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Habitat selection for calving by ungulates is an important behavioral trait because it affects neonate survival. Generally, ungulate calving site selection varies by vulnerability to predators, local topography, habitat quality and level of human disturbance. The Mongolian saiga (Saiga tatarica mongolica) is endemic to Mongolia where a threatened population of ∼7000 exists in the northern Gobi Desert. We analyzed factors that could affect selection of saiga calving locations in the Sharga Nature Reserve, western Mongolia, using data obtained from ground surveys over 4 years between 2008 and 2012. Multiple factors explain calving location selection by saiga antelopes, based on the results of a generalized linear mixed model within a use availability framework. Individual saiga females preferred calving locations that were away from settlements and closer to water sources and avoided steeper slopes in comparison with random locations. These results demonstrate that the choice of calving locations for saiga antelope is driven by both internal and external factors. Understanding which factors influence calving location selection for saiga provides insights to protect important habitats.

Factors that affect group sizes in large ungulates are generally poorly understood for species from remote regions. Understanding grouping patterns is important for effective species management, but is lacking for the endangered Mongolian saiga (Saiga tatarica mongolica). We studied seasonal changes in the group size and social structure of saigas in relation to environmental and anthropogenic factors in western Mongolia during 2009–2012. To identify group size and composition, we observed saigas monthly while conducting monitoring surveys, and weekly while tracking radio-collared animals. We observed 9268 individuals; median group size was 6.5 (se = 1.7; range = 1–121), and groups of 1–5 animals were most common. Seasonality exerted strong effects with the smallest groups in June and largest in December. The largest mixed and nursery groups formed during pre-rutting and summer seasons, respectively, but no seasonal differences were detected for bachelor groups. The best fitting model, including Normalized Difference Vegetation Index, predation rate and season as covariates, explained ~76% of the variation in monthly ‘typical’ group size. Our results are concordant with studies of other arid-adapted ungulates and suggest vegetation productivity, predation rate and biological cycles are responsible for saiga grouping patterns in Mongolia.

Much of the narial anatomy of the enigmatic antelope Saiga tatarica has been described by previous workers. However, the anatomy of the nasal cavity and the causally associated osteological correlates of proboscis structure require closer attention, because these data are integral for both a more comprehensive understanding of saiga functional morphology and more robust reconstructions of proboscis structure in fossil taxa. Saiga and outgroup specimens were subjected to X-ray computed tomographic (CT) imaging, gross dissection and skeletonization. The nasal cavity of saiga is characterized by an enlarged nasal vestibule and basal conchal fold. Many structures (e.g. turbinates, lateral cartilages, mucosal folds, nasolacrimal duct) are retracted caudally to a small area in the caudodorsal part of the nasal cavity proper. The enlarged vestibule is associated laterally and ventrally with paired sacs. The nasal septum is largely membranous and contains a large patch of cavernous tissue that serves as a dynamic baffle modifying the flow of inspired air. Bones comprising the narial margin have modified attachment sites for buccinator group muscles and the reduced lateral cartilages. The premaxilla is greatly modified by the enlarged musculature associated with nasolabial fusion. Maintenance of the topological relationships of narial structures compared to bovid outgroups has resulted in a nasal cavity with much larger area for seromucous glands of the vestibule as well as narial musculature capable of controlling the aperture of the nasal cavity. Maxillolabial muscles and the lateralis nasi act together both to compress the nasal cavity and to control the dilation of the nostrils such that air flow through the cavity is highly modified relative to bovid outgroups. The lateral vestibular recess is an outpocketing of the nasal vestibule that produces supplementary seromucous secretions and seems to have no homologue among outgroups. The enlarged nasal vestibule, lateral vestibular recess, repositioned basal fold, and septal cavernous mass are regarded as a coordinated adaptation to dusty habitats, such that nasal air flow can be dynamically regulated allowing for collection of inspired particulates in the vestibule and thus cleansing of air destined for the lungs.

The partial mitochondrial 12S rRNA and 16S rRNA gene sequences (440 bp and 590 bp or so, respectively were determined of the Przewalski's gazelle Procapra przewalskii, Mongolian gazelle P. gutturosa, Tibetan gazelle P. picticaudata, goitered gazelle Gazella gutturosa, saiga Saiga tatarica, Tibetan antelope Pantholops hodgsoni, and thar Hemitragus jemlahicus. The average sequence divergence for all the species studied when both rRNA genes were combined was 8.4% (±0.7%), and the divergence values ranged from 0.5% to 13.3%. The average sequence divergence values for 16S rRNA gene and for 12S rRNA gene were 9.9% (±1.1%) and 6.3% (±1.1%), respectively. The sequence divergences among species of Procapra for 16S rRNA gene and for 12S rRNA gene were 1.4%(±0.5%) and 1.1% (±0.6%), respectively. Our phylogenetic analysis revealed the monophyly of the genus Procapra and that Przewalski's gazelle is more closely related to the Mongolian gazelle than to the Tibetan gazelle. We also found that the genus Procapra is closely related to Antilopini. We argued that the critically endangered Przewalski's gazelle should be treated as a species, not a subspecies of the Tibetan gazelle, which clearly warrants more attention from conservationists.