Introduction

Animals use movement to adapt to changing food resources, improve reproductive success, evade predators, and identify suitable habitats1,2,3,4. Movement plays a pivotal role in shaping the spatio-temporal distribution of species and significantly influences their ability to access resources and engage in vital intra- and inter-species interactions5,6,7. The dynamics of animal locomotion serve as a crucial link between these processes, allowing individuals to adaptively respond to the constantly changing, heterogeneous environments they inhabit8,9,10. These varied movement patterns emerge from evolutionary adaptations, resulting in a spectrum of strategies. For instance, migratory birds undertake extensive latitudinal journeys, while large herbivores in mountainous regions exhibit altitudinal movements throughout the year11,12,13. The timing, location, distance, and direction of these movements are predominantly influenced by climatic conditions and habitat alterations14,15,16.

As climate change accelerates, terrestrial animals are increasingly compelled to migrate longer distances, shift their migration timings, and alter their numbers, seeking new habitats to find suitable conditions17,18,19,20. Many species now migrate earlier in spring or summer and later in fall or winter, and the number of individuals migrating during these periods has increased in some cases21. Large mammal species, in particular, are moving toward northern latitudes or ascending to higher elevations, where alpine pastures provide refuge and support these migratory populations22,23. The movements of terrestrial mammals face mounting challenges from factors such as habitat fragmentation due to human development and changes in the suitability of destination habitats. These obstacles pose significant threats to the survival of large terrestrial mammal populations24,25,26,27,28. Human-induced barriers to mammal movement have resulted in population declines and degraded habitat quality, adversely affecting nutrition, reproduction, physiology, epidemiology, and phenology, thereby heightening their vulnerability29,30,31,32,33,34,35.

While climate change has not affected all ecosystems and species uniformly, the level of threat varies significantly based on habitat type and species characteristics36,37,38. In particular, countries in Southwest Asia, such as Iran, have experienced severe impacts from climate change, with large mammals facing greater threats compared to other species39,40,41,42,43. Large mammals contend with a multitude of challenges, including habitat loss, illegal hunting, human-wildlife conflict, and diminishing food resources, all of which are exacerbated by the adverse effects of climate change44,45,46,47. Understanding how species’ movement responses to climate change evolve over time is crucial for conserving large mammal populations.

Although several studies have examined the broader effects of climate change on large mammal movements48,49, only a limited number have specifically addressed the unique dynamics of high-altitude movement ecology50,51. These existing studies tend to focus on aspects such as seasonal migration shifts52,53 and habitat preferences54,55,56, yet they often overlook the complexities of altitudinal movement, particularly in response to fluctuating climatic conditions. Moreover, long-term datasets on high-altitude adaptations remain exceedingly rare, especially in mountainous ecosystems, where the lack of sustained monitoring severely limits our understanding of how large mammals respond to climate change across temporal and spatial scales48. This scarcity of data represents a critical gap, constraining both predictive modeling and the development of targeted conservation strategies for these vulnerable populations.

We studied the altitudinal migratory patterns of four large mammalian species in the Central Alborz Protected Area (CAPA) of northern Iran, one of the primary habitats for endangered large mammals in the area57,58,59,60,61,62. Since 1994, strict conservation measures including the construction of a ranger station, the prohibition of livestock grazing, the restriction of unauthorized human activity, and the enforcement of anti-poaching laws have facilitated significant ecological restoration in this area63. These actions have led to increased densities of large mammals, which use this high-altitude refuge for breeding between late spring and early autumn. Mount Alborz is recognized as one of the world’s biodiversity hotspots64, yet studies focusing on the impacts of climate change on the altitudinal movements of large mammals in this region and globally remain extremely limited. This is particularly concerning given the critical role that such research plays in understanding the adaptability of species in response to environmental changes48. Furthermore, the scarcity of long-term data on the movement ecology of endangered and vulnerable species amplifies the urgency of our investigation.

Given Iran’s position within one of the most climate-sensitive regions globally40,65 this study aims to fill a crucial knowledge gap by using long-term data (1999 to 2022) on the altitudinal movements of four large mammal species, alongside daily weather parameters. Our study is designed around the following hypotheses:

Hypothesis 1

The altitudinal movement patterns of Caspian red deer, brown bears, wild goats, and wild boar during the summer months have shifted significantly in response to climate variability over recent decades.

Prediction: We expect to observe earlier ascents to higher altitudes and extended periods of residency at these elevations as temperatures in the region have increased.

Hypothesis 2

Climatic factors such as temperature, humidity, and precipitation play a key role in influencing the altitudinal movement patterns of these species during the summer.

Prediction: Higher temperatures during the spring and summer months are anticipated to be associated with earlier and more prolonged migrations to elevated areas.

Hypothesis 3

Significant changes in climate parameters over the study period have influenced the movement ecology of these species during their summer ranges.

Prediction: We expect to observe rising average temperatures and altered precipitation patterns, in line with global climate trends, which are likely contributing to shifts in the species’ altitudinal movement patterns.

This study is essential not only for understanding how large mammals in the Alborz Mountains are responding to climate change but also for informing future conservation strategies in similarly vulnerable high-altitude ecosystems. By addressing the gap in long-term data from a less-studied highland site, this research enhances the broader understanding of large mammal movement ecology under changing climatic conditions, with particular emphasis on global biodiversity hotspots.

Materials and methods

Study area

Mount Alborz, located to the south of the Caspian Sea, is recognized as one of the world’s biodiversity hotspots, distinguished by its unique fauna and flora64,66,67,68. The CAPA in Mazandaran province is situated at coordinates 36° 29′ N and 51° 34′ E, encompassing an area of approximately 2950 km2, with an elevation range from − 26 m to over 4000 m above sea level. This region extends from the southern shores of the Caspian Sea in the north to the high ridges of the Alborz mountains in the south, resulting in a rich mosaic of habitats, from dense Hyrcanian forests to alpine meadows. The area experiences an average annual rainfall of 1300 mm and an average temperature of 16.1 °C (Fig. 1).

Fig. 1
figure 1

Map of the study area, generated using ArcGIS 10.8.

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The CAPA is one of the most crucial habitats for several species classified as endangered (EN) in Iran, including the brown bear (Ursus arctos), Persian leopard (Panthera pardus tulliana), Caspian red deer (Cervus elaphus maral), and roe deer (Capreolus capreolus). It also supports vulnerable (VU) species such as the wild goat (Capra aegagrus) and species classified as near-threatened (NT) in Iran, like the gray wolf (Canis lupus) and wild boar (Sus scrofa)57,58,59,60,69,70,71.

The CAPA is an ecologically significant region facing considerable threats from human development. The area includes approximately 226 villages, 400 km of paved roads, and 190 km of dirt roads. Key conservation challenges stem from habitat conversion, overgrazing, beekeeping, human-wildlife conflicts, and poaching, which collectively put substantial pressure on biodiversity within CAPA72,73,74,75,76,77. Since 1994, strict prohibitions on livestock grazing and unauthorized human activities have been enforced in the Golestanak core zone. This area, previously impacted by unrestricted livestock grazing and high levels of human disturbance, suffered significant ecological degradation due to these pressures. The introduction of stringent protection measures has been instrumental in mitigating these adverse impacts, allowing for the gradual restoration of the region’s ecological integrity. Over recent decades, the cessation of livestock grazing and restriction of human access have created conditions favorable for the natural regeneration of habitats, reinforcing Golestanak status as a critical seasonal refuge for large mammal communities77. Golestanak is uniquely positioned as the only habitat within the CAPA that supports direct observation of large mammals during warm seasons66. From late spring (approximately the end of May) through early autumn (late September), four key large mammal species representative of the studied populations are observed in Golestanak for summer residency. As autumn approaches, these species undertake seasonal migrations to lower-altitude forests in the northern and western regions, where they remain for winter until May63.

Data collection

This study examined the altitudinal movement patterns of four large mammal species red deer, brown bear, wild goat, and wild boar during the summer months (May 25–September 29) from 1999 to 2022 within the Golestanak core zone, a critical high-altitude habitat amenable to direct observation63. Species-specific population data were gathered through systematic daily observations, employing established methodologies58,78,79,80,81,82,83.

Research on species inhabiting remote, high-altitude environments, particularly those with low population densities, poses significant logistical challenges. To mitigate these difficulties and improve the reliability of population estimates, we adhered to a rigorous, standardized data collection protocol. Field patrols were conducted in pairs, each led by an experienced senior ranger to ensure methodological consistency and accuracy in data recording. Pre-determined, repeatable patrol routes were followed to reduce observational bias and enhance data reliability. All observers utilized identical tools, such as binoculars and cameras, to maintain uniformity across observations84,85,86,87. The terrain and vegetation characteristics of the study area facilitated optimal visual detection of individuals, thereby improving the precision of species identification and population counts66.

Standardized data collection protocol

Observers recorded critical parameters for each sighting using standardized data sheets provided by the Department of Environment (DOE). Key variables included the date, species, number of individuals, and demographic information (such as sex and age class, when identifiable). Data were systematically recorded by the senior ranger at the end of each patrol day, ensuring a consistent and unbiased approach to data collection85,86,87.

Monitoring efforts and data validity

Over the course of the study, a total of 3036 monitoring days were completed, yielding a robust dataset for analyzing population trends. The number of individuals recorded represented minimum population estimates rather than actual population sizes. To minimize the influence of temporary absences due to poor weather conditions (e.g., rain or fog), we calculated the average number of individuals and weather parameters over five-day intervals.

Weather data

Daily weather data were collected from three synoptic weather stations (Siah Bisheh, Nowshahr, and Kojur) at elevations of 2200 m, − 3 m, and 1500 m, respectively. The Siah Bisheh station is the nearest meteorological site to the Golestanak core zone, sharing a similar altitude, while the other two stations provided additional context for CAPA climate changes. Climatic parameters analyzed in relation to migration ecology included mean daily temperature (tm °C), relative humidity (um%), and mean daily precipitation (rrr24 mm)88,89,90,91,92,93,94.

To improve the interpretation of temperature and humidity variations across the CAPA, we conducted spatial analysis and map production using ArcGIS 10.8. The CAPA was divided into 5 × 5 km grid cells95,96,97,98,99,100,101, providing a balanced resolution that reflects the diverse and expansive home ranges of the four target species. This cell size was chosen to align with spatial scales commonly used in management plans and to ensure that the maps produced were both accurate and accessible for practical applications.

We produced maps to depict temperature and humidity variations across the study area. To enhance the clarity and transparency of the study, we highlighted points where large mammals were most likely to be present. These points were determined using reliable distribution data, which included species occurrences, indirect evidence (e.g., tracks, scats, and other traces), and prior reports from the Department of Environment (DOE)63,95,102,103. This approach was designed to visually contextualize the study’s findings and facilitate their application in conservation planning. By highlighting areas of likely large mammal presence, the maps serve as a valuable resource for management and restoration efforts, particularly in the design of protection programs and ecological corridors connecting low- and high-elevation habitats.

Statistical analysis

Mixed effects model

We employed a mixed effects model to differentiate the contributions of fixed and random effects on the response variables, providing a rigorous statistical framework for ecological data analysis104,105,106. In this study, year was treated as a random factor, while key climatic variables, including temperature, precipitation, and humidity, were incorporated as fixed covariates. This approach allowed us to evaluate the specific influence of each climatic parameter on the population size of the four target species over the study period. Maximum likelihood (ML) estimation was used to quantify the strength and significance of these effects.

Linear regression analysis

To assess long-term trends in climatic variables, we applied linear regression analysis at a 95% confidence level, consistent with its established use in ecological research107,108,109. The model examined the direction and magnitude of changes over time by treating year as the independent variable and the climatic parameters as dependent variables, thereby capturing temporal trends in the environmental drivers affecting species populations.

Pearson’s pairwise correlations

We used Pearson’s pairwise correlation to explore the relationships between climatic parameters at a 95% confidence level, following the methodology outlined by110. This analysis quantified the degree of association between key climatic variables, allowing us to identify potential interdependencies and covariation patterns among the climatic drivers.

Results

Climate change trend over the study period (1999–2022)

Data were collected continuously from 1999 to 2022 to assess long-term climate trends in the study area. To illustrate the pattern of change over the full study period, we compared the first five years (1999–2003) with the final five years of the study (2018–2022). A clear warming trend was observed at the Siah Bisheh meteorological station. Between May 28 and July 17, the average daily temperature increased by approximately 2.5 °C, rising from 15.7 °C in the early period to 18.3 °C in the late period. Concurrently, relative humidity decreased by 4.6% during the same period (Fig. 2). This comparison highlights significant climatic changes over the 23-year study period.

Fig. 2
figure 2

The change in the pattern of altitudinal movements of the studied species, temperature and humidity between 1999 and 2003 compared to the average year of 2018 to 2022.

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Comparative number of individuals trends

Over the course of the study, red deer and wild goats exhibited notable increases in population size. Between 1999 and 2003, the average number of red deer observed from May 25 to June 5 ranged from 6 to 12 individuals. By the final five years of the study (2018–2022), this range had increased sharply to 12–52 individuals, reflecting a two- to fourfold rise. Wild goats showed a similar upward trend, with average counts increasing from 20–70 individuals in the first five years to 36–137 individuals in the last five years of the study. In contrast, brown bear and wild boar populations followed divergent trajectories, indicating distinct ecological responses compared to the herbivores.

We used mixed effects models to evaluate the impact of climate parameters, including mean temperature (tm), relative humidity (um), and annual precipitation (rrr24), on the number of individuals of the studied species. Year was included as a random effect to account for inter-annual variability and isolate the influence of fixed climatic factors on the number of observed individuals of the studied species.

Red deer

The mixed effects model revealed that year explained 30.58% of the total variance in red deer population size (P = 0.001). Temperature (tm) had a highly significant positive effect on the number of red deer (P < 0.001, Coef = 10.25, T = 13.89), indicating that a 1 °C increase in temperature was associated with an increase of approximately 10.25 individuals. Similarly, relative humidity (um) showed a significant positive association with population size (P < 0.001, Coef = 1.76, T = 12.45), suggesting that higher humidity levels were linked to larger population sizes. Annual precipitation (rrr24) had no significant effect (P = 0.814). Overall, the model explained 47.87% of the variation in red deer population size, demonstrating that increasing temperature and humidity are strongly associated with higher red deer abundance.

Brown bear

The model showed that year accounted for 7.15% of the total variance in brown bear population size (P = 0.013). Temperature had a very significant positive effect on the number of brown bears (P < 0.001, Coef = 0.49, T = 8.8), indicating that a 1 °C increase in temperature corresponded to an increase of approximately 0.49 individuals. Relative humidity also had a significant positive effect (P < 0.001, Coef = 0.08, T = 7.8), reflecting that higher humidity levels were associated with increased population sizes. Precipitation (rrr24) was not statistically significant (P = 0.547). The model explained 19.17% of the variation in brown bear population size, highlighting the positive influence of temperature and humidity on brown bear abundance.

Wild boar

Year accounted for 10.10% of the total variance in wild boar population size (P = 0.006). Temperature showed a significant positive effect on the number of wild boars (P = 0.004, Coef = 0.48, T = 2.91), suggesting that a 1 °C increase in temperature was associated with an increase of approximately 0.48 individuals. Relative humidity (P = 0.08) and precipitation (P = 0.101) were not significant predictors. The model explained 14.36% of the variation in wild boar population size, indicating that temperature is a key driver of population changes in this species.

Wild goat

The mixed effects model showed that year explained 14.88% of the total variance in wild goat population size (P = 0.003). Temperature had a very significant positive effect on wild goat population size (P = 0.001, Coef = 6.41, T = 3.42), indicating that a 1 °C increase in temperature resulted in approximately 6.41 more individuals. Relative humidity (P < 0.001, Coef = 1.6, T = 4.42) also showed a significant positive effect, suggesting that higher humidity levels are associated with increased population sizes. Precipitation (rrr24) had no significant effect (P = 0.955). The model explained 20% of the variation in wild goat population size, reinforcing the significant role of temperature and humidity in driving population dynamics.

Our findings demonstrate that the altitudinal movement of the studied species is significantly influenced by temperature and humidity at the Siah Bisheh station during the months of May to September. To gain a more comprehensive understanding of the overall climatic changes affecting the CAPA region, we incorporated data from two additional meteorological stations (Nowshahr and Kojur). This broader approach allowed for a more accurate assessment of temperature and humidity trends across the CAPA.

The regression analysis revealed significant changes in temperature and humidity during the critical months of May, June, and July across all stations (Fig. 3). The results from Siah Bisheh station showed that temperature changes were significant for May (P = 0.034, R2 = 18.9%, df = 23), June (P < 0.001, R2 = 47%, df = 23), and July (P = 0.008, R2 = 28.2%, df = 23). Humidity in June also exhibited significant changes (P = 0.002, R2 = 37%, df = 23). Similarly, at Nowshahr station, temperature changes were significant for May (P = 0.008, R2 = 27.8%, df = 23), June (P < 0.001, R2 = 39%, df = 23), and July (P = 0.005, R2 = 31%, df = 23). Humidity in June (P < 0.001, R2 = 52.7%, df = 23) and July (P = 0.001, R2 = 34.5%, df = 23) also showed significant changes. At Kojur station, temperature changes were significant for June (P = 0.046, R2 = 24%, df = 16), and humidity changes were significant in June (P = 0.006, R2 = 41%, df = 16).

Fig. 3
figure 3

The regression results show an increase in temperature and a decrease in humidity in all three meteorological stations.

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A pairwise Pearson correlation analysis was conducted to assess the relationship between humidity (um) and temperature (tm). The correlation coefficient was − 0.685 (95% CI − 0.725, − 0.639), indicating a strong negative correlation between these two variables (P < 0.0001). Due to the high degree of correlation between humidity and temperature, humidity was excluded from further analyses, and only temperature was retained as the most influential climate parameter for the subsequent phases of the study.

Figure 4 illustrates the spatial distribution of temperature and the average annual temperature increase in CAPA, focusing on the potential habitats of the studied species (hatched cells). In the low-elevation northern area, the average annual temperature increase during May, June, and July was 0.078, 0.17, and 0.076 °C, respectively. In contrast, the high-elevation southwestern region experienced corresponding increases of 0.055, 0.14, and 0.12 °C. These results indicate that the potential northern habitats experience higher temperatures than the southern highlands during May, June, and July, with average temperatures in the southern highlands being 5 to 6 °C lower than those in the northern lowlands during the same period.

Fig. 4
figure 4

Average temperature over the last five years and their annual changes during May, June, and July in CAPA. (Map generated using ArcGIS 10.8).

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It is important to note that this step was not intended as a spatial analysis of species distribution. Instead, the purpose of overlaying these points was to provide clarity and transparency to the study, enabling easy interpretation of the results.

Discussion

The results of this study reveal significant impacts of climate change on the altitudinal movements of four large mammal species within the CAPA, particularly in the Golestanak protected area. Over the past two decades, the average daily temperature has increased by 2.5 degrees Celsius, while relative humidity has decreased by 4.6% during the warm season. These climatic changes have resulted in notable shifts in the number of individuals of the studied species, with individuals migrating earlier and in greater numbers to their summer habitats in the highlands in response to rising temperatures. These findings underscore the intricate relationships between climatic factors and species responses, indicating that rising temperatures and altered moisture levels are critical determinants of habitat suitability and seasonal movement patterns. A comprehensive understanding of these dynamics is essential for developing effective conservation strategies aimed at mitigating the adverse effects of climate change on vulnerable mammal populations in mountainous ecosystems.

Based on the findings of this study, the increase in temperature over the last two decades has resulted in the Caspian red deer being observed in the Golestanak core zone as early as late May, with their summer number of individuals exceeding four times that of the previous two decades. This observation aligns with the research of111,112,113,114,115,116 which collectively indicate that rising temperatures enhance the availability of forage during critical periods, positively impacting herbivore survival, particularly among calves. Additionally, our findings reveal that Caspian red deer in the CAPA are now arriving in Golestanak 15 to 20 days earlier for summering than they did two decades ago; previously, they would typically migrate by mid-June, but now this occurs by late May.

Supporting our results, studies conducted by103,117,118,119,120,121 affirm that the movement ecology of deer is primarily governed by climatic conditions, with temperature playing a crucial role. Our study further indicates that temperature is the most significant weather parameter influencing the altitudinal movement of deer. Research by103,116,122,123,124 corroborates this, showing that temperature directly affects plant phenology, which in turn influences all aspects of deer feeding and movement ecology. The results of95,102,103 demonstrate that the forested area in the northern part of the CAPA represents one of the two primary habitats for red deer. However, individuals inhabiting this relatively low-elevation forest region may face several human-related obstacles when attempting to access the high-altitude summer habitats in the southwest. These obstacles may include roads in CAPA, the periphery of villages, and potential hunting pressures, which could hinder their movement and habitat utilization.

The positive trend in the red deer number of individuals likely results from a combination of factors such as enhanced protective measures, improved habitat conditions, and climatic factors. A portion of this increase can be attributed to the stringent protections implemented through the establishment of the Golestanak ranger station and CAPA ranger patrols aimed at combatting poaching identified as the primary threat to the Caspian red deer population by59,70,95,125,126. Additionally, we suspect that the ban on livestock grazing in the Golestanak core zone has contributed to this increase, as72 demonstrated that livestock presence adversely affects the distribution of Caspian red deer.

Our findings indicate that the altitudinal movements of brown bears to their summer habitats are influenced by temperature, similar to red deer, but to a lesser degree. Research60,127,128,129,130 corroborates these findings, demonstrating the effects of rising temperatures on bear altitudinal movement. However, unlike the red deer, the brown bear number of individuals does not exhibit a significant increase. We hypothesize that this may be related to decreased moisture levels, as studies131,132,133,134,135,136 have shown that reduced humidity can influence bear occurrence by affecting the availability of insects and other food sources, such as fruits. Moreover, several studies137,138,139,140,141,142,143 suggest that climate change particularly rising temperatures and decreasing humidity may lead brown bears to venture beyond their protected habitats and current ranges, potentially escalating human-wildlife conflicts and jeopardizing their survival. Based on this, brown bears residing in the forested section of northern CAPA are likely to encounter human-related obstacles when attempting to access the cooler habitats of the southern highland.

Our results indicate that wild boars have experienced a rise in temperature in recent years compared to the previous two decades, coinciding with an approximate 40% increase in their number of individuals within the Golestanak core zone. However, unlike in the past, they have not migrated to their summer habitats significantly earlier. Conversely, at the end of summer, wild boars tend to return to lower-altitude areas. Studies144,145,146,147,148 support these findings, confirming that changes in the movement behavior of wild boars in response to weather conditions, particularly rising temperatures, have been documented.

The findings of this study indicate that wild goats, like red deer, have shown approximately a twofold increase in the number of individuals by early June, likely influenced by rising temperatures. This is supported by studies88,149,150,151,152 which demonstrate that weather conditions are a strong driver of herbivore movement. Additionally, research by153,154,155 suggests that increased temperatures can affect food resource availability for herbivore populations. Despite the broader habitat range of wild goats, they may encounter human-related obstacles, such as the Chalus road, nearby villages, and potential illegal hunting in the western region during migration within CAPA. In general, the study of156 shows that in the future, wild goats will lose more than 50% of their habitats in Iran.

To safeguard the ecological integrity of CAPA and ensure the survival of its large mammal populations, comprehensive management strategies are essential. Climate change is clearly reshaping the altitudinal movement patterns of species such as the Caspian red deer, brown bear, wild boar, and wild goat, with rising temperatures and decreasing humidity altering seasonal migration timing and habitat preferences. These changes not only affect habitat suitability and resource availability but also expose these species to increased human-wildlife conflicts, especially when individuals extend their ranges beyond protected areas5,6,7. Effective conservation in this context demands a multifaceted approach that includes the restoration, identification, and protection of critical movement corridors26,27,28 within and beyond CAPA’s boundaries, with particular focus on high-pasture areas such as Zānoos that may serve as key summer refuges77.

Protecting and restoring movement corridors is essential to ensure that large mammals can access suitable high-altitude habitats for summer grazing21,22,23. Expanding CAPA’s boundaries and reclassifying it as a national park would provide stronger legal protections against habitat fragmentation and human encroachment, which currently restrict species’ natural movement patterns. This effort must be complemented by participatory conservation involving local communities, whose cooperation is critical in addressing challenges such as poaching, illegal grazing particularly the timing and intensity of livestock movement in May and June and other anthropogenic pressures. Engaging local stakeholders would also facilitate the adoption of sustainable livestock management practices in and around CAPA, alleviating grazing pressure on the reserve’s pastures and indirectly benefiting large herbivores by preserving forage resources.

The observed annual increase in large mammal counts at high-altitude sites like Golestanak may reflect density shifts caused by rising temperatures in lower-elevation habitats, rather than a true population increase across CAPA. To improve the accuracy of population estimates on a landscape scale, we recommend employing advanced monitoring techniques, including systematic camera trapping, capture-recapture methods, and genetic analyses. These approaches enable robust population metrics by allowing for individual identification and movement tracking across altitudinal gradients, providing critical insights into population dynamics and distributional changes driven by environmental factors.

To further enhance conservation efforts, CAPA would benefit from an increase in both ranger personnel and their equipment to monitor human activities and combat illegal hunting, particularly in vulnerable areas like the Chalus road and village peripheries. Additionally, a comprehensive, science-based management plan should include assessments of suitable summer habitats and high-pasture areas to guide potential species relocations or establish alternative pathways. This would enable species such as wild goats and red deer to migrate safely within CAPA. A data-driven approach, integrated with climate adaptation strategies, would strengthen ecosystem resilience, ensuring the long-term sustainability of biodiversity in this ecologically significant region amidst ongoing climatic pressures.

Conclusion

This study highlights the substantial impacts of climate change on the altitudinal movement patterns and the number of individuals of large mammals within the CAPA region, particularly in the Golestanak core zone. Rising temperatures and reduced humidity over the past two decades have prompted species such as the Caspian red deer, brown bear, wild boar, and wild goat to alter their migration timings, arriving earlier at higher altitudes and sometimes experiencing increases in the number of individuals as a result. These findings underline the essential role of climatic factors in shaping mammal behavior, habitat suitability, and resource availability in mountainous regions.

Given the heightened pressures these species face, proactive conservation strategies, including protecting ecological corridors linking low- and high-elevation habitats, enhancing local community engagement, and extending protected area boundaries, are crucial for mitigating the adverse effects of climate change. Such efforts will help maintain ecological resilience and support the long-term survival of these vulnerable mammal populations within CAPA and beyond.