Gazelle Populations Research Articles

Social behaviour mediates the microbiome response to antibiotic treatment in a wild mammal.

High levels of social connectivity among group-living animals have been hypothesized to benefit individuals by creating opportunities to rapidly reseed the microbiome and maintain stability against disruption. We tested this hypothesis by perturbing the microbiome of a wild population of Grant's gazelles with an antibiotic and asking whether microbiome recovery differs between individuals with high versus low levels of social connectivity. We found that after treatment, individuals with high social connectivity experienced a faster increase in microbiome richness than less socially connected individuals. Unexpectedly, the rapid increase in microbiome richness of highly connected individuals that received treatment led to their microbiomes becoming more distinct relative to the background population. Our results suggest that the microbiome of individuals with high social connectivity can be rapidly recolonized after a perturbation event, but this leads to a microbiome that is more distinct from, rather than more similar to the unperturbed state. This work provides new insight into the role of social interactions in shaping the microbiome.

Vocalisation in wild-living mountain gazelles (Gazella gazella): structure and context of acoustical signals

Abstract Describing vocalisations of species in the wild is an important step to understanding their function. A wild-living population of mountain gazelles (Gazella gazella) was monitored in Israel, using camera traps, thereby providing a first detailed description of the acoustic repertoire. We described six acoustical signals that were either reported by previous authors or that were hitherto not reported. Acoustic signals were categorised according to behavioural context as alarm calls, courtship calls or threat calls and — if possible — characterised by four acoustic variables, i.e., duration, maximum amplitude frequency, three power quartiles and fundamental frequency. Vocalisations were illustrated as spectrograms supplemented by full video sequences to show the acoustical signal in its environmental, social, and behavioural context. Given the rather inconspicuous character of many acoustic signals, we proposed further in-depth studies of vocalisation in mountain gazelles and other Antilopine species to unravel new insights into their behaviour and social organisation.

An improved mountain gazelle optimizer based on chaotic map and spiral disturbance for medical feature selection.

Feature selection is an important solution for dealing with high-dimensional data in the fields of machine learning and data mining. In this paper, we present an improved mountain gazelle optimizer (IMGO) based on the newly proposed mountain gazelle optimizer (MGO) and design a binary version of IMGO (BIMGO) to solve the feature selection problem for medical data. First, the gazelle population is initialized using iterative chaotic map with infinite collapses (ICMIC) mapping, which increases the diversity of the population. Second, a nonlinear control factor is introduced to balance the exploration and exploitation components of the algorithm. Individuals in the population are perturbed using a spiral perturbation mechanism to enhance the local search capability of the algorithm. Finally, a neighborhood search strategy is used for the optimal individuals to enhance the exploitation and convergence capabilities of the algorithm. The superior ability of the IMGO algorithm to solve continuous problems is demonstrated on 23 benchmark datasets. Then, BIMGO is evaluated on 16 medical datasets of different dimensions and compared with 8 well-known metaheuristic algorithms. The experimental results indicate that BIMGO outperforms the competing algorithms in terms of the fitness value, number of selected features and sensitivity. In addition, the statistical results of the experiments demonstrate the significantly superior ability of BIMGO to select the most effective features in medical datasets.

Assessment of the global population size of the Mongolian gazelle Procapra gutturosa

Abstract The Mongolian gazelle Procapra gutturosa is a wild ungulate ubiquitous across the largest remaining temperate grasslands of Mongolia, Russia and China. The species is nomadic and ranges over long distances, resulting in widely fluctuating abundance in any given location. Therefore, a comprehensive and range-wide survey is required to accurately estimate its global population size, but challenges are posed by the expansive geographical distribution and the political boundaries across the species’ vast range. To obtain an estimate of the total population, we compiled data from recent range-wide surveys. During 2019–2020, we estimated the population size in Mongolia by conducting line transect distance surveys and total counts, and by deriving numerical predictions for unsurveyed areas through data analysis. The gazelle's population in Russia was surveyed in 2020 across its summer range using simultaneous counts, transect surveys and expert knowledge. The distance sampling surveys in Mongolia revealed that slightly more than half of the gazelles along the transects were detected. Our assessment of the gazelle population, although probably an underestimate, suggests there are c. 2.14 million individuals in Mongolia and c. 30,000 in Russia. These results confirm that the Mongolian gazelle is the most abundant nomadic ungulate in the open plains across its range. However, to obtain more accurate estimates across all range states and effectively monitor the gazelle's population status, it is essential to implement standardized survey protocols that correct for imperfect detection. At present, the management of the Mongolian gazelle is inadequate, as there is a lack of regular monitoring to identify any adverse population changes that could necessitate conservation interventions.

Helminths of captive and free-ranging populations of the mountain gazelle (Gazella gazella): Evidence from faecal examination.

Understanding parasite diversity in wild and captive animal populations has critical implications for both individual animal health and ecosystem dynamics in a broader sense. In mountain gazelles (Gazella gazella), the gastrointestinal helminth community is poorly understood, limiting our efforts in the conservation of this endangered bovid species. This species has only two remaining populations in the world, including the isolated northernmost population in Türkiye. To identify and compare the diversity and prevalence of gastrointestinal helminths in captive and free-ranging populations of mountain gazelles in Hatay, Türkiye, and to assess potential zoonotic risks. In total, 105 fresh faecal samples, 45 individual samples and 60 faecal samples, representing 16 pools, from both captive and free-ranging populations were collected and analysed using Fulleborn flotation, Benedek sedimentation and Bearman-Wetzel methods faecal flotation methods, including the McMaster technique to determine the severity of infection. We detected 12 helminth taxa in our examination of faecal samples, including gastrointestinal nematodes, lungworms and trematodes. Parasites from the Trichostrongyloidea family demonstrated variable hatching stages and rates, potentially influenced by ambient conditions. We also detected one protozoan among the samples. Our results revealed a higher diversity of parasites in free-ranging populations compared to captive ones. This study underscores the necessity for regular parasitological surveillance in both captive and free-ranging wildlife populations for effective conservation management. It also contributes to the 'One Health' perspective by highlighting the potential zoonotic risks posed by parasites in wild ruminants. Our results have implications for the conservation and management of the mountain gazelle.

Genetic diversity and structure of mongolian gazelle (Procapra gutturosa) populations in fragmented habitats

BackgroundThe Mongolian gazelle (Procapra gutturosa) population has shown a considerable range of contractions and local extinctions over the last century, owing to habitat fragmentation and poaching. A thorough understanding of the genetic diversity and structure of Mongolian gazelle populations in fragmented habitats is critical for planning effective conservation strategies.ResultIn this study, we used eight microsatellite loci and mitochondrial cytochrome b (Cytb) to compare the levels of genetic diversity and genetic structure of Mongolian gazelle populations in the Hulun Lake National Nature Reserve (HLH) with those in the China-Mongolia border area (BJ). The results showed that the nucleotide diversity and observed heterozygosity of the HLH population were lower than those of the BJ population. Moreover, the HLH and BJ populations showed genetic differentiation. We concluded that the HLH population had lower genetic diversity and a distinct genetic structure compared with the BJ population.ConclusionThe genetic diversity of fragmented Mongolian gazelle populations, can be improved by protecting these populations while reinforcing their gene exchange with other populations. For example, attempts can be made to introduce new individuals with higher genetic diversity from other populations to reduce inbreeding.

Immunohistological study of the unexplored vomeronasal organ of an endangered mammal, the dama gazelle (Nanger dama).

Dama gazelle is a threatened and rarely studied species found primarily in northern Africa. Human pressure has depleted the dama gazelle population from tens of thousands to a few hundred individuals. Since 1970, a founder population consisting of the last 17 surviving individuals in Western Sahara has been maintained in captivity, reproducing naturally. In preparation for the future implementation of assisted reproductive technology, certain aspects of dama gazelle reproductive biology have been established. However, the role played by semiochemical-mediated communications in the sexual behavior of dama gazelle remains unknown due partially to a lack of a neuroanatomical or morphofunctional characterization of the dama gazelle vomeronasal organ (VNO), which is the sensory organ responsible for pheromone processing. The present study characterized the dama gazelle VNO, which appears fully equipped to perform neurosensory functions, contributing to current understanding of interspecies VNO variability among ruminants. By employing histological, lectin-histochemical, and immunohistochemical techniques, we conducted a detailed morphofunctional evaluation of the dama gazelle VNO along its entire longitudinal axis. Our findings of significant structural and neurochemical transformation along the entire VNO suggest that future studies of the VNO should take a similar approach. The present study contributes to current understanding of dama gazelle VNO, providing a basis for future studies of semiochemical-mediated communications and reproductive management in this species. RESEARCH HIGHLIGHTS: This exhaustive immunohistological study of the vomeronasal organ (VNO) of the dama gazelle provides the first evidence of notable differences in the expression of neuronal markers along the rostrocaudal axis of the VNO. This provides a morphological basis for the implementation of pheromones in captive populations of dama gazelle.

Movement drives population dynamics of one of the most mobile ungulates on Earth: Insights from a mechanistic model.

Long-distance movements are hypothesized to positively influence population size and stability of mobile species. We tested this hypothesis with a novel modeling approach in which moving herbivores interact with the environment created by a dynamic global vegetation model using highly mobile Mongolian gazelles in the eastern Mongolian grasslands as a case study. Gazelle population dynamics were modeled from 1901 to 2018 under two scenarios, one allowing free movement and one restricting movement. Gazelles were 2.2 times more abundant when they could move freely and were extirpated in 71% of the study area when mobility was restricted. Mobility resulted in greater population increases during times of abundant forage and smaller population decreases during drought. Reduced thermoregulatory costs associated with climate change, combined with an increase in vegetation biomass, increased gazelle abundance. Since high abundances often resulted in overgrazing and, thus, extirpation when movement was restricted, mobility had an important role in maintaining higher densities. The novel modeling approach shows how accounting for not just herbivore but also plant ecophysiology can improve our understanding of the population dynamics of highly mobile herbivores, in particular when examining the effects of habitat and climate change. Since the model simulates herbivores based on general physiological mechanisms that apply across large herbivores and the vegetation model can be applied globally, it is possible to adapt the model to other large-herbivore systems.

Animal behavior informed by history: Was the Asiatic cheetah an obligate gazelle hunter?

Understanding key ecological adaptations, such as foraging, when a predator is almost extinct is complex. Nonetheless, that information is vital for the recovery of the persisting individuals. Therefore, reviewing historical, ethnobiological and recent records can assist in exploring the species behavioral ecology. We applied this approach to Asiatic cheetahs (Acinonyx jubatus venaticus), which once roamed most west and central Asian countries but now is confined to a few dozens in Iran, at historical (pre-1970) and recent (post-1970) scales. We addressed a widely popular perception that Asiatic cheetahs were subjected to prey shifts from gazelles (Gazella spp.) in open plains areas to urial (Ovis vignei) in mountains because of gazelle populations declines due to anthropogenic influences. We also quantified recent prey choice of Asiatic cheetahs and their behavioral plasticity in foraging different prey species types. Although ethnobiological and historical records suggested that gazelle species were the main prey for cheetahs across their Asian range. However, urial were also commonly reported to be hunted by cheetahs across their historical Asian range, showing that the predation on mountain ungulates is not an emerging hunting behavior in Asiatic cheetahs. We found spatiotemporal plasticity in recent hunting behavior of cheetahs with selective predation on adult urial males. There was temporal overlap in hunting times for plains dwelling versus mountain ungulates, albeit with some minor differences with morning mostly for gazelles while the predation on mountain ungulates was predominantly post-midday. We provided three management implications for the recovery and restoration of cheetahs in Asia. Our work highlighted the importance of historical studies in informing the behavioral ecology of rare species.

Conservation of the Goitered gazelle (Gazella subgutturosa) under climate changes in Iraq

Climate is a vital factor that shapes habitat suitability for many species across space and time. Gazella subgutturosa (Goitered gazelle) is a globally vulnerable mammal already extinct in some areas of Armenia and Georgia and is highly threatened in other areas of its distribution. In this study, new data were gathered for 33 locations in north-eastern Iraq, and then together with literature data, Species Distribution Models (SDMs) were used to explore the geographical distribution of the gazelle under current and future climate change scenarios. We studied the relationship between seven climate variables and 43 occurrence records to predict habitat suitability of the gazelle under the current climate, and also under four future climate scenarios (RCP2.6 and RCP8.5 for both 2050 and 2080). Annual precipitation and isothermality had the most influence on the distribution of Gazella subgutturosa. The most suitable habitat in both the current and future scenarios was located in north-eastern Iraq close to the Iranian border near the Zagros Mountains. There was no difference in habitat suitability for the gazelle inside Iraqi Protected Areas (PAs) compared to outside the PAs. Using the occurrence records and IUCN Red List national assessments, we found Iraqi Goitered gazelle populations to be classified as Endangered (EN). Our results suggest urgent conservation planning is needed to save this species, including the establishment of new PAs. These results contribute new baseline information, which was currently missing Goitered gazelle in about Iraq, to the IUCN SSC Antelope Specialist Group, which will hopefully aid with future global assessments and conservation.

Finding slender-horned gazelles in the Sahara's Grand Erg Oriental, Tunisia

North-African slender-horned gazelles are facing extensive poaching pressure. The main remaining population patch occurs in Saharan habitat between Tunisia and Algeria. Access to the species' distribution range in both countries is limited by difficult terrain and strict permitting requirements. We explored a mix of aerial (1365 km) and ground transects (351 km) to monitor the Grand Erg Oriental which covers the species' range in Tunisia. Only ungulate spoors but no gazelles were observed during the aerial survey over the southern part of the study area. Ground survey in the northern part revealed more conclusive results with evidence and observation of one couple, one group of three and another of four individuals. Our results confirm the presence of a slender-horned gazelle population in Tunisia yet support the need for immediate intervention to halt its decline. Ex-situ conservation is essential to the species’ future survival and continuous monitoring of the wild range is recommended.

The Characteristics of the Main Habitats of Goitered Gazelle (Artiodactyla, Bovidae) in Azerbaijan

The goitered gazelle was widely distributed in semi-desert plains and mountain foothills of the country. In historical times the distribution and number of gazelles was depending on alluvial activity of Kura and Araxes Rivers, level of the water in the Caspian Sea, irrigation and cultivation of steppes and semideserts, persecution of the gazelles by numerous tribes and peoples that inhabited this territory etc. By the mid XX century the number of gazelles in Azerbaijan declined catastrophically and was about to be extinct. By common efforts of state and international conservation organizations it was possible to significantly restore the historical range and the number of gazelle population in the country. Our studies covered current and potential gazelle habitats with purpose to find perspective sites for reintroduction. The article is devoted to a description of main habitats of the goitered gazelle in Azerbaijan.

Revisiting Late Pleistocene-Early Holocene mountain gazelle (Gazella gazella) body size change in the southern Levant: A case for anthropogenic impact.

The average body size of human prey animals in archaeological sites is influenced by myriad environmental, physiological and anthropogenic variables. When combined with supporting evidence, body size has the potential to provide a proxy for several variables of fundamental interest to archaeologists including climatic change, food availability and hunting impacts, among other things. In the southern Levant changes in mountain gazelle (Gazella gazella) body size in the Late Pleistocene were initially interpreted as evidence for a climatic downturn, but the picture has become increasingly murky as data has grown. Here we reconsider trends in gazelle body size using an updated dataset from the Mediterranean zone that spans the Early Epipaleolithic to the Middle Pre-Pottery Neolithic B period (ca. 24,000–9,500 cal BP). Our results reveal that gazelle were smallest in the Early and Middle Epipaleolithic (Kebaran and Geometric Kebaran), reached their largest size in the early Late Epipaleolithic (Early Natufian) and then shrunk slightly before stabilizing in size through the Middle Pre-Pottery Neolithic. We see no evidence that sex ratio, or climatic factors influenced this trend. Instead, we explore the role of human impacts on gazelle populations and their habitats as they grew in earnest at the beginning of the Late Epipaleolithic when people first began to settle into more permanent communities. Initially, in the Early and Late Natufian, anthropogenic impacts related to more intensive hunting and the increased footprint of more permanent settlements on the landscape. This may have pushed gazelle numbers below what could be supported by the environment, thus increasing the amount of food available for each animal and hence average body size. Later, as humans began to cultivate plants, manage animals and establish permanent villages, avoidance of humans and livestock by gazelle, and greater stability in food and water availability provided by agriculture, may have similarly reduced gazelle population size and intraspecific competition, thus allowing individual animals to grow larger on average.

Monitoring threatened ungulates (Gazella cuvieri and Ammotragus lervia) in the semi-arid North African Nador Mountains

Cuvier’s gazelle (Gazella cuvieri) and aoudad (Ammotragus lervia) are listed as Vulnerable in the IUCN red list, and any population should be the subject of scientific attention. Both ungulates were monitored for a year in the Nador Mountains (western Algeria). This is the first record of aoudad in this part of Tiaret province. Both species are partly sympatric. However, the aoudad was sighted only in small numbers in the roughest valleys in the north. The gazelle population is larger, but with few juveniles. The future of these wild ungulates is therefore worrying, and new conservation measures are required, including protecting this area.

Body size variation in a modern collection of mountain gazelle (Gazella gazella) skeletons

Two-dimensional measurements of skeletal elements are important zooarchaeological tools that not only provide crucial information about the sex and age of an animal, but on past environmental conditions and human-animal interactions as well. The causes of animal body size variation are many and thus problems of equifinality make it difficult to interpret archaeological measurement data. Here, we explore the sources of body size variation in a modern skeletal collection of mountain gazelle (Gazella gazella) composed of individuals of known sex, age and geographic location. We investigate the relative contribution of sex, age and environmental factors (temperature and precipitation) to variation in the 2D measurements of five commonly preserved skeletal elements (scapula, humerus, second phalanx, tibia and astragalus) to determine which factors are most influential. Overall, sex is the most powerful determinant of gazelle body size, while age has little impact on most elements. Importantly, although the breadth of the trochlea of the distal humerus has often been used to sex archaeological gazelle specimens, this element did not differ statistically for males and females. Maximum July temperature also influenced the distal depth of the tibia and the trochlea of the humerus. This may relate to reduced food availability during the critical period of juvenile growth in areas with hotter summers due to higher rates of evaporation and shorter growing seasons. The absence of a significant relationship between the other climatic variables and body size, and the large amount of variability that these factors could not account for, may relate to the confounding impact of anthropogenic activities. In recent decades human landscape modification and agriculture have impacted the natural scheduling of plant and water resources and gazelle population size.

Gazella arabica dareshurii: a remarkable relict population on Farur Island, Iran

BackgroundThe islands in the Persian Gulf are home to several species of gazelles, i.e., Gazella bennettii, G. subgutturosa, and a new subspecies of Mountain gazelles which was discovered on Farur Island and described for the first time in 1993 as Gazella gazella dareshurii. Later, phylogenetic analyses showed that the Mountain gazelles consist of two species: G. gazella and G. arabica. As the Farur gazelles are more closely related to the Arabian forms of the Mountain gazelles, this subspecies is regarded to be G. arabica dareshurii. Until now, the origin of this subspecies has been an enigma.ResultsHere, we used mitochondrial cyt b, two nuclear introns (CHD2 and ZNF618), and morphological data to address this question by investigating the taxonomic position of the Farur gazelles. The results show that this population is monophyletic and split from other G. arabica populations probably 10,000 BP.ConclusionsIt is a natural relict population that was trapped on the island due to the rising sea levels of the Persian Gulf after the Last Glacial Maximum. Intermittent drought and flooding are suggested to be the main factors balancing population growth in the absence of natural predators on this monsoon-influenced island. Conservation actions should focus on preserving the natural situation of the island (cease introducing mesquite tree and other invasive species, stop building new construction and roads, and caution in providing water sources and forage), and possibly introducing individuals to other islands (not inhabited by gazelles) or to fenced areas on the Iranian mainland (strictly isolated from other gazelle populations) when the population reaches the carrying capacity of the island.

Fecal Bacterial Community of Allopatric Przewalski's Gazelles and Their Sympatric Relatives.

Mammal gastrointestinal tracts harbor diverse bacterial communities that play important roles in digestion, development, behavior, and immune function. Although, there is an increasing understanding of the factors that affect microbial community composition in laboratory populations, the impact of environment and host community composition on microbiomes in wild populations is less understood. Given that the composition of bacterial communities can be shaped by ecological factors, particularly exposure to the microbiome of other individuals, inter-specific interactions should impact on microbiome community composition. Here, we evaluated inter-population and inter-specific similarity in the fecal microbiota of Przewalski’s gazelle (Procapra przewalskii), an endangered endemic ruminant around Qinghai Lake in China. We compared the fecal bacterial communities of three Przewalski’s gazelle populations, with those of two sympatric ruminants, Tibetan gazelle (Procapra picticaudata) and Tibetan sheep (Ovis aries). The fecal bacterial community richness (Chao1, ACE) did not vary across the three Przewalski’s gazelle populations, nor did the composition vary between species. In contrast, the managed Przewalski’s gazelle population had higher bacterial diversity (Shannon and Simpson) and was more similar to its sympatric Tibetan sheep in beta diversity than the wild Przewalski’s gazelle populations. These results suggest that ecological factors like host community composition or diet affect Przewalski’s gazelle’s gastrointestinal bacterial community. The role of bacterial community composition in maintaining gastrointestinal health should be assessed to improve conservation management of endangered Przewalski’s gazelle. More broadly, captive breeding and reintroduction efforts may be impeded, where captive management results in dysbiosis and introduction of pathogenic bacteria. In free ranging populations, where wildlife and livestock co-occur, infection by domestic pathogens and diseases may be an underappreciated threat to wild animals.

Степень изученности джейрана (Artiodactyla, Bovidae) в Азербайджане

The Goitered gazelle is the only representative of true antelopes’ subfamily in the Caucasus. It was widely distributed in semi-desert plains and mountain foothills of the country. By the mid XX century the number of gazelles in Azerbaijan declined catastrophically and was about to be extinct. By common efforts of state and international conservation organizations it was possible to significantly restore the historical range and the number of gazelle population in the country. The Goitered gazelle is one of the priority species and much attention paid to its conservation and restoration in Azerbaijan. But the ecology of this species is still not studied properly. The article is devoted to a brief overview of the main literary sources concerning various population aspects of gazelle and the level of their study in Azerbaijan.

An attempt to restore the population of the Goitered Gazelle (Gazella subgutturosa) in its indigenous range in the Caucasus (Mammalia: Bovidae)

Since the 1930s, the range and numbers of the Goitered Gazelle Gazella subgutturosa declined rapidly in the Caucasus and fell to a critical size in the 1960s when the species became extinct in Georgia and in most parts of the species range in Azerbaijan. After the establishment of target protected areas in Azerbaijan, the number of gazelles significantly increased, but the population is mostly concentrated in the isolated Shirvan protected areas on the Caspian Sea coast, which currently holds more than 10% of the global Goitered Gazelle population. Using Shirvan as a source population, regular reintroduction activities started in the early 2010s: Azerbaijan-Georgia transboundary area became the priority for the last decade. In total 174 individuals have been translocated and released directly after transportation (hard release) in two sites. At first, growth of the reintroduced population was slow, but now, 7–9 years after the translocation started a clear increase of the population size has been recorded. Today, the total population of the two groups is around 312 individuals (including juveniles). It is expected that with further growth the groups will unify and create a stable, new, trans-boundary gazelle population.

Optimizing livestock carrying capacity for wild ungulate-livestock coexistence in a Qinghai-Tibet Plateau grassland

Wild ungulates are an important part of terrestrial ecosystems and play a critical role in maintaining ecosystem health and integrity. In many grassland ecosystems that are habituated by wild ungulates, the coexistence of domestic ungulates has created a conflict over grazing resources. Solving this conflict requires a balanced and sustainable policy that satisfies both the needs of wildlife protection and food production. Here, we assess the optimal grassland livestock carrying capacity of an alpine grassland on the Qinghai-Tibet Plateau, given the coexistence of wild populations of kiangs (Equus kiang) and Tibetan gazelles (Procapra picticaudata), two key species grazing in this region. We use kriging and the MaxEnt method to estimate the population sizes of kiangs and Tibetan gazelles in Maduo County, Qinghai Province. We then convert the estimated population size of the two species into sheep units and calculate the residual carrying capacity for livestock grazing. We show that after accounting for the grazing need for kiangs and Tibetan gazelles, grassland in Maduo is capable of supporting 420,641 sheep units, which is slightly more than the current livestock population. However, the residual carrying capacity is highly uneven across the region, and overgrazing is found in many areas of Maduo, especially in northern Maduo. This research provides a useful framework for planning sustainable livestock farming for the Qinghai-Tibet Plateau and other regions facing wildlife-livestock conflict.