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Summary • Historically, the overlap zones of wild equids were small in Africa but extensive for Przewalski's horses Equus ferus przewalskii and Asiatic wild asses Equus hemionus in Asia. Currently, the Great Gobi B Strictly Protected Area in south-western Mongolia is the only place where sympatric, free-ranging populations of these equids occur. This provides a unique opportunity to test the hypothesis that Przewalski's horses are primarily adapted to mesic steppes and Asiatic wild asses to arid desert steppes and semi-deserts. Understanding the spatial needs and habitat requirements of these little-studied species is a pre-requisite for setting aside and managing protected areas and planning future re-introductions. • From 2001 to 2005, we followed nine Przewalski's horses and seven Asiatic wild asses using satellite telemetry and direct observations to assess differences in their resource selection strategies and social organization. • Przewalski's horses had non-exclusive home ranges of 152–826 km2, selected for the most productive plant communities and formed stable harems groups. • Asiatic wild asses had non-exclusive home ranges of 4449–6835 km2, showed little preferences for any plant community and seemed to live in fission–fusion groups. • Synthesis and applications. Our results provide evidence for different resource selection strategies in two sympatric equid species. Our findings indicate that the Gobi areas provide an edge, rather than an optimal habitat for Przewalski's horses. Consequently, only small and isolated pockets of suitable habitat remain for future re-introductions. Asiatic wild asses, on the other hand, need access to large tracts of land to cope with the unpredictable resource distribution of the Gobi. Managers should be aware that protecting habitat where Asiatic wild asses occur does not necessarily benefit Przewalski's horse restoration, whereas setting aside habitat for the conservation of Przewalski's horses will only locally benefit Asiatic wild asses.
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Journal of Applied Ecology
2008 doi: 10.1111/j.1365-2664.2008.01565.x
© 2008 The Authors. Journal compilation © 2008 British Ecological Society
Blackwell Publishing Ltd
Resource selection by sympatric wild equids in
the Mongolian Gobi
P. Kaczensky
*, O. Ganbaatar
, H. von Wehrden
and C. Walzer
Research Institute of Wildlife Ecology, University of Veterinary Medicine, Austria;
International Takhi Group, Mongolia;
Department of Zoology, Faculty of Biology, National University of Mongolia, Mongolia;
Gobi B Strictly Protected Area
Administration, Mongolia; and
Institute of Biology/Geobotany and Botanical Garden, University of Halle, Germany
Historically, the overlap zones of wild equids were small in Africa but extensive for Przewalski’s
Equus ferus przewalskii
and Asiatic wild asses
Equus hemionus
in Asia. Currently, the Great
Gobi B Strictly Protected Area in south-western Mongolia is the only place where sympatric,
free-ranging populations of these equids occur. This provides a unique opportunity to test the
hypothesis that Przewalski’s horses are primarily adapted to mesic steppes and Asiatic wild asses to
arid desert steppes and semi-deserts. Understanding the spatial needs and habitat requirements of
these little-studied species is a pre-requisite for setting aside and managing protected areas and
planning future re-introductions.
From 2001 to 2005, we followed nine Przewalski’s horses and seven Asiatic wild asses using
satellite telemetry and direct observations to assess differences in their resource selection strategies
and social organization.
Przewalski’s horses had non-exclusive home ranges of 152826 km
, selected for the most
productive plant communities and formed stable harems groups.
Asiatic wild asses had non-exclusive home ranges of 44496835 km
, showed little preferences
for any plant community and seemed to live in fission–fusion groups.
Synthesis and applications
. Our results provide evidence for different resource selection strategies
in two sympatric equid species. Our findings indicate that the Gobi areas provide an edge, rather
than an optimal habitat for Przewalski’s horses. Consequently, only small and isolated pockets of
suitable habitat remain for future re-introductions. Asiatic wild asses, on the other hand, need
access to large tracts of land to cope with the unpredictable resource distribution of the Gobi.
Managers should be aware that protecting habitat where Asiatic wild asses occur does not necessarily
benefit Przewalski’s horse restoration, whereas setting aside habitat for the conservation of
Przewalski’s horses will only locally benefit Asiatic wild asses.
Asiatic wild ass,
Equus hemionus
Equus ferus przewalskii
, Mongolia, Przewalski’s
horse, resource selection, satellite telemetry, social organization
Journal of Applied Ecology
(2007) >doi: 10.1111/j.1365-2664.2007.0@@@@.x
There are seven species of wild equids, of which four occur in
Africa and three in Asia (Moehlman 2002). All species are
similar in size and body shape and have a polygynous mating
strategy with monomorphic sexes. They inhabit open, grass-
or shrub-dominated habitats and are predominantly grazers
(Bauer, McMorrow & Yalden 1994; Rubenstein 1989; Moehlman
2002). Equids are highly efficient hind-gut fermentors,
adapted to compensate for low-quality food by consuming
large quantities (Janis 1976). Different species seem to have
very similar ecological requirements and interspecific com-
petition can be expected to be high where species share the
same range (Hutchinson 1957).
Overlap zones of the African equids were small and
occurred only between two pairs of species. Competitive
exclusion, specific adaptations, and historic colonization
patterns are believed to be the driving forces behind the observed
succession of species along the environmental gradient from
desert, over steppe to savanna habitat (Bauer
et al
. 1994).
et al.
speculated that the degree of similarity in the
social system and resource selection pattern does not allow
for a sympatric occurrence of African wild ass
Equus asinus
and Grévy’s zebra
Equus grevyi
, whereas Grévy’s and plains
*Correspondence author. E-mail:
P. Kaczensky
et al.
© 2008 The Authors. Journal compilation © 2008 British Ecological Society,
Journal of Applied Ecology
Equus quagga
are sufficiently different to co-exist in
areas with mixed habitats and high environmental fluctuations.
Equids have a polygynous mating system (Emlen & Oring
1977) and appear to follow two major strategies based on
climate as a proxy for resource availability. Under mesic con-
ditions, where resource distribution tends to be predictable in
time and space, females form year-round stable groups.
Female cohesion allows males to monopolize mating access
by defending a harem group (Emlen & Oring 1977). Under
arid conditions, resource distribution tends to be patchy and
unpredictable. During droughts, food plants are scare and
highly dispersed, discouraging aggregations of animals due to
high interspecific competition (Jarman 1974, Moehlman
1998). After rainfall events, biomass becomes temporarily
overabundant and attracts many conspecifics, making it
difficult to monopolize access to females. Therefore, equids in
arid environments tend to live in fission–fusion groups,
characterized by loose associations of female–offspring pairs
and single individuals (Emlen & Oring 1977; Rubenstein
1989; Moehlman 1998). Empirical evidence from the small
overlap zone of plains and Grévy’s zebras in Kenya seems to
confirm that differences in resource selection strategy are
linked with the social system. Plains zebras do not venture far
from open water sources and form stable harem groups,
whereas Grévy’s zebras, which do not have to drink daily,
forage farther away from water and live in fission–fusion
groups (Rubenstein 1989).
From central Asia, there is evidence for a large overlap in
the historical distribution range of the Przewalski’s horse
Equus ferus przewalskii
et al
. 2002) and the Asiatic
wild ass
Equus hemionus
et al
. 2002). This strongly
suggests differences in resource selection strategies. Empirical
data is lacking because the Przewalski’s horse became extinct
in the wild and the Asiatic wild ass disappeared from most of
its historic range. Anecdotal evidence and data from closely
related species indicates Przewalski’s horses are primarily
adapted to mesic steppe habitats and Asiatic wild asses to arid
desert-steppes and semi-deserts (van Dierendonck & Wallis
de Vries 1996; Bahloul
et al
. 2001; Feh
et al
. 2002; Wakefield
et al
. 2002). The social organization of wild asses is still
poorly understood and may vary depending on environmental
conditions (Feh, Boldsukh & Tourenq 1994; Feh
et al
. 2002).
Przewalski’s horses are known to form stable harem groups,
at least under mesic conditions (Bahloul
et al
. 2001; King
2002; Zimmermann 2005). Today, Mongolia is the most
important stronghold of the Asiatic wild ass (Reading
et al
2001; Lkhagvasuren 2007) and the only country where
Przewalski’s horses have been successfully released into the
wild (Zimmermann 2005). One of the two release sites is the
Great Gobi B Strictly Protected Area. Although the last wild
horses were seen in this area in the 1960s, it is not known
whether the Gobi area represents a mere refuge or was once
typical Przewalski’s horse habitat (van Dierendonck & Wallis
de Vries 1996).
In this study, we aim to identify differences in resource
selection patterns of the two equid species derived from
satellite telemetry and observational data collected from
2001–2005. Based on the literature, we expected to see the
following differences:
Przewalski’s horses are primarily adapted to mesic steppe
habitats. They stay close to open water sources and show a
stronger preference for plant communities with a high
productivity and a low inter-annual variance in biomass.
Given the fairly reliable and predictable nature of their
selected resources, Przewalski’s horses are organized in stable
harem groups.
Asiatic wild asses are primarily adapted to arid desert
steppes and semi-deserts. They can venture farther away from
water and are better able to exploit resources that vary in
space and time. Given the unreliable nature of their resource
distribution, Asiatic wild asses live in fission–fusion groups.
Besides the theoretical aspects of exploring differences in
social organization and resource selection in two sympatric
species, a better understanding of habitat requirements of
these little-studied species is important to design and adapt
conservation strategies (Clark
et al
. 2006).
Materials and methods
The Great Gobi B Strictly Protected Area was established in 1975
and encompasses some 9000 km
of desert steppes and semi-deserts
(Zhirnov & Ilyinsky 1986). Herder camps are allowed outside of the
1800 km
core zone at pre-established locations (Fig. 1). These are
used by ~100 families with ~60 000 head of livestock (sheep and
goats, horses, cattle and camels), predominantly in winter and
during the spring and autumn migration (Kaczensky
et al
. 2007). In
summer, human presence in the park is almost negligible. No paved
roads exist and dirt tracks are not maintained. In winter, access and
mobility within the park is often limited by snow cover. Poaching
occurs but, based on the small number of wild ass carcasses found
during this study, seems to be of minor importance compared to
other Gobi areas (Kaczensky
et al
. 2006).
The climate of the Great Gobi B Strictly Protected Area is continental
with long cold winters and short, hot summers. Monthly temperatures
average 14 to 19
C in summer (May–September) and 4 to
C in
winter (October–April; Baitag weather station 1970–2007). Average
annual rainfall is 96 mm with a peak during summer. Average snow
cover lasts 97 days. Rain and snowfall can be highly variable from
year-to-year in space and time (Zhirnov & Ilyinsky 1986). The area
is generally considered to follow a non-equilibrium dynamics as
biomass production, and as a consequence, ungulate population
fluctuations are driven by the amount and timing of rainfall events
(Fernandez-Gimenez & Allen-Diaz 1999; von Wehrden & Wesche
The landscape of the Great Gobi B Strictly Protected Area is
dominated by plains in the east and rolling hills in the west. The
Altai Mountains flank the park to the north, and the Takhin Shar
Naruu Mountains form the southern border with China. Elevations
range from 1000 to 2840 m above sea level. Although the international
border is fenced in the more accessible areas, the rest of the park is
not surrounded or dissected by fences. Open water (rivers and
springs) is unevenly distributed with almost no water in the central
or western part of the park (Fig. 1). In locations where several
springs occur together, they are surrounded by intermittent swamps
and form oases. Desert areas are widely dominated by Chenopodiaceae,
Resource selection by wild equids in Mongolia
© 2008 The Authors. Journal compilation © 2008 British Ecological Society,
Journal of Applied Ecology
such as saxaul
Haloxylon ammodendron
Anabasis brevifolia
. The
steppe areas are dominated by Asteraceae, such as
, and Poaceae like
(Hilbig 1995; von
Wehrden, Tungalag & Wesche 2006a). High-productivity riparian
vegetation and
Nitraria sibirica
communities are rare and restricted
to larger oases and intermittent river valleys (Figs 1 and 2).
The ungulate community of the steppe areas consists of goitered
Gazella subgutturosa
, Asiatic wild ass, and Przewalski’s
horse. Common mammalian predators are the grey wolf
Canis lupus
and red fox
Vulpes vulpes
(Zhirnov & Ilyinsky 1986).
Park rangers check individual Przewalski’s horse groups 1– 4 times
each week for group composition, independent of radiotelemetry
et al
. 2007). Between October 2002 and December 2005,
rangers located different Przewalski’s horse groups on 478 days for
a total of 1739 group observations. All rangers were experienced
domestic horse breeders and were able to identify individual
Przewalski’s horses based on shape, coat colour, size, scars and/or
freeze brands. The Przewalski’s horse population increased from 59
in 2003 to 95 in 2005.
From April 2003 until December 2005, we documented wild ass
group sizes during 29 surveys, attempted on a monthly basis.
Nineteen surveys covered the eastern part of the park (track length
per survey: 350– 370 km, search area: 3500 km
) and 10 surveys
covered the entire Great Gobi B Strictly Protected Area (track
length per survey: 766– 803 km, search area: 9000 km
). We always
travelled with a minimum of four people at a maximum speed of
40 km h
. Flight distances of wild asses were in the range of 0·5 –2 km,
Fig. 1. (A) Location of the Great Gobi B
Strictly Protected Area in Mongolia. (B) Detailed
map of the study area.
Fig. 2. Plant communities of the Great Gobi
B Strictly Protected Area imposed with
(A) locations of seven Asiatic wild asses and
their subsequent minimum convex polygons
(MCPs), (B) locations of nine Przewalski’s
horses and their subsequent MCPs.
P. Kaczensky
et al.
© 2008 The Authors. Journal compilation © 2008 British Ecological Society,
Journal of Applied Ecology
which only rarely allowed for a reliable determination of sex or age
classes. Previous estimates of the wild ass population in the Great
Gobi B Strictly Protected Area have been around 2000 individuals
et al
. 2001; Lkhagvasuren 2007).
Between November 2001 and May 2004, we captured and monitored
nine Przewalski’s horses and seven wild asses (see Supporting
Information Appendix S1). For darting, we approached animals by
jeep or hid at water points (for details see Walzer
et al
. 2007). In any
given year, only one collared Przewalski’s horse was present per
group. Although Przewalski’s horses move in social groups, we
treated eight out of the nine individual horses as independent units
because group composition changed among years and can be
assumed to have affected group leadership and thus group movements
(see Supporting Information Appendix S2). We treated the two
horses where group composition did not change as one individual
for all statistical analysis. Because we were unable to observe if
collared Asiatic wild asses travelled together, we used the average
distance between wild ass pairs on the same day and not separated
by more than 1 h as an indirect measure to detect possible associations.
The average distance of 533 locations of wild ass pairs was 37 km.
Only 2 pairs (0·4%) were within 500 m and only 39 pairs (7·3%)
within 5 km of each other. We thus concluded that none of the
collared animals moved in close association with another collared
conspecific. Of the 16 animals collared, we equipped four with
ARGOS collars (2-D cell Doppler PTT; NorthStar, Baltimore,
Maryland USA) and 12 with GPS/ARGOS collars (2-D cell PTTs,
NorthStar, Baltimore, USA and TGW-3580, Telonics, Mesa,
Arizona, USA). For animal welfare reasons and to allow collar
retrieval, we equipped all collars with pre-programmed drop-off
devices (CR-2a, Telonics). Precisions of the GPS locations were in
the range of ±15 –100 m (P. Kaczensky, unpublished data). For
ARGOS locations, we only used the three most precise location
classes, where the expected error is ±150–1000 m (Hays
et al
. 2001).
For all statistical analysis, we used the individual animal and not
the telemetry location as sample unit, except for the mixed models,
where individuals were set as a random factor. To avoid problems of
autocorrelation in bivariate comparisons, we first used the average
value of all locations per day, than calculated mean values per
individual and subsequently used those to compare species and
seasons. We tested for a possible influence of season, by splitting the
data into summer as defined from May to September and winter as
defined from October to April. Summer has a low probability of
temperatures below freezing and a higher probability of rain, thus
allowing for plant growth and biomass production. Winter has a
high probability of temperatures below freezing and snow cover provides
an alternative water source away from open water. We calculated
the average daily distances travelled by calculating the straight line
distance between locations that were 21– 27 h apart and standardized
the average distance for 24 h by assuming a linear relationship.
von Wehrden
et al
. (2006a) described 12 plant communities for the
Great Gobi B Strictly Protected Area based on supervised Landsat
imagery (also see von Wehrden
et al
. 2006b). Of those, two montane
plant communities did not occur within the wild equid range and
five others were merged into two new categories (Fig. 2). We expected
equid use of different plant communities to match productivity.
Because we lacked plant community specific biomass production
data, we based productivity estimates and expected equid use on the
association of plant communities with different moisture regimes
(H. von Wehrden, unpublished data). We expected to see the following
ranking: riparian vegetation >
(see Supporting Information
Appendix S3).
For an overall estimate of biomass production, we used the global
layer of biomass production expressed in gram carbon per square
metre and year (gC m
) for 1981–2000 (Prince & Small 2003).
This open-source GIS data set is available on an 8
8 km raster
basis under with data
processing described in Prince & Goward (1995). For our analysis,
we used the mean biomass production over all 20 years. We digitized
rivers, springs and elevation from Russian 1:100 000 topographic
maps. For data analysis we used ArcView 3·1 and ArcMap 9·1
(ESRI, Environmental Systems Research Institute, Inc., Redlands,
California, USA) with the Spatial Analyst and Animal Movement
(Hooge & Eichenlaub 1997) extensions.
We tested for habitat preferences comparing availability (random
points) and use (animal locations). For availability, we created 1000
random points within the buffered minimum convex polygon (MCP)
of each individual. Based on the average daily distance covered
within 24 h, buffers were 8·3 km for Asiatic wild asses and 3·5 km for
Przewalski’s horses. From the animal locations, we used only GPS
and ARGOS locations separated by
1 h. For each location and
each random point, we derived plant community, slope, average
biomass production, elevation, and distance to nearest water source.
To correct for temporal autocorrelation, we checked for the
relationship of distance covered vs. time (since the last location, the
before last, the two before last and so on; for a similar approach see
Swihart & Slade 1985) for all possible time intervals up to 72 h apart.
For both species, the relationship was best fitted by a power function
with exponent 0·6792 (r
= 0·141, d.f. = 7,824,
< 0·001) for Asiatic
wild asses and exponent 0·3793 (
= 0·044, d.f. = 27 694,
< 0·001)
for Przewalski’s horses. All locations separated by
72 h were
subsequently given a weight less than 1 based on the following
species-specific equation:
(hours since the last location
species exponent
)/(72 h
species exponent
Weighting of locations reduced effective sample size to
= 2400 in
Przewalski’s horses and
= 1181 in Asiatic wild asses. Weighting
locations over longer time periods seemed unnecessarily conservative
as animals are highly mobile, and within 72 h, all parts of the
individual home range may be accessed, especially because there are
no movement barriers. We recalculated the model with a less
conservative weighting approach, only down-weighting locations
separated by less than 24 h. However, this had little effect on the
main results (see Supporting Information Appendix S5A). To check
for a possible influence of the different precision of ARGOS and
GPS locations on model performance, we recalculated the regression
model using only those ARGOS locations with an expected error of
±150 m (see Supporting Information Appendix S4B). Differences in
model output were small as compared to the model including all
locations, and did not alter the main results; hence, we used the latter
in the final results.
All variables were fed into a species-specific mixed-effect logistic
regression model. To account for the unbalanced sampling design,
we treated individuals as random factors (Gillies
et al
. 2006) and
habitat variables as fixed effects. We selected habitat variables
stepwise in a forward fashion, dropping those that failed to be
significant or those with elevated Akaike Information Criterion
Resource selection by wild equids in Mongolia
© 2008 The Authors. Journal compilation © 2008 British Ecological Society,
Journal of Applied Ecology
values. For the factor variable ‘plant community’, the effect size of
the different communities were first tested relative to the most productive
riparian vegetation. With a subsequent Tukey
post hoc
test, we tested
for significant differences in the effect size of each plant community
relative to all others, thus creating a plant community ranking
scheme. The logistic regression models were performed in the
Development Core Team 2005) with the lme4, MASS,
and multcomp packages. All other statistical analyses were done in
14·0 (Statistical Package for the Social Sciences; SPSS Inc.,
Chicago, Illinois, USA). Mean values between species were com-
pared using non-parametric
-tests when the data was not normally
distributed, else parametric
-tests. For multiple comparisons of
count data, we used Kruskal–Wallis H-tests and subsequent
with Bonferroni corrections. To test for the simultaneous influence
of collar type, monitoring period and sex on MCP size, we used a linear
regression model. We selected variables stepwise in a backwards
fashion, removing those that failed to be significant. For all tests the
significance level was set to
< 0·05.
Total home range sizes, measured as the 100% MCP, of indi-
vidual Przewalski’s horses and wild asses were significantly
different and averaged 471 km
(range: 152 826 km) for horses
and 5860 km
for asses (range: 4449– 7186;
< 0·001;
see Supporting Information Appendix S1). MCP size was
independent of the length of the monitoring period, sex and
sensor type (ARGOS vs. GPS) in both species (linear regression
model, all variables
> 0·05) and it seems reasonable to lump
data by species. MCPs started to level out after 5 6 months
for both species (see Supporting Information Appendix S5).
Range use was not exclusive and reciprocal home range
overlap averaged 60% among individual horses (range: 13–
100%) and 84% among individual asses (range: 61–100%;
Fig. 2). Wild ass home ranges were almost identical with the
boundaries of the Great Gobi B Strictly Protected Area, but
excluded the high mountains in the south. Przewalski’s horse
ranges were confined to the north-eastern corner of the Great
Gobi B Strictly Protected Area and also did not include any
steep mountain ranges (Fig. 1 and Fig. 2).
Plant community was the strongest predictor for resource
selection in both species. Slope, biomass, distance to the nearest
water source, and elevation had no or only very limited additional
predictive value and the effect was negligible (Table 1). Prze-
walski’s horses showed the expected use of plant communities,
suggesting a preference from most to least productive com-
munity. Except for the two most productive plant communities,
riparian vegetation and Nitraria, all differences were highly
significant. Asiatic wild asses, on the other hand, did not use
plant communities as expected. Although riparian vegetation
was ranked highest, differences to Nitraria and Caragana
were not significant and Stipa grassland was ranked second to
the last (Table 1, see Supporting Information Appendix S6).
In addition, effects were generally small, suggesting little
preference for any particular plant community.
Distance to the nearest water source was significantly shorter
for Przewalski’s horses (9·0 ± 2·9 km) than for Asiatic wild
asses (13·5 ± 0·9 km; T = 4·12, d.f. = 8·43, P = 0·003). The
mean distance to the nearest water source was significantly
Table 1. Results of the species-specific mixed-effect logistic regression models
Przewalski’s horses (AIC = 9131) Asiatic wild asses (AIC = 6300)
Estimate SE PEstimate SE P
(Intercept) 0·69 0·58 0·23 0·34 0·53 0·52
Plant community**
Nitraria 0·18 0·20 0·39 0·22 0·47 0·64
3 Stipa 2·26 0·11 < 0·001 1·15 0·41 0·01
4 Caragana 3·10 0·14 < 0·001 0·70 0·44 0·11
5 Haloxylon 3·35 0·12 < 0·001 0·99 0·41 0·01
6 Reaumuria 3·42 0·26 < 0·001 1·02 0·41 0·01
7 Nanophyton 3·53 0·13 < 0·001 1·47 0·49 0·00
Slope 0·05 0·01 < 0·001 0·05 0·01 < 0·001
Biomass 0·005 < 0·001 < 0·001 0·01 0·001 < 0·001
Elevation 0·001 < 0·001 < 0·001 0·001 < 0·001 < 0·001
Distance to water < 0·001 < 0·001 < 0·001
Ranks of plant
community based
on post hoc tests***
AIC, Akaike Information Criterion; SE, standard error.
*Individuals were treated as random factor.
**The estimates for the factor variable ‘plant community’ are relative to the most productive type 1 riparian vegetation.
***Lines connecting numbers show significant differences based on a post hoc test of the factor variables within the full model (see Supporting
Information, Appendix S4).
6P. Kaczensky et al.
© 2008 The Authors. Journal compilation © 2008 British Ecological Society, Journal of Applied Ecology
longer in winter as compared to summer in both species
(Przewalski’s horses: 10·4 ± 2·7 km in winter, 6·9 ± 1·9 km in
summer; T = 2·6, d.f. = 12, P = 0·023; Asiatic wild asses:
15·8 ± 0·9 km in winter, 10·3 ± 2·9 km in summer; T = 4·9,
d.f. = 12, P < 0·001). Average biomass production in
8 × 8 km habitat squares used by Przewalski’s horses was
significantly higher (209·2 ± 22·4 gC m2 year1) than in those
used by Asiatic wild asses (149·2 ± 4·9 gC m2 year1; T = 7·4,
d.f. = 7·8, P < 0·001). Mean daily straight line distance
between consecutive days was significantly longer for wild
asses (8·3 ± 0·7 km) than for Przewalski’s horses (3·5 ± 0·9 km;
U-test, U < 0·01, P < 0·001).
Przewalski’s horses were organized in 3– 5 female–offspring
groups with one dominant stallion and 1–3 bachelor groups
of variable composition. Group stability of female–offspring
groups was high for adult mares ( 3 years) and the dominant
stallion, and confirms social organization in stable harem
groups. Most changes of adult females occurred when a new
harem group formed in 2005 (see Supporting Information
Appendix S7). Averaged over all years and groups, a harem
group consisted of 1 harem stallion, 5·6 adult mares (range:
3– 9), and their offspring (mean total: 11·1, range: 4–23).
Single Przewalski’s horses were seen in 3%, groups of 2 3 in
5·3%, groups of 4 23 in 87·8%, and groups 24 (close
associations of 1–5 groups) in 3·9% of all group observations.
Between April 2003 and December 2005, we counted 1036
wild ass groups. Mean group size was 28·4 animals (range: 1–
1000, median: 5) and was almost identical from year to year
(28·1 in 2003, 28·3 in 2004, and 28·8 in 2005; χ2 = 5·73,
P = 0·06). Although groups tended to be bigger in winter
(mean: 38·8, range: 1– 634, median: 10) than in summer (mean:
24·2, range: 1–1000, median: 4; U = 77 185·00, P < 0·001),
large groups of several hundred animals were encountered in
both seasons. Single individuals accounted for 20%, groups of
2–3 for 20·8%, groups of 4–23 for 38·5%, and groups 24 for
20·7% of all groups encountered. A statistically sound comparison
of group size distributions between species is hindered by the
small population size of the Przewalski’s horse population
and the resulting pseudo-replication in the horse group data.
The two equid species used the landscape at totally different
scales, with the ranges of Asiatic wild asses being 10 times
larger than those of Przewalski’s horses. Differences are unlikely
an artefact of releasing zoo-born animals into the wild because
home range sizes of Przewalski’s horses in the Great Gobi B
Strictly Protected Area are more than 10 times larger than
those of horses in the mountain steppe ecosystem of Hustain
Nuruu (King & Gurnell 2005; N. Bandi, unpublished data).
This suggests that zoo-born Przewalski’s horses are able to adapt
their spatial use to differences in the local habitat conditions.
Przewalski’s horses seem to drink daily (Scheibe et al.
1998). For wild asses, reliable data are lacking, but it is often
assumed that they can ‘regularly do without water’ (e.g.
Bahloul et al. 2001: p. 320). However, range contraction
around water sources (Kaczensky et al. 2007) and shortest
distance to the nearest water source during the summer
months show that availability of water is an important factor
determining space and habitat use for both species. Although
average distances to the nearest water source were significantly
longer for individual Asiatic wild asses, the high variability
among individual Przewalski’s horses shows that distance to
water is unlikely to be the key factor explaining the spatial
difference in range use.
Striking differences also occurred with respect to the use of
different plant communities. Przewalski’s horses selected
plant communities relative to their estimated productivity.
Selection was strongest for the two most productive habitat
types of the Gobi ecosystem, the riparian vegetation and
Nitraria sibirica communities associated with oases, a strategy
generally expected when dealing with resource selection by
animals in stable environments (Manly et al. 2002). In con-
trast to Przewalski’s horses and to earlier observations made
by Feh et al. (2001), Asiatic wild asses do not seem to strongly
target the most productive habitat types, but rather use plant
communities almost relative to their availability. Avoidance
of Przewalski’s horses is not a likely explanation for these
differences, as both species often graze in close proximity
(O. Ganbaatar, unpublished observation).
Then why do Przewalski’s horses prefer high-productivity
habitats and Asiatic wild asses do not? Apparently, Asiatic
wild asses can thrive on lower-quality pastures. They are
about 20% smaller than Przewalski’s horses (Clark et al.
2006) and need less food to cover their daily energy demand
(Nagy 2001). Furthermore, anecdotal observations (Bannikov
1958) and preliminary results of scat composition analysis
indicate that Asiatic wild asses make more use of coarse and
woody plants than do Przewalski’s horses (J. Lengger, unpub-
lished data). Furthermore, the Gobi regions are considered
non-equilibrium landscapes, where rainfall patterns and
subsequent pasture production are highly stochastic in time
and space (Fernandez-Gimenez & Allen-Diaz 1999). Based
on annual or multi-annual means, habitat productivity varies
among different plant communities. However, a patch of
habitat which does not receive rain has little biomass to offer,
regardless of its mean productivity. Exceptions are riparian
and oases vegetation which profit from the surrounding high
mountains providing them with a year-round stable supply of
water. In the remaining habitats, productivity changes across
different habitat types according to local rainfall patters,
resulting in a mosaic of ‘green-up’ patches. We believe that
Asiatic wild asses are able to track these green-up patches as
has been documented for several other large ungulates in
semi-arid and arid ecosystems in Africa (Wolanski et al. 1999;
Musiega & Kazadi 2004) and Asia (Mueller et al. 2008).
Tracking green-up patches that occur decoupled from a
particular plant community necessitate large-scale movements
and can be expected to blur selectivity.
Resource selection by wild equids in Mongolia 7
© 2008 The Authors. Journal compilation © 2008 British Ecological Society, Journal of Applied Ecology
As expected, Przewalski’s horses in the Great Gobi B Strictly
Protected Area live in stable harem groups. Thus, social
organization in Przewaski’s horse is remarkably stable over a
wide range of ecological conditions (Bahloul et al. 2001; King
2002; Wakefield et al. 2002; Zimmermann 2005). These
findings are somewhat in contradiction to Moehlman (1998)
who postulated that social organization in equids may be
primarily habitat-specific. One could, on the other hand,
argue that even under the very arid conditions of the Great
Gobi B Strictly Protected Area, Przewalski’s horses are able
to find pockets of suitable habitats that are predictable and stable
enough to allow them to maintain a harem social organization.
While we were unable to determine the nature of social
organization in Asiatic wild asses, we observed an average
group size that was double that of Przewalski’s horses, and
seasonally large aggregations throughout the year including
the mating season. In contrast, close associations of several
Przewalski’s horse harem groups were only observed during
winter, outside of the mating season (O. Ganbaatar, unpub-
lished data). However, differences in the group sizes of the two
equids may also be attributed to a factor 20 difference in the
overall population size.
Previous studies claimed that Asiatic wild asses lived in
family groups because stallions were repeatedly observed
herding several mares and their foals (Feh et al. 1994; Feh
et al. 2001). However, data from other ungulates show that
although one might observe a family-group-type structure,
the composition of these ‘family groups’ may well change as
females and juveniles move freely among groups (e.g. Sarno
et al. 2006). The huge annual ranges, the long flight distances,
the relative large size of the population and the uniform coat
coloration make it difficult to determine group composition
and stability in Asiatic wild asses. We therefore suggest
caution in overstressing the results of Feh et al. (1994) as
facts, and would rather label them as a working hypothesis.
The habitat-use analysis suggests that Asiatic wild asses are
better adapted to cope with unpredictable resource distribution
than Przewalski’s horses. Under such conditions, a harem-
type social organization might not allow sufficient flexibility
to quickly locate and fully exploit temporary overabundant
green-up patches. We suggest an additional working hypothesis
that Asiatic wild asses in the Gobi are more likely to be
organized in fission–fusion groups, as observed in the onager
Equus hemionus khur (Sundaresan et al. 2007).
Given their different resource selection strategies, managers
should be aware that protecting habitat where Asiatic wild
asses occur does not necessarily benefit Przewalski’s horse
restoration, whereas setting aside habitat for the conservation
of Przewalski’s horses will only locally benefit Asiatic wild asses.
The habitat types preferred by Przewalski’s horses – riparian
and oasis vegetation – constitute only 1·5% of the Great Gobi
B Strictly Protected Area. During severe droughts or in areas
where water sources regularly dry up or riparian vegetation is
minimal (e.g. in the Great Gobi A or the Small Gobi Strictly
Protected Areas), we predict that Przewalski’s horses will
fail to thrive. Thus, we support the view of van Dierendonck &
Wallis de Vries (1996) that the Great Gobi B Strictly Protected
Area probably represents an edge, rather than representative
habitat for Przewalski’s horses. The dilemma is that most
productive steppe habitats with sufficient water supply are
intensively used for livestock grazing (Kaczensky et al. 2006).
In these areas, several of the original causes for the species
extinction – competition with livestock and interbreeding
with domestic horses – are still in place. This leaves only small
and isolated pockets of suitable habitat for future re-introductions.
Asiatic wild asses, on the other hand, can make use of a
wider variety of habitats in the Gobi. This was most probably
the reason why Przewalski’s horses became extinct, whereas
Asiatic wild asses are still numerous. However, in order to
thrive, the species needs access to large tracts of land. Given
the stable water resources, the Great Gobi B Strictly Protected
Area seems large enough to support and protect a relatively
large population. However, the majority of the wild asses live
in the south-eastern Gobi, and preliminary data suggest that
animals may need access to much larger tracts of land when
water availability is more variable (Kaczensky et al. 2006). To
guarantee the survival and connectivity of the wild ass
population in the entire Gobi, conservation management
should aim for a landscape-level approach.
This research was conducted within the framework of the Przewalski’s horse
re-introduction project of the International Takhi Group (ITG), in cooperation
with the Mongolian Ministry of Nature and Environment and the National
University of Mongolia. Funding was provided by the Austrian Science
Foundation (FWF project P11529 & P14992) and the Austrian National Bank
(Jubileums Fonds). We thank R. Samjaa, N. Enkhsaikhaan, D. Lkhagvasuren,
J. Lengger, R. Tungalag, ITG staff and the local rangers and their families for
their much needed support. J. Hanspach, T. Ruf, F. Knauer and R. Reading
provided valuable input and comments on earlier drafts of this manuscript.
This work is dedicated to Z. Suchebaatar (1963– 2007) a true pioneer of
Przewalski’s horse re-introductions.
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Received 27 September 2007; accepted 12 August 2008
Handling Editor: Mark Hebblewhite
Supporting Information
Additional Supporting Information may be found in the
online version of this article:
Appendix S1. Przewalski’s horses and wild asses monitored
in the Great Gobi B Strictly Protected Area in Mongolia.
Appendix S2. Criteria for treating individual horses as
independent groups.
Appendix S3. Plant communities and their estimated
Appendix S4. Logistic regression models for additional data
selection scenarios.
Appendix S5. The relationship of home range size and
monitoring interval.
Appendix S6. Results of the Tukey post hoc test subsequent
to the logistic regression model.
Appendix S7. Group composition of Przewalski’s horse
harems in the Great Gobi B Strictly Protected Area.
Please note: Wiley-Blackwell are not responsible for the
content or functionality of any supporting materials supplied
by the authors. Any queries (other than missing material)
should be directed to the corresponding author for the article.
... The steppe was also considered as optimal habitat of Przewalski's horse by biological arguments that feral and free ranging horses thrive best on steppe-like grasslands [68,89,90], implying that availability of critical resources may affect the habitat use of the horses [91]. Several studies also suggested that feral horses, including Przewalski's horses, preferred proximity to rivers, forest and simple plant communities with the preferred species, flatter and lowland areas where they could more easily notice the movement of predators [62,[91][92][93]. They use the shade of trees for temperature regulation during summer [94,95], and they climb to windy hillsides located close to such forests to avoid attack from flies [96], as reported previously in feral horses [62,91,92,94,97]. ...
... Several studies also suggested that feral horses, including Przewalski's horses, preferred proximity to rivers, forest and simple plant communities with the preferred species, flatter and lowland areas where they could more easily notice the movement of predators [62,[91][92][93]. They use the shade of trees for temperature regulation during summer [94,95], and they climb to windy hillsides located close to such forests to avoid attack from flies [96], as reported previously in feral horses [62,91,92,94,97]. In summary, the view that the Przewalski's horses are primarily a steppe herbivore has received growing support in the captive breeding as well as reintroduction projects [6,9,11,19,[85][86][87][88]. ...
... Males devote more time to harem acquisition and defense in the wild, which would maximize male reproductive success while females devote more energy to foraging which influences their reproductive success [24,90,[157][158][159]. These gender differences are in consistent with the speculations that, in equids, as in other polygynous mammals, males commonly invest more time and resources in intrasexual competition for access to mates than do females [92] while females typically provide the most parental investment in offspring [160]. ...
Full-text available
Simple Summary: The Przewalski's horse (Equus ferus przewalskii), the only extant species of wild horse, was extinct in the wild in 1960s. The wild horse has been successfully saved from extinction by captive breeding projects outside the historic range. Although multiple studies were conducted, the main problems such as loss of founder genes, inbreeding depression, hybridization with domestic horses, high morbidity and mortality, and a lack of reliable prevention strategies and treatment limitations of these problems are still unresolved and require further scientific effort. This review aims to increase understanding of the scientific attributes that make the survival of the species possible and how these attributes can be useful for appropriate design of conservation and management strategies oriented to improve the viability of the existing population of the species. Abstract: This review summarizes studies on Przewalski's horse since its extinction in the wild in the 1960s, with a focus on the reintroduction projects in Mongolia and China, with current population status. Historical and present distribution, population trends, ecology and habitats, genetics, behaviors, conservation measures, actual and potential threats are also reviewed. Captive breeding and reintroduction projects have already been implemented, but many others are still under considerations. The review may help to understand the complexity of problem and show the directions for effective practice in the future.
... The Great Gobi B SPA was established in 1975, stretching over ≈9 0 0 0 km 2 of semideserts and desert-steppes ( Kaczensky et al. 2004 ) and was recently extended to ≈18 0 0 0 km 2 ( Sansarbayar 2019 ) covering similar steppe plant communities. The Great Gobi B SPA is part of the Dzungarian Gobi, bordering China in the South along the Takhin Shar Naruu Mountains and framed by the Altai Mountains in the North ( Kaczensky et al. 2008 ). The international border is fenced, but the remainder of the protected area is not ( Kaczensky et al. 2008 ). ...
... The Great Gobi B SPA is part of the Dzungarian Gobi, bordering China in the South along the Takhin Shar Naruu Mountains and framed by the Altai Mountains in the North ( Kaczensky et al. 2008 ). The international border is fenced, but the remainder of the protected area is not ( Kaczensky et al. 2008 ). The Great Gobi B SPA is registered as IUCN category Ib ( UNEP-WCMC 2022 ) with a core, limited use, and buffer zone. ...
... Most common livestock in the region are, in decreasing order of abundance, goats (Capra aegagrus hircus), sheep (Ovis aries), cows (Bos taurus turano mongolicus), horses (Equus ferus caballus), camels (Camelus bactrianus), and yaks (Bos grunniens; Kaczensky et al. 2008 ). Only sheep and goats ("small livestock") are tended in mixed herds on a daily basis while large livestock is only checked daily or weekly and may even go unaccompanied over extended periods ( Kaczensky et al. 2008 , personal observation). ...
Livestock grazing often intensifies around herder camps, which can lead to degradation, particularly in arid areas, where vegetation is scarce. In Mongolia, nomadic herders have covered long distances between camps and changed camps regularly for centuries. However, changing socioeconomics, rising livestock numbers, and climatic change have led to growing concerns over rangeland health. To understand travel mobility and livestock grazing patterns, we combined Global Positioning System tracking data of goats, remotely sensing pasture productivity, and ground-based vegetation characteristics in the Great Gobi B Strictly Protected Area, Mongolia. We assessed herder preferences for camp selection, followed 19 livestock herds over 20 months, determined use and nutrient contents of the most dominant plant communities, and estimated plant species richness, vegetation cover, and biomass within different grazing radii around camps. Biomass availability was key for herder decisions to move camps, but in winter, other factors like shelter from wind were more important. Camps were mainly located in Stipa spp. communities, agreeing with herder preferences for this highly nutritious species, and its dominance around camps. Herders changed their camp locations on average 9 times yearly, with a maximum distance of 70–123 km between summer and winter camps, and an average visitation period of 25–49 d per camp, depending on season. Small livestock spent > 13−17 h daily within a radius of 100 m from camp, and livestock use intensity decreased steeply with distance from camp but was remarkably similar around spring, autumn, and winter camps on the Gobi plains. However, we found little evidence for a corresponding gradient in plant species richness, biomass, and cover on the Gobi plains. The high mobility of local herders and the overriding impact of precipitation on pasture dynamics contribute to a sustainable vegetation offtake by livestock in the nonequilibrium rangelands of the Dzungarian Gobi.
... It is located in south-western Mongolia and is dominated by semi-deserts and deserts habitats with poorly developed soils (Wehrden et al. 2006). The climate is characterized by short hot summers and long cold winters, and highly variable in precipitation averaging 96 mm rainfall per year (Kaczensky et al. 2008). The flagship species of the Great Gobi B SPA is the Przewalski's horse (Equus ferus przewalskii) numbering around 300 Przewalski's horses, the Asiatic wild ass (Equus hemionus) estimated to number around 9,000 animals, and the goitered gazelle (Gazella subgutturosa) estimated to number around 14,000 animals (Kaczensky et al. 2017b). ...
... The Przewalski's horses are rather conservative in their movement patterns, stay close to water, and do not show seasonal migrations (Ganbaatar 2003, Kaczensky et al. 2008. The range of the Przewalski's horses in 2018-2019 was still focussed around the main release site in the NE part of Great Gobi B SPA and a secondary release site in the North-western part. ...
... In line with Kaczensky et al. (2007), our results show that Przewalski's horses seem to avoid areas of livestock presence and wildlife-livestock interactions are negligible during summer months when herders move to the summer pastures high in the Altai Mountains (Kaczensky et al. 2008). We found that, in times when livestock is absent, the Przewalski's horses use the same water points that were visited by herders and their livestock during spring and autumn. ...
Full-text available
Conference Paper
In the Great Gobi B Strictly Protected Area (SPA), wild and domestic ungulates seasonally share the forage of the semi-desert and desert habitat. Around 130 herder families are grazing their livestock, mainly goats and sheep, in the protected area in winter. Wild ungulates of global significance in Great Gobi B SPA include the reintroduced Przewalski's horse (Equus ferus przewalskii), which had previously been extinct in the wild. To determine potential habitat overlaps between Przewalski's horses and livestock, we mapped the movements of 19 livestock herds monitored via GPS collars and ranger observations of Przewalski's horse herds over one year period from September 2018 to August 2019. We additionally conducted focus group interviews with nomadic herders about their rangeland management. We found that pasture use in and around the Great Gobi B SPA is still following the nomadic tradition, with herders moving camp locations on average eleven times per year, depending on forage availability. Our results show that the range of Przewalski's horses and livestock mostly overlaps around permanent and ephemeral water points. However, the same resources are used in different seasons. The protected area was recently expanded to twice its size, now also including additional herder households and traditional pastures. For the ongoing discussion about concerning the new zonation of the enlarged protected area, it is important to consider both, herder and wildlife movements patterns, to meet the conservation goals of the protected area but also meet the needs of the traditional pastoral herding community.
... In the Great Gobi B Strictly Protected Area (SPA) in southwestern Mongolia, Przewalski's horses have been reintroduced since 1992 (KACZENSKY et al. 2017;KING et al. 2015). Behavioural observations of free-ranging Przewalski's horses in the Gobi have been challenging due to their large ranges (being 10-times larger than in the more productive mountain steppe habitat in Hustai National Park), the remoteness of the study area, and the harsh climate (KACZENSKY et al. 2008b;KING 2002;SOURIS et al. 2007). The overall aim of this study was to explore the potential of camera collars as an additional tool for studying Przewalski's horse behaviour and ecology in the Mongolian Gobi. ...
... Other large mammalian wildlife in the study area include Asiatic wild ass (khulan; Equus hemionus), goitered gazelles (Gazella subgutturosa), ibex (Capra sibirica), and grey wolf (Canis lupus). Whereas ibex are largely constrained to mountainous terrain, which is rarely used by the Przewalski's horses, the other large mammals roam widely (KACZENSKY et al. 2008a;KACZENSKY et al. 2008b). ...
... The absence of images of other wildlife may have been due in part to the relatively small area the Przewalski's horses initially utilized and the short operation time of the camera collar for only 91 days. Khulan presence throughout the summer, for example tends to be focused around the larger water points to the south and west of the area Erkhes harem used from June to September (Kaczensky et al. 2008b;Nandintsetseg et al. 2016). ...
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Remote sensing and satellite telemetry have allowed to greatly expand the understanding of how species use various the landscapes, even in remote settings. However, remotely collecting data also harbours 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 behaviour and ecology of free-ranging Przewalski’s horse in the remote Great Gobi B Strictly Protected Area in south-eastern 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, e.g. 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.
... Habitat selection and use are primarily influenced by forage availability and quality [91,92], with distance to water also being important [93]. The primary determinant of habitat use in free-roaming horses in all seasons has been shown to be availability of preferred forage [34,37,[94][95][96]. ...
... An alternative social structure is observed in some other equid species, where the social group is dynamic with no long-lasting bonds other than between mares and their current foal [93,[176][177][178]182]. In this social structure stallions are territorial and sometimes alone, or at other times they have temporary associations with mares; although mares are rarely alone, their social associations are only temporary. ...
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A detailed understanding of what is usual for a species under optimal conditions is critical for identifying and interpreting different features of body function that have known impacts on animal welfare and its assessment. When applying the Five Domains Model to assess animal welfare, the key starting point is therefore to acquire extensive species-specific knowledge relevant to each of the four physical/functional Domains of the Model. These Domains, 1 to 4, address areas where objective information is evaluated and collated. They are: (1) Nutrition; (2) Physical environment; (3) Health; and (4) Behavioural interactions. It is on the basis of this detailed knowledge that cautious inferences can then be made about welfare-relevant mental experiences animals may have, aligned with Domain 5, Mental State. However, this review is focused entirely on the first four Domains in order to provide a novel holistic framework to collate the multidisciplinary knowledge of horses required for undertaking comprehensive welfare assessments. Thus, inferring the potential mental experiences aligned with Domain 5, the final step in model-based welfare assessments, is not considered here. Finally, providing extensive information on free-roaming horses enables a better understanding of the impacts of human interventions on the welfare of horses in both free-roaming and domestic situations.
... According to Hampson et al. (2011), the movement behaviour, range use, and health consequences of relocating equids may be of great importance to wildlife ecologists, animal behaviourists, and horse welfare groups engaged in relocating domestic or native horses to novel habitats. The study on Przewalski's horses was carried out in Mongolia by Kaczensky et al. (2008) using the ARGOS and GPS systems. It showed that the average daily straight-line distance between the consecutive days of observation was 3.5 km. ...
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The aim of the present study was to analyse the mobility of Polish Konik horses in their natural environment. The study was conducted on a herd of 15 Polish Konik horses in 2018. The Global Positioning System (GPS) transmitter was used to track the horses' movements. Two habitats (forest and meadows), four seasons (autumn, winter, spring, and summer), and four times of the day (morning, midday, evening, and night) were distinguished. Season, habitat, and time of the day as well as the interaction among them significantly (p<0.0001) affected the mobility of Polish Konik horses. The use of the GPS device enabled tracking of horses' mobility also at night, which made the results more complete compared with other similar studies.
... Both wild horses and wild asses are grazing herbivores, consuming grasses (e.g., Stipa spp.), forbs (e.g., Salsola spp.), and shrubs (e.g., Haloxylon), with highly overlapping dietary niches [17,18]. However, wild asses are highly seasonal and ate more shrubs in autumn and winter, while Przewalski's horses are consistently adapted to more productive habitat types, are less versatile in their feeding choices, and are more constrained by water availability [18][19][20]. In marginal habitats, such as the Junggar Basin, where water and food resources are scarce, ecological niche separation is crucial for sustaining the coexistence of sympatric species. ...
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The gut microbiome offers important ecological benefits to the host; however, our understanding of the functional microbiome in relation to wildlife adaptation, especially for translocated endangered species, is lagging. In this study, we adopted a comparative metagenomics approach to test whether the microbiome diverges for translocated and resident species with different adaptive potentials. The composition and function of the microbiome of sympatric Przewalski’s horses and Asiatic wild asses in desert steppe were compared for the first time using the metagenomic shotgun sequencing approach. We identified a significant difference in microbiome composition regarding the microbes present and their relative abundances, while the diversity of microbe species was similar. Furthermore, the functional profile seemed to converge between the two hosts, with genes related to core metabolism function tending to be more abundant in wild asses. Our results indicate that sympatric wild equids differ in their microbial composition while harboring a stable microbial functional core, which may enable them to survive in challenging habitats. A higher abundance of beneficial taxa, such as Akkermansia, and genes related to metabolism pathways and enzymes, such as lignin degradation, may contribute to more diverse diet choices and larger home ranges of wild asses.
... Currently, it encompasses over 18,350 km 2 of desert steppe and desert habitat [26]. This protected area located in SW Mongolia is a reintroduction site for the Przewalski's horse and an important refuge for several other endangered species [39,40]. Despite its protected area status, the GGBSPA is used by about 130 families with close to 70,000 heads of livestock mainly in winter and during spring and fall migration [41]. ...
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Background Reintroduction is a common technique for re-establishing threatened species. However, the adaptation to novel habitats with distinct conditions poses a risk of failure. Weather conditions affect the behaviour of animals, and thus, their adaptation to new conditions and survival. Reintroduced Przewalski’s horses living in Mongolia’s continental arid climate with extreme temperature and precipitation variability, serve as an ideal model species for studying the behavioural response of selected groups to these harsh conditions. Methods The research was conducted in The Great Gobi B Strictly Protected Area, Mongolia. In summer 2018, three groups were recorded (Azaa, Tsetsen and Mares18) involving 29 individuals. In Spring 2019, 4 groups were recorded (Azaa, Tsetsen, Hustai1 and Mares19) involving 34 individuals. In Autumn 2019, 4 groups were recorded (Azaa, Tsetsen, Hustai2 and Tanan) involving 35 individuals. Thirteen weather variables were recorded in 10-min intervals, together with the percentage representation of selected behavioural categories (feeding, locomotion, resting, and social). The effect of weather on behaviour was analysed through GLMM. Influence of the group-history factors (recently reintroduced, long-term reintroduced and wild-born) was also analysed. Results Feeding significantly increased with cloudy and windy conditions and was more frequent in autumn than spring and summer. Locomotion was positively explained by temperature and cloudiness and was higher in summer than spring and autumn. Resting behaviour decreased with altitude and cloudiness, and the dispersion of the group was lower when resting. Increased social interactions were observed with higher temperatures and were more frequent in summer compared to spring and autumn. Differences were found in the display of the behaviours among the selected harems, showing interesting patterns when grouping them according to their origin and experience. Conclusions Weather patterns seem to influence the behaviour of Przewalski’s horse. These results might assist in further management plans for the species, especially in the view of intensifying climate change and alteration of weather patterns. As previously suggested, after approximately 1 year, horses adapt to novel conditions and display the typical behavioural pattern of wild-born Przewalski’s horses.
The aim of this study was to determine the most suitable and practical definition of spatial and temporal proximities between grouped-housed horses by comparing GPS position data. In total, 43 horses held in a “HIT Active Stable®” were equipped with GPS loggers. Different definitions of spatial (≤ 1, 2, 3, 4, 5 m) and temporal proximity (≤ 10, 30, 60, 90, 120 s interruptions between recording points) were investigated for morning pasture periods of 30 days analyzing proximity lengths, number of proximities as well as the network parameters density and fragmentation. With increasing spatial proximity definition, the duration of proximities rose from 9 % (4 compared to 5 m) to 76 % (1 compared to 2 m). The number of proximities also increased accordingly. Ascending temporal proximity definitions provided a lower number of proximities by 13 -21 % (10 s to 30 s) depending on the spatial definition and the proximities became longer. Further, with higher spatial proximity definition, the network density ascended and fragmentation decreased, which shows that more horses had proximities and group formation occurred. We identified a proximity definition of 3 m for at least 60 s as the most useful solution because of a decreasing change in proximity length and number due to biological and technical restrictions. Further, it is suspected that this approach helps to better characterize the group formation of horses kept in groups.
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The data presented here suggest that 18,411 (± 224) khulan inhabit southern Mongolia with a density of 1.4 individuals per 1,000 km2 within the 157,525 km2 territory of its actual distribution. The Dornogobi province contains the highest number of khulan with a mere 67%, while 20% are found in the Ömnögobi province, 12% are in Djungarian Gobi and only 1% in the Gobi-Altay and Bayankhongor provinces. According to the proportion of foals and yearlings within each aimag, the Dornogobi, Ömnögobi east and Khovd populations have an average reproduction rate.
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Examines whether the particular reproductive and subsequent social patterns of ungulates living in arid habitats differ significantly from those living in mesic ones. The author begins by outlining the basic tenets of life history and mating system theory, then using environmental features of arid habitats he uses the theories to make predictions about what life history and mating patterns should occur under extremely arid conditions. Comparisons of closely related species, and even different populations of one species, living in habitats of varying aridity are then used to evaluate the accuracy of the predictions. -from Author
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The Asiatic wild ass Equus hemionus, or khulan, once ranged across much of Central Asia, but is now globally threatened. The largest free-ranging populations are now restricted to a 250-km wide area (range 100±400 km) across the Gobi Desert region of southern Mongolia. Over the last 23 years the population has moved further north and east into its former range. Surveys conducted in the 1970s and 1980s estimated that the Mongolian population contained fewer than 15 000 animals and was declining as a result of human exploitation and livestock competition. Aerial surveys (one in autumn 1994, two in spring 1997) were ¯own as line transects over portions of the khulan's range in Mongolia and ground surveys (®ve in spring, summer, and autumn 1994±97) were conducted by vehicle and foot.