Abstract: Naturally, horses live in groups in which all individuals are long-term acquainted with each other and a stable hierarchical system is established. In conservation management, introduction of horses into foreign groups is often required but will lead to fights, stress and increased health risks for the animals. We investigated the integration process of four Przewalski mares from the Zoo Leipzig into the herd of five Przewalski horses of the semireserve Liebenthal (Brandenburg, Germany). We observed changes in social hierarchy as well as a higher stress level (expressed by disturbed activity pattern and lower synchronization with environmental conditions) especially in the introduced horses (from Zoo Leipzig). We investigated the animals continuously over two years to detect what time is needed for a successful integration. Finally, we give some advice for the integration of Przewalski horses into a new herd to reduce the stress of the animals substantially.

Abstract: Conservation of endangered species in zoos and other protected areas has saved several species from extinction. The Przewalski horse (Equus ferus przewalskii) is one of that species and, being an attractive large ungulate, it is a “flagship species” for conservation projects. Reintroduction into its former habitat is accompanied by many difficulties and is a great challenge. Semireserves have been defined as enclosures large enough to maintain groups of Przewalski horses throughout all seasons of the year without any supplemental provisioning. The animals are kept isolated from external human influences as far as possible, except for necessary interventions such as veterinary care. Hence, the purpose is not limited to preparing animals for survival under natural conditions, but is equally related to the need to gain experience in establishment of free-ranging populations. Naturally, horses live in groups in which all individuals are long-term acquainted with each other and a stable hierarchical system is established. In conservation management an integration of horses into strange groups is often need but at the same time implies social fights, stress and risks for the animals. We investigated the integration process of 4 Przewalski horses from Zoo Leipzig into the herd of 5 Przewalski horses in the semireserve Liebenthal (Brandenburg, Germany). Before transportation the social structure was determined in both the herd in Zoo Leipzig and in Liebenthal. After transportation the social hierarchy and the individual dominance indices were determined by daily observation. Continuous records of activity and feeding were taken from several individuals using the ETHOSYS-storage telemetry system. The automatically recorded behaviours were analysed for daily and ultradian rhythms and used for stress detection by calculating a value (DFC) representative for regularity and stability of rhythmic structures. In zoo conditions, the behaviour was very regular and the daily pattern nearly identical from day to day as expressed by DFC´s near of 100%. After transportation, the behaviour became much less regular, DFC´s dropped significantly, recovered slowly and stabilised on values typically for semireserve conditions. Social bindings and dominances of the former two herds were mainly retained. As an important result, long lasting and stepwise transition from zoo to natural habitats with special training using new observing techniques can be strongly recommended.

Abstract: Przewalski horses (Equus ferus przewalskii), also known as takhi, were first re-introduced to the wild in Hustai National Park, Mongolia, in 1994. Since then the number of free harems increased to a maximum of seven; there are currently six (October 2000). The size of the home range of each of the harems changed among years and among seasons. The horses tended to settle in a home range close to where they were released although they explored the surrounding area. The use of the habitat within each home range changed through the day, with the horses grazing in the valleys during the morning and evening, and moving to higher places to stand rest and use as a refuge from heat and flies during the middle of the day. Range establishment and area, as well as habitat use are discussed.

Abstract: An ethogram of play behavior among equids was developed. Several key English-language studies on equids were reviewed to derive a preliminary inventory of specific behaviors to be included in the ethogram. Our primary observations were based on a herd of semi-feral Shetland-type ponies kept at New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, PA. Greater than 100 h of direct observation and photo-documentation focused specifically on play in order to identify play behaviors to be added to the preliminary inventory and to obtain detailed descriptions of each behavior. Additionally, these observations were supplemented with photographs obtained during several years of observational study of this herd for other purposes, and with the cumulative equid observational experience and study notes of the principal investigator with other equid species. An initial draft was sent out to 18 equine behavior colleagues for review. A total of 38 individual behaviors classified into four distinct categories were included in the ethogram. These included object play (14 entries), play sexual behavior (3 entries), locomotor play (14 entries) and play fighting (7 entries). All of the behaviors catalogued from direct observation of the herd were also found in the equid literature. The resulting ethogram offers a practical tool as a field guide or reference for quantitative research and other studies of equid play behavior as well as for teaching of equid behavior.

Abstract: The aim of this study was to investigate social behaviour in differently reared stallions in their respective environments; one group of stallions was reared under typical domestic conditions whereas the other group was reared and lives under natural conditions. The domestic group consisted of 19, 2-year-old stallions (Equus caballus), which were all weaned at 4 months of age and experienced either individual or group housing facilities before being pastured with the other similarly aged stallions. The natural living and mixed age group of Przewalski stallions (E. przewalskii) consisted of 13 stallions, most of which were juveniles (n=11, <=4 years; n=2, >9 years). The domestic group was studied in a 4-ha enclosure at the Danish Institute of Agricultural Sciences and the Przewalski group under free-ranging conditions in a 75-ha enclosure in the Askania Nova Biosphere Reserve, Ukraine. Behavioural data was collected during 168 h of direct observation. The occurrence of 14 types of social interactions was recorded and group spacing behaviour was studied using nearest neighbour recordings. In spite of very different environments, reflecting domestic and natural rearing conditions, many similarities in behaviour was found. Play and play fight behaviour was very similar in the two stallion groups. Quantitative differences were found in social grooming since Przewalski stallions groomed more frequently (P=0.004), and in investigative behaviours, since domestic stallions showed more nasal (P=0.005) and body sniffing (P<0.001), whereas Przewalski stallions directed more sniffing towards the genital region (P<0.001). These differences may, however, be attributed to environmental factors and in the period of time the stallions were together prior to the study period. Quantitative differences appeared in some agonistic behaviours (kick threat, P<0.001; and kick, P<0.001), but data do not support earlier findings of Przewalski horses being significantly more aggressive than domestic horses. In general, Przewalski stallions engaged in more social interactions, and they showed less group spacing, i.e. maintained a significantly shorter distance between neighbours (P<0.001). The study indicates that also domestic horses, which have been reared under typical domestic conditions and allowed a period on pasture, show social behaviour, which is very similar to that shown by their non-domestic relatives.