Methodical studies on birth monitoring in the mare Birth monitoring is an important part of horse breeding in order to avoid losses during birth. The aim of this study was to detect typical behaviors of mares associated with the opening phase of parturition. For this purpose, the mares were recorded before and during parturition with a video camera. Furthermore, a commercial birth monitoring system was evaluated. 70 warmblood mares were observed during 86 births in the 2021 and 2022 foaling seasons. The mares were fitted with a commercially available birth monitoring system attached to the mares' vulva and foaled in a camera-monitored foaling stable. Video recordings of the parturitions were made in order to be able to retrospectively evaluate the behavior of the mares in the four hours before parturition and to be able to assess the parturition reported by the transponder via video. The exact time and reason for each alarm was documented and the percentage of correctly recognized births, false alarms and unrecognized births was calculated. For the evaluation of the video recordings, a list of criteria was drawn up in order to be able to retrospectively analyze and evaluate the behavior of the mares before parturition. For this purpose, four hours before the appearance of the amniotic sac between the mare's labia were divided into intervals in which the duration or frequency of occurrence was evaluated for the previously defined behaviors. 96.5% of parturitions were reported correctly using the birth monitoring system. The system is characterized by a sensitivity of 96 % and a specificity of 91 %. False alarms were mainly caused by the tail rubbing against the stall wall. In summary, it could be shown that the tested transponder is well suited for birth monitoring in mares. However, as not all births could be detected without exception, its use in combination with another method of birth monitoring would be advisable. The video analysis showed that the behavior of the mares in proximity to the time of parturition is subject to strong individual differences and that there is no pattern of specific behaviors that can be used to reliably predict parturition. Nevertheless, typical behaviors associated with the opening phase of parturition could be described on the basis of the observations. Individual observation of the mares always revealed a change in behavior as the time of birth approached. When considering all mares, typical behaviors were observed that increased in intensity in proximity to the time of parturition. This includes a highly significant (p < 0.001) increase in the duration of lying in the sternal and lateral position in the last hour of the observation period. The locomotor activity of the mares also increased highly significantly (p < 0.001) within the last four hours of the observation period. The frequency of looking around towards the abdomen and lifting the tail increased significantly (p < 0.001) in the last 30 minutes of the observation period. Furthermore, these two parameters were also shown by 100 % respectively 97 % of the mares during this period, which makes the parameters particularly interesting for the development of a birth monitoring system. A statistically significant influence of parity was found on the frequency of lying in a sternal position (p < 0.05). A statistically significant influence of the birth process on the behavior of the mares could be demonstrated for the repetitions of lying in the lateral position (p < 0.05). In summary, it could be shown that due to the very individual behavior of the mares, a general statement about the behavior of mares before parturition cannot be made. Nevertheless, behaviors could be described that can be interpreted as typical signs of impending parturition and are of interest for the development of birth monitoring systems. A further study with a larger number of maiden mares and mares with dystocia would have to be carried out in order to be able to make a more differentiated statement about the influence of parity and the birth process on the behavior of the mares ante partum.