Impact of communal breeding disruption on behavioral synchronization, activity budget and reproduction in zoo-housed mara pairs

Introduction The mara ( Dolichotis patagonum ; Caviomorpha) is an endemic species that faces conservation problems in Argentina. The mara is categorized as near threatened at international level, as vulnerable in Argentina, and as threatened in the Dry Chaco (Córdoba province). To overcome this threat, maras could benefit from conservation actions both in situ (e.g., protected zones) and ex situ (e.g., breeding 85 program). Maras are monogamous and, in the wild, they exhibit a communal 86 breeding strategy. However, ex situ management may alter social strategies and/or compromise individuals’ preferences. Due to space restrictions in ex situ facilities, behavioral preferences such as communal breeding may be affected by management decisions. Hence, to assess whether shifting from communal to solitary breeding can disrupt behavior and reproduction, the study was carried out under semi-controlled environmental conditions (Córdoba Zoo). Methods From a group of 70 individuals, monogamous pairs of maras were separated into two experimental groups: control (C; 5 pairs in a community pen) and treatment (T; 6 pairs, each 94 housed in a solitary pen). After an acclimatization period (two months), behaviors were monthly assessed on individual focal basis during the spring-summer seasons (7:30-12:30 h, 30-min sampling interval). Results The sum of all active behaviors was not affected in T, and there was no effect on the synchronization of typical activities (50% in both groups). Remarkably, as the breeding season progressed, maras stopped showing synchronization. The proportion of time allocated to each behavior was different between groups, feeding and resting were observed mainly in C, while resting and sitting in alert mainly in T. Besides, T exhibited an increase in sitting in alert behavior and a reduction in feeding with respect to C. The total production of offspring did not differ between groups. Discussion The increase of the alert state in T could imply a situation of welfare compromise and/or chronic social distress over the reproductive season. Therefore, housing pairs in solitary ex situ pens should not be recommended. Whether increased alert corresponded to an overload of behavioral stress should be explored, increasing descriptive data about basal and reactive ranges.