Dynamics of Gastro-Intestinal Strongyle Parasites in a Group of Translocated, Wild-Captured Asiatic Wild Asses in Kazakhstan

Abstract

Asiatic wild ass (Kulan, Equus hemionus) population range and numbers became severely reduced and a reintroduction project is currently aiming to re-establish a population in the Central Steppe of Kazakhstan. Pre-emptive deworming is often recommended for equid translocations but eliminating parasites prior to translocation could cause disruptions in a balanced host-parasite relationship, adding an additional stressor to an already stressful intervention involving capture, transport, and adaptation to a new environment. Following a disease risk assessment, we decided against pre-emptive deworming and focused on monitoring the first group of nine translocated kulan in a large acclimatization enclosure prior to release. Over the 5-month acclimatization period, we regularly collected fecal samples and analyzed the shedding intensity of gastro-intestinal parasite eggs, obtained time budgets through behavioral observations, and visually assessed body condition. We identified strongyles (Strongylinae and Cyathostominae) and pinworms (Oxyuris equi) in fecal samples. All individuals shed strongyle eggs and two of the nine individuals had higher shedding intensities, but rarely reached levels for which deworming is recommended. All kulan appeared healthy throughout the observation period, aggressive interactions were very rare, and time budgets were very similar and dominated by feeding. Our results suggest that in translocation projects where the risk of introducing new parasites is minimal, pre-emptive treatment in wild equids can be replaced with non-invasive monitoring during the acclimatization period. We acknowledge that the small number of kulan, the large size of the enclosure, and the low temperatures during the animals stay in the acclimatization enclosure may all have reduced infestation pressure.

Post-release Movement Behaviour and Survival of Kulan Reintroduced to the Steppes and Deserts of Central Kazakhstan

“…In October 2017, the first group of nine wild kulan (four adult mares, four foals, one subadult stallion) were captured and airlifted by helicopter over 1300 km from Altyn Emel NP to a 55-ha pre-release enclosure at Alibi in the Torgai region (Figure 1), where they were held for 5 months over the winter until release in early April 2018 (Kaczensky et al, 2018b;Gliga et al, 2020). In 2019, two additional wild kulan (one adult mare, one subadult stallion) were successfully transported via truck over 850 km from Barsa Kelmes SNR to the pre-release enclosure (Figure 1; Supplementary Table 1; Kaczensky et al, 2020).…”

“…In the pre-release enclosure, body condition and behaviour were observed twice a day. From late fall to early spring, kulan were provided with hay, and water in troughs during periods when the oxbow lake in the enclosure was frozen and there was no snow on the ground (Gliga et al, 2020).…”

“…Behavioural observations over the winter 2017/18 documented that the nine kulan in the pre-release enclosure formed a cohesive group (Figure 2; Gliga et al, 2020) which resulted in a very high level of movement correlation [97% correlated diffusion (UC) indicative of social correlation]. After release in early April, the group initially stayed tightly together (100% correlated diffusion UC) but started to split up in mid-May (mare 26860 on 21.05.2018, mare 26859 on 02.06.2018, and mare 26855 on 19.08.2018), which resulted in a drop of the UC to only 15%; the drift correlation remained 0% suggesting that there was no tendency for the kulan to move in the same direction.…”

“…The reintroduced kulan behaved like a group of horses in the pre-release enclosure, forming a tightly knit and extremely coordinated group with animals staying together virtually the entire time and with little signs of aggression (Gliga et al, 2020). After release the kulan initially stayed together and were highly synchronised in their movements, but the group broke up starting in mid-May.…”

“…Future releases should aim to keep kulan in the pre-enclosure until after foals are born and mating has happened in the hope that this will lower the mortality risk for foals and increase the chances of new foals in the following year. However, such an approach needs to be carefully monitored (Gliga et al, 2020) as kulan held in captivity can show highly aggressive behaviour to conspecifics and infanticide is a known phenomenon in equids (Cameron et al, 2003) both of which could easily result in losses and welfare issues in the enclosure if animals are not released before things escalate.…”