Goat culling project Slagbaai, Bonaire: 1st Year Progress Report, Field Assessment and Key Recommendations

Summary

There are many clear indicators of the deleterious impacts of grazing livestock on the flora and vegetation of Slagbaai, Bonaire. The Washington-Slagbaai National Park has seriously degenerated vegetation, second only to the vegetation of the Arikok National Park of Aruba. Similar degraded landscapes previously existed in the Christoffelpark of Curacao into the 1970s but have since largely disappeared due to vegetation recovery following livestock removal. Livestock densities in Slagbaai are estimated at 2.69 goats/ha. Based on comparative studies from arid ecosystems elsewhere, these livestock densities well-exceed the ecological carrying capacity of the semi-arid vegetation of the Washington-Slagbaai National Park. If goats are not culled, then ecological restoration of the park will not be possible. Prior trials using grazer exclosures inside Slagbaai prove that vegetation recovery will be rapid following goat removal and prove that reforestation with rare native species is possible using simple methods. Baseline studies were conducted by four Wageningen University students. The main results are briefly presented in this report and will provide a solid baseline from which to work as the culling program is implemented over the course of the next few years. Based on these studies, several recommendations are made for monitoring project progress and further follow-up research. Several infrastructural needs to enable culling of the Slagbaai goat population were achieved by the end of the year (2015)- such as restoring roads for access and securing the perimeter fencing- but other critical needs-such as closing watering holes to control and restrict grazer access- were largely not achieved. Documented goat catches for the culling program amounted to a total of 937 animals in 2015. At present goat removal rates remain well-below projected intrinsic population growth rates. The numbers of animals caught represent a large increase compared to prior years but still fall greatly short of the 2400 goats that minimally should have been caught in the first year to be able to meet project goals. Goats are currently almost exclusively being caught using small funnel traps. This method is labourintensive and has significant (but recently reduced) impacts on the native vegetation, particularly on plants that are being used as bait to attract goats into the trap. New and improved goat catching methods need to be introduced as soon as possible in 2016. There are a variety of tried and tested systems by which to trap and remove goats. For this, the remaining planned infrastructural improvements (closing freshwater access) are essential as is the use of new and more effective techniques for goat control and eradication. Several of these have been discussed or even already partially tried but must be effectively implemented in 2016. Goat trapping and removal rates must significantly surpass intrinsic population growth to be able to significantly decrease population size within the project period.