Water Use by Khulan in the Dzungarian Gobi in SW Mongolia

Water is the lifeline for the world’s drylands and the key for the distribution of water-dependent equids like khulan. We developed a simple algorithm using khulan tracks from GPS telemetry to identify waterpoints. This approach allowed us to obtain the first landscape-scale information on the use of waterpoints by khulan in Great Gobi B SPA. We discuss the merits and limitations of the algorithm and the implication for landscape level conservation

Steppe ungulate count in Great Gobi B Strictly Protected area 2022

English: The plains of Great Gobi B Strictly Protected Area (subsequently “Great Gobi B”) in southwestern Mongolia are home to three endangered wild ungulates, khulan (Equus hemionus), takhi (Equus ferus przewalskii), and goitered gazelle (Gazella subgutturosa). With Mongolia holding the largest populations of these species, their conservation is of global importance. To assess the effectiveness of conservation efforts, robust survey methods are needed to monitor population development. In late summer 2022 we conducted the 3rd plains ungulate count in Great Gobi B to estimate population size of khulan and goitered gazelle and describe population developmentsince the counts in 2010 and 2015 and tested the method for estimating the growing population of reintroduced Przewalski’s horses. We conducted Distance Sampling point counts at 101 observation points over 6 counting events (at 19:00, 7:00, 9:00, 11:00, 13:00, and 15:00) at each observation point. During each counting event the observers scanned the surroundings using binoculars and registered species, number of animals, time, bearing and distance for each observation. Over the 606 counts, we observed 5,744 khulan, 3,150 gazelles and 922 Przewalski’s horses. Using these observations, we created global models(over all observation points and counting events) using the distance analysis framework and selected models with the best fit based on AIC values. Populations estimates for 2022 were 5,204 (95% CI = 2,121 – 12,771) khulan, 10,980 (95% CI = 7,473 – 16,132) goitered gazelles, and 1,288 (95% CI = 213 – 7,776) Przewalski’s horses within the 13,000 km2 survey area. Population estimates of both khulan and goitered gazelle suggested an increase from 2010 to 2015, while the 2022 estimated is closer to the 2010 estimates for khulan and in between for goitered gazelles. However, confidence intervals, especially for khulan, are large and population development cannot be determined conclusively. The uncertainty in the khulan estimate for 2022 was caused by the combination of a highly clumped distribution due to draught conditions and a large variation in group sizes. Goitered gazelles were more evenly distributed and group sizes less variable. Estimating Przewalski’s horse population resulted in a gross overestimate because of the knowledge rangers had about the location of Przewalski’s horse groups from intensive weekly monitoring. The data suggests that they specifically looked for groups, as Przewalski’s horses were detected almost equally likely over all distance categories. Confidence intervals were large because the population is still small (numbering just over 400) and distribution was also highly clumped due to the drought condition. The 2022 population estimates for khulan and goitered gazelles and the comparison with the estimates from 2010 and 2015 should be regarded as preliminary because: 1) The 3 surveys were analysed using slightly different distance analysisframeworks and 2) Distance Sampling does not take the spatial distribution of groups into account and we plan to explore such methods before we will reanalyse the 3 surveys within the same analysis framework.Norsk: På de mongolske slettene lever det tre truede ville klovdyrarter; asiatisk villesel (Equus hemionus), Przewalskihest (Equus ferus przewalskii) og struma gaselle (Gazella subgutturosa). De største populasjonene av disse artene på verdensbasis lever i Mongolia, og landet har dermed et særskilt ansvar for å ta vare på og forvalte disse artene. For å sikre en kunnskapsbasert og bærekraftig forvalting av populasjonene trengs informasjon om populasjonsutvikling og bestandsstørrelse. I denne undersøkelsen har vi gjennomført tellinger av viltlevende klovdyrarter i «Great Gobi B» i SV Mongolia for å estimere populasjonsstørrelsen og populasjonsutviklingen av asiatisk villesel og struma gaselle. Det har tidligere blitt gjennomført tellinger i 2010 og 2015, men dette er første gang det blir forsøkt å estimere populasjonsstørrelsen av przewalskihest. Vi gjennomførte tellinger fra 101 observasjonspunkter fordelt på 3 områder med 24 timers økter på hvert punkt. På hvert observasjonspunkt ble det gjennomført 6 runder med tellinger hvor observatørene skannet området med kikkert og registrerte antall dyr, tidspunkt, kompassretning og avstand. Vi lagde ulike modeller ved bruk av distance sampling metoden for å estimere populasjonsstørrelsen av asiatisk villesel, przewalskihest og struma gaselle i studieområdet for alle observasjonene samlet, og valgte den modellen med best AIC verdi. I tillegg analyserte vi data fra hver observasjonsrunde separat for å estimere populasjonsstørrelse på de forskjellige tidspunktene for asiatisk villesel og struma gaselle. I løpet av alle 6 observasjonsrundene telte vi totalt 5 744 asiatiske villesel, 3 150 struma gaseller og 922 przewalskihester. Populasjonsstørrelsen ble estimert til 5 204 (95% KI = 2 121 – 12 771) asiatiske villesel, 10 980 (95% KI = 7 473 – 16 132) struma gaseller og 1288 (95% KI = 213 – 7 776) przewalskihester innenfor studieområdet. Populasjonene for asiatisk villesel og struma gaselle viste en positiv utvikling mellom 2010 og 2015, men hadde en negativ utvikling fra 2015 til 2022. Usikkerheten i estimatene, spesielt for asiatisk villesel, er høy og det er vanskelig å trekke konklusjoner om populasjonsutvikling ut ifra dataene. 2022 var et uvanlig tørt år, og de asiatiske villeslene samletseg i en mindre del av studieområdet i nærheten av en vannkilde der beitegrunnlaget var bedre. Denne ujevne fordelingen i studieområdet er mest sannsynlig årsaken til den store usikkerheten i estimatene. Struma gaseller var mere jevnt fordelt i studieområdet, men usikkerheten i dataene var fortsatt høy, dog på et nivå som kan forventes av en stor‐skala undersøkelse i et system med lav tetthet. Å estimere przewalskihest populasjonen bød på samme problemer som for asiatiske villesel, men gir enda større usikkerhet på grunn av det lave antallet observasjoner. Det ble brukt litt ulike analysemetoder innenfor distance metodikken i de 3 undersøkelsene fra 2010, 2015 og 2022, og det ble ikke tatt hensyn til forskjell i størrelsen av studieområdene mellom de ulike årene. For videre arbeid planlegger vi å analysere alle dataene samlet for å oppnå mer pålitelige resultater. Et av problemene med distance metoden er at analysene ikke tar hensyn til den romlige fordelingen av grupper, noe som vi ønsker å utforske ved bruk av andre metoder.Financed by: Vontobel‐Stiftung, International Takhi Group, Inland Norway University of Applied Sciences, Great Gobi B administration, Prague Zo

First Experience with a Camera Collar in a Free-Ranging Przewalski’s Horse Group in the Mongolian Gobi

Remote sensing and satellite telemetry have allowed to greatly expanding the understanding of how species use various landscapes, even in remote settings. However, remotely collecting data also harbors the risk of losing “touch with the ground.” We explore the possibility of the additional insight cameras integrated in GPS-satellite collars can provide for the behavior and ecology of free-ranging Przewalski’s horse in the remote Great Gobi B Strictly Protected Area in southeastern Mongolia. Over a 91-day period, the camera collected 1,080 images. 62% of the images showed Przewalski’s horses and provided insights into behavior and grouping patterns and can supplement indirect measures of behavior from acceleration sensors. Other images provided first information on insect harassment and show the potential of images for ground-truthing environmental conditions, for example, the occurrence of rainfall. The potential for camera collars as an additional tool to study large-bodied ungulates in remote ecosystems seems really promising, although this relatively new technology seems still prone to technical failures

To move or not to move—factors influencing small-scale herder and livestock movements in the Dzungarian Gobi, Mongolia

In Mongolia, where nomadic pastoralism is still practiced by around one-third of the population, increasing livestock numbers, socio-economic constraints and climate change raise concerns over rangeland health. Little empirical evidence explains what triggers camp moves of pastoralists in the Dzungarian Gobi in Mongolia, which factors influence grazing mobility around camps, and how altitudinal migration benefits small livestock. We combined GPS tracking data of 19 small livestock herds monitored from September 2018 to April 2020 with remotely sensed climate and environmental data. We used general linear-mixed models to analyse variables influencing camp use duration and daily mobility patterns. To understand the importance of the altitudinal migration, we compared climatic conditions along the elevation gradient and looked at seasonal body weight changes of small livestock. We found that available plant biomass and season best explained camp use duration. Daily walking distance and maximum distance from camp increased with camp use duration. Pasture time increased with increasing biomass and rising temperatures. We conclude that herders in the Dzungarian Gobi have optimized pasture use by reacting to changes in biomass availability at landscape and local scale, and by embracing altitudinal migration. Flexibility in grazing mobility seems to have enabled local herder communities to practise sustainable pasture use. Maintaining this mobility will most likely be the best strategy to deal with environmental change under the current climate change scenarios.publishedVersio

Isotope analysis combined with DNA barcoding provide new insights into the dietary niche of khulan in the Mongolian Gobi

With increasing livestock numbers, competition and avoidance are increasingly shaping resource availability for wild ungulates. Shifts in the dietary niche of wild ungulates are likely and can be expected to negatively affect their fitness. The Mongolian Gobi constitutes the largest remaining refuge for several threatened ungulates, but unprecedentedly high livestock numbers are sparking growing concerns over rangeland health and impacts on threatened ungulates like the Asiatic wild ass (khulan). Previous stable isotope analysis of khulan tail hair from the Dzungarian Gobi suggested that they graze in summer but switch to a poorer mixed C3 grass / C4 shrub diet in winter, most likely in reaction to local herders and their livestock. Here we attempt to validate these findings with a different methodology, DNA metabarcoding. Further, we extend the scope of the original study to the South Gobi Region, where we expect higher proportions of low-quality browse in the khulan winter diet due to a higher human and livestock presence. Barcoding confirmed the assumptions behind the seasonal diet change observed in the Dzungarian Gobi isotope data, and new isotope analysis revealed a strong seasonal pattern and higher C4 plant intake in the South Gobi Region, in line with our expectations. However, DNA barcoding revealed C4 domination of winter diet was due to C4 grasses (rather than shrubs) for the South Gobi Region. Slight climatic differences result in regional shifts in the occurrence of C3 and C4 grasses and shrubs, which do not allow for an isotopic separation along the grazer-browser continuum over the entire Gobi. Our findings do not allow us to confirm human impacts upon dietary preferences in khulan as we lack seasonal samples from the South Gobi Region. However, these data provide novel insight into khulan diet, raise new questions about plant availability versuspreference, and provide a cautionary tale about indirect analysis methods if used in isolation or extrapolated to the landscape level. Good concordance between relative read abundance of C4 genera from barcoding and proportion of C4 plants from isotope analysis adds to a growing body of evidence that barcoding is a promising quantitative tool to understand resource partitioning in ungulates.publishedVersio

Seasonal host and ecological drivers may promote restricted water as a viral vector

In climates with seasonally limited precipitation, terrestrial animals congregate at high densities at scarce water sources. We hypothesize that viruses can exploit the recurrence of these diverse animal congrega- tions to spread. In this study, we test the central prediction of this hypothesis — that viruses employing this transmission strategy remain stable and infectious in water. Equid herpesviruses (EHVs) were cho- sen as a model as they have been shown to remain stable and infectious in water for weeks under labo- ratory conditions. Using fecal data from wild equids from a previous study, we establish that EHVs are shed more frequently by their hosts during the dry season, increasing the probability of water source contamination with EHV. We document the presence of several strains of EHVs present in high genome copy number from the surface water and sediments of waterholes sampled across a variety of mamma- lian assemblages, locations, temperatures and pH. Phylogenetic analysis reveals that the different EHV strains found exhibit little divergence despite representing ancient lineages. We employed molecular approaches to show that EHVs shed remain stable in waterholes with detection decreasing with increas- ing temperature in sediments. Infectivity experiments using cell culture reveals that EHVs remain infectious in water derived from waterholes. The results are supportive of water as an abiotic viral vector for EHVacceptedVersio

First field-based observations of δ2H and δ18O values of event-based precipitation, rivers and other water bodies in the Dzungarian Gobi, SW Mongolia

For certain remote areas like Mongolia, field-based precipitation, surface and ground water isotopic data are scarce. So far no such data exist for the Mongolian Gobi desert, which hinders the understanding of isotopic fractionation processes in this extreme, arid region. We collected 26 event-based precipitation samples, 39 Bij river samples, and 75 samples from other water bodies in the Dzungarian Gobi in SW Mongolia over a period of 16 months for hydrogen and oxygen stable isotope analysis. δ2H and δ18O values in precipitation show high seasonal variation and cover an extreme range: 175 ‰ for δ2H and 24 ‰ for δ18O values. The calculated local meteoric water line (LMWL) shows the isotopic characteristics of precipitation in an arid region. Individual water samples fall into one of three groups: within, above or below the 95 % confidence interval of LMWL. Data presented provide a basis for future studies in this region

Capture and Anaesthesia of Wild Mongolian Equids – the Przewalski’s Horse ( Equus ferus przewalskii ) and Khulan ( E. hemionus )

Science-based conservation efforts in general, and wide-ranging equid conservation speci fi cally, of- ten require capture and subsequent handling of the subject animal. Safe and animal-welfare appropriate wild equid capture and anaesthesia is a complex operation necessitating a multitude of skills that require appropriate veterinary training. The agent of choice for wild equid capture and anaesthesia is the potent opiate ethorphine in combination with speci fi c opiate antagonists that allow for the complete reversal of the anaesthetic effects. The recommended dosage for a healthy, wild adult Przewalski’s horse is 2.5- 3.0 mg ethorphine, 10 mg of the alpha2-agonist detomidine and 10 mg of the opioid agonist-antagonist butorphanol. In Przewalski’s horses ethorphine is reversed with the opioid antagonist naltrexone (200 mg). In khulan procedures anaesthesia was induced with a combination of 4.4 mg Ethorphine, 10 mg Detomidine and 10 mg Buthorphanol. Anaesthesia was reversed with the opioid antagonist-agonist di- prenorphine or a combination of 200 mg naltrexone and the alpha2-antagonist 20 mg atipamezole. All equids were standing and alert approximately two minutes following administration of the antagonists