Forecasting the outcomes of anthropogenic climate change on the geographical distribution of species is crucial, given that these shifts may result in mass extinctions (Wallingford et al., 2020). The vast majority of existing data points to climate change as the primary driver of widespread species extinctions, and its effects on species distributions or hastening the rate of extinction should be anticipated (Román-Palacios and Wiens, 2020; Kemp et al., 2022). Predicting how a species like Hangul, with only 250 + individuals left, will react to climate change is difficult because unsuccessful reproduction and colonization are dependent on diverse factors, including geographic range, ecologically isolated populations, low reproductive rates, and a high degree of specific habitat requirements (Maviya Majid et al., 2019; Mukherjee et al., 2019; Malhi et al., 2020; Inouye, 2022). Hangul is already facing the risk of low reproductive rates and isolated populations (Ahmad et al., 2023) and thus climate change may aggravate it further. However, SDMs offer a valuable method for integrating future conditions into approaches and choices in conservation and management, when the consequences of incorrect conservation strategies or inaction are balanced against the uncertainties of model forecasts (Hu and Jiang, 2011). In light of this, we investigated any potential changes in the Greater Dachigam landscape’s distribution of endangered species caused by climate change. Based on the current suitable habitat in the Greater Dachigam landscape, our findings highlight the complexity of changes in species distributions under climate change (Table 1). Hangul's distribution is therefore anticipated to decrease in the Dachigam landscape (Table 1). According to earlier findings, individual species' distributions are uniformly influenced by climate change because they react to it in the same patterns (Semenzato et al., 2021; Haq et al., 2023). The ability of individuals from the same species to adapt to local climate change is probably similar (Thurman et al., 2020), the likelihood of those individuals surviving in their current habitats in the face of large climate change decreased as the time horizon grew longer and the severity of the consequences from climate change increased (Pearce-Higgins et al., 2022). Similar findings were also reported by Hu and Jiang (2011) and Mason et al. (2014) when predicting the likely responses of endangered ungulates to future climatic conditions. When Thorstad et al. (2021) studied the effect of climate change on the survival of Atlantic salmon, they came to similar findings. Our conclusions are supported by Scapini et al. (2019).
Our model's goal was to elucidate if environmental factors may independently predict the habitat that is suitable for Hangul within the Himalayas surrounding the Dachigam landscape. Bio14 was the most important variable, showing that the precipitation in the driest month may have a greater impact on species distributions. According to Bradie and Leung (2017), precipitation and temperature had the greatest overall contributions to species distribution for terrestrial species. Similarly, Jiang (2018), and Chen et al. (2023) observed that the driest months' precipitation exerted a notable influence on the distribution of endemic, rare, and threatened species, similar to our findings. This is corroborated by numerous other investigations, e.g., for Pygathrix cinerea (Tran et al., 2018); Himalayan Goral (Haq et al., 2023), Red panda (Thapa et al., 2018) and Tragopan melanocephalus (Jameel et al., 2023). The second most important variable was bio19 (coldest month precipitation), the third elevation, and the fourth was bio08 (wettest quarter mean temperature). Previous studies revealed that average precipitation alone may not accurately predict bioclimatic variance and that the mean temperature of the bio19 (coldest month precipitation), (Jiang et al., 2019); wettest quarter (bio08) (Zhong et al., 2022) and elevation (Campos et al., 2020; Jameel et al., 2023) may also play a key role in species distributions potentially causing species to extend or decrease their ranges. Our findings underline that rather than focusing solely on rising global temperatures, it is necessary to incorporate precipitation and other climate variables (including extreme circumstances) into future expected species distributions.
When assessing important environmental variables, our model of the appropriateness of the current Hangul habitat functioned well (Table 1). Our best model suggested that the overall suitable Hangul habitat spanned 13936 km2 based on a 10-percentile criterion, accounting for 8% of moderately suitable habitat and 7% of high-suitability habitat. Ali et al. (2021) compare well to our findings, indicating that under current climatic conditions, 9% of the overall study region was suitable for blue sheep from the Hindu Kush ranges. When the repercussions of global warming are considered, the highly suitable habitats for Hangul distributions in the Dachigam Landscape will decrease in the future (from 5.06 to 9.33 km2). Numerous other studies also emphasized how threatened species will face a considerable loss of their habitats due to the altering climate, particularly in the Himalayan regions (Ali et al., 2021; Liang et al., 2021; Jameel et al., 2023; Haq et al., 2023). Examples include Himalayan musk deer (Khadka and James 2017) blue sheep (Islam et al., 2023), and NilgiriTahr (Sony et al. 2018).
The current distribution of the Hangul is anticipated to shift along both elevational and latitudinal gradients because of climate change. Instead of an expansion of their range to higher altitudes, the projected changes along the elevational gradient were mostly attributable to a significant reduction in their geographic distribution. This result was consistent with the idea put forth by Luo et al. (2015), and it is possible that the geography of the Dachigam terrain, covering a relatively narrow range, may have had a major role in these results. Our data indicate that Hangul is mostly found at the elevation of 2000 to 4000m, which highlights the species' preference for high-elevation habitats with colder climates and less anthropogenic disturbance. It aligns with the findings of Ahmad et al. (2016) in Dachigam National Park, reporting Hangul occurrence at elevations ranging from 1700–2300 m and an altitudinal range of 1700–3500 m (Qureshi et al. 2009). Our findings confirmed what was previously known about the altitudinal habitat range of Hangul and this helps to understand the ecological needs and niche of Hangul for formulating an effective conservation strategy. This altitudinal preference can be seen as a result of different bioclimatic and anthropogenic factors, including vegetation types occurring at that elevation and less snow cover. Similar preferences for vegetation types were determined by Sharma et al. (2010) and Qureshi et al. (2016). However, our results indicate that climate change is likely to cause the Hangul population to move upwards to northern regions as its habitat range shifts to higher elevations. Similarly, Chen et al. (2011) noted that species were rapidly moving towards higher elevations to combat heat due to climate change. This is further corroborated by the study results of Lenoir et al. (2008) who determined an upward shift of plant species especially in mountainous regions due to climate change. Agnihotri et al. (2017), He et al. (2019), and Yadav et al. (2021) also documented the climate change-driven altitudinal shift of Himalayan vegetation. As a result, animal species will follow, e.g. Himalayan Goral (Haq et al. 2023). We suggest that climate change is causing altitudinal shift in Hangul and there is a need to conserve the present and future habitat range for Hangul so that climate change and elevation shifts could not pose a threat to the survival of this species.
Currently, Hangul populations are also found outside the protected areas, particularly during summer. Of the 34975 km2 of predicted habitat, 30445 km2 (93%) lie outside the protected areas, which is a serious concern for this highly threatened species. The effectiveness of this unprotected network and potential changes in protected habitat suitability for the Hangul have not yet been assessed under climate change. Different parts of the unprotected habitat are under varying levels of restrictions on human activity. As a result, the effectiveness of some of these sites under climate change may be significantly influenced by the management techniques used in the future. This holds particularly true for unprotected regions but has the potential to have high conservation value in the future. Considering the crucial role that unprotected regions play in the survival of the Hangul, projecting the species' future distribution to guide the selection of new sites or expanding the current array of protected zones could be an efficient conservation approach to confronting the challenges posed by climate change. More crucially, in response to climate change, the effectiveness of the network of protected zones might be significantly increased by sustaining crucial corridors that permit Hangul mobility. Given the expansion of anthropogenic activities, several protected sites already become unsuitable for Hangul. The Zonation analysis (Fig. 7) has given a very good and practical result for Hangul conservation. The securement and protection of very high and high-priority zones occurring between the existing protected areas can boost the conservation of hangul for the long term. For example, the areas between Tral and Achabal PAs, between Dachigam and Wanghat, Wanghat and Ajas, and Ajas and Kishan Ganga (Fig. 7). Securing such an area will provide a contiguous landscape for long-term conservation for a mobile species like Hangul.
We identified critical sites with the potential for future Hangul conservation. We also identified corridors for Hangul that would last well into the future, enabling affected populations to relocate in response to climate change. Enhancing habitat availability and accessibility is crucial for species adjusting to the challenges of climate change. Improving landscape connectivity, and the facilitation of species movement emerge as a key conservation strategy. Identifying and maintaining well-suited corridors through methods like Species Distribution Models (SDMs) enhances animal resilience by providing avenues to escape unsuitable conditions. Our forecast identified south Kashmir, notably the high-altitude conifer forest areas of Anantnag, Kulgam, and Pulwama districts, as highly suitable habitats for Hangul conservation in the Kashmir Himalayas. Kaul et al. (2018) also found Cervus hangul hanglu in Central/north Kashmir conifer woodlands such as Wanghat-Naranag, Rajparian-Daksum, Overa-Aru, and Thajwas-Baltal, confirming our predictions with field-based survey data.
4.1. Implications for conservation of Dachigam landscape
Habitat conservation through protected areas has been a primary issue in maintaining the survival and sustainability of the critically endangered Hangul population. However, isolated protected areas cannot help to conserve the hangul population for the long term due to the issues of inbreeding, and thus connectivity among these isolated protected areas becomes crucial. Existing PAs cover only 7.7% (2220 km2) of the expected future Hangul habitat. This indicates that most of the Hangul habitat (93%) is currently unprotected, highlighting a huge risk of extinction as anthropogenic disturbance and climate change increase. As a result, we propose that nearby core habitat regions must be protected to connect the Hangul subpopulations. Our results revealed that 9.33% of high-suitability areas for the Hangul movement might become unsuitable by 2070 (Fig. 9), adding to the issues of Hangul conservation. On the other hand, overexploitation in the form of illicit wildlife poaching, habitat degradation, and fragmentation pose serious threats to its main abode, the Greater Dachigam landscape. These issues have led to ecological isolation, population decline, and inbreeding and brought the species to the brink (Ahmad, 2022; Ahmad et al., 2023). Although the establishment of protected areas is a helpful conservation strategy, it has been found that poor management and smaller size may negate the advantages of all conservation initiatives aimed at enhancing biodiversity. There restricted distribution of Hangul and its core areas in the context of existing and prospective climate change scenarios implies that the Dachigam Landscape is seriously lacking in space. As a result, Dachigam Landscape urgently needs to be expanded or connected to the potential hangul sites including the neighboring reserves and the hotspots/core areas. Ecological corridors around greater Dachigam landscape should be prioritized for conservation and management to secure it and the Hangul. According to our findings, hotspots may mostly move outside of the Dachigam landscape due to climate change. Therefore, our suggestions can assist in developing dynamic protected areas within the Dachigam landscape over an extended period.