Analyzing social networks is a powerful tool for understanding the ecology of social species. While most studies focus on the role of each group member, few compare groups with different characteristics. The current population of Przewalski's horses Equus ferus przewalskii at the Great Gobi B Strictly Protected Area (Mongolia) includes groups of wild-born and captive-bred individuals with different experiences with the area (acclimatizing, long-term reintroduced, and wild-born), therefore serving as an ideal natural behavioral lab. We filmed 11 groups for 141.5 hours in summer 2018 (July), late spring 2019 (May, June), and autumn 2019 (September, October). Affiliative and agonistic interactions were recorded, and social networks were created. We tested the influence of origin, experience, season, sex, age, relative time belonging to the group, relatedness, and dominance rank on different network indices at the individual and group levels. We found that groups with greater experience in the area are generally better connected than members of the newly formed groups. However, these strong networks were created by wild-born individuals with very low interaction rates. On the contrary, inexperienced groups composed of captive-bred individuals displayed many interactions but created weak social networks. The results show a trend of behavioral transition from acclimatizing through long-term reintroduced to wild-born groups, supporting that the newly formed groups of released Przewalski's horses need time to display the typical social behavior patterns of wild-born individuals. Long-term monitoring of released Przewalski's horses is recommended to promote the success of this reintroduction program.

Faculty of Tropical AgriSciences Czech University of Life Sciences Prague Czech Republic

Great Gobi B Strictly Protected Area Takhin Tal Mongolia

Zoo Praha U Trojského zámku 120 3 Prague Czech Republic

Zobrazit více v PubMed

Ballou JD, Lacy RC, Pollak JP, 2020. PMx: software for demographic and genetic analysis and management of pedigreed populations (Version 1.6. 2.20200110). Brookfield, Illinois, USA: Chicago Zoological Society.

Berger A, Scheibe K-M, Eichhorn K, Scheibe A, Streich J, 1999. Diurnal and ultradian rhythms of behaviour in a mare group of Przewalski horse Equus ferus przewalskii, measured through one year under semi-reserve conditions. Applied Animal Behaviour Science 64:1–17.

Berger J, 1977. Organizational systems and dominance in feral horses in the Grand Canyon. Behavioral Ecology and Sociobiology 2:131–146.

Berger J, 1986. Wild Horses of the Great Basin. Chicago: University of Chicago Press.

Berger A, Scheibe KM, Eichhorn K, Scheibe A, Streich J, 1999. Diurnal and ultradian rhythms of behaviour in a mare group of Przewalski horse (Equus ferus przewalskii), measured through one year under semi-reserve conditions. Appl Anim Behav Sci 1:1–7.

Berger-Tal O, Polak T, Oron A, Lubin Y, Kotler BP. et al., 2011. Integrating animal behavior and conservation biology: A conceptual framework. Behav Ecol 22:236–239.

Bernátková A, Oyunsaikhan G, Šimek J, Komárková M, Bobek M. et al., 2022. Influence of weather on the behaviour of reintroduced Przewalski’s horses in the Great Gobi B Strictly Protected Area (Mongolia): Implications for conservation. BMC Zoology 7(1):1–17. PubMed PMC

Blakeslee J, 1974. Mother-young relationships and related behavior among free-ranging appaloosa horses. MSc thesis, Idaho State University, Pocatello.

Bourjade M, Tatin L, King SRB, Feh C, 2009b. Early reproductive success, preceding bachelor ranks and their behavioural correlates in young Przewalski’s stallions. Ethology Ecology & Evolution 21:1–14.

Bourjade M, Thierry B, Maumy M, Petit O, 2009a. Decision-making in Przewalski horses Equus ferus przewalskii is driven by the ecological contexts of collective movements. Ethology 115:321–330.

Bousquet CAH, 2011. Group decision-making in Meerkats Suricata suricatta. Ph.D. Thesis. University of Zurich, Zurich, Switzerland.

Boyd L, Bandi N, 2002. Reintroduction of takhi Equus ferus przewalskii to hustai National Park, Mongolia: Time budget and synchrony of activity pre- and post-release. Applied Animal Behaviour Science 78:87–102.

Boyd LE, Houpt KA, 1994. Przewalski’s Horse: The History and Biology of an Endangered Species. Albany: State University of New York Press.

Boyd LE, Scorolli A, Nowzari H, Bouskila A, 2016. Social organization of wild equids. In: Ransom JI, Kaczensky P editors. Wild Equids: Ecology, Management, and Conservation. Baltimore: John Hopkins University Press, 7–22.

Bremner-Harrison S, Prodohl PA, Elwood RW, 2004. Behavioural trait assessment as a release criterion: boldness predicts early death in a reintroduction programme of captive-bred swift fox (Vulpes velox). In Animal conservation forum. Cambridge: Cambridge University Press, 7(3):313–320.

Burnik Šturm M, Ganbaatar O, Voigt CC, Kaczensky P, 2017. First field-based observations of δ 2H and δ 18O values of event-based precipitation, rivers and other water bodies in the Dzungarian Gobi, SW Mongolia. Isotopes in Environmental and Health Studies S. 53(2):157–171. PubMed PMC

Ceacero F, Landete-Castillejos T, García AJ, Estévez JA, Gallego L, 2007. Kinship discrimination and effects on social rank and aggressiveness levels in Iberian red deer hinds. Ethology 113(12):1133–1140.

Clutton Brock TH, Greenwood PJ, Powell RP, 1976. Ranks and relationships in highland ponies and highland cattle. Zeitschrift für Tierpsychologie 41:202–216. PubMed

Clutton-Brock TH, Albon SD, Gibson RM, Guinness FE, 1979. The logical stag: Adaptive aspects of fighting in red deer (Cervus elaphus L.). Animal Behaviour 27:211–225.

Clutton-Brock TH, Guinness FE, Albon SD, 1982. Red Deer: Behavior and Ecology of Two Sexes. Chicago: University of Chicago Press.

Conradt L, Krause J, Couzin ID, Roper TJ, 2009. “Leading according to need” in self-organizing groups. The American Naturalists 173:304–312. PubMed

Cozzi A, Sighieri C, Gazzano A, Nicol CJ, Baragli P. et al., 2010. Post-conflict friendly reunion in a permanent group of horses Equus caballus. Behavioural Processes 85:185–190. PubMed

Croft DP, James R, Krause J, 2008. Exploring Animal Social Networks. Princeton: Princeton University Press.

Crowell-Davis SL, Houpt KA, Carini CM, 1986. Allogrooming and nearest-neighbour relationships among foals of Equus caballus. Applied Animal Behaviour Science 15:113–123.

de Silva S, Schmid V, Wittemyer G, 2017. Fission–fusion processes weaken the dominance networks of female Asian elephants in a productive habitat. Behavioral Ecology 11:243–252. 10.1093/beheco/arw153 DOI

Dickens MJ, Delehanty DJ, Romero LM, 2010. Stress: an inevitable component of animal translocation. Biol Cons 6:1329–1341. 10.1016/j.biocon.2010.02.032 DOI

Ebhardt H, 1957. Drei unterschiedliche Verhaltensweisen von Islandpferden in norddeutschen Freigehegen. Saugetierkd. Mitt. 5:113–117.

Feh C, 1988. Social behavior and relationships of Przewalski horses in Dutch semi-reserves. Applied Animal Behaviour Science 21:71–87.

Feh C, 1999. Alliances and reproductive success in Camargue stallions. Animal Behaviour 57:705–713. PubMed

Feh C, de Grammont SC, 1995. A natural herd of Przewalski horses on the Causse Méjan: technical and scientific report (1993–1995). Le Villaret, Meyrueis: Association pour le Cheval de Przewalski—TAKH.

Fischer J, Lindenmayer DB, 2000. An assessment of the published results of animal relocations. Biological Conservation 96:111.

Friard O, Gamba M, 2016. BORIS: a free, versatile open‐source event‐logging software for video/audio coding and live observations. Methods Ecol Evo 11:1325–1330. 10.1111/2041-210X.12584 DOI

Gaudioso VR, Sánchez-Garcí C, Pérez JA, Rodríguez PL, Armenteros JA, Alonso ME, 2011. Does early antipredator training increase the suitability of captive red-legged partridges (Alectoris rufa) for releasing? Poult Sci 9:1900–1908. 10.3382/ps.2011-01430 PubMed DOI

Gersick AS, Rubenstein DI, 2017. Physiology modulates social flexibility and collective behaviour in equids and other large ungulates. Philosophical Transactions of the Royal Society B Biological Sciences 372:20160241. PubMed PMC

Goldenberg SZ, Owen MA, Brown JL, Wittemyer G, Oo ZM. et al., 2019. Increasing conservation translocation success by building social functionality in released populations. Global Ecology and Conservation 18:e00604.

Gusset M, Stewart GB, Bowler DE, Pullin AS, 2010. Wild dog reintroductions in South Africa: a systematic review and cross-validation of an endangered species recovery programme. J Nat Conserv 3:230–234. 10.1016/j.jnc.2009.11.001 DOI

Griffin RH, Nunn CL, 2011. Community structure and the spread of infectious disease in Primate Social Networks. Evolutionary Ecology 26:779–800.

Gumert MD, 2007. Payment for sex in a macaque mating market. Animal Behavior 74:1655–1667.

Heitor F, Oom M, Vicente L, 2006. Social relationships in a herd of Sorraia horses. Behavioural Processes 73:170–177. PubMed

Henzi S, Barrett L, 1999. The value of grooming to female primates. Primates 40:47–59. PubMed

Hinde RA, 1976. . Interactions, relationships, and social-structure. Man. 11:1–17.

Hogan E, Houpt K, Sweeney K, 1988. The effect of enclosure size on social interactions and daily activity patterns of the captive Asiatic wild horse’s Equus przewalskii. Applied Animal Behaviour Science 21:47–168.

Holme P, Min Park S, Kim BJ, Edling CR, 2007. Korean university life in a network perspective: dynamics of a large affiliation network. Physica A: Statistical Mechanics and its Applications 373:821–830.

Houpt KA, Law K, Martinisi V, 1978. Dominance hierarchies in domestic horses. Applied Animal Ethology 4:273–283.

International Takhi Group. Save the Wild Horse, 2021. [cited 2022 Jun 23]. Available from: https://savethewildhorse.org/en/

IUCN/SSC, 2013. Guidelines for Reintroductions and Other Conservation Translocations. Gland: IUCN Species Survival Commission.

Kaczensky P, Enkhsaihan N, Ganbaatar O, Samjaa R, von Wehrden H, Walzer C, 2004. Takhis, Khulans, wolves and vegetation – an ecosystem approach for Takhi conservation. Mong J Biol Sci 2:60.

Kaczensky P, Oyunsaikhan G, von Wehrden H, Walzer C, 2008. Resource selection by sympatric wild equids in the Mongolian Gobi. J App Ecol 6:1762–1769. 10.1111/j.1365-2664.2008.01565.x DOI

Keiper R, 1988. Social interactions of the Przewalski horse herd at the Munich Zoo. Applied Animal Behaviour Science 21:89–97.

Keiper R, Receveur H, 1992. Social interactions of freeranging Przewalski horses in semi-reserves in the Netherlands. Applied Animal Behaviour Science 33(4):303–318.

Keiper R, Sambraus H, 1986. The stability of equine dominance hierarchies and the effects of kinship, proximity, and foaling status on hierarchy rank. Applied Animal Behaviour Science 16:121–130.

Kelley JL, Magurran AE, García CM, 2006. Captive breeding promotes aggression in an endangered Mexican fish. Biol Conserv 2:169–177. 10.1016/j.biocon.2006.06.002 DOI

Kimura R, 1998. Mutual grooming and preferred associate relationships in a band of free-ranging horses. Applied Animal Behaviour Science 59:265–276.

King SRB. 2002. Behavioural Ecology of Przewalski Horses Equus przewalskii Reintroduced to Hustai National Park, Mongolia. PhD thesis, Queen Mary, University of London, London, UK.

King SRB, Asa C, Pluhacek J, Houpt KA, Ransom JI, 2016. Behavior of horses, zebras, and asses. In: Ransom JI, Kaczensky P editors. Wild Equids: Ecology, Management, and Conservation. Baltimore: John Hopkins University Press, 23–40.

King SRB, Boyd LE, Zimmermann W, Kendall BE, 2015. Equus ferus. The IUCN Red List of Threatened Species. Available from: 10.2305/IUCN.UK.2015-2.RLTS.T41763A45172856.en DOI

King SRB, Gurnell J, 2019. Associative behaviour in Przewalski’s horses reintroduced into Mongolia. Nature Conservation Research 4: 1–9

Knight J, 2001. If they could talk to the animals. Nature 414:246–247. PubMed

Lehner PN, 1996. Handbook of ethological methods. 2nd edn. Cambridge: Cambridge University Press.

Linklater WL, 2000. Adaptive explanation in socio-ecology: Lessons from the equidae. Biological Reviews 75:1–20. PubMed

Linklater WL, Cameron EZ, Minot EO, Stafford KJ, 1999. Stallion harassment and the mating system of horses. Animal Behavior 58:295–306. PubMed

Macdonald DW, 2016. Animal behaviour and its role in carnivore conservation: Examples of seven deadly threats. Animal Behaviour 120:197–209.

McDonnell SM, Haviland JC, 1995. Agonistic ethogram of the equid bachelor band. Applied Animal Behaviour Science 43:147–188.

McDonnell SM, Poulin A, 2002. Equid play ethogram. Applied Animal Behaviour Science 78:263–290.

Michler LM, Kaczensky P, Ploechl JF, Batsukh D, Baumgartner SA. et al., 2022. Moving toward the greener side: environmental aspects guiding pastoral mobility and impacting vegetation in the Dzungarian Gobi, Mongolia. Rangeland Ecology & Management 83:149–160.

Miller R, Denniston RH, 1979. Interband dominance in feral horses. Zeitschrift für Tierpsychologie 51:41–47.

Monard AM, Duncan P, 1996. Consequences of natal dispersal in female horses. Animal Behaviour 52:565–579.

Mooring MS, Hart BL, 1995. Costs of allogrooming in impala: Distraction from vigilance. Animal Behaviour 49:1414–1416.

Moseby KE, Blumstein DT, Letnic M, West R, 2020. Choice or opportunity: Are post-release social groupings influenced by familiarity or reintroduction protocols? Oryx 54(2):215–221.

National Statistic Office of Mongolia. 2021. [cited 2022 Jun 24]. Available from: https://www.1212.mn/default.aspx?fbclid=IwAR0BEXeCvXQhyRjP_kUAmDcNmEHTl40knH-nMilphtaOsOvy2UZLDZAr7x8//

Newman MEJ, 2006. Modularity and community structure in networks. Proceedings of the National Academy of Sciences of the United States of America 103:8577–8582. PubMed PMC

Nowzari H, Hemami M, Karami M, Zarkesh MMK, Riazi B. et al., 2013. Habitat use by the Persian onager, Equus hemionus onager (Perissodactyla: Equidae) in Qatrouyeh National Park, Fars, Iran. Journal of Natural History 47:2795–2814.

Pereladova OB, Sempéeré AJ, Soldatova NV, Dutov VU, Fisenko G. et al., 1999. Przewalski’s horse: Adaptation to semi-wild life in desert conditions. Oryx. 33:47–58.

Ramos A, Manizan L, Rodriguez E, Kemp YJM, Sueur C. et al., 2019. The social network structure of a semi-free roaming European bison herd Bison bonasus. Behavioural Processes 158:97–105. PubMed

Rubenstein DI, 1994. The ecology of female social behaviour in horses, zebras and asses. In: Jarman P, Rossiter A editors. Animal Societies: Individuals, Interactions, and Organization. Kyoto: Kyoto University Press, 13–28.

Sarrazin F, Barbault R, 1996. Reintroduction: challenges and lessons for basic ecology. Trends in Ecology & Evolution 11:474–478. PubMed

Scheibe KM, Lange B, Lange V, Eichhorn E, Scheibe A. et al., 1997. Przewalskipferde in einem Semireservat–Verhaltensuntersuchungen zur Vorbereitung einer Auswilderung. Curr. Res. Appl. Ethol. 376:120–131.

Schino G, 2007. Grooming and agonistic support: A meta-analysis of primate reciprocal altruism. Behavioural Ecology. 18:115–120.

Schoenecker KA, King SRB, Nordquist MK, Nandintsetseg D, Cao Q, 2016. Habitat and diet of equids. In: Ransom JI, Kaczensky P editors. Wild Equids: Ecology, Management, and Conservation. Baltimore: John Hopkins University Press, 41–57.

Seddon PJ, 1999. Persistence without intervention: Assessing success in wildlife reintroductions. Trends in Ecology & Evolution 14:50–53. PubMed

Shier DM, 2006. Effect of family support on the success of translocated black-tailed prairie dogs. Conservation Biology 20(6):1780–1790. PubMed

Snijders L, Blumstein DT, Stanley CR, Franks DW, 2017. Animal social network theory can help wildlife conservation. Trends in Ecology & Evolution 32:567–577. PubMed

Sueur C, Petit O, De Marco A, Jacobs AT, Watanabe K. et al., 2011. A comparative network analysis of social style in macaques. Animal Behaviour 82:845–852.

Tai YM, Chen MM, Zhang YH, Ma AX, Wang H. et al., 2022. Social rank or social bonds: which one facilitates coalition formation in male Tibetan Macaques? Biology 11(9):1269. 10.3390/biology11091269 PubMed DOI PMC

Teixeira CP, De Azevedo CS, Mendl M, Cipreste CF, Young RJ, 2007. Revisiting translocation and reintroduction programmes: the importance of considering stress. Ani Behav 73:1–3. 10.1016/j.anbehav.2006.06.002 DOI

Tyler SJ, 1972. The behaviour and social organization of the New Forest ponies. Anim Behav Monogr 5:87–196.

van Dierendonck MC, de Vries H, Schilder MBH, 1995. An analysis of dominance, its behavioural parameters and possible determinants in a herd of Icelandic horses in captivity. Netherlands Journal of Zoology 45:362–385.

van Dierendonck MC, de Vries H, Schilder MBH, Colenbrander TB. et al., 2009. Interventions in social behaviour in a herd of mares and geldings. Applied Animal Behaviour Science 116:67–73.

van Dierendonck MC, Sigurjónsdóttir H, Colenbrander B, Thorhallsdóttir AG, 2004. Differences in social behaviour between late pregnant, post-partum and barren mares in a herd of Icelandic horses. Applied Animal Behaviour Science 89:283–297.

Vervaecke H, Stevens JMG, Vandemoortele H, Sigurjonsdottir H, De Vries H. et al., 2007. Aggression and dominance in matched groups of subadult Icelandic horses Equus caballus. Journal of Ethology 25:239–248.

Wells S, von Goldschmidt-Rothschild B, 1979. Social behaviors and relationships in a herd of Camargue horses. Zeitschrift für Tierpsychologie 49:363–380.

Whitehead H, 2008. Analyzing Animal Societies: Quantitative Methods for Vertebrate Social Analysis. Chicago: The Unviersity of Chicago Press.

Whitehead H, 2009. SOCPROG programs: Analysing animal social structures. Behavioral Ecology and Sociobiology 63:765–778.

Whitehead H, 2015. SOCPROG: Programs for analyzing social structure. Canada: Universidad de Dalhousie.

Zhang Y, Cao QS, Rubenstein DI, Zang S, Songer M. et al., 2094. 2015. Water use patterns of sympatric przewalski’s horse and Khulan: Interspecific comparison reveals niche differences. PLoS ONE 10:e013. PubMed PMC