TERF Project detail
Indirect Observation
Surveys are divided into three phases:
- Recce walks where we walk along existing forest trails recording elephant sign to get an overall estimate of where elephants are. (see findings of Recce Walk)
Recce Walk Analysis From the recce walks we found out the forest types the elephants used the most and then divided the park into three Strata for High, Medium and Low densities of elephants. We will now use this in our dung decay survey and dung density line transects.
- Dung Surveys – finding fresh dung and recording how long it takes to decay, following elephants to see how many times they defecate per day and line transects to sample dung density in different parts of Khao Yai.
Researching Elephant Dung
1. Dung Decay Rates: find over 60 piles of fresh dung every month in 7 different forest types and monitor how long they take to disappear.
2. Defecation Rate over 24 hours: follow at least 10 different elephants for 48 hours and count how many times they defecate.
3. 120 x 2km line transects to sample dung density: count the number of dung piles visible from a 2km straight line transect cut through the forest. - Using camera traps to take pictures of elephants away from the roads
The currently accepted method of counting elephants in forests is to count elephant dung and to convert the amount of dung found into elephants by using information about the decay rate of the dung and the number of times elephants defecate per day.
The first stage of this research was completed in 2003 and 2004 as part of the earlier elephant research project. The elephant research team completed reconnaissance surveys looking for signs of elephant along over 200km of trails in Khao Yai. Mr Or analysed the results from these surveys to divide Khao Yai into three strata of relative elephant densities – High, Medium and Low.
These strata are the basis for the amount of effort we put in to each area with regards to the dung decay and dung line transect surveys.
We used the DUNGSURV method to analyse decay rate. This means that we need to regularly find fresh dung and monitor it to see how long it decays. As dung in different forest types (and at different elevations) will decay at different rates, we need to find dung in as many places as possible. We are aiming to find one cohort of dung from each strata per month and are so far doing well. From a study completed by WCS in Sumatra, dung in tropical areas can take almost one year to decay. We need to wait for the all the dung from the first group of dung to have decayed before we can start the second part of the dung survey which is the line transect survey.
Line transects are a recognized way to sample wildlife (or wildlife sign) over large areas. We aim to survey at least 100 2km line transects in Khao Yai. The transect line needs to be completely straight and then we count all the dung piles seen along each transect line and measure the perpendicular distance. This will provide us with the relative densities of dung in different parts of the park which is then converted into relative densities of elephant.
The third part of this study involves tracking an elephant and counting how many dung piles he or she produces. We completed the trial run of this study in late October 2005 with Dingru as the target elephant. The team followed him for over 48 hours and are certain they found all of his dung piles. We were lucky, he stayed by himself. Now we are looking for another subject to follow.
We do a Recce survey along 20 forest trails which will give us a basic idea of where the elephants are in the whole park. So far we have done 11 of the 20 trails and have covered Km of the park. We then do 3 km Transect Lines in areas of high elephant activity and survey these every 15 days. We currently have 3 Transect lines in three different areas of Khao Yai.
The Food Plants of Elephants
As we walk our transect lines and survey trails, we look for evidence of elephants eating plants. We make notes on which parts of the plants have been eaten (leaves, roots, seeds, trunk stem etc) and also what type of plant it is and take photographs. Sometimes when we see elephants on the road we see them eating and where possible identify these plants too.
Findings So far we have identified over 102 different types of plants that elephants eat in Khao Yai. We have seen elephants eating bark, roots, fruits, leaves, stems, and vines.(more photos of the plants)