|Karyn Rode, PhD|
|Post-doctoral Associate, Cornell University, Bioacoustics Research Program|
|Monitoring Forest Elephants to Promote Conservation in Central Africa: Poaching and Patterns of Elephant Activity at Bais|
|Location: Ivindo, Mwange and Minkebe National Parks, Gabon|
|Species: African Forest Elephant (Loxodonta africana cyclotis)|
|Abstract: Acoustic monitoring has recently emerged as a promising new technique for providing continuous data on spatial and temporal patterns of elephant activity while simultaneously documenting human activity, such as gunshots. As a result of recent advances, including a statistical model that can be used to estimate elephant abundance from vocal rates and automated detection for efficient data analysis, this study proposes to use acoustics to estimate elephant density and gunshot occurrence at five bais, mineral-rich forest clearings, in northeastern Gabon. Bais were chosen as focal points for monitoring since they attract concentrations of forest elephants and other wildlife and are hotspots of poaching activity. The monitoring proposed in this study is expected to be complemented with a more extensive monitoring effort (including additional bais and monitoring over a 12 month period) that will continue into early-mid 2008.|
|Photos: Melissa Gro|
Project Update: September 2007
In June 2006, the Elephant Listening Project began the groundwork for research in Gabon with a reconnaissance trip by Karyn Rode, funded by the Cleveland Metroparks Zoo. It was during this initial trip that key contacts were established, potential research sites identified, and some of the more difficult logistical issues determined. This initial grant was instrumental in attracting additional funding for full implementation of the proposed research. Based on experience and information gained by Karyn, we were able to make modifications to some of the equipment, and were prepared for many of the logistical challenges that we encountered during implementation. In June and July 2007, in collaboration with the Wildlife Conservation Society (WCS-Gabon), we initiated an ambitious research program. Research activities are focused in two areas of interest, supported by a research grant from the U.S. Fish and Wildlife Service. Considerable logistical assistance has come from WCS-Gabon, and 'Projet Protection des Gorilles' (in Plateau Batéké N.P.). This report summarizes activities in each of the targeted areas of interest.
Use of Forest Clearings (Bias) by Forest Elephants
Autonomous Recording Units (ARUs) were placed at six different bais in July 2007. We attempted to assemble a sample that would give reasonable variation on the factors of interest, and this appears to have been achieved. Each of the study sites is described below.
Effects of Human Activity and Environmental Variables - In order to develop a protocol for acoustically monitoring elephant populations from activity at bais, information is needed on the human and environmental variables that affect bai use. Human and environmental factors quantified at all bais will include: 1) gunshot occurrence, 2) rainfall, 3) surface area of the bai, 4) number of waterholes or soil excavation sites, 5) mineral availability in bai water (e.g. sodium, calcium, etc.), 6) hours of patrols/monitoring at each bai and 7) proximity to villages and roads. Bais with heavy hunting pressure are thought to alter elephant use patterns by increasing night-time use ((Maisels, 2002); S. Blake pers. comm.), and this study will also examine whether consistent eco-tourism activity alters elephant activity in a similar manner. In areas where long-term monitoring has occurred and poaching has increased significantly, elephants became increasingly nocturnal (e.g., Odzala National Park; (Maisels, 1996).
Autonomous Recording Units at the bais will record for 60-90 days on a set of batteries. Although only a single ARU was placed at each bai, each unit will record from an area of 1.5-3.5 km2, depending on the signal/noise ratio. Two bais in the CEB forestry concession had fast-flowing streams running through them, decreasing the signal/noise ratio and thus reducing the distance at which we can detect elephant vocalizations. Nonetheless, a detection area of 1.5 km2 will still easily cover all elephant activity in the vicinity of the bai. Between October 2007 and early January 2008 the acoustic data will be recovered from ARUs at each bai and the batteries replaced for a further three months of recording. Funding has been requested from the International Elephant Foundation to extend this study for an additional three month period of recording, which would provide data from all seasons of the year.
Call Rates vs. Elephant Numbers- Validation at Low Density
In October, 2007, an array of 6 ARUs will be established at Langoué Bai, each ARU equipped with a GPS receiver to provide highly accurate time information on the acoustic recordings. This will allow us to localize the source of each recorded vocalization. Observations will be made for 6-8 weeks, including regular scan samples of the number, sex, and age class of elephants in the clearing, as well as video records of behaviors. Observations will be concentrated during daylight hours, but nighttime observations will be made when possible on clear moonlit nights. We will test the use of night-vision equipment to extend the days on which we can make nocturnal observations.
MAISELS, F. (1996). Synthesis of information concerning the Parc National d'Odzala, Congo. -- In. Projet ecofac-Composante Congo.
-. (2002). Long term monitoring, research, and protection of elephants in the tri-national region (Nouabale-Ndoki Nation Park - Republic of Congo; Dzanga Sangha Reserve - Central African Republic; Lobeke Reserve - Cameroon): Final Report September 200-November 2001. -- In. U.S. Fish and Wildlife Service.
MORGAN, B. J. & LEE, P. C. (2007). Forest elephant group composition, frugivory and coastal use in the Réserve de Faune du Petit Loango, Gabon. -- African Journal of Ecology 'OnlineEarly',???-???
THOMPSON, M., PAYNE, K. B., SCHWAGER, S. J. & TURKALO, A. K. (submitted). Acoustic estimation of wildlife abundance part I: Methodology for African forest elephants. --.
WHITE, L. J. T., TUTIN, C. E. G. & FERNANDEZ, M. (1993). Group Composition and Diet of Forest Elephants, Loxodonta-Africana-Cyclotis Matschie 1900, in the Lope Reserve, Gabon. -- African Journal of Ecology 31, 181-199.