Using activity patterns and STR markers to distinguish between blesbok (Damaliscus pygargus phillipsi) and bontebok (Damaliscus pygargus pygargus) in the Free State

English: Two subspecies of Damaliscus pygargus, blesbok (D. p. phillipsi) and bontebok (D. p. pygargus), are recognised based on phenotypical and native geographical distribution differences. Past introductions of bontebok lead to extensive hybridisation that produced numerous fertile hybrids in the Free State. The present study aimed at investigating behaviour of introduced herds by quantifying activity budgets and patterns to examine diurnal and seasonal effects on certain behavioural aspects, allowing comparisons with blesbok. A secondary objective was to determine amplification of ungulate microsatellite primers in D. pygargus. Activity data on bontebok totalling 1 098 hours were collected during 2006/2007 and 2009 in the Free State. Observational measurements involved instantaneous scan sampling as well as focal animal sampling. Blesbok and bontebok hair samples were also collected for genetic analysis. Time budgets revealed that equal amounts of time (50%) were spent on active and inactive phases. Grazing and lying were the major activities identified and represented more than three quarters (83%) of total observed activities. Less than one fifth of their time was diverted to standing (9%) and moving (8%). Behaviour of bontebok deviated slightly from blesbok as blesbok allocated more time to lying (40.4%) than to grazing (35.5%), while standing (16.5%) and moving (7.7%) represented nearly a quarter of the general time budget. The subspecies spent almost equal amounts of time on lying and moving, whereas bontebok allocated more time (6.5%) to grazing and less time (7.5%) to standing. Differences between bontebok social groups indicated that females spent the most time grazing (41%) and territorial males the least (31%). Juveniles spent nearly half of their time budget on lying and territorial males were least observed to be lying down (36%). However, territorial rams exhibited much higher standing (19%) and moving (14%) activity compared to any of the other social classes. Comparisons with blesbok social groups indicated similarities as well as discrepancies. Territorial rams also spent the least time grazing, but spent the most time lying. Blesbok juveniles allocated the most time to standing, however territorial rams also spent the most time on moving behaviour. Bontebok exhibited the same diurnal pattern as blesbok. A typical bimodal feeding pattern with principal grazing bouts in the early morning and late afternoon and a reciprocal pattern of lying activity around mid-day were observed. Adverse weather conditions had a seasonal effect on the basic pattern, while grazing and lying time budgets showed significant seasonal differences. Noteworthy differences were thus found regarding bontebok behaviour categories among subsets classified by time of day, season, gender and age. Consistencies between certain behavioural aspects of bontebok and blesbok can be considered indicative that behavioural differences are insufficient to prevent hybridisation incidents. The occurrence of past hybridisation events can therefore not only be ascribed primarily to their relatively recent phylogenetic divergence and overlapping breeding seasons, but also as a result of the convergent behaviour observed in comparable habitats. Following screening of a preliminary panel of 72 ungulate microsatellite loci a concluding bovine and ovine panel of five microsatellite loci was identified. Disregarding MAF46 monomorphic pattern for D. p. pygargus, microsatellite loci showed moderate levels of polymorphism. Allelic variation ranged from one (MAF46) to six (OarFCB304) alleles per locus, with an average allelic diversity of 2.9. Alleles per locus per population ranged from one to four. Data obtained not only confirmed that informative polymorphic microsatellites can be cross-amplified between closely related representatives of Artiodactyla, but were also testimony of noteworthy differences in microsatellite allelic variation in D. pygargus. These findings thus represent baseline data that could assist future molecular studies aiming to identify alleles that would substantiate discrimination between pure and hybrid taxa.