Diet Switching and Interspecific Competition in Sympatric Steppe Ungulates Under Seasonal Resource Variability

Ecological adaptation mechanisms of plateau ungulates to seasonal nomadic pastoralism on the eastern Qinghai-Tibetan plateau

There is an urgent need of understanding the distribution and abundance of the key species, Tibetan wild ass ( Equus kiang ), Tibetan gazelle ( Procapra picticaudata ) and Tibetan antelope ( Pantholops hodgsonii ) in the Three-River-Source National Park, especially after the first national park in China established there. We carried out field surveys in summers from 2014 to 2017 following the distance sampling protocol in the park, covering an area of 538000 km2. The total length of the survey routes is 14597.8 km. We recorded 3711 individuals of Tibetan wild ass, 1187 individuals of Tibetan gazelles, and 423 individuals of Tibetan antelopes. In order to accurately estimate the species abundance, we used species distribution models to quantify the relationship between species accurrences and 22 environmental variables, and predicted the population density in the whole study area. We compared the model prediction and field survey results, and made adjustment accordingly. The estimated abundance of Tibetan wild ass, Tibetan gazelle and Tibetan antelope in the study area is 44240, 13162, and 2390, respectively. To evaluate the potential bias of the estimation, we took into account of survey uncertainties, model uncertainties, and adjustment uncertainties using the detaction function based on distance sampling, R 2 of species distribution models, and spatial heterogeneity of model-observation matchness. Our new method for estimating species abundance is suitable for species whose distribution is well correlated with environmental varibles, and the results of distance sampling are available.

Using the Yellow-River-Source National Park (YRSNP) as a study site, an unmanned aerial vehicle (UAV) remote sensing and line transect method was used to investigate the number of wild herbivorous animals and livestock, including the kiang (Equus kiang) and Tibetan gazelle (Procapra picticaudata). A downscaling algorithm was used to generate the forage yield data in YRSNP based on a 30-m spatial resolution. On this basis, we estimated the forage–livestock balance, which included both wild animals and livestock, and analyzed the effects of functional zone planning in national parks on the forage–livestock balance in YRSNP. The results showed that the estimates of large herbivore population numbers in YRSNP based on population density in the aerial sample strips, which were compared and validated with official statistics and warm season survey results, indicated that the numbers of kiangs and Tibetan gazelles in the 2017 cold season were 12,900 and 12,100, respectively. The numbers of domestic yaks, Tibetan sheep, and horses were 53,400, 76,800, and 800, respectively, and the total number of sheep units was 353,200. The ratio of large wild herbivores and livestock sheep units was 1:5. Large wild herbivores have different preferences for functional zones, preferring ecological restoration areas consisting mainly of sparse grassland. The grazing pressure indices of the core reserve areas and ecological restoration areas were 0.168 and 0.276, respectively, indicating that these two regions still have high grazing potential. However, the grazing pressure index of the traditional utilization areas was 1.754, indicating that these grasslands are severely overloaded. After the planning and implementation of functional zones, the grazing pressure index of YRSNP was 1.967. Under this measure, the number of livestock was not reduced and the grazing pressure nearly doubled, indicating that forage–livestock conflict has become more severe in YRSNP.

Ungulates are essential for maintaining the health of grassland ecosystems on the Tibetan plateau. Increased livestock grazing has caused competition for food resources, threatening ungulates’ survival. The survival risk of food resources for ungulates can be quantified by the grazing pressure index, which requires accurate grassland carrying capacity. Previous research on the grazing pressure index has rarely taken into account the influence of wild ungulates, mainly due to the lack of precise spatial data on their quantity. In this study, we conducted field investigations to construct high-resolution spatial distributions for the four endemic ungulates on the Tibetan plateau. By factoring in the grazing consumption of these ungulates, we recalculated the grassland carrying capacity to obtain the grazing pressure index, which allowed us to assess the survival risks for each species. The results show: (1) Quantity estimates for Tibetan antelope (Pantholops hodgsonii), Tibetan wild donkey (Equus kiang), Tibetan gazelle (Procapra picticaudata), and wild yak (Bos mutus) of the Tibetan plateau are 24.57 × 104, 17.93 × 104, 7.16 × 104, and 1.88 × 104, respectively; they mainly distributed in the northern and western regions of the Tibetan plateau. (2) The grassland carrying capacity of the Tibetan plateau is 69.98 million sheep units, with ungulate grazing accounting for 5% of forage utilization. Alpine meadow and alpine steppe exhibit the highest grassland carrying capacity. (3) The grazing pressure index on the Tibetan plateau grasslands is 2.23, indicating a heightened grazing pressure in the southern and eastern regions. (4) The habitat survival risk analysis indicates that the high survival risk (the grazing pressure index exceeds 1.2) areas for the four ungulate species account for the following proportions of their total habitat areas: Tibetan wild donkeys (49.76%), Tibetan gazelles (47.00%), Tibetan antelopes (40.76%), and wild yaks (34.83%). These high-risk areas are primarily located within alpine meadow and temperate desert steppe. This study provides a quantitative assessment of survival risks for these four ungulate species on the Tibetan plateau grasslands and serves as a valuable reference for ungulate conservation and grassland ecosystem management.

The extent to which a species responds to environmental changes is mediated not only by extrinsic processes such as time and space, but also by species-specific ecology. The Qinghai-Tibetan Plateau uplifted approximately 3000 m and experienced at least four major glaciations during the Pleistocene epoch in the Quaternary Period. Consequently, the area experienced concurrent changes in geomorphological structure and climate. Two species, the Tibetan antelope (Pantholops hodgsonii, chiru) and Tibetan gazelle (Procapra picticaudata), both are endemic on the Qinghai-Tibetan Plateau, where their habitats overlap, but have different migratory behaviors: the chiru is inclined to have female-biased dispersal with a breeding migration during the calving season; in contrast, Tibetan gazelles are year-round residents and never migrate distantly. By using coalescence methods we compared mitochondrial control region DNA sequences and variation at nine microsatellite loci in these two species. Coalescent simulations indicate that the chiru and Tibetan gazelle do not share concordant patterns in their genealogies. The non-migratory Tibetan gazelle, that is more vulnerable to the impact of drastic geographic changes such as the elevation of the plateau, glaciations and so on, appears to have a strong population genetic structure with complicated demographic history. Specifically, the Tibetan gazelle population appears to have experienced isolation and divergence with population fluctuations since the Middle Pleistocene (0.781 Ma). However, it showed continued decline since the Upper Pleistocene (0.126 Ma), which may be attributed to the irreversible impact of increased human activities on the plateau. In contrast, the migratory chiru appears to have simply experienced population expansion. With substantial gene flow among regional populations, this species shows no historical population isolation and divergence. Thus, this study adds to many empirical studies that show historical and contemporary extrinsic and intrinsic processes shape the recent evolutionary history and population genetic structure of species.

Reference values were established for some serum hematological and biochemical constituents in Przewaiski’s and Tibetan gazelles in China. The contents of mineral elements in the blood, hair, liver, lung and muscle of Przewaiski’s and Tibetan gazelles were also measured. All values are reported for the first time for Przewaiski’s and Tibetan gazelles. Most hematological and serum biochemical values were similar to those of Tibet sheep, yaks, and camels, but the mean serum albumin concentration and the albumin/globulin ratio in Przewaiski’s and Tibetan gazelles were significantly higher than those in other ruminants and the mean thyroxine (T 4 ) concentration was half that in Tibet sheep. Liver contains the highest concentrations of copper (Cu), zinc (Zn), manganese (Mn) and iron (Fe). Hair contains higher amount of Sulphur (S). The concentrations of cobalt (Co), molybdenum (Mo), S and Mn from Przewaiski’s and Tibetan gazelles in the blood, hair, liver, lung and muscle were within the reference range for other ruminants. The concentration of selenium (Se) from Przewaiski’s gazelles in the blood and liver was significantly lower than that in Tibetan gazelles. Key words : Przewaiski’s gazelle, Tibetan gazelle, minerals, hematological values, biochemical constituents.

Vigilance is an important antipredation technique that can be affected by many factors, such as body size and group size. Small animals are more vulnerable than large ones, so the former are expected to behave more vigilantly than the latter. This effect of body size on vigilance may occur inter- or intraspecifically. We studied the vigilance behavior of two sympatric wild ungulates, Tibetan antelopes (Pantholops hodgsonii) and Tibetan gazelles (Procapra picticaudata). Tibetan antelopes, with a body size of 33 kg are much larger than Tibetan gazelles, with a body size of approximately 14 kg. Tibetan antelopes are sexually and body-size dimorphic; that is, males are much heavier than females. Alternately, Tibetan gazelles are sexually dimorphic but the sexes do not differ in weight. Tibetan gazelles scanned their environment more frequently than Tibetan antelopes did. Small female Tibetan antelopes scanned their environment more frequently than males did, whereas male Tibetan gazelles scanned their environment more frequently than females did. Group size did not affect the vigilance of Tibetan gazelle, but its negative effect on the vigilance of male Tibetan antelopes was marginally significant. In female Tibetan antelopes, vigilance in large groups was high probably because of scramble competition and social monitoring. Our results suggested that body mass and group size play an important role in shaping the vigilance of these two rare Tibetan ungulates.

Tibetan Gazelle (Procapra picticaudata) are native wildlife to the Qinghai-Tibet Plateau, China. During the past five years, Tibetan Gazelle have been affected by rickets and osteomalacia, characterized by emaciation, growth retardation, lameness, enlargement of the costochondral junctions and abnormal curvature in long bones. The aim of the study was to determine possible relationships between the illness and mineral deficiency. The present result showed that phosphorus contents in soil and forage from affected pastures were significantly lower than those from healthy areas (P<0.01) and the ratio of calcium to phosphorus (Ca:P) in affected herbages was 13.16:1. Phosphorus contents of blood and hair from the affected animals were also significantly lower than those from healthy animals (P<0.01). Serum alkaline phosphatase values from affected Tibetan gazelles were significantly higher than those from healthy ones (P<0.01). Serum inorganic phosphorus contents of affected Tibetan gazelles were about half of those in healthy animals. Oral supplementation of disodium hydrogen phosphate in affected Tibetan gazelles successfully treated the illness. This study demonstrated that the ailment of the Tibetan gazelle was mainly caused by the phosphorus deficiency in forage.

Using biomarkers to assess the toxicity of environmental concentrations of heavy metals to the marine gastropod Thais mutabilis

We used unmanned aerial vehicles (UAVs) to carry out a relatively complete population census of large wild herbivores in Maduo County on the Tibetan Plateau in the spring of 2017. The effective area covered by aerial surveys was 326.6 km2, and 23,784 images were acquired. Interpretation tag libraries for UAV images were created for wild animals, including Kiang (Equus kiang), Tibetan gazelle (Procapra picticaudata), and blue sheep (Pseudois nayaur), as well as livestock, including yaks and Tibetan sheep. Large wild herbivores in the survey transect were identified through manual imagery interpretation. Densities ranged from 1.15/km2 for Kiang, 0.61/km2 for Tibetan gazelle, 0.62/km2 for blue sheep, 4.12/km2 for domestic yak, and 7.34/km2 for domestic sheep. A method based on meadows in the cold and warm seasons was used for estimating the densities and numbers of large wild herbivores and livestock, and was verified against records of livestock numbers. Population estimates for Kiang, Tibetan gazelle, blue sheep, domestic yak, and domestic sheep were 17,109, 15,961, 9324, 70,846, and 102,194, respectively. Based on published consumption estimates, the results suggest that domestic stock consume 4.5 times the amount of vegetation of large wild herbivores. Compared with traditional ground survey methods, performance of UAV remote sensing surveys of large wild herbivore populations was fast, economical and reliable, providing an effective future method for surveying wild animals.

Forensic entomology is the study and use of insects and other arthropods in forensic investigations associated with death, abuse and neglect of both humans and animals. Although there has been an increased interest in forensic entomology and its application in predicting post-mortem interval (PMI) amongst other issues in many developed countries, the results cannot be extrapolated beyond the countries/regions of study since the arthropods species spectra may vary with region and geographical conditions. The present study aimed to determine the arthropod species of forensic importance found during different stages of decomposition of sheep (Ovis aries) and pig (Sus scrofa domesticus) carrion during the warm and cold season in KwaZulu-Natal province of South Africa. A scoping review was conducted to determine the state of knowledge of forensic entomology research and application in southern Africa. To determine the arthropod species associated with sheep and pig carcass during different stages of decomposition, two medium sized Large-White pigs and two medium sized Merino sheep were humanely killed and used for the cold and warm season. Adult arthropods found on and around the carcasses during different stages of decomposition were collected and identified using combined morphological identification keys and molecular technique based on the mitochondrial gene. The review showed that arthropod species that were found on a decomposing carcass could be useful in the estimation of PMI and provided clues in cases of criminal investigations. The review also confirmed the scarcity of forensic entomology research, and its application in southern Africa. Experimental results from this study showed that dipteran flies from the families Calliphoridae, Muscidae and Sarcophagidae were the first to colonize the sheep and pig carcasses during both warm and cold seasons. These include species of Chrysomya marginalis, Ch. putoria, Ch. albiceps, Ch. chloropyga, Lucilia cuprina, Musca domestica and Sarcophaga calcifera. On the sheep carcasses, Ch. marginalis, Ch. albiceps and M. domestica were the most dominant fly species, contributing 63.2 % of the collected flies in the warm season, and 68.9 % in the cold season. Colonization by coleopterans during the warm season started as early as the fresh stage with Dermestes maculatus, Thanatophilus micans and Onthophagus crassicollis. In the cold season these same beetle species were collected from the bloated stage of the sheep carcass. On the pig carcasses, Ch. marginalis (n = 111), Ch. albiceps (n = 99) and M. domestica (n = 131) were the most abundant species during the warm season. The same species were the most abundant species in the cold season (n = 55), (n = 34) and (n = 81) respectively, although in lower numbers than the warm season. Among the collected Coleoptera species, D. maculatus (n = 112) and N. rufipes (n=62) were the most abundant species found on the carcass during the warm season and the same species were the most abundant species in the cold season (n = 66) and (n = 48) respectively. In the warm season Dermestes maculatus was recorded on the pig carcass during the fresh stage and persisted on the carcass until the last of decomposition. However, in the cold season Dermestes maculatus was first recorded on the carcass during the active stage of decomposition. Molecular analyses confirmed the identification of twelve (12) arthropod taxa collected from both sheep and pig carcasses during the cold season. Results showed that 11/12 arthropod species were common in both sheep and pig carcasses, with exception to Onthophagus sp. and Atherigona soccata species which were unique to sheep and pig carcasses respectively. However, during the warm season, the sheep carcass attracted more (n=13) taxa as compared to the pig carcass. The variation in the arthropod was due to the presence of Onthophagus sp. which was also unique to the sheep carcass during this season. Furthermore, there was an addition of a beetle species Hycleus lunatus, which was collected from both sheep and pig carcasses but unique to the warm season. This study generated important information on the endemic arthropod species that are of forensic importance KwaZulu-Natal province. The arrival time and association of arthropods species with different stages of decomposition during the warm and cold season highlighted their value in estimating the PMI in forensic investigations in the locality of KwaZulu-Natal province. The studied arthropods can potentially be useful in the estimation of PMI and other cases of criminal investigations. The seasonal variations in abundance of both Diptera and Coleoptera in the two seasons seemed to indicate influence of seasons which subsequently influenced temperature. It is recommended that similar studies be conducted at other geographical locations of South Africa with a different ecological system to build a database of dipteran and coleopteran species of forensic importance which are endemic in these areas.

Grooming is an important behavioral defense against tick infestation for ungulates. The ‘programmed grooming model' explains the endogenous regulation of tick‐defense grooming and predicts different inter‐ and intra‐specific grooming patterns owing to the body size principle. Here, we studied the summer grooming behaviors of two sympatric Tibetan ungulates, to explore whether or not body size principle works inter‐ and intra‐specifically. The ungulates were sexually and body‐size dimorphic Tibetan antelopes (Pantholops hodgsonii) with body weight of c. 33 kg and sexually dimorphic but body‐size monomorphic Tibetan gazelle (Procapra picticaudata) with body weight of c. 14 kg. Group size was also included in our negative binominal regression model to determine whether or not the ungulates groomed more or less with the increasing group size. Results showed that large Tibetan antelopes groomed much less than small Tibetan gazelles inter‐specifically. Intra‐specifically, sex–age significantly affects the grooming rate of Tibetan antelopes. The largest adult males groomed the least, whereas the smallest fawns groomed the most. However, this sex–age effect is not found in Tibetan gazelle: males and females groomed similarly. These findings indicate that body size principle is fully supported inter‐ and intra‐specifically. Positive group size effect on grooming is observed in Tibetan gazelle, suggesting that released vigilance time from group size effect is probably transferred to grooming. From a conservation point of view, we suggest further studies on the testosterone effect on grooming patterns during the rut as well as on tick biology on the plateau.

A statistical analysis is conducted on the hourly precipitation at 105 national meteorological stations in the Xinjiang region of China from 2011 to 2020. The purpose of this analysis is to determine the total quantity of precipitation during the warm and cold seasons, as well as the precipitation frequency at each station. The results of the analysis indicate that there is a more pronounced inter-annual variation in precipitation during the warm and cold seasons in Xinjiang, where the total amount of precipitation during the warm season is significantly higher than that during the cold season, with the warm season experiencing at least twice as much precipitation. In terms of the inter-annual incremental amount of precipitation, both the warm and cold seasons exhibit a trend of increasing and then decreasing over the years. However, the curvature change is more prominent in the cold season compared to the warm season, suggesting that the inter-annual variation in precipitation during the warm season remains relatively stable. The spatial distribution characteristics of the total precipitation in Xinjiang indicate that warm-season precipitation is more scattered, while cold-season precipitation is mainly concentrated in the northern region of the territory. This pattern holds true at low, medium, medium–high, and high altitudes. The cumulative precipitation during the warm season is always higher than that in the cold season, and this difference becomes more prominent with increasing altitude. This indicates that warm-season precipitation in Xinjiang is closely related to its complex topographic structure, particularly the convective weather generated by topographic clouds. On the other hand, precipitation in the cold season is mainly concentrated in the low- and medium-altitude stations, and there is not much correlation between precipitation and altitude. Precipitation is mainly affected by the mesoscale and the direct influence of large-scale weather systems. Analysis of precipitation in extreme moments reveals that during the warm season, extreme precipitation events occur mainly from the evening to early morning (19:00–03:00 the next day), accounting for 75.24% of the 105 stations. In contrast, during the cold season, extreme precipitation events occur between 03:00 and 18:00, corresponding to 74.29% of the stations. The relationship between precipitation and altitude differs in the warm and cold seasons. In the warm season, there is a linear relationship between precipitation and altitude, with a slope of 0.72 and a correlation coefficient of 0.52, indicating that precipitation increases with increasing altitude. However, in the cold season, the linear relationship between precipitation and altitude is very inconspicuous, with a slope of −0.05 and a correlation coefficient of −0.05, suggesting that there is no significant relationship between precipitation and altitude during this season. These findings provide valuable insights into the changing patterns of precipitation gradients at different altitudes and seasons in Xinjiang. This information can be used for the site selection of smokestack operations in high-altitude areas and for ground and air weather modification operations in low-altitude areas. Additionally, these data contribute to the understanding of precipitation patterns in Xinjiang, further improving the effectiveness of weather modification efforts and increasing the utilization of airborne water resources.

The current study aimed at molecular identification and comparing the diversity of arthropods communities between pig and sheep carcasses during the cold and warm season in KwaZulu-Natal province of South Africa. Adult arthropods found on and around the carcasses were collected using either fly traps or forceps. Molecular analyses confirmed the identification of twelve arthropod species collected from both sheep and pig carcasses during the cold season. Results showed that 11 of 12 arthropod species were common in both sheep and pig carcasses, with exception to Onthophagus vacca (Coleoptera: Scarabaeidae) (Linnaeus, 1767) and Atherigona soccata (Diptera: Muscidae) (Rondani, 1871) species which were unique to sheep and pig carcasses respectively. However, during the warm season, the sheep carcass attracted more arthropod (n = 13) species as compared to the pig carcass. The difference in the obtained arthropod was due to the presence of O. vacca which was also unique to the sheep carcass during this season. Furthermore, there was an addition of a beetle species Hycleus lunatus (Coleoptera: Meloidae) (Pallas, 1782), which was collected from both sheep and pig carcasses but unique to the warm season. The pig carcass attracted more dipteran flies during both warm (n = 1,519) and cold season (n = 779) as compared to sheep carcass during the warm (n = 511) and cold season (n = 229). In contrast, coleopterans were more abundant on the sheep carcass during the warm season (n = 391) and cold season (n = 135) as compared to the pig carcass in both warm season (n = 261) and cold season (n = 114). In overall, more flies and beetles were collected on both sheep and pig carcasses during the warm season, and this further highlight that temperature influenced the observed difference in the abundance of collected arthropod between seasons.

The Mongolian gazelle is one of the few CentralAsian ungulates that have retained high numbers andvast geographic ranges. To date, there is no commonopinion on the population structure of this species. Toclarify this issue, we analyzed tissue samples ofgazelles from eastern Mongolia and neighboringregions with respect to two fragments of mtDNA differ-ing from each other in mutation rate: a fragment of thecytochrome b gene and the hypervariable fragment ofthe D-loop. We obtained the first data on the nucleotidesubstitution accumulation rates in these fragments ofthe genome of this species. It was found that the cur-rent, single population of gazelles is genetically hetero-geneous and includes two differentiated phylogeneticgroups. The two genetically different groups wereprobably formed within this steppe species more than100 000 years ago, when the gazelle geographic rangewas split by a forest zone during the interglacial epoch.The molecular genetic analysis of the fragments ofthe cytochrome b gene and D-loop was performed insamples of different tissues (muscles, dry skins, andhorns) of 13 Mongolian gazelles collected in Russia,Mongolia, and China between 1999 and 2005. We alsoused tissues of the Mongolian gazelle horn from thecollection of Zoological Institute of the Russian Acad-emy of Sciences (no. 8343) collected in 1914. ATibetan gazelle (goa or Tibetan gazelle, Procapra pic-ticaudata) from the collection of Zoological Institute(no. 602) obtained in 1874 and a Persian gazelle(Gazella subgutturosa) obtained from Mongolia in2005 were used as outgroups. The DNA isolation andthe amplification of the D-loop fragment were per-formed as described earlier [2–3]. The PCR of the cyto-chrome b gene fragment was carried out with the use ofthe primers Glu-(L14724) (TGATATGAAAAAC-CATCGTTG) and Cb2-(H15174) (CCCTCAGAAT-GATATTTGTCCTCA) as follows: (I) 3 min at 94°C;(II) 15 s at 94°C, 15 s at 50°C, and 45 s at 72°C(35 cycles); (III) 6 min at 72°C. The nucleotidesequence in the mtDNA fragment studied was deter-mined by means of an ABI 310 automatic analyzerusing a Big Dye kit (Applied Biosystems). The Mega3.0 and Arlequin 2.000 software was used for statisticaltreatment [4–5].We found seven haplotypes of a 375-bp fragment ofthe cytochrome b gene, five of which were unique, in asample of 13 specimens. The nucleotide diversity (π)was 0.5 ± 0.3%. In the same specimens, we found12 unique haplotypes of a 644-bp fragment of theD-loop; the nucleotide diversity was there 5.2 ± 0.7%.All nucleotide sequences have been inputted to theinternational genetic database GenBank (DQ266310,DQ266321– DQ266324, DQ266326, DQ266332–DQ266334, DQ266336, DQ266337, DQ266352, andDQ269150–DQ269162). Phylogenetic analysisshowed that all haplotypes from the studied sample fellinto two groups (Figs. 1, 2). It is noteworthy that thedistribution of the specimens between these two groupswas the same for the cytochrome b gene and the D-loophypervariable fragment. In neither case did we foundany association between the current territorial distribu-tion and genetic relationship between the animals.Therefore, we hypothesized that, in the past, there weretwo isolated populations of gazelles, which intermixedafterwards. The intergroup genetic distance (Net dis-tance, D) between these two clusters calculated for thecytochrome b gene fragment was 0.4%. Comparisonwith outgroups showed that the genetic distancebetween the Tibetan and Mongolian gazelles was 3.2%and that between all gazelles and the Persian gazellewas 11.4%.According to paleontological data, there were twoevolutionary lineages of gazelles in the late MioceneEpoch. One of them has led to the currently existingMongolian and Tibetan gazelles and the other, to thePersian gazelle [6]. Gazella gaudryi from the lateMiocene and early Pliocene Yushi sediments in China