Assessment of Adaptation Status of Reintroduced Equus Przewalskii Based on Comparative Analysis of Fecal Bacteria with Those of Captive E. Przewalskii, Domestic Horse and Mongolian Wild Ass

Abstract

Intestinal microbiota play an important role in the survival of the host. However, no study to date has elucidated the adjustment of intestinal microbiota of the host during rewilding. Thus, this study aims to describe the intestinal bacterial community of reintroduced Przewalski’s horse (RPH) after being released into their original habitat for approximately 20 years in comparison with that of captive Przewalski’s horse (CPH), sympatric domestic horse (DH) and Mongolian wild ass (MWA) by sequencing the 16S rRNA gene. The results showed that the prevalent bacterial communities were different among CPHs, RPHs, DHs and MWAs at the family level. NMDS and ANOSIM analysis showed that the pattern of bacterial community composition in captive equines was distinct from that in the wild groups. It is shown that some bacteria had significant differences among different taxa (p < 0.001), such as Firmicutes, Bacteroidetes, Armatimonadetes, Clostrida, Bacteroidia, Clostridiales, Bacteroidales, Rikenellaceae and Bacteroidales_UCG-001. These bacteria were associated with the transition from in captive to in the wild (CPH and RPH), which reflected the change of environmental conditions. Meanwhile, Proteobacteria, Clostridia, Bacilli, Negativicutes, Gammaproteobacteria, Clostridiales, Bacillales, Selenomonadales, Pseudomonadales and Planococcaceae were the changed groups among RPHs, MWAs and DHs, which are related to feeding habits and diseases. Our results clearly showed the differences between intestinal microbiota in reintroduced animals and wild animals and led us to understand the survival state of reintroduced animals in the wild.

Biological response to Przewalski’s horse reintroduction in native desert grasslands: a case study on the spatial analysis of ticks

“…This implies that the higher the abundance of fresh feces from Przewalski's horses, and the closer the proximity to water sources and donkey trails, the higher the probability of the distribution of the H. asiaticum. This not only intensifies the threat of the H. asiaticum in these regions but also exposes other wildlife species, including the Mongolian wild ass and the goose-throated gazelle, which visit these water sources to drink, to increased risks of parasitic infestations [31,33]. Due to the unique digestive system of Przewalski's horse, it is highly dependent on water sources during the spring and summer tick peak period [10,16,33].…”

“…This not only intensifies the threat of the H. asiaticum in these regions but also exposes other wildlife species, including the Mongolian wild ass and the goose-throated gazelle, which visit these water sources to drink, to increased risks of parasitic infestations [31,33]. Due to the unique digestive system of Przewalski's horse, it is highly dependent on water sources during the spring and summer tick peak period [10,16,33]. Long-term gathering near water sources may lead to the risk of infestation with the H. asiaticum in these areas, which will affect the success rate of its reintroduction process and aggravate the expansion of tick-borne diseases in the desert steppe ecosystem [12,31,33].…”

“…Due to the unique digestive system of Przewalski's horse, it is highly dependent on water sources during the spring and summer tick peak period [10,16,33]. Long-term gathering near water sources may lead to the risk of infestation with the H. asiaticum in these areas, which will affect the success rate of its reintroduction process and aggravate the expansion of tick-borne diseases in the desert steppe ecosystem [12,31,33].…”

“…In the spring and summer, they frequently travel along designated paths, known as 'donkey trails' [11], to reach water sources. They tend to congregate around these water sources and the adjacent grasslands, showing a pronounced propensity to cluster more notably than other ungulate species such as the Mongolian wild ass (E. hemionus) and the Goose-throated gazelle (Gazella subgutturosa) [7,11,33]. This behavioral pattern does not only highlight the attraction of water sources for Przewalski's horses but also presents potential opportunities for the local parasite populations to spread [11,12].…”