Biodiversity, Geographical Distribution, and Faunal Study of Tick Populations Infesting Livestock in an Elevated County of Midwest Iran

Biodiversity, Geographical Distribution, and Faunal Study of Tick Populations Infesting Livestock in an Elevated County of Midwest Iran | Authorea try { document.documentElement.classList.add('js'); } catch (e) { } var _gaq = _gaq || []; _gaq.push(['_setAccount', 'G-8VDV14Y67G']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); Skip to main content Preprints Collections Wiley Open Research IET Open Research Ecological Society of Japan All Collections About About Authorea FAQs Contact Us Quick Search anywhere Search for preprint articles, keywords, etc. Search Search ADVANCED SEARCH SCROLL This is a preprint and has not been peer reviewed. Data may be preliminary. 1 February 2026 V1 Latest version Share on Biodiversity, Geographical Distribution, and Faunal Study of Tick Populations Infesting Livestock in an Elevated County of Midwest Iran Author : Ebrahim Abbasi 0000-0003-1861-5321 [email protected] Authors Info & Affiliations https://doi.org/10.22541/au.176990961.12148215/v1 220 views 79 downloads Contents Abstract Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract Introduction: Ticks are major ectoparasites of livestock and important vectors of zoonotic and veterinary pathogens. Data on tick biodiversity and distribution in mountainous regions of western Iran remain limited. This study investigated the species composition, biodiversity, seasonal activity, and geographical distribution of ticks infesting livestock and birds in Delfan County, Lorestan Province. Materials and Methods: A 12-month cross-sectional survey (February 2019–February 2020) was conducted across 16 sampling sites. Ticks were collected monthly from 1,280 examined hosts (cattle, sheep, goats, chickens, and pigeons), preserved in ethanol, and morphologically identified. Biodiversity was assessed using Margalef, Shannon–Wiener, and Simpson indices, and spatial, topographical, and seasonal patterns were analyzed. Results: A total of 1,337 ticks belonging to eight species and three genera (Hyalomma, Rhipicephalus, and Argas) were identified. Hyalomma anatolicum was dominant (49%). Sheep were the most infested hosts. Tick abundance was higher in mountainous areas (75.3%) and peaked in summer (53%). Biodiversity varied markedly among sites, with the highest diversity observed at Kafraj. Discussion: Tick communities exhibited strong spatial and seasonal heterogeneity influenced by altitude, host availability, and climate. The dominance of medically important Hyalomma species highlights potential risks for tick-borne zoonoses and underscores the need for continuous ecological surveillance. Keywords: Ticks; Biodiversity; Livestock; Hyalomma; Seasonal dynamics; Iran Biodiversity, Geographical Distribution, and Faunal Study of Tick Populations Infesting Livestock in an Elevated County of Midwest Iran Dr. Ebrahim Abbasi 1, 2* 1 Research Center for Health Sciences, Institute of Health, Shiraz University of Medical Sciences, Shiraz, Iran 2 Department of Medical Entomology and Vector Control, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran Email: [email protected] \RL [email protected] \RL Mobile: +98912-4338389 \RL ORCID: 0000-0003-1861-5321 * Corresponding Author: Dr. Ebrahim Abbasi Running Title: Biodiversity and Ecology of Ticks in a Mountainous Region of Iran Abstract Introduction: Ticks are major ectoparasites of livestock and important vectors of zoonotic and veterinary pathogens. Data on tick biodiversity and distribution in mountainous regions of western Iran remain limited. This study investigated the species composition, biodiversity, seasonal activity, and geographical distribution of ticks infesting livestock and birds in Delfan County, Lorestan Province. Materials and Methods: A 12-month cross-sectional survey (February 2019–February 2020) was conducted across 16 sampling sites. Ticks were collected monthly from 1,280 examined hosts (cattle, sheep, goats, chickens, and pigeons), preserved in ethanol, and morphologically identified. Biodiversity was assessed using Margalef, Shannon–Wiener, and Simpson indices, and spatial, topographical, and seasonal patterns were analyzed. Results: A total of 1,337 ticks belonging to eight species and three genera ( Hyalomma, Rhipicephalus , and Argas ) were identified. Hyalomma anatolicum was dominant (49%). Sheep were the most infested hosts. Tick abundance was higher in mountainous areas (75.3%) and peaked in summer (53%). Biodiversity varied markedly among sites, with the highest diversity observed at Kafraj. Discussion: Tick communities exhibited strong spatial and seasonal heterogeneity influenced by altitude, host availability, and climate. The dominance of medically important Hyalomma species highlights potential risks for tick-borne zoonoses and underscores the need for continuous ecological surveillance. Keywords: Ticks; Biodiversity; Livestock; Hyalomma; Seasonal dynamics; Iran Introduction Ticks are obligate hematophagous ectoparasites belonging to the subclass Acari within the phylum Arthropoda and represent one of the most widespread groups of parasitic arachnids worldwide. These metastigmatid arthropods parasitize a broad range of vertebrate hosts and are recognized as highly significant vectors of zoonotic and veterinary pathogens. Despite their global distribution and medical importance, the ecological and epidemiological roles of ticks remain insufficiently appreciated in many endemic regions. Through biological and, in some cases, mechanical transmission mechanisms, ticks are capable of harboring and disseminating a wide array of pathogenic microorganisms, including bacteria, rickettsiae , protozoa, and viruses, thereby posing serious threats to both human and animal health. Numerous debilitating and sometimes fatal diseases are associated with tick bites, including viral hemorrhagic fevers, relapsing fevers, rickettsioses, and several emerging tick-borne infections of global concern(Estrada-Peña et al. 2008; Sonenshine & Roe 2014). In addition to their role as disease vectors, ticks exert direct harmful effects on their hosts through persistent blood feeding, which may lead to skin irritation, hypersensitivity reactions, dermatitis, anemia, fatigue, and, in severe cases, tick-induced paralysis. These adverse effects are primarily mediated by the prolonged attachment of ticks during feeding and the bioactive compounds present in their saliva. Collectively, the direct and indirect impacts of tick infestations contribute substantially to livestock productivity losses and represent a significant burden on rural and pastoral communities, particularly in regions where animal husbandry constitutes the primary livelihood(Jongejan & Uilenberg 2004; Mans et al. 2017). The spatial distribution and population dynamics of ticks are strongly influenced by a complex interplay of environmental, climatic, and anthropogenic factors. Changes in climate patterns, alterations in land use, intensification of agricultural practices, expansion of livestock farming, and increased movement of domestic animals across geographical boundaries all contribute to shifts in tick abundance and distribution. Moreover, the long-distance migration of birds, transboundary trade of livestock, and the introduction of animals from tropical or subtropical regions into temperate zones can facilitate the dispersal of tick species and the pathogens they carry. Over recent decades, these drivers have collectively reshaped tick fauna in many parts of the world, leading to the emergence or re-emergence of tick-borne zoonoses in areas previously considered low risk(Estrada-Peña et al. 2014; Ogden & Lindsay 2016). Tick-borne diseases are inherently sensitive to ecological conditions that regulate vector survival, host availability, and pathogen transmission efficiency. Temperature, humidity, altitude, vegetation cover, and seasonal variability directly affect tick development, questing behavior, and host-seeking success. Consequently, the prevalence and intensity of tick infestations are often heterogeneous, exhibiting pronounced spatial and temporal variability. Understanding these patterns remains challenging, as the transmission dynamics of tick-borne pathogens involve multiple interacting components, including vector biology, host competence, environmental suitability, and human exposure pathways. A comprehensive understanding of these interdependencies is still beyond current scientific capabilities, highlighting the need for localized ecological investigations(Eisen & Eisen 2018; Randolph 2004b). Ticks are relatively large acarines, ranging in size from a few millimeters to several centimeters depending on species and feeding status. They are taxonomically divided into two principal families of medical and veterinary importance: hard ticks (Ixodidae) and soft ticks (Argasidae). Both groups are highly adaptable and capable of exploiting diverse ecological niches. Their life cycles are complex, involving multiple developmental stages that may parasitize different host species. In particular, hard ticks may exhibit one-host, two-host, or three-host life cycles, with the latter being especially efficient in transmitting pathogens due to repeated host switching across developmental stages. Although ticks often display broad host ranges at a global scale, they may demonstrate marked host specificity at local or regional levels, reflecting ecological specialization(Anderson 2002; Walker 2003). Quantifying tick diversity and distribution requires the application of robust ecological metrics. Biodiversity indices are widely used statistical tools that integrate species richness, evenness, and abundance to describe the structure of biological communities. Variations in any of these components can substantially alter community composition and stability. In parasitological studies, diversity indices provide valuable insights into host–parasite interactions, habitat suitability, and ecosystem balance. Environments characterized by minimal anthropogenic disturbance and stable ecological conditions are generally expected to support higher parasite diversity, whereas disturbed habitats often exhibit reduced diversity and dominance by a limited number of species(HAEMOSPORIDIOS et al. ; Magurran 2021). From an epidemiological perspective, the distribution of tick species cannot be meaningfully interpreted without considering the underlying ecological processes governing their populations. Ecological stability and biodiversity play critical roles in modulating disease risk, as changes in vector diversity may influence pathogen amplification and transmission pathways. Identifying spatial patterns of tick abundance, mapping high-risk areas, and assessing environmental determinants of tick distribution are therefore essential components of effective vector surveillance and control strategies(Estrada-Peña & de la Fuente 2014; Ostfeld & Keesing 2000). Delfan County, located within the mountainous Zagros ecosystem of western Iran, represents a region where such investigations are particularly warranted. The local population relies heavily on traditional animal husbandry, and livestock are frequently grazed across diverse altitudinal zones, creating favorable conditions for tick maintenance and dispersal. Despite these factors, comprehensive data on tick fauna, biodiversity, and geographical distribution in this area have been lacking. Accordingly, the present study was designed to provide the first detailed assessment of tick species composition, ecological diversity, and spatial distribution in Delfan County. By generating baseline ecological data, this work aims to contribute to improved understanding of tick ecology and to support evidence-based strategies for the prevention and control of tick-borne diseases within a One Health framework(Dhooria 2016; Ganjali et al. 2014). Materials And Methods Study Area and Geographical Setting This investigation was conducted in Delfan County, located in Lorestan Province in western Iran, with Noorabad serving as the administrative center. The county lies within the central Zagros Mountain range and is geographically bordered by Nahavand to the north, Sahneh to the west, Harsin to the south, Kuhdasht and Chegini to the southeast, and Selseleh County to the east (Fig. 1). Delfan County is characterized by a predominantly mountainous landscape, with elevations ranging approximately from 1,600 to over 2,100 m above sea level. The region contains numerous mountain ridges and limited narrow plains, resulting in pronounced altitudinal heterogeneity. The climatic and ecological conditions of Delfan County, including relatively cool temperatures, seasonal precipitation, and extensive rangelands, provide favorable environments for livestock grazing. Animal husbandry represents the primary economic activity for most households in the area. Livestock are typically grazed freely in natural pastures during spring, summer, and autumn, while they are kept in temporary or semi-enclosed shelters during the winter months. These management practices create diverse microhabitats that support tick survival, development, and host contact across seasons(Manzano-Román et al. 2012; Telmadarraiy et al. 2010). Selection of Sampling Sites Based on preliminary assessments of ecological characteristics, livestock density, and accessibility, a total of 16 sampling localities were selected across Delfan County to represent both mountainous and plateau environments. The selected sites were spatially distributed to capture variation in elevation, vegetation cover, and grazing intensity (Fig. 1). Geographic coordinates and altitude for each sampling location were recorded using a GPS device and are summarized in Table 1(Randolph 2004a; Uiterwijk et al. 2021). Tick Collection and Sampling Design Tick sampling was carried out over a continuous 12-month period from February 2019 to February 2020 to account for seasonal fluctuations in tick activity. Sampling was conducted once per month at each of the selected localities. Five host species were included in the survey: cattle ( Bos taurus ), sheep ( Ovis aries ), goats ( Capra hircus ), pigeons ( Columba livia ), and chickens ( Gallus gallus domesticus ). All available animals at each site were physically examined for tick infestation during routine grazing in pastures or while housed in barns. Inspections were performed during daylight hours, primarily between 09:00 and 16:00, when host accessibility and visibility were optimal. Each animal was carefully examined over the entire body surface, with particular attention to predilection sites such as the ears, neck, axillae, groin, perineal region, and under the tail. Ticks were gently removed using fine, curved-tip forceps to avoid damage to the specimens or injury to the host. Each collected tick was immediately placed into a labeled glass vial containing 70% ethanol supplemented with 5% glycerin for preservation. All samples were transported to the laboratory for subsequent identification and analysis(Guglielmone et al. 2010; Walker 2003). Host Examination and Infestation Assessment During the study period, a total of 1,280 animals were examined across all sampling sites. Host species, number of examined individuals, infestation status, and tick burden were systematically recorded. The distribution of tick genera among different host species is presented in Table 2. Host-specific infestation patterns were evaluated to assess the relative contribution of each livestock species to tick maintenance and dispersion within the study area(Estrada-Peña & de la Fuente 2014; Jongejan & Uilenberg 2004). Topographical Classification Sampling locations were categorized into two main topographical classes: mountainous and plateau areas. This classification was based on elevation, terrain morphology, and land use characteristics. The distribution of collected ticks between these two topographical categories was quantified and is summarized in Table 2, allowing comparison of tick abundance and composition across contrasting landscapes(Perveen et al. 2021; Randolph 2004a). Tick Identification In the laboratory, all preserved specimens were examined and identified to species level using a stereomicroscope (OLYMPUS SZ61). Morphological identification was performed based on standard diagnostic characters, including scutum ornamentation, capitulum structure, leg segmentation, and festoon patterns. Both hard ticks (Ixodidae) and soft ticks (Argasidae) were identified. The final species composition and relative abundance of collected ticks are presented in Table 2(Estrada-Peña et al. 2004; Guglielmone et al. 2010). Seasonal Activity Analysis Seasonal distribution of tick species was assessed by pooling monthly collections into four meteorological seasons: spring, summer, autumn, and winter. The frequency of each tick species across seasons was calculated to evaluate seasonal activity patterns and population dynamics. Seasonal abundance data for all identified species are summarized in Table 2(Estrada-Peña & Jongejan 1999; Randolph 2000). Biodiversity Analysis Tick biodiversity was assessed separately for each sampling site using three widely applied ecological indices: Margalef’s richness index, Shannon–Wiener diversity index, and Simpson’s diversity index. These indices collectively account for species richness, evenness, and dominance structure within tick communities. Calculations were performed using PAST software (version 4.0.3). Diversity values for each site, along with species counts and sampling effort, are provided in Table 1 and graphically illustrated in Fig. 2(Hammer & Harper 2001; Magurran 2021). Data Management and Visualization All field and laboratory data were compiled into structured datasets for statistical analysis. Geographic coordinates were mapped to visualize spatial distribution patterns of tick species across Delfan County (Fig. 1). Comparative analyses of biodiversity indices across sampling sites were used to evaluate ecological stability and heterogeneity of tick populations (Fig. 2)(Bivand et al. 2008; Zuur et al. 2007). Overall Tick Infestation and Collection Summary During the continuous 12-month sampling period conducted across Delfan County, a total of 1,280 domestic animals were examined for tick infestation, including cattle ( Bos taurus ), sheep ( Ovis aries ), goats ( Capra hircus ), pigeons ( Columba livia ), and chickens ( Gallus gallus domesticus ). Among these hosts, 423 animals (33.04%) were found to be infested with ticks. From the infested hosts, a total of 1,337 tick specimens were collected and preserved for further analysis (Table 2). All collected ticks belonged to two families, Ixodidae (hard ticks) and Argasidae (soft ticks), and were classified into three genera. The genus Hyalomma constituted the overwhelming majority of specimens, accounting for approximately 79.9% of all collected ticks, followed by Rhipicephalus (11.1%). The genus Argas was the least abundant, representing 9.0% of the total tick population (Table 2)(Anderson & Magnarelli 2008; Guglielmone et al. 2010). Species Composition and Host Associations Within the genus Hyalomma , four species were morphologically identified: H. anatolicum , H. marginatum , H. asiaticum , and H. detritum , comprising a total of 1,068 specimens. The genus Rhipicephalus was represented by two species, R. sanguineus and R. bursa , with 148 specimens collected. Similarly, the soft tick genus Argas included two species, A. persicus and A. reflexus , with a total of 121 specimens, making them the least frequently encountered taxa (Table 2). Host-specific analysis revealed that the majority of Hyalomma and Rhipicephalus ticks were collected from ungulate livestock. Sheep accounted for the highest proportion of infested hosts (61.2%), followed by goats (29.0%) and cattle (0.8%). In contrast, all Argas specimens were exclusively collected from avian hosts, with A. persicus and A. reflexus removed from chickens (7.3%) and pigeons (1.7%), respectively (Table 2)(Perveen et al. 2021; Randolph 2004b). Topographical Distribution of Tick Populations Given the predominantly mountainous nature of Delfan County, tick distribution was further analyzed across two distinct topographical categories: mountainous and plateau areas. The results demonstrated that the majority of ticks (75.3%) were collected from mountainous locations, whereas only 24.7% were recovered from plateau regions (Table 2). Among the three genera, Hyalomma showed the highest frequency in mountainous areas, reflecting its strong ecological association with elevated and rugged terrain. In contrast, Argas species were the least represented in both topographical zones, with particularly low frequencies in plateau environments (Table 2)(Estrada-Peña & Jongejan 1999; Randolph 2004b). Species Abundance and Seasonal Variation Among the eight identified tick species, H. anatolicum was the most prevalent, accounting for 49% of all specimens, followed by H. marginatum (21%), R. sanguineus (10%), and H. asiaticum (9%). Lower frequencies were observed for A. persicus (7%), A. reflexus (2%), while R. bursa and H. detritum were the rarest species, each representing approximately 1% of the total collection (Table 2). Seasonal analysis indicated pronounced temporal variation in tick activity. The highest number of ticks was collected during the summer season, comprising 53% of all specimens. Spring accounted for 26% of collections, followed by autumn (17%), while winter exhibited the lowest tick activity, with only 4% of specimens recorded (Table 2). The overall seasonal trend in tick abundance followed a descending order from summer to spring, autumn, and winter. Most tick species reached their peak abundance during summer, reflecting optimal climatic conditions for tick development and host contact. Notably, H. detritum was exclusively collected during autumn, suggesting a distinct seasonal activity pattern and possible adaptation to cooler environmental conditions in this region. Similarly, A. persicus showed increased activity during autumn, consistent with its close association with poultry housing environments, where birds spend more time indoors during cooler months (Table 2)(Randolph 2004a; Uiterwijk et al. 2021). Spatial Distribution Across Sampling Sites Substantial spatial heterogeneity was observed in tick abundance and species composition among the 16 sampling localities. Site 4 (Kafraj) recorded the highest number of collected ticks (184 specimens) and harbored seven out of the eight identified species, ranking as the most infested and species-rich location. This was followed by Site 13 (Bagverdiye-Olya) with 146 specimens and Site 7 (Golam Bahri) with 133 specimens, each supporting six tick species (Table 1). In contrast, Sites 5 (Zaliabad) and 16 (Baba Bozorg) exhibited the lowest tick abundance, with only 36 and 44 specimens collected, respectively. These sites also showed reduced species richness compared to other locations (Table 1). Analysis of species distribution across sampling sites demonstrated that H. anatolicum was the most geographically widespread species, occurring in 14 of the 16 locations. This was followed by H. marginatum (10 sites), R. sanguineus (8 sites), and both H. asiaticum and A. persicus (7 sites each). A. reflexus , H. detritum , and R. bursa exhibited more restricted distributions, being detected in five, four, and three locations, respectively (Table 1). Biodiversity Indices and Community Structure Biodiversity analyses revealed marked variation in tick community structure among sampling sites. According to Margalef’s richness index, Shannon diversity index, and Simpson’s diversity index, Site 4 (Kafraj) exhibited the highest diversity values (Margalef = 6.8; Shannon = 1.6; Simpson = 0.77), indicating a relatively stable and well-balanced tick assemblage (Table 1, Fig. 2, Fig. 3). Sites 13 (Bagverdiye-Olya) and 7 (Golam Bahri) each supported six tick species. While Margalef’s index showed comparable richness between these two locations, Shannon and Simpson indices indicated greater evenness and diversity at Site 7, suggesting differences in species dominance patterns (Table 1, Fig. 2). The lowest species richness (two species) was recorded at Sites 1, 5, 12, 14, and 16. Biodiversity indices at these locations were consistently low, reflecting reduced community complexity. Among them, Site 12 (Balut Bazeh) exhibited the lowest Simpson diversity value, indicating strong dominance by one or two species and reduced ecological stability (Table 1, Fig. 2)(Langendorf & Doak 2019; Magurran 2021). Discussion The findings of the present study demonstrate that tick populations in Delfan County exhibit pronounced spatial and ecological heterogeneity, characterized by uneven distribution patterns across sampling locations, host species, seasons, and topographical zones. Tick assemblages were largely overdispersed, such that a limited number of sites harbored relatively high species richness and diversity, whereas most localities were dominated by fewer species with low overall biodiversity. This aggregated distribution pattern is typical of macroparasites and must be interpreted in conjunction with host availability, seasonal activity, altitude, and local environmental conditions that collectively shape tick population dynamics. Sites such as Kafraj, Golam Bahri, and Bagverdiye-Olya exhibited elevated diversity indices and higher species richness compared with other sampling locations. These areas likely provide more favorable ecological conditions, including suitable microclimates, stable host presence, and limited anthropogenic disturbance, which together facilitate the coexistence of multiple tick species. In contrast, sites with low diversity indices were characterized by dominance of one or two species, suggesting ecological imbalance or reduced habitat suitability. From an ecological standpoint, higher tick biodiversity is often associated with greater community stability and closer proximity to an equilibrium state, whereas reduced diversity may reflect environmental stressors or disruption of host–parasite interactions. Iran is characterized by four major ecological zones that differ markedly in climate, topography, and vegetation cover (Fig. 4)(HAEMOSPORIDIOS et al. ; Randolph 2004a). Comparison of biodiversity indices observed in this study with those reported from other parts of Lorestan Province indicates that tick communities in Delfan County display relatively high structural stability. Elevated diversity values suggest reduced likelihood of extreme dominance by a single species, which may, in theory, limit the amplification of specific tick-borne pathogens. In contrast, ecosystems with impoverished tick diversity may facilitate pathogen emergence through dominance of competent vector species. Therefore, biodiversity assessments provide valuable indirect insights into potential disease transmission risk. The predominance of Hyalomma species, particularly H. anatolicum and H. marginatum , is epidemiologically significant, as these ticks are well-recognized vectors of major zoonotic pathogens. A substantial proportion of the collected specimens belonged to species previously implicated in the transmission of Crimean-Congo hemorrhagic fever virus and other pathogens of medical and veterinary importance. The widespread geographical distribution of H. anatolicum across most sampling sites further emphasizes its ecological adaptability and vector potential in mountainous regions of western Iran(Estrada-Peña & de la Fuente 2014; Klompen et al. 1996). Nearly all tick species identified in this study are known to infest livestock and serve as vectors of economically important and zoonotic pathogens, including agents of viral hemorrhagic fevers, piroplasmosis, anaplasmosis, and theileriosis. These findings underscore the importance of continuous entomological surveillance and biodiversity monitoring as integral components of vector-borne disease prevention programs. Analyses of tick population structure and diversity offer essential information for understanding vector establishment, persistence, and spread, thereby supporting more targeted and effective control strategies. The observed infestation rate per livestock in Delfan County was comparable to those reported from other regions of Lorestan Province and adjacent areas, suggesting a broadly similar ecological context across the province. Nevertheless, variations in dominant tick species among different regions of Iran reflect the influence of climate, host composition, altitude, and land use. For instance, regions with extensive camel husbandry tend to exhibit dominance of camel-associated Hyalomma species, whereas areas dominated by small ruminants often support different tick assemblages. These regional differences highlight the need for localized studies rather than reliance on generalized national-level data(Estrada-Peña et al. 2008; Jongejan & Uilenberg 2004). Seasonal dynamics observed in this study are consistent with the biological characteristics of ticks as poikilothermic organisms. Tick abundance peaked during summer and declined sharply during autumn and winter, reflecting the strong dependence of tick activity, development, and host-seeking behavior on temperature and humidity. Warmer months provide optimal conditions for tick reproduction and survival, as well as increased host exposure due to grazing practices. Conversely, colder seasons impose physiological constraints on ticks and reduce host–tick contact, leading to decreased infestation rates. Among the identified species, H. detritum displayed a restricted seasonal pattern, being detected exclusively during autumn. This suggests a narrower ecological niche and adaptation to cooler conditions in this mountainous region. Similarly, the autumnal peak observed for A. persicus can be explained by its close association with poultry housing, where birds spend extended periods indoors during cooler months, facilitating tick detection and collection. Such species-specific seasonal behaviors underscore the complexity of tick ecology and the importance of year-round surveillance(Estrada-Peña & Jongejan 1999; Randolph 2004b). Host-related analyses revealed that sheep were the most heavily infested livestock species, accounting for the majority of collected ticks. This finding is of particular concern given the high mobility of sheep flocks and their close and frequent contact with humans. The dense wool, grazing behavior, and management practices associated with sheep likely contribute to increased tick attachment and survival. These factors collectively elevate the risk of tick-borne zoonotic transmission, especially in rural communities where human–livestock interactions are intense. Iran’s diverse ecological zones play a fundamental role in shaping tick fauna and distribution. Delfan County is situated within the Zagros Mountain range, a transitional region that may support species from both adjacent ecological zones. Such mountainous barrier areas can act as corridors or filters for species dispersal and may contribute to unique assemblages or ongoing speciation processes. The ecological complexity of the Zagros Mountains reinforces the need for intensive and geographically focused studies to accurately characterize tick diversity and distribution patterns in these regions(Jongejan & Uilenberg 2004; Uiterwijk et al. 2021). Overall, the results of this study indicate that tick biodiversity in Delfan County is highly site-specific and influenced by a combination of ecological, climatic, and host-related factors. Variations in species richness, evenness, and dominance across sampling sites reflect differences in environmental stability and anthropogenic pressures. Understanding these patterns is essential for interpreting vector population dynamics and assessing potential risks of tick-borne diseases. Within the framework of the One Health approach, which emphasizes the interconnectedness of human, animal, and ecosystem health, the findings of this study highlight the necessity of integrating ecological surveillance into public health and veterinary programs. Mitigating anthropogenic drivers of zoonotic disease emergence, improving livestock management practices, and adopting innovative monitoring technologies are critical steps toward reducing the burden of tick-borne diseases. Given the substantial role of ticks as vectors affecting both livestock productivity and human health, continuous assessment of their fauna and biodiversity is particularly vital in regions where animal husbandry remains the cornerstone of local livelihoods(Estrada-Peña & de la Fuente 2014; Estrada-Peña et al. 2008). Declaration Ethics approval and consent to participate This study was approved by the Research Ethics Committee of Shiraz University of Medical Sciences (Approval ID: IR.SUMS.SCHEANUT.REC.1401.121). Tick collection was performed through non-invasive inspection of livestock during routine veterinary practices. No animals were harmed or subjected to experimental interventions. Prior to sampling, informed verbal consent was obtained from all livestock owners, who were assured of the harmless nature of the procedures. Data Availability Statement All data generated or analyzed during this study are included in this published article. Competing interests The authors declare no competing interests\RL. Consent for publication Not applicable Funding No funding was received for this research. Authors’ contributions E.A. has conducted all parts of the study, including design, execution, and writing the manuscript. Acknowledgments The author would like to thank the Research Vice-Chancellor of Shiraz University of Medical Sciences. \RL The author would like to acknowledge that a preliminary version of this study was previously released as a preprint at SSRN: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4701483(Abbasi 2024) List of Abbreviations TBZ Tick-Borne Zoonoses CCHF Crimean-Congo Hemorrhagic Fever GPS Global Positioning System spp. Species (plural form) spp. Species (unspecified, plural) H. anatolicum Hyalomma anatolicum H. marginatum Hyalomma marginatum H. asiaticum Hyalomma asiaticum H. detritum Hyalomma detritum R. sanguineus Rhipicephalus sanguineus R. bursa Rhipicephalus bursa A. persicus Argas persicus A. reflexus Argas reflexus spp. Several species within the same genus DNA Deoxyribonucleic Acid ORCID Open Researcher and Contributor ID N/A Not Applicable References Abbasi E (2024) Biodiversity, geographical distribution, and faunal study of tick populations infesting livestock in an Elevated County of Midwest Iran. 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Oxford University PressTelmadarraiy Z, Vatandoost H, Chinikar S, Oshaghi M, Moradi M, Ardakan EM, Hekmat S, Nasiri A (2010) Hard ticks on domestic ruminants and their seasonal population dynamics in Yazd Province, Iran. Iranian journal of arthropod-borne diseases 4: 66. Uiterwijk M, Ibáñez-Justicia A, van de Vossenberg B, Jacobs F, Overgaauw P, Nijsse R, Dabekaussen C, Stroo A, Sprong H (2021) Imported Hyalomma ticks in the Netherlands 2018–2020. Parasites & vectors 14: 244. Walker AR (2003) Ticks of domestic animals in Africa: a guide to identification of species. Bioscience Reports EdinburghZuur AF, Ieno EN, Smith GM (2007) Analysing ecological data. Springer Figure legend Figure 1. Location of sampling sites in Delfan county, Lorestan province, Iran Caption : This map shows the spatial distribution of the 16 sampling localities selected for tick collection across Delfan County, with Noorabad indicated as the administrative center. Sampling sites are plotted according to their recorded geographic coordinates (latitude and longitude) and are distributed across both mountainous and plateau landscapes within the central Zagros range. The figure illustrates county boundaries, surrounding administrative regions, major roads, and topographical context, allowing visualization of elevation-related heterogeneity and spatial coverage of the study area. The selected sites represent a range of ecological conditions, livestock management systems, and grazing environments, ensuring comprehensive representation of local habitats relevant to tick survival and host–vector interactions during the study period (February 2019–February 2020). Figure 2. Comparative graphical representation of the three biodiversity indices (Margalef, Shannon, and Simpson) of ticks in Delfan showing their fluctuations over the 16 study sites. Caption : This figure illustrates the site-specific fluctuations of three widely used ecological diversity metrics Margalef’s richness index (d), Shannon–Wiener diversity index (H′), and Simpson’s diversity index (1–D) calculated for tick communities collected from 16 geographically distinct sampling localities in Delfan County, Lorestan Province, during a 12-month survey (February 2019–February 2020). Margalef’s index reflects inter-site variation in species richness, highlighting differences in the number of tick species recorded per locality. The Shannon–Wiener index integrates both species richness and evenness, providing a measure of community complexity and relative abundance distribution among species. Simpson’s index emphasizes species dominance and ecological stability, with higher values indicating more even and less dominance-driven assemblages. Collectively, the graphical comparison reveals pronounced spatial heterogeneity in tick community structure, with certain sites exhibiting high richness and balanced species composition, while others are characterized by low diversity and strong dominance by one or a few species. These patterns reflect local ecological conditions, host availability, and habitat heterogeneity across the mountainous and plateau environments of Delfan County and provide an ecological basis for interpreting site-specific risks of tick persistence and tick-borne pathogen transmission. Figure 3. Radar chart comparison of Margalef, Shannon–Wiener, and Simpson biodiversity indices of tick communities across representative sampling sites in Delfan County, western Iran Caption : Radar chart illustrating the comparative patterns of tick biodiversity across four representative sampling sites in Delfan County, Lorestan Province, western Iran. The chart integrates three widely used ecological indices: Margalef’s richness index, Shannon–Wiener diversity index (H′), and Simpson’s diversity index (1–D). Site 4 (Kafraj), Site 7 (Golam Bahri), and Site 13 (Bagverdiye-Olya) exhibit higher species richness, greater evenness, and increased ecological stability, whereas Site 12 (Balut Bazeh) demonstrates markedly reduced diversity and strong dominance by one or two species. This visualization highlights site-specific heterogeneity in tick community structure and emphasizes the influence of local ecological conditions on biodiversity patterns within the mountainous landscapes of Delfan County. Figure 4. Distribution of four ecological zones of Iran Caption : This map presents a refined and high-resolution depiction of Iran’s principal ecological zones based on broad climatic, physiographic, and biogeographical characteristics. The Caspian (Hyrcanian) forest zone is shown along the northern coastal belt of the Caspian Sea and the northern slopes of the Alborz Mountains, characterized by high precipitation, dense temperate broadleaf forests, and high biodiversity. The Alpine and montane zone encompasses the major mountain systems, including the Alborz and Zagros ranges, where elevation-driven gradients in temperature and moisture shape cold to cool climates, rugged topography, and specialized flora and fauna. The Irano–Turanian zone, occupying much of the central plateau and interior basins, is defined by semi-arid continental conditions, steppe and shrubland vegetation, and strong seasonal climatic variability. The Arid and desert zone dominates southern, southeastern, and eastern regions, including extensive deserts and coastal lowlands, characterized by low precipitation, high temperatures, sparse vegetation, and extreme environmental conditions. Major cities, international borders, coastlines, and surrounding water bodies are included for geographic reference. This ecological zonation provides an essential framework for interpreting spatial patterns of biodiversity, vector ecology, and environmental determinants of species distribution across Iran. Table legends Table 1. Spatial distribution, species richness, abundance, and biodiversity indices of tick communities across sampling sites in Delfan County, Lorestan Province, western Iran 1 Babajan Tappe 34°01′24.8″ 47°56′05.9″ 1891 53 2 41 12 0 0 0 0 0 0 1.75 0.53 0.37 Low diversity; strong dominance by H. anatolicum 2 Dare Dah Pahlavan 34°08′40.6″ 47°54′46.8″ 1879 68 3 34 0 22 0 0 12 0 0 2.76 1.02 0.63 Moderate richness; uneven species distribution 3 Abbas Abad Kani Kabood 34°00′28.5″ 47°58′17.6″ 1772 65 3 26 21 0 0 0 18 0 0 2.76 1.09 0.67 Moderately stable tick assemblage 4 Kafraj 34°06′04.5″ 48°04′14.3″ 1812 184 7 65 43 37 3 15 9 12 0 6.81 1.63 0.77 Highest diversity and ecological stability 5 Zaliabad 34°00′41.2″ 48°01′49.7″ 1904 36 2 0 13 0 0 0 0 23 0 1.72 0.65 0.49 Low richness; dominance of soft ticks 6 Deh Firoozvande Bala 34°07′58.0″ 47°59′58.0″ 1840 71 3 0 57 0 0 0 0 9 5 2.77 0.63 0.35 Uneven structure; limited species evenness 7 Golam Bahri 34°08′33.8″ 48°01′34.5″ 1801 133 6 48 28 22 5 0 26 0 4 5.80 1.54 0.77 High diversity; well-balanced tick community 8 Salianeh 34°03′37.3″ 48°04′54.0″ 1849 102 5 63 0 8 0 0 14 11 6 4.78 1.18 0.59 Moderate diversity; mixed host associations 9 Deh Kabood Chovari 34°11′02.4″ 47°58′28.7″ 1866 75 5 66 1 6 1 1 0 0 0 4.77 0.49 0.23 High dominance; low evenness 10 Dam Bagh 33°54′32.6″ 47°56′15.9″ 1653 95 4 66 0 11 0 0 13 0 5 3.78 0.77 0.49 Moderate richness; dominance by Hyalomma 11 Gur Mohammad 33°56′42.3″ 47°48′55.2″ 1777 75 3 42 16 0 0 0 0 17 0 2.77 0.99 0.60 Moderate diversity; limited species spectrum 12 Balut Bazeh 34°01′29.8″ 47°46′55.7″ 1792 62 2 58 0 0 0 0 0 0 4 1.76 0.24 0.14 Lowest diversity; highly unstable community 13 Bagverdiye-Olya 34°02′56.8″ 48°09′09.3″ 1893 146 6 47 63 18 7 4 0 7 0 5.80 1.38 0.70 High richness; near-equilibrium structure 14 Sormeh 34°04′48.7″ 47°36′26.7″ 1580 58 2 42 0 0 0 0 16 0 0 1.75 0.59 0.42 Low diversity; strong species dominance 15 Mehrabad-e Tudehrud 34°10′47.1″ 47°44′33.1″ 1676 70 3 32 0 0 0 0 20 18 0 2.76 1.07 0.66 Moderately balanced assemblage Caption: Spatial variation in tick species composition, abundance, and biodiversity indices across 16 sampling localities in Delfan County, Lorestan Province, western Iran. The table presents geographic coordinates and elevation for each site, total number of collected tick specimens, species richness (S), absolute abundance of each identified tick species, and corresponding biodiversity metrics, including Margalef’s richness index, Shannon–Wiener diversity index (H′), and Simpson’s diversity index (1–D). These indices collectively describe species richness, evenness, and dominance patterns of tick communities at each locality, providing insight into ecological stability and site-specific heterogeneity of tick assemblages across mountainous and plateau environments during the study period (February 2019–February 2020). Table 2. Integrated summary of tick species composition, host association, topographical distribution, and seasonal activity of ticks collected from livestock and birds in Delfan County, Lorestan Province, Iran (February 2019–February 2020) Ixodidae Hyalomma Hyalomma anatolicum Ungulates Sheep, goats, cattle 647 49.0 Predominant (majority of specimens; >70%) Minority 152 (23.5) 427 (66.0) 52 (8.0) 16 (2.5) Most abundant and geographically widespread species; dominant vector of zoonotic pathogens; high ecological plasticity Ixodidae Hyalomma Hyalomma marginatum Ungulates Sheep, goats, cattle 281 21.0 Predominant Minority 76 (27.0) 134 (47.7) 65 (23.1) 6 (2.1) Major vector species; broad seasonal activity with summer peak Ixodidae Hyalomma Hyalomma asiaticum Ungulates Sheep, goats 124 9.0 Predominant Minority 63 (50.8) 28 (22.6) 19 (15.3) 14 (11.3) Adapted to mountainous and semi-arid environments; extended seasonal persistence Ixodidae Hyalomma Hyalomma detritum Ungulates Sheep 16 1.0 Exclusive Absent 0 (0) 0 (0) 16 (100) 0 (0) Highly seasonal species; activity restricted to cooler autumn conditions Ixodidae Rhipicephalus Rhipicephalus sanguineus Ungulates Sheep, goats, cattle 128 10.0 Moderate Moderate 38 (29.7) 64 (50.0) 23 (18.0) 3 (2.3) Generalist tick with high host adaptability; important zoonotic vector Ixodidae Rhipicephalus Rhipicephalus bursa Ungulates Sheep, goats 20 1.0 Limited Limited 7 (35.0) 9 (45.0) 4 (20.0) 0 (0) Low abundance species; localized distribution Argasidae Argas Argas persicus Birds Chickens 97 7.0 Low Moderate 13 (13.4) 24 (24.7) 53 (54.6) 7 (7.2) Poultry-associated soft tick; autumn peak linked to indoor housing Argasidae Argas Argas reflexus Birds Pigeons 24 2.0 Very low Moderate 0 (0) 15 (62.5) 0 (0) 9 (37.5) Nest-associated soft tick; limited host range and distribution Total — 8 species — Livestock & birds 1337 100 1007 (75.3) 330 (24.7) 349 (26.1) 701 (52.4) 232 (17.4) 55 (4.1) Integrated dataset combining host, habitat, and seasonal dynamics Caption : Integrated overview of tick species composition, host associations, topographical distribution, and seasonal activity patterns of ticks collected from livestock and birds in Delfan County, Lorestan Province, western Iran, during a 12-month sampling period (February 2019–February 2020). The table summarizes absolute and relative abundances of each identified tick species, their primary host groups and specific host species, distribution across mountainous and plateau environments, and seasonal occurrence (spring, summer, autumn, and winter). Percentages are calculated relative to the total number of collected specimens (n = 1,337) or within each ecological or temporal category, as appropriate Information & Authors Information Version history V1 Version 1 01 February 2026 Copyright This work is licensed under a Non Exclusive No Reuse License. Keywords 1: evolutionary ecology 36: biodiversity 4: population ecology 5: species interaction 7: ecosystem ecology biodiversity hyalomma livestock seasonal dynamics ticks Authors Affiliations Ebrahim Abbasi 0000-0003-1861-5321 [email protected] Shiraz University of Medical Sciences View all articles by this author Metrics & Citations Metrics Article Usage 220 views 79 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation Ebrahim Abbasi. Biodiversity, Geographical Distribution, and Faunal Study of Tick Populations Infesting Livestock in an Elevated County of Midwest Iran. Authorea . 01 February 2026. DOI: https://doi.org/10.22541/au.176990961.12148215/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. For more information or tips please see 'Downloading to a citation manager' in the Help menu . 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