops, livestock predation, increased risk of livestock diseases, competition for grazing and water, and even direct threats to human life. Three main outcomes of HWC can be identified in nature; extinction of numerous species; changes in ecosystem structure and function; and immense loss of human lives, crops, livestock, and property (Waters et al. 2016;Woodroffe et al. 2005;Estes et al. 2011;Conover 2002).
Large-scale environmental changes, increment of human activities in wildlife habitats, and expansion of few wildlife populations have resulted in increasing intensity of HWC (Treves 2008). Apart from those, different authorities previously believed that HWC can be attributed to factors such as close proximity to forests, rural or agricultural problems (Messmer 2000). Despite, in the recent past, different authorities have observed that ever-escalating human population and associated development activities have increased HWC in urban and suburban areas (Soulsbury and White 2015).
There should be a variety in the mitigatory methods introduced to prevent or minimize HWC to aid the protection of both humans and wildlife. The establishment of mitigatory methods requires baseline information, knowledge, and active involvement of ecologists, wildlife biologists, wildlife managers, and other major stakeholders across the globe who will assist protected area management and sustainable livelihood (Messmer 2000;Bowen-Jones 2012;Dickman, 2010). Neglected HWC give rise to deprived conservation in the conflict area (Hill et al. 2002) and result in the death of wild species (Mateo-Tomas et al. 2016). Ultimately this will lead to threatening the wild fauna and some species reaching the brink of extinction. According to Woodroff et al. (2005) and Michalski et al. (2006), wildlife declining in an area causes a high degree of conflict between humans and wildlife. Therefore, unmitigated conflict areas will threaten both humans and wildlife by changing their livelihood (Sahoo and Mohnot 2004;Gillingham and Lee 2003;Rao et al. 2002). Brara (2013) and Schön (2013) state that these will lead to economic loss due to the damaged crops and livestock. Lamarque et al. (2009) further state that, it will directly affect the financial loss of a country that can be observed greatly among developing countries (Anthony and Wasambo 2009).
HWC has shown a high prevalence in areas where there is a high degree of interaction between humans and wildlife (Pack et al. 2013).
Such conflicts occur at a lower percentage in developed regions compared to developing regions due to less competition for resources (Engemen and Sterner 2002). Developing regions (South and Southeast Asia) show a high degree of HWC due to their rich biological diversity and escalating human population (Madhusudan and Karanth 2002;Birch and Grahn 2007;Seoraj-Pillai and Pillay 2016). In such regions, people depend highly on forest ecosystems because of poverty and due to the conversion of forests into agricultural lands (Chao 2012; Sodhi et al. 2010;The World Bank 2015). Sodhi et al. (2010) indicated that nearly 14.5 million hectares of forest resources were converted to cash crop plantations from 2000 to 2010 leading to an increment in HWC.
HWC scenario in Sri Lanka may also be considered the same as the conflict situation in South and Southeast Asia. Numerous incidents regarding HWC have been reported from different parts of the country. Out of these conflicts, the most prominent is the conflict between humans and elephants. According to Prakash et al. (2020), the intensity of the HWC has been increased over the past few decades. Considering the human population density among the Asian countries, Fernando and Pastorini (2011) revealed that Sri Lanka is in third place. In fact, HWC in Sri Lanka is very high due to the huge densities of both humans and elephants. This has become a major conservation, socio-economic and political issue (Prakash et al. 2020).

Causative Wildlife for HWC
Human-wildlife conflict is a rising concern and the animals that cause this conflict have been identified from several modes of research conducted around the world (Greeshma et al. 2016). The vertebrates who contribute to HWC include the animals that belong to Class Mammalia, Reptilia, and Aves. Orders Primates, Rodentia, Artiodactyla, Perissodactyla, Proboscidea, Carnivora, Chiroptera, and Lagomorpha are the major groups of mammals that are involved in the conflict. Anand and Radhakrishna (2017) summarized that a total of 88 wild species belonging to 9 taxonomic groups are involved in HWC. Among the above-mentioned Orders, the animal species of Carnivora, Artiodactyla, Proboscidea, and Rodentia are the most common contributors to this conflict. To find the solutions to such conflicts, it is very much important to study ecology, behavioural patterns, habitat, and their interactions with the environment. These animals can be further described as carnivores (adapted to eat animal flesh) and herbivores (adapted to eat plant matter) for ease of study, according to their feeding habits. Omnivores are kept under carnivore and herbivore categories based on their major feeding habit. A brief introduction to the causative wildlife of HWC is given below.  (Sinha et al. 2011). The crocodile is a large amphibious, carnivorous reptile that belongs to the Class Reptilia. They inhabit rivers, swamps, and lakes. Predatory attacks by Mugger crocodile and Saltwater crocodile on humans, domestic animals, and livestock lead to creating conflict between them and humans. Adverse effects of conflict between these animals and humans include livestock depredation, human injuries, and casualties (Bajimaya, 2012). Ursids and human conflict is a major concern. Brown bear is the most common mammal that belongs to the family Ursidae. Their large body size, diet pattern, and distribution lead to creating conflicts with humans (Can O' et al. 2014).

Herbivorous animals
Ungulates are a group that consists of large mammals. Almost all ungulates are herbivores that feed on different plant species. They can be distinguished from other mammals by their hooves. These ungulates can be further divided into two Orders: Artiodactyla and Perissodactyla. Order Artiodactyla is commonly known as even-toed ungulates. More than 220 extant species can be found within this Order. Among them, the following species contribute to this HWC. Spotted deer, swamp deer, Al-pine musk deer, sambar, wild buffalo, Indian wild pig, hippopotamus (Anand and Radhakrishna 2017). Order Perissodactyla is commonly known as odd-toed ungulates represented by about 17 extant species which are distributed through Africa, America, and Asia. Among these odd-toed ungulates, rhinos which inhabit grasslands, savannas, and wetlands are the animals that collide with people (Anand and Radhakrishna, 2017). The conflict with these animals is somewhat serious, as they mainly damage crops and attack humans (Eguchi et al. 2002). Similarly, Order Proboscidea (Elephants) is another conflict causing Order which causes severe damages in different ways. Due to their large bodies, poor food digestion and absorption, high food requirement, wide distribution, they are in constant conflict with humans (Lindstedt et al. 1996). Elephants are responsible for 87.1% of all reported crop-raiding incidents (DNPWC, 2017). According to Madhusudan (2003), the production loss due to crop raiding is about 14% of the annual production.

Factors influencing HWC
There is no individual factor that contributes to conflict between man and nature across the continents (Naughton Treves and Treves, 2005

Human population growth and land transformation
The rapid increase in human and some wild animal populations increases basic needs (Madden 2008; Kumara et al. 2012, Newmark et al. 1993. This is the key factor of direct and indirect transactions between humans and wildlife (Edward and Frank 2012). As a result of this increase in human population, the human settlements are spread into the protected areas due to the limited space available, geographically (IUCN World Park Congress 2003). According to statistics, the human population will grow more than 50% by 2050. That is from 6 billion in 2000 to over 9 billion by 2050 (Taylor -Zubiri and Switzer 2001). This increment can create a competition between humans and wildlife for limited resources such as food, water, and land on earth (Sillero-Zubiri and Switzer 2001). Hence this competition leads to an increase in HWC, when people enjoy limited resources, they tend to migrate into areas with rich resources like forests (Lamarque et al. 2009;Joseline 2010;Western 1995). This factor is directly associated with increased basic human needs. Hence, forests, Savannas, and other ecosystems are being used for agriculture and other construction purposes. This leads to a huge decrease in the natural habitats of wildlife (Silleru-Zubiri and Switzer 2001;Lamarque et al. 2009;Eyebe et al. 2012). An increase in population means an increase in cultivated lands (Lamprey and Reid 2004;Mukeka et al. 2018). This directly contributes to the rise in HWC. Developed countries have access to many resources to meet the needs of people which reduces the competition for resource pursuits thus reducing HWC (Engemen and Sterner 2002;Tzilkowski et al. 2002). But the HWC is more prevalent in developing parts of the world like South and South-East Asia than in developed countries (Madhusudan and Karanth 2002). High biodiversity and human attitudes towards nature are the factors influencing this. HWC incidents are common in Kenya where more than 65% of its wildlife is found in private lands outside the protected areas (Western et al. 2009). According to the statistics based on South East Asia, 14.5 million hectares of forest cover has been lost due to crop plantation (Sodhi et al. 2010). For instance, in Gujarat State in India, on the edge of Gir National Sanctuary, the alteration of land which cultivated millet and groundnut into the mango and sugarcane plantation have been led to increase conflict with leopards (Panthera pardus) and lions (Panthera leo persica) (Vijayan and Pati 2002). In case of unavailability of the essential components in natural habitats, wild animals are caused to move out causing several types of conflict (Lamarque et al. 2009).

Habitat loss, fragmentation and degradation
Human population growth and land transformation have together led to habitat degradation, fragmentation and habitat loss (Mekonen 2020; Kangwana 1993;Okello et al. 2003). Humans severely disrupt natural habitats by cutting trees for timber and charcoal, digging the land, making fires, arranging lands for chena cultivations, etc (Mekonen 2020). Due to the gradual loss of habitats due to anthropological impact, wildlife populations become fragmented and eventually leaving smaller habitat pockets for them to survive. For instance, that minimizes the nesting areas, mating sites, and feeding lands. This creates more chances to maintain contact with each animal, which ultimately leads to a rise in HWC (Edward and Frank 2012; Lamarque et al. 2009;Mekonen 2020;Sillero-Zubiri and Switzer 2001;Kumar et al. 2012). In most parts of the world due to deforestation habitat loss of primates can be identified which resulting human-primate conflict. Thus the conservation is a major concern when pacifying HWC (Ogra and Badola 2008;Hill 2005;Hill and Wallace 2012). Wildlife corridors that allowed wild animals to cross through forests have been blocked for human needs such as road development, railways, and border fences. Obstruction of habitat corridors can disturb the function of meta-populations (Krebs 2009). Habitat loss can create problems with food security. Thus, human activities over the past decades have contributed to an increase in HWC (Graham et al. 2005). Another good case study is from Sumatra where altered forest areas for agricultural activities and grazing have restricted the Sumatra tigers (Panthera tigrissumatrae) into few forest patches (Nyhus and Tilson 2004b). These habitat degradations and modifications lead to ecological dislocation of wildlife (Sethy and Mardaraj 2015). Kangwana (1993), Conover (2002, and Okello et al. (2003) identified that increasing human population has resulted in encroachment into more marginal lands inhabited by wildlife and leads to habitat loss, fragmentation, and degradation of them due to the conversion of lands to agricultural fields and other activities harming wildlife.

Impact of conservation management
Interestingly, there are occasions where conflicts have arisen due to the introduction of conservation and management programs to augment declining and threatened wildlife populations. Such programmes aimed to recover and restore declining, threatened or nearly extinct species from over-exploitation have become problematic due to geometric growth of population size, in-situ conservation and their impact on available resources (Fall and Jackson 2002;Messmer, 2000). A classic example is the last free-ranging population of Asian lions (Panthera leo persica) which faced a population bottle-neck due to hunting and habitat loss in Gir National Park in the Indian state of Gujarat during the onset of the ertheless, the Asian lion population size in Gir NP doubled between 1970 and 1993 upon implementation of stringent conservation measures that reduced human-caused mortality by appropriate habitat management and effective conservation measures (Vijayan and Pati 2002). Consequently, lions began to roam the surrounding villages of Gir forests in search of prey and caused conflicts with humans (Vijayan and Pati 2002).

Impact of tourism and ecotourism initiatives
The trend towards ecotourism and natural resource-based tourism increases the number of local people and tourists visiting protected areas causing HWC worse in certain regions (Shannon et al. 2017). Number of studies have showed that tourism and ecotourism initiatives can have some negative effects in different ways. Among them habitat destruction, physiological and behavioural changes in animals are some severe impacts on wildlife (Karis et al. 2013). Habitat destruction due to various recreational activities such as safaris, camping, fishing, diving is the main effect here. Apart from that deforestation, use of land for hotel constructions also affect the wildlife in direct and indirect manner. In addition, taking close photographs of wild animals, which can be frightening to animals. In 2016, a tourist was attacked by an elephant, used to roam around Minneriya park boundaries when trying to capture a photograph (Prakash and Kumarathunga 2016). Studies have shown that this affects the animals who spent some specific stages of their life cycle, as well as their mating patterns. Feeding wildlife is another conflict causing incident (Shannon et al. 2017). This causes changes in the diet and behaviour of the wildlife. Similarly this leads to arise conflicts in between humans and wildlife. As Prakash and Kumarathunga (2016), one tourist has been attacked by Rambo, a free ranging elephant in 2014 at Udawalawa park boundary Sri Lanka. This elephant is used to roam around the electric fence near the Udawalawa park boundary, Thanamalwila road Sri Lanka. According to their case study, Prakash and Kumarathunga (2016) further explained that this lady tourist has tried to follow and fed the Rambo which led to being attacked. The increasement of HWC has a severe impact not only on human life but also on animal life. Hunting, fishing, vehicle collisions, recreational boat rides have been reported as causes for loss of wild species (Fennell 2015;Pienaar 1968;Cannell et al. 2016). There are reports of two casualties among visitors involving hippo due to unawareness and ignorance about wildlife (Durrheim and Leggat 1999). They further stated that injuries and deaths from elephants, tigers, lions, crocodiles, and other wildlife are reported every year in different parts of Africa and Asia. In 2004, an American tourist was killed in a crocodile attack in a canoe, Mana Pools National Park in Zimbabwe (United States Department of State 2007). According to Durrheim and Leggat (1999), seven tourists have been killed by wild mammals during 1988 to 1997 period in South Africa. Two of the dead were students from Thailand and the other one was a German traveller. Similarly 14 nonfatal incidents have been reported including hippo(05); buffalo(03); rhino(02); lion(01); leopard(01), zebra(01); musth elephant(01) during the 1988 to 1997.

Climate change and extreme environmental factors
Climate change and extreme environmental factors can aggravate HWC, even though it is the least concerned. Heavy rainfall, droughts, landslides, and bushfires are some of the threats to wildlife assemblages. Wild animals approaching human settlements are common under such drastic changes (Amaja et al. 2016). Observations related to research conducted in Kenya show that there is a direct relationship between seasonal patterns in rainfall and the frequency of occurrence of predators (Patterson et al. 2004). Environmental degradation has made climatic and weather changes difficult to predict, thus causing a remarkable impact on HWC. Not only the man-made activities but also some extreme environmental factors such as high temperature and hot waves of winds can cause forest fires resulting in increased HWC (Sethy and Mardaraj 2015). Drought and fires caused by an El Nino due to Southern Oscillation in 1997-1998 destroyed large parts of Sumatran forests harbouring rich biodiversity (Nyhus and Tilson 2004a). HWC is further increasing indirectly due to air pollution that causes acid rains and destruction of forest cover (McLaughlin et al. 1983). People who inhabit wildlife areas always exploit natural water bodies for various purposes which leads to scarcity of water to wildlife, thus augmenting HWC (Fujie and Ying 2000; Odaka and Peterson 2000).

Influence of livestock development
About 30% of the ice-free arable land area on earth is used for livestock. This is the fastestgrowing subfield in agriculture in many developing countries and tropics as livestock is the livelihood of many rural people (Thornton 2010;Else 1991;Treves et al. 2006;Eniang et al. 2011). The high demand for livestock has created many conflicts including HWC (Sethy and Mardaraj 2015). The rapid growth of the livestock population creates competition for food among wild herbivores due to increased grazing pressure. This leads to overgrazing and a considerable decrease in the wild herbivore population (Mishra et al. 2003;Mekonen 2020). Due to this conflict over food, wild animals such as elephants tend to move into the villages. In the meantime, the increased population of livestock becomes victims of carnivores (Sangay and Vernes 2008). Usually, depredation is high in the dry season. Studies conducted in Narok indicate livestock depredation is much higher even in wet, rainy seasons if migratory ungulates are absent. Studies have shown that carnivores such as lions, leopards move towards the livestock for hunting their prey due to the scarcity of ungulates in the forests (Mekonen 2020).

Changes in social relationships in the rural community
People's power in rural areas has declined and there is no adequate human labour to guard their agricultural fields. Thus, cultivations are easily raided by the wild animals increasing HWC (Lahm 1996). In other words, HWC is affected by changes in social interactions in rural communities. Among those changes, the migration of villagers to the city for employment is a major factor contributing to HWC.
Similarly, with the increase in educational opportunities, children also move away from their traditional lifestyle (Goldman 1996). In addition, due to certain cultural and religious beliefs people allow certain animals to reach into their villages (Dickman et al. 2013;Manfredo and Dayer, 2004). Those animals also can make an impact on the HWC. As an example, the attitude of some Orthodox Hindus in India towards monkeys led to an increase in the conflict (Imam et al. 2002;Anand et al. 2018;Beisner et al. 2015;Saraswat et al. 2015). As described by Butchart et al. (2010), the increasing human pressure on biological diversity leads to a decline in their populations during the last four decades in South East Asia. Overexploitation of biological diversity is resulting in habitat loss including microhabitats of some animal species, especially influence on bird populations (Mallari et al. 2011;Holmes and Sherry 2001). Birdlife International (2014), and McGowan et al. (1999) have categorized Green Peafowl as vulnerable to endangered bird species in South East Asia due to anthropogenic activities. Hoffman et al. (2018) also named peafowl species as a threatened species in South East Asia. However, In Sri Lanka the peafowl population is increasing due to two main reasons; the peacock is not hunted or killed due to religious beliefs (Fitzpatrick 1923;Choskyi 1988;Ali and Ripley 1980), and lack of jackal population in natural habitats. Rodrigo (2020) mentioned that jackals are always co-existing with the human landscapes, which leads to the ultimate kill of jackals by humans due to predation of their livestock or human bites. Rodrigo (2020) further states that jackals are the top predators of herbivores in most of Sri Lankan wild localities, and the decline of their population promotes peafowl populations and finally, now they have become a major pest in our agricultural crops, especially on grain crops.

Zoonosis and disease transmission
Human activities such as the transformation of lands into agricultural lands or industries, human and animal migrations, overgrazing in wild habitats are major driving forces in the transmission of zoonotic diseases from wildlife to domestic animals and vice versa (Phukon 2015). Thereby, livestock brings the above closer to wildlife (Phukon 2015). In this case, the transmission of zoonotic diseases by wildlife to humans or livestock has a major impact on wildlife, livestock, and human health (Karesh and Cook 2005;Woodroffe et al. 2005). The rapid growth of the human population by 4 folds over the last century is the major factor causing the spread and transmission of diseases. Apart from those factors, meat consumption, live animal markets, use of animals in transportation, habitat destruction are other risk factors (Greger 2007). Therefore, it is important to know the causative animals and the spreading method to minimize the conflict. Wild animals can be interpreted as a pool of zoonotic diseases caused by viruses, bacteria, and parasites (Kruse et al. 2004). The total number of zoonotic diseases has not been confirmed. According to Taylor et al. (2001), 62% have been classified as zoonotic from a total of 1415 pathogens. As revealed by Woolhouse and Gowtage-Sequeria (2005), there are about 1407 species of human pathogenic organisms, out of them 816 were classified as zoonotic. This is a significant figure of about 58%. Thus, humans are at a higher risk of getting diseases from wild animals. Out of 177 reported cases, 73% were zoonotic (Greger 2007). Mosquitoes, flies, reptiles, wild passerine birds, vultures, wild rodents, shrews, fruit bats, hares, hedgehogs, deer, deer mouse, monkeys, pigs, and horses are some examples of the animals who spread diseases (Barbour and Fish 1993;Schmaljohn and Hjelle 1997;Dumler and Walker 2001). Based on studies done in Europe, the mode of transmission of these diseases is widespread and multifaceted (Gortazar 2007). Infections can be transmitted directly from wild animals, through direct skin contact (tularemia) with sick or dead hares and rodents, through animal bites (rabies virus), and by rodent aerosols in the dust (Hantaviruses) (Kruse et al. 2004;Peterson et al. 2004). Contaminated water and food are indirect methods of disease (Salmonella spp. and Leptospira spp.) transmission. SARS, Tuberculosis, Rabies, Hepatitis, Anthrax, Hantavirus, Lyme borreliosis, Rift valley fever, Equine encephalitis, Japanese encephalitis, Leishmania, Anaplasma, Ebola, Marburg disease, Nipah virus, Monkey fox are examples of few zoonotic diseases which affect both humans and livestock (Kruse et al. 2004;Peterson et al. 2004;Reed et al. 2004;Chua 2003;Hofshagen et al. 2003). Rabies is one of the major zoonotic viral diseases which attacks the central nervous system and causes paralysis followed by death. Several wild animals have been identified as rabies reservoirs in Sri Lanka. Among them Mongoose (Herpestes sp.), Grizzled giant squirrels (Ratufa macroura), Asian palm civets (Paradoxurus hermaphrodites), Golden palm civets (Paradoxurus zeylonensis), and small Indian civets (Viverricula indica) are more common (Rodrigo, 2020). This has a high impact on livestock and domestic pets (Woodroffe et al. 2005). When considering SARS, according to the WHO, 8,098 cases were reported with 774 fatalities (Kruse et al. 2004). Also, Aftosa (2007) states that transmission of the Foot and Mouth Disease Virus (FMDV) has occurred in cattle and European hedgehogs. Livestock movements tend to increase disease transmission and make it difficult to control (Wright 2001). However, livestock plays an important role in contributing economy. FAO (2006) has mentioned that, as a result of livestock diseases, the global livestock market has shown its lowest growth rate within the last decade. The diseases associated with livestock directly affect the livelihood of many people. This increases the economic instability by spending money to treat diseases. As a result, the conflict between wildlife and humans is constantly intensifying.

Impacts of human-wildlife conflict
The history of HWC runs back to the humans evolved on the earth. Since then, various impacts have occurred to both humans and animals in many directions which can be classified as direct and indirect impacts.

Direct impacts on humans
The conflict between wildlife and humans has widely spread. It affects both groups at different levels. These effects can be categorized in different areas. Direct impacts on humans lead to loss of human lives, damage, and destruction of crops, livestock losses destruction of properties (Conover 2002;Dickman and Hazzah 2016;Gemeda and Meles 2018;Norton-Griffiths 1996;Campbell et al. 2000). Similarly, the loss of lives and their habitats can be taken as a direct influence on wildlife.

Human casualties and injuries
The direct impact of HWC leads to injuries or loss of human life (Nyhus 2016;Nyhus and Tilson 2000;Bandara and Tisdell 2002;Lamichhane et al. 2018). The most harmful effect of HWC is the fear of losing lives due to the large carnivores and mega-herbivores. Human carnivore conflict is currently the most common global crisis in rural areas surrounded by forests as well as semi-urban areas all over the world (Dickman 2008). Wild animal migration and distribution patterns are controlled by the availability of water, food, and mates (Mace and Paul 1983). Wild animals tend to emigrate from the forest due to the lack of the above-mentioned needs and it results in conflict with humans. The fear of carnivores in the human mind can be identified as an impulsive anti-predatory reaction (Kruuk 2002;Quammen 2003;Packer et al. 2005b). According to Kruuk (2002), the damages and attacks which have been occurred by cats, bears, and wolves descended from the past to the present day. Generally, most of the cases are simply presented by the villagers, however, due to insufficient evidence and information, those cases cannot be considered as valid data. Despite, reliable evidence and data show that there are hundreds of people killed annually by wild animals (Kruuk 2002). Most of the cases which are related to human deaths and injuries are due to animals in the cat family-such as lions (Panthera leo) and tigers (Panthera tigris). According to Kruuk (2002), 8 tigers in India, were accused of killing nearly 1000 people. According to Sanyal (1987), nearly 100 human lives have been lost annually in Sundarbans of India and Bangladesh due to the tigers. Deadly attacks are rare in Asia, but 22 people were killed by tiger attacks between 1985 and 2001 in Kanha reserve in Madya Pradesh (Karanth and Gopal 2005). Similarly, Saberwal et al. (1994) showed, between 1978 and 1991, 28 people were killed by lions in the Gir forest in Gujarat State. Nyhus and Tilson (2004b) had documented an interesting case analysis on the human-tiger conflict in Sumatra islands. They focused on the distribution and impact of critically endangered Sumatran tiger (Panthera tigrissumatrae), by using the incidents reported over 20 years. Their study showed that tiger conflict is more common in intermediate disturbance zones. The areas thus identified are isolated human settlements associated with tiger habitats. However, they revealed that this tiger conflict is lower in the high and low disturbance zones compared to the above intermediate zones.
Crocodile-human conflict is much higher when compared with the other carnivores. Number of large crocodiles roaming around the riversides and human settlements. Due to their wide distribution range, the possibility of having conflict with humans is higher. They also can coexist with people without being caught. According to Magane (2003), it shows that although information and evidence are scarce, crocodiles are largely responsible for human deaths. In Mozambique, the majority of human deaths due to crocodiles are not being reported due to the problems in getting people to government offices. Mombaur (2020) summerized that 10-15 crocodile attacks can be recorded annually especially in the Sothern part of Sri Lanka and one third of them are fatal cases. Ironically, FAO (2005) stated that approximately 300 people are killed by crocodiles within all the regions every year.
According to Acharya et al, (2016) and Gubbi (2012), elephants are the leading conflictcausing animals among mega-herbivores. Due to their large bodies, high food requirements, and wide home range, this pachyderm is in constant conflict with humans (Lindstedt et al. 1986;Thouless 1996).
As mentioned in section 2.2, habitat loss, fragmentation, and degradation due to human activities and other natural causes are thus major factors influencing Human elephant conflict (HEC). Elephants invade rural areas, due to food shortages in their natural habitats. WWF 2007 states that over 200 people have been killed by elephant attacks within the last seven years, in Kenya. Similarly, around 10 people were attacked and killed by elephants over the last five years in the Kakum conservation area, Ghana. The largest elephant population in Namibia has been found in the Caprivi region. (O'Connell Rodwell et al. 2000). According to Prakash et al. (2020), a total of 14516 HEC incidents were recorded in Sri Lanka during 2010-2019. Under this, a total of 807 human casualties and 579 human injuries were recorded. Out of these deaths, the majority represent male animals (Prakash et al. 2020). Crop guarding and the presence of males to confront elephants are key factors to male deaths. The home range of male elephants is known to be higher than that of herd dwelling females (Fernando et al. 2011). In addition, Fernando et al. (2011) had illustrated that the roaming of men around the village at night and being on roads after dark also caused these types of conflicts.

Crop destruction
Crop raiding is one of the most common phenomena and it is a process that has been occurring since the beginning of the human farming era (Blair 2008;Datta-Roy et al. 2009;Joseline 2010;Blair et al. 1979;Nath and Sukumar 1998;Newmark et al. 1994;Sekhar 1998;Williams and John Singh 1996). As per Lamarque et al., (2009) and Priston (2009), this is one of the direct effects of HWC, which is common around forests and protected areas. Crop damage by elephants is a global concern, as elephants can destroy a whole cultivation over one night (Treves and Karanth 2003). Elephants enter cultivated lands due to the abundance of nutritious food. Similarly, in drought seasons, water-seeking animals invade villages and destroy the crops. This is most common in dry zones. Even though people are blamed only for the damage-causing elephants, they are not the only animals who damage the crops. Red-tailed monkeys cause severe damage to farmlands. Damage due to these red-tailed monkeys throughout the year is greater than the damage caused by elephants. (Naughton-Treves 1997. Therefore, attention should be paid to big losses as well as small scale massive losses (Treves et al. 2006). There are many other different types of wild animals that cause de-structions, such as huge mammals, birds, smaller animals like rodents (Saj et al. 2001;Rao et al. 2002;Osborn and Parker 2003;Sitati et al. 2003;Gunn 2009). Apart from the above-mentioned animals, barking deer, Eurasian wild boar, Himalayan black bear, Indian crested porcupine, Indian hare (Rufoustailed), Nilgai, one-horned rhinoceros, rhesus monkey, spotted deer are among the animals who create conflict by damaging crops (DNPWC 2017). Thus, crop-raiding leads to reduced crop yield, quality, and post-harvest losses. This situation has a direct impact on the economic status of farmers (Osborn andParker 2003: Marchal andHill 2009). At the same time damages to farmlands is a significant impact on humans (Mayberry et al. 2017). These damages affect the production of staple food grains like rice, wheat, millet, maize, and other food crops such as vegetables, sugar cane, coconut, potatoes, manioc, etc (Sethy and Mardaraj, 2015). According to Parker and Osborn (2001), Malima et al. (2005), Jackson et al. (2008), Gunn (2009) and Malugu (2010) the peak level of this crop raiding is around the harvest season. According to a study report by Gyelmo (2016), at least two people were needed to guard the paddy fields at night in the Punakha district, Bhutan. They had to spend sleepless nights to save the field from wild boars, monkeys, and deer and this scenario are common to many localities where human-elephant conflict prevails in Sri Lanka. This vast damage often results in food shortage for the poverty-laden rural communities, as they used to consume some simple staple food (Osborn and Parker 2003;Marchal andHill 2009). Prakash et al. (2020) documented destruction of the postharvest crop stored at farmer's homes as well as grain huts, would occur due to elephants raiding villages in search of food, however, such happenings are common in the dry zone of Sri Lanka.

Damages to livestock
Another destructive effect is the killing of domestic or livestock animals by wild predators. This livestock depredation by large carnivores is a widespread phenomenon around the world (Sillero-Zubiri and Laurenson 2001; Mekonen 2020). One of the reasons for this is anti-predator behavior shown by domestic animals and overgrazing by livestock. The number of domestic animals that are hunted varies according to the species, the abundance of prey, time of the year, and other factors (Treves and Karanth 2003). Pastoralism or livestock raising in savanna and grasslands is the main source of income for the people who live in such areas. Loss of livestock due to predation has become a threat to people's livelihoods. While this may not seem like much of an impact on a large and national scale, it does put a strain on small-scale livelihoods. The detrimental effects of this are the collapse of the economic status of those people and the emergence of poverty. Both large and small carnivores are also responsible for the damages to livestock. Research conducted in Bhutan and Pakistan has shown that leopards are major livestock predators (Wang and Macdonald 2006;Sangay and Vernes 2008). A study in Pakistan shows that the percentage of goats and sheep killed by leopards was very high. Similarly, Bhutan reports indicate that the number of goats and horses killed by leopards is higher than expected (Sangay and Vernes 2008). In the Sariska tiger reserve in India, leopards kill 88% of livestock including goats, sheep, and calves (Sekhar 1998). In terms of livestock damage from black bears, Pakistan and Bhutan reported 6% and 8% casualties respectively (Sangay and Vernes 2008). According to the Ogada and Ogada (2004), the number of domestic animals killed by wild predators in the African Wildlife Foundation (AWF) Samburu Heartland of Kenya is reported to be leopards (35%), lions (35%), hyenas (18%), baboons (4%), elephants (3%), buffalo (2%), wild dogs (2%) and cheetahs (1%). As per Dar et al (2009) 64.2% of these livestock deaths occurred during the night and the remaining 35.8% occurred during the daytime. Lamb captured by large eagles is another problem around the world. Many studies have discussed the diet of eagles and their effect on sheep production (Leopole and Wolfe 1970;Brooker and Ridpath 1980;Berger 1987;Matchett and O'Gara 1987;Phillips and Blom 1988). Therefore, the annual livestock loss due to predator impact is substantial. Although the loss caused by these predators is much lower than the loss caused by animal diseases, the impact on the economy is substantial (Woodroffe et al. 2005). Human activities such as hunting, fishing, and poaching make it difficult for carnivores to find their prey. In response, lions tend to enter villages and hunt cattle, sheep, and goats (Nowell and Jackson 1996). According to the study done during 2004 -2007 in the Azad Jammu and Kashmir in Pakistan, out of 4654 households, 148 were reported to be facing livestock threats (Dar et al, 2009). Due to inland fishing, predators like crocodiles run out of food. As a result, these predators tend to catch up with livestock who come to drink water (Sethy and Mardaraj 2015). Similarly, the effect of wolves on livestock depredation is somewhat significant. According to Distefano (2010), livestock depredation by wolves is a major concern in remote parts of the Abruzzo region in Italy. Even though both wolves and bears inhabit there, wolves tend to cause 94% more livestock killings than bears. Similarly, in the Alberta region of Canada, wolves caused 2086 deaths of livestock from the year 1982 to 1996. In natural ecosystems, the Indian Grey Mongooses control ecological balance by regulating the wild populations of reptiles, ground Birds, small mammals and insects (Furqan et al. 2021). As described by Fedriani et al. (2001) and Santiapillai et al. (2000) there are several depredations of poultry occurring in different parts of the countries like, India, Pakistan and Sri Lanka which creates HWC. According to Jayewardene (2008) in Sri Lanka, Polecat (Paradoxurus hermaphroditus) and Mongoose (Herpestes sp.) raid poultry cages and kill the chicken. Thus, damage to livestock can be considered as an indicator of the magnitude of HWC. Wild Animals like wild boars, giant squirrels and porcupines cause HWC in agricultural sector in Sri Lanka (Mombauer 2020).

Property damage
Even though casualties and injuries are equally reported, property damage is another common negative effect. This varies from severe damages to homes and other properties. Although the number of reported cases is low, the actual number of damages is relatively high (Gross et al. 2020). When elephants roam in search of food, they cause severe damage to the houses where the grain is stored. In addition to the damages that happen to houses, damage to other properties such as fences, ponds, canals, pipes, roads in national parks, electric goods like TV, radio, bicycles, and other structures in villages is also a major concern (Muruthi 2005;Eniang et al. 2011). For example, in Namibia, elephants in the arid Northwest damage the water storages (Government of Namibia 2007) which results in loss of resources. Thouless (1994) revealed that artificially maintained water sources attract elephants to human settlements during droughts.

Direct impacts on wildlife
Losses of lives of wild animals are a major problem in almost all countries due to HWC. Some of this wildlife is endangered. In Sri Lanka, elephants and leopards are the main animals facing these threats. Similarly, this is a major concern in countries in Asia, Europe, Africa and all over the world (Swenson and Andre'n 2005;Pletscher et al. 1997;Bangs et al. 2005).

Loss of lives and habitats of animals
HWC causes huge damages to human lives as well as wildlife. Animals show their habitual behaviours even after they lose their habitats due to human activities. Migrating in search of food is a characteristic feature of many wild animals. During this migration, these animals tend to enter rural areas bordering their sites. Animals such as elephants, tigers, leopards, and lions often move towards the villages. In addition, animals such as wolves, bears, wild boars, and monkeys can be considered. Fear and other attitudes towards this wildlife lead to conflict between these two parties (Woodroffe 2000). People often tend to kill wild animals when they are fighting against them in aid of protecting their lives. According to Fernando et al. Through the reported incidents it is clear that Sri Lanka has a high number of annual elephant deaths. In comparison, the rate of elephant deaths due to HEC in Sri Lanka is higher than that of humans. Further compared human to elephant death ratio due to HEC is about 0.30 in Sri Lanka while it is at 0.2-0.5 in Kenya, 0.2 in Indonesia, and 0.2-0.5 in Sabha-Borneo (Prakash et al. 2020). According to the Department of wildlife conservation, 100 elephants had been killed within Sri Lanka from January to March 2021. Among them, 21 had died from electrocution, 18 from jaw exploders (hakkapatas), and 12 from gunshots. Significantly many male elephant deaths were reported. The male, female elephant death ratio in Sri Lanka is around 2.01 while it was 1.29 in South India from 1976 to 2000 (Haturusinghe and Weerakoon 2012; Ecology Centre 2019). Similarly, carnivores such as tigers, leopards, lions enter villages in search of food. People show more fear of these carnivores than the megaherbivores such as elephants or rhinos. Ultimately, this conflict ends by killing both carnivore and herbivore animals. According to Bhattarai (2009), in Nepal 29 tigers has been killed between 1989 to 2009 in Bardia National Park. The small carnivorous population of red fox, stoat, weasel, and other common animals were reduced due to trapping, snaring, and shooting (Reynolds and Tapper 1996). Due to human population pressure and urbanization in South African reserves over 200 vertebrates are known to have culled between 2010 to 2012 which is driven by lack of space and habitat (Manfredo et al, 1998). Meantime, in the African continent, some illegal culling and poaching have been identified as elephants for ivory and rhinoceros for horns (Naughton-Treves 1999;Nemtzov 2003). As per Pletscher et al. (1997), Bangs et al. (cited in Bangs et al. 2005 humans have been accused of 85% of adult wolf deaths in the Northern Rocky Mountains of the UK. Sweden and Norway have granted permission to culled wild Lynx and culling bear allowed only in Sweden under quoted regulations. However, people tend to kill both the animals with other large carnivores in Sweden illegally due to livestock depredation (Swenson and Andre'n 2005). Although it is difficult, some estimations have been taken regarding those mortalities. Between 1984 to 1998, it has been estimated that nearly 40 bears have become the victims of illegal killing within Sweden (Swenson and Sandegren cited in Swenson and Andre'n, 2005). Also according to Andre ń (cited in Swenson and Andre'n 2005) the annual mortality of Lynx in Sweden due to illegal killings is between 133-157. Other than the above-listed animals, large numbers of snakes, monkeys, giant squirrels, birds such as peacocks, and game birds have been killed. These killings have been done purposely and some were by road accidents as most of the transport lines are crossing wildlife habitats in several countries and animals are used to visit or attracted by roadsides.

Indirect effects on humans
Other than general direct impacts, there are also unreported hidden effects that are associated with HWC (Hunter et al. 1990). People also have to suffer from these kinds of effects, both physically and mentally (Chowdhury et al. 2008;Dixon et al. 2009). These effects are more likely to have long-term impacts than immediate losses and damages. Though great attention has been focused on finding solutions for directly visible problems, very little attention has been paid to these indirect effects (Sangay and Vernes 2008;Treves 2009;Treves et al. 2006;Vidya and Thuppil 2010;Woodroffe et al. 2005). Therefore, the damage caused by these types of problems is severe. Chronic injuries and disabilities are the most common indirect effects that can be experienced. Most of the rural people survive from farming and related activities. Often the men in the family are the principal earners. Due to the chronic disabilities of men that occur from HWC, all the responsibilities are transferred to women and children. In addition to household work, women have to bear the burden of earning for the family. Jadhav (2011), Jadhav and Barua (2012) have explained that this fatality of men leads to an increase in the burden of living and eventually falls into poverty. Lamarque et al. (2009) state that if the injury or disability is caused to the woman in the family, the responsibilities and burden of earning shifted to children. As a result, the education of children will be interrupted and it will affect them mentally as well as socially (Hoare 1992;Treves et al. 2006;Muruthi 2005). Similarly, education is disrupted due to fear of being caught by animals such as elephants and bears while traveling to school. So, there is a risk of declining literacy among children living in rural areas and this can affect their career goals later in their life (Barua et al. 2013;Ogra 2008). This can be described as a hidden tragedy in the HWC. In addition, it affects the interactions between family members and leads to conflicts and even unnecessary quarrels. Loss of crops and livestock also have important roles in indirect impact. Loss of crops and other food sources leads to an increase in severe economic unbalances. With the collapse of the economy, difficulties in reaching the nutritional needs of the family would be a problem. Several health issues would occur due to the lack of highquality nutrition (Ogra 2008). Breastfeeding women would have to face malnutrition. In the meantime, there is a high risk of having babies with low birth weights, even premature births. According to Jadhav (2011), Barua et al. (2013), Chowdhury (2014), Ogra, (2008) and Jadhav and Barua (2012) some children have been found with various mental disorders because of the loss of their beloved. Clinical depression, post-traumatic stress disorder, and childhood emotional disorders are also some other examples of the indirect effects on humans (Chowdhury 2014). Sometimes, social and spiritual long-term adverse effects other than the issues regarding mental health can also occur. Due to the continuous cropraiding and destructions, people also tend to abandon their inherited lands and farms. Such conditions can even lead to breakdown the family relationships and increase stress.

Indirect effects on the wildlife
The impacts of HWC are not affecting only individuals but also the entire ecosystem. Most of the species that contribute to these conflicts are keystone species, where their presence is highly important for the conflicts. Removal of these species affects the stability of the entire ecosystem. Preparation of agricultural lands, modification of forests and grasslands for various activities lead to a decrease in the population as well as habitat degradation and fragmentation (Treves et al. 2006;Haddad et al. 2015). According to a study in Kenya, the wildlife population has been declined by 50%, between the year 1978 to 1998 (Okello 2009). Ecological consequences and impacts result in the isolation of populations. When the population becomes small and isolated, inbreeding within the animals increase. Inbreeding is a way of mating closely related sexual organisms within the same breed (Ceballos et al. 2017). Thus, genetic variation seems to be reduced by decreasing heterozygosity. The major aim of inbreeding is to increase the homozygosity in the progeny (Huisman et al. 2016;Keller 1998;Chapman et al. 2009;Camillo et al. 2016). This accompanies the loss of fertility, loss of efficiency, strength, and productivity which is called inbreeding depression of an organism (Stoffel et al. 2021;Darwin 1876). Comparable, this reduces the body size, reproduction ability, increases the risk of getting diseases, and quality of progeny. Therefore, if there is a prevailing epidemic situation within the population, there is a high risk of the whole population being vanished. Thus, animals that are highly exposed to conflicts are at a high risk of extinction (Ogada et al. 2003). Small population sizes are often associated with poor age structure and skewed sex composition of populations that are vulnerable to such stochasticity. The population of elephants (Elephas maximus maximus) in the world heritage site, the Sinharaja forest reserve situated in the wet zone of Sri Lanka, is composed of two male adult elephants and no females, thus exists at the brink of extinction due to demographic stochasticity and imbalanced sex composition. In addition, extinction of animals can be happened by killing animals, hunting, shooting, road, and railway accidents, falling into farm wells, and trapping (Sethy and Mardaraj 2015). It is apparent that HWC indirectly threatens biodiversity, ecological balance, and social sustainability (Mojo et al. 2013). Deforestation is a major cause of soil erosion and other types of environmental pollution (Tefera 2011). Global warming is the result of increasing CO 2 levels in the atmosphere along with deforestation and environmental pollution. Adverse effects of global warming include climate change, melting of glaciers, rising sea levels, severe droughts, and massive flooding which guide to declining wildlife populations. In addition to the loss of life, being disabled is another misfortune faced by wild animals (Betty and Frank 2010).

Prevention and mitigation strategies
Several practices are prevailing to prevent and mitigate HWC in different parts of the world. Some practices are very much unique to a particular region. Geography and several other factors prevent the application of those techniques to all countries which have HWC.
These strategic approaches are varying from region to region and as well as species to species (Hoare 1995;Western 1989;Muldere and Copolillo 2005;Hulme and Murphree 2001). Due to the exponential growth of the worldwide human population, people used to encroach into wildlife habitats. This may result in the loss of wild habitats, their degradations, and fragmentations, and such conditions are very common in highly populated regions like Africa and Asia. With the establishment of human settlements and agricultural fields in the wild areas, other than the habitat loss, degraded forage and reduced landscape connectivity would result. Eventually, this is accompanied by the devaluation of large mammal populations like elephants (Thouless et al. 2016, Calabrese et al. 2017. Explanations have been given by Leimgruber et al, (2003), Newmark (2008), Mcdonald et al. (2009), Ward (2011), andLiu et al. (2017) about the consequences of human and wildlife conflict over space and resources ranging from crop-raiding to reciprocal loss of life. As per Fernando et al, (2005), Baruch -Mordo et al., (2013), andHoare (2012) there are several suggestions for the development and adoption of a wide range of approaches for prevention and mitigation of the HWC.
Prevention and mitigation are the basic concepts used to manage HWC. Preventive methods are generally applied for symptom management strategies. There are several preventive measures adopted to minimize HWC. However, in extreme situations of competition completely removing either human or wildlife in a particular area or physically separating the two parties by the use of barriers or applying scares and repelling techniques are employed (Muruthi 2005). Kangwana, (1993), Conover (2002), and Treves and Karanth (2003 classified preventive techniques as short-term conservation of individuals, mid-term conservations of species, and long-term conservation of species. However, finding lasting solutions to HWC needs cause management of the problems which is rare throughout the world Hoare 2012;Thomassen et al. 2010). As per Leakey (1990), Kenya Wildlife Service maintains a greater job to the surrounding communities at their National Park by providing a portion of the entrance fee in the aid of encouraging them for conservation.

Role of protected areas and ecological corridors
This is a kind of physical separation applied in both humans and wildlife conflict areas which are declared by wildlife authorities (Rodrigues et al. 2004;Hansen and Defries 2007). The concept of ecological corridors is adapted to combining isolated protected areas or fragmented habitats to minimize genetic disorders of wildlife species having inbreeding depression (Brown and Kodric Brown 1977;Blair 2008;Rabinowitz and Zeller 2010). Other than that, these corridors allow wild animals as an additional routing to move between habitats during different seasons and also assist especially elephants in their raging behaviour for food and water (Adams et al. 2017). As to Roever et al. (2013) and Adams et al. (2017) these types of corridors are very popular among some countries in Asia and Africa. During the early time, MacArthur and Wilson (1967) have pointed out the importance of establishing corridors or steppingstones between isolated habitats. Diamond (1975) and Ratcliff (1977) have confirmed this idea of establishing conservation corri-dors to ensure gene flow and reducing inbreeding depression among wild populations. Paradoxically, Krebs (2009) has listed some disadvantages of establishing conservation corridors as invasive species, fire can spread, and gene pool can be contaminated.

Electric fences and trenches
Electric fences and trenches are other kinds of physical barriers and are used to deter elephants from agricultural fields and human settlements. Considerable costs have to be spent on the construction and long-term maintenance of these fences (Perera 2009;Kioko et al. 2008;Wijayagunawardane et al. 2016). Properly designed fences are very much effective to prevent conflicts between humans and wild animals. The cost of these fences varies according to the topography and the type of materials used (Muruthi 2005;Massey et al. 2014). However, elephants are adapted to break up electric fences using several behavioural techniques; i.e. using tusk, throwing timber. This can be considered as the main disadvantage of using electric fences Graham et al. 2009). Electric fences are normally arranged to surround the protected areas, which will hinder the gene flow among the species due to the lack of random mating (Lee and Graham 2006). Some countries use stone walls to protect crops from the wild buffalos. Trenches and moats are also used to keep elephants away from the cultivated lands and villages in India. Bengis et al. (2002) had mentioned that practicing fences surrounding agricultural lands also helps in reducing crop damages. Combining some traditional methods along with electric fences helps to reduce crop damages and livestock predations considerably within a conflict area (Ogada et al. 2003).

Eradication
This technique is largely used in Africa to manage the damages causing to people and their livestock by animals. Large mammals like lions, leopards, elephants, buffaloes, rhinoceros, and large antelope species were eradicated in the large areas of Africa (Treves and Karanth, 2003). Today this is also practiced by wildlife managers in the African continent if the animal is identified as a threat to people or their crops (Treves and Naughton Treves 1999 ). For these eradication practices, several different methods are used by different regions, such as different traps, snares, hunting with dogs, shooting, roast sprays, poisons, and the deliberate introduction of diseases (Naughton-Treves 1999). Also, games or hunting for sports have been applied to eradicate large carnivorous animals to give better livelihood to people who live in adjacent protected areas (Naughton-Treves 1999). Today, other than the alien species, there are no applications to eliminate the entire population (Muruthi 2005).
Some farmers are practicing illegal persecution in some parts of the world to prevent predatory attacks by applying poisons, shooting, using jaw explosives, and/ or trapping. As described by Crook (2002), once large predators are eradicated from a particular area, it will result in an increasing population density of small and medium-sized carnivores within that area and that will affect the ecological balance very highly and sometimes will cause the extinction of some herbivores.

Regulated harvesting and storing
Regulation of harvested and stored crops or grains would help in managing the property damage caused by wild animals (Prakash et al. 2020;Muruthi 2005). If the people are not keeping more stored yields in their houses, it will help to minimize Human-Elephant Conflict (HEC) and that will protect both lives and properties (Prakash et al. 2020). Fernando et al. (2011) have revealed that HEC has strongly associated with agriculture and higher HEC cases have been observed during the cultivation period in Sri Lanka. Fernando et al. (2005), Gunaryadi et al. (2017, have mentioned that different types of acoustic deterrents are practiced by farmers such as guarding crop, scaring crop-raiding animals away, yelling, setting off firecrackers, carbide cannons, throwing stones, or other things to hit an animal which are effective to keep animals away from the farm fields (Davies et al. 2011). Creating threatening sounds using audio playback also another type of method used to chase crop-raiding animals but it is effective only for short terms and short distance due to quick learning, habituation, and adoption to those by animals and returns to raid crop (Thuppil and Coss 2016; Wijayagunawardane et al. 2016;Moss 1988;Gamage and Wijesundara 2014). From history, dogs were the first animal used as a guard to protect the herds in different parts of the world. Archaeological studies conducted in China also had proven this (Axelsson et al. 2013;Frantz et al. 2016;Freedman et al. 2014;Morey and Jeger 2015;Perri 2016). In addition to dogs, some regions used donkeys as a guard animal to protect flocks of sheep and goats from cheetah (Murathi 2005). According to recent research conducted by Mekonen (2020), 34% of farmers practice group guarding, 26% of live fencing, 22% of scaring, 14% of chasing, whereas 5% used smoking to repel the crop raiders. Fernando et al. (2005), Davis et al. (2011), andShaffer (2010) highlighted that, to protect ripening crops and deter raiding elephants, farmers use flaming torches or flashlights. In some agricultural fields, some farmers use solar spotlights that shone in elephant's eyes to drive them (Gunaryadi et al. 2017;Davis et al. 2011) but due to the high cost to purchase, it prevents widespread adoption among rural households and communities. As per Sukumar (1991Sukumar ( , 1992 like the acoustic methods, lightbased deterrents are also a short-term solution to prevent HWC.

Agriculture based deterrents
Other than the above-mentioned acoustic and light methods, few other prevention actions are used in different parts of the world to protect the crops from wildlife. Bio-fences are used in several African and Asian regions as a strategy to keep wildlife species away from cultivations and property. Among them, farmers practice chili-grease-covered fences, pepper grease-covered fences, and the burning of chili, and elephant dung (Graham et al. 2009;Hedges and Gunaryadi 2010;Chang'a et al. 2016). However, due to the high cost and less effectiveness, these methods are prohibitive for many communities (Sitati and Walpole 2006;Baishya et al. 2012). Gross et al. 2016;Gross et al. 2017) have mentioned another method to prevent elephant raiding food crop by planting less attractive, less palatable crops like chamomile, coriander, mint, ginger, onion, garlic, lemongrass, and citrus family trees as a barrier for crop-raiding elephants (Osborn 2002;Chang'a et al. 2016;Parker and Osborn 2006). Some chemical repellents like lithium chloride used against African carnivores to protect livestock (Forthman-Quick et al. 1985). Graham et al. (2012) revealed that communication between farmers and local wildlife officers is an effective manner to chase problematic animals or herds before crop raiding. Also, establishing an early warning alarm system to identify possible crop-raiding, for instance detecting infrasonic calls of elephants over long distances is possible (Zeppelzauer et al. 2015;Dabare et al. 2015). The main disadvantage of this technique is lacking internet facilities among farmers and other local wildlife officers in remote areas (Dabare et al. 2015). Monitoring radio collard elephants or herd movement using satellite tracking also gives immense benefits to identify cropraiding elephants or herd (Shaffer et al. 2019). Paradoxically, practicing these techniques is very much difficult due to the initial cost for capturing and collaring elephants and the material cost.

Supply alternative sources to wildlife
This is commonly known as the diversion of some wild animals by supplying their limited resources such as water. According to Conover (2002), this is a successful method that is used to reduce crop damage in the USA. In the natural environment, some animal populations are increased due to immigration, reproduction, and enhance survival. As a result, they try to find their resources from outside of their territory due to natural food scarcity. So as a knowledgeable wildlife manager, it is essential to identify the ecology of different animal groups before starting prevention programs. Liyanage et al. (2021) indicate the possibility of the use of organic food such as extra harvest during harvesting of seasonal crops that are discarded daily at markets and agricultural fields to feed wildlife such as elephants.

Gender balance
Normally, this technique can be applied to control insect pests in agricultural fields using irradiation methods. Other than the abovementioned methods, to control the fertility of wildlife, several other techniques such as mechanical, surgical endocrine disruptive, or fertility control measure-immuno-contraceptive can be used (Kirkpatrick et al. 2009). As mentioned by Butler (1998) some of these are under experimental level but in Kruger National Park immuno-contraceptive methods applied to elephants and some countries applied to wild boar (Tshewang et al. 1999;Hobbs and Hinds 2018;Delsink and Kirkpatrick 2015;Emmons 2017).

Problem animal control
Few techniques can be applied to control problem animals. Domestication, keeping under domestic conditions, culling, and translocations are the main mechanisms used by wildlife managers or authorities for the mitigation of nuisance animals (Makindi et al. 2014).

Domestication
Domestication practices were started 10,000 years before present in Neolithic Age. In India, it was about 4,500 BCE and in Sri Lanka, as to Premathilake (2012) incipient domestication started around 17,000 BP. Cave arts suggest that these dates can attribute to more than that (Sukumar 2008;Clutton-Brock 2012). Domestication is done to several animals. If their populations increased in the wild; they face the problem of limited resources and try to move out of their territory that guides for HWC. Such a nuisance animal or a herd can be captured for domestication, especially this is done for elephants in both Asia and Africa. Clutton-Brock (2012) had illustrated that domestic elephants can be used for various purposes like ceremonial activities, transporting people and heavy loads, warfare, hunting, and help to capture other wild elephants (Bist et al. 2002;Mar et al. 2012). Domestication and keeping animals in domestic conditions are different phenomena as the latter can be done to any problem animal. Sukumar (1991Sukumar ( ,1992 had mentioned that generally culling is applied to crop-raiding elephants or to those that kill humans in the African region where there is a large elephant population. This was practiced largely during the pre-colonial and colonial periods in Sri Lanka during the British colonial period (Naughton-Treves 1999). Selective culling is acceptable and periodically practiced in many elephant range countries (Naughton-Treves 1999;Isenberg 2000;Breitenmoser et al. 2005;Woodroffe 2000). Van Aarde et al. (1999) revealed that culling is practiced largely for bull elephants due to their wide home range. Culling is practiced for a fragmented population of elephants, they show inbreeding depression and already change their genetic variations, and ultimately, they become endangered or vulnerable within many countries. Also, a skewed sex ratio will degrade the genetic health of wild animals, therefore culling is not advisable in such countries (Manferdo et al. 1998, Naughton-Treves 1999. In upland Wales, the UK under 'Good neighbour policy, over-winter culling of fox (Vulpes vulpes) by driving foxes to guns using dogs and rifle shooting has practiced to reducing the density of fox (Baker and Harris 2006).

Translocation
Translocation involves drugging or immobilization, capturing, and transportation of nuisance animals from human settlements to protected areas for release (Tshewang et al. 2021). This is commonly practiced minimizing HEC (Nyhus 2016;Nyhus et al. 2005b, Fernando et al. 2012Saaban et al. 2011), however, other nuisance species are treated in the same manner in different parts of the globe. According to Pinter-Wollman (2009), Fernando et al. (2012, recorded cases are available for returning some of the translocated elephants to their first territory, There are several disadvantages of translocations such as increased elephant mortality during capture and translocation, deliberate killing in the new location (Fernando et al. 2012;Fernando and Pastorni 2011;Conover 2002;Craven et al. 1998, Gammons et al. 2009Letty et al. 2003). Conover (2002 indicates that due to translocated animals some diseases can transfer to resident populations in the new location or arisen new competition for food resources or territory.

Compensation
This process is usually applied to predetermined causes due to HEC such as casualties or injuries to humans, property damages, livestock, and crop damages. However, compensation for crop damage is not practiced much in several countries. In Sri Lanka, this compensation is given to victims by the government but in other countries, it is governed by NGOs or other private agencies (Murathi 2005;Brooks et al. (2013), Hartter et al. 2014Snyman 2014). Although in elephant range countries, these compensation programs are not much successful for HEC because of criticism due to insufficient compensation, logistical challenges, a lack of transparency, and limitations (Bulte and Rondeau 2005;Treves and Karanth 2003;Mishra et al. 2003;Nyhus et al. 2005a;Li et al. 2013).

Conclusion
HWC can be depicted as a consequence of sharing the common natural resources by humans and wildlife. Many authors have identified that increasing human population has resulted in encroachment into more marginal lands inhabited by wildlife and leads to habitat loss, fragmentation, and degradation due to the conversion of lands to agricultural fields and other activities imposing an impact on wildlife. In most of the conflict areas in the world, many large mammals including large carnivores and mega-herbivores roam free in marginal rangelands, buffer zones, and transitional areas of protected areas. There are several direct and indirect effects on both humans and wildlife due to these conflicts. Several authors have proved that people inhabiting the areas that depend more on natural resources are intimidated by the threats to their lives and livelihood within their homelands, finally resulting in conflicts. Crop damages, competition for water and grazing, livestock predation, increasing the risk of livestock diseases, various inconveniences while protecting farmyards, and even human casualties can be observed in the affected areas of HWC. Wildlife has become threatened with various types of conflicts. Apart from the direct human threat to wildlife, inbreeding depression consequence severe damage to them by reducing heterozygosity and increasing homozygosity. The above-mentioned one can be categorized as an indirect effect faced by wildlife.
It was evident that two basic approaches of controlling and managing HWC prevail, namely prevention and mitigation. The major goal of these two strategies is to minimize HWC that is common everywhere in the world. However, different remedial measures have been developed around the world but have not been implemented globally due to different ecological, cultural, and economic realities and they are also targeting a variety of taxonomic groups. In general, preventive measures are practiced minimizing the risk of conflicts or in extreme situations either people or animals have to be completely relocated. Relocating has several advantages as well as disadvantages. The main disadvantage is it associated with a huge cost and longer periods required to establish. Problem-solving using animal control strategies is commonly known as mitigations that are mostly done by the involvement of wildlife authorities. This can be done by culling, keeping under domestic conditions, or capture for translocating. Also, other mitigatory methods have been practiced by the governments in several countries such as to produce compensations to affected parties, however, this is not much successful due to some inefficient organizations.
Better applications for the prevention and mitigation strategies needed to approach the affected communities in different ways rather than practicing traditional ways or remedies must be produced. These include educational programs, consolation payments, the introduction of border sharing benefits associated with the presence of wildlife, detailed study of social and ecology outline and evaluating, monitoring strategies which are more valuable to management. Wildlife Service maintains a greater job to the surrounding communities of protected areas to uplift the social status.

Summary of best solutions to mitigate HWC
For better solutions to HWC, the following steps should be followed.