methods 11

Methods

The information for this book was gathered during 29 years of research in . Observations and collections were made during many expeditions to the interior of Suriname, but also during specific research projects that were often not focused on amphibians, but on various issues including caiman ecology, freshwater fish diversity, aquatic ecology, mercury pollution and environmental impact assessment. However, to carry out the different research projects we had to visit the forests of the interior. During these visits observations on amphibians and reptiles were made despite a different research focus at that time. From 2004 on, amphibians were selected as one of the main indicator groups for biodiversity monitoring purposes in Suriname. Amphibians were chosen because of their sen- sitivity for pollutants and for changes in micro-climate. Table 1 gives an overview

Table 1. Expeditions, environmental studies and research projects carried out by the senior author between 1988 and 2010.

Subject /Period Area Expeditions 1988 River and Savanna 1989 Zuid River 1989 River, Sipaliwi Savanna, Apalagadi 1991 Upper River 1993 Paloemeu River/Kasikasima Mt. 1998 Oelemari River 2003 Tafelberg Mt. 2004 Upper Coppename River 2005 Tafelberg Mt. 2006 Nassau Mt. 2010 Sipaliwini/Koetari River Baseline studies/EIA’s 1994 1994 Gros-Rosebel area 1995 Wane Hills 1996 Kleine Saramacca River 1998 Tambaredjo 2006-2007 Bakhuis Mts. 2010 Nassau Mt. Research projects/monitoring 2006-2011 Gros-Rosebel area 2008-2009 Raleighvallen/Voltzberg area 2007-2010 Brownsberg Mt. 2010 Coesewijne area 12 methods of expeditions, environmental impact assessments and research projects focused on amphibians and the geographic area involved.

Figure 14 shows all localities where amphibians were collected or observed by us. See Hoogmoed (1969a; 1973) for a map of his sampling localities in Suriname. Field research on amphibians was usually carried out using strict protocol. Transects with a length of 1 km were established on existing roads or trails or were created in the forest by machete, and flagged. Disturbance on these trails was kept to a minimum (however, some transects were existing roads and trail systems for eco-tourists or miners or loggers, where disturbance could not be con- trolled by us). A 300 to 500m section of each transect, usually including a creek, was marked separately for night surveys. Surveys were carried out starting at 8-9h till 10-12h walking the 1 km transects concentrating on call records and visual encounters. Night surveys were carried out on the 300-500m sections of transects between 19.30h and 22h. During night surveys visual encounters and call records were usually of equal importance. Calls were recorded using a Marantz PMD661

Fig. 14 Map of Suriname with amphibian sampling locations of the authors.