Presentation summarizing results of MSc theses of various students
Feral livestock grazing has long been recognized to have a negative effect on the ecosystem of the Washington Slagbaai National Park, Bonaire. Because of this STINAPA, the management of the national park, started a goat-catching project. In this study, the population density of feral livestock was estimated for the park and the Labra-Brasil area using the Distance method. The results indicate a goat density of 2.7 goats per hectare in the national park, corresponding to an abundance of about 11000 goats. Looking at the population structure of goats, around 20% are young animals and there are twice as many females as there are males. The population density of the other animal species was much lower. The Opuntia distribution was also assessed in the study area, a density dependent relation between Opuntia density and goat density was found. Finally, seasonal differences in diet composition of goats were observed; goats seem to become less specific and eat only cacti in the dry period. The study concludes with several recommendations. On the short-term, the priority STINAPA should be to control the goat population, preventing further damage to ecosystem. For this a more effective way of catching the goats should be used. Next to bringing down goat population density, it is also important to monitor the development of the other animal populations so the goat-catching project can be adjusted in time. Eventually the goal is to restore the original ecosystem of Bonaire. This will require more research and monitoring but most importantly a lower feral livestock density.