Project PteroCount

South Asian Bat Monitoring Programme
Pteropus giganteus Population Monitoring Project


The South Asian Bat Monitoring Programme aims to create awareness about bat conservation issues, involve and educate biologists and nature-lovers in studies about the biology of bats, and establish a conservation action plan. The Programme will initially focus on one species, the Indian flying fox (Pteropus giganteus) as it is the most known and recognizable bat species in South Asia.

The Program is based on a collection of volunteers from a broad range of backgrounds who have identified Pteropus roosts in their area and have committed to studying the roost and obtaining population information on a regular basis. It consists entirely of volunteers and is the first such network to monitor the population of a species in South Asia. The information from all these sites will be compiled and analyzed for trends in the population of Pteropus giganteus, identify key threats to roosts and provide recommendations for their conservation.

Little is known about the population status of Pteropus or any other bat species in any country of South Asia. While we have a good idea of the number of species, and limited information about their distribution, the actual numbers of individuals of each species remain an unknown.
It is difficult to assess whether a species requires any conservation measures without reliable population estimates. That is, unless one cannot show that a population is declining or under threat of decline, one cannot create a plan to conserve it.
Although there are anecdotal accounts which indicate that populations and roosts of many bat species are decreasing, there is no hard evidence. There is thus an urgent need to assess the populations of bats and to monitor them on a regular basis to determine population trends.
Bat populations face some of the same threats that other species do, including direct disturbance by humans, habitat loss, and limited roosting sites.
Pteropus giganteus, the Indian flying fox, is an ideal first candidate to study population trends because it:

is the only large pteropodid on the subcontinent and is easily identified
is visible during day
is large and easy to count
often roots near humans
is often easy to acquire historical information about roost from locals (like age of roost, behaviour of the animals and population trends)

To establish an organised group of individuals that monitors Pteropus roosts and provides information on population size as well as threats.
To have a significant number of participants throughout South Asia
To establish long term data on roost size, fidelity, etc.
To collate this information and analyze the data for trends in populations
To make this information readily available for dissemination to all interested parties
To create a conservation plan for Pteropus based upon the information collected

The methodology requires three simple steps
Locate and describe the roost site
Count the number of bats at this roost
Provide the information via the printed or online form

Information Required
(Minimum) - The following items are essential and necessary.
Location (State, District, Taluka, Village)
Roost Size
Protocol used to count bats: Exact or Estimate (see below)
Observer's Name
Observer's Address

(Additional) - The following are very useful, but not absolutely necessary. Participants are encouraged to provide as much as possible, without making the task of monitoring too difficult.
GPS Location of roost site (Degrees-Minutes-Seconds or UTM)
Number of roost trees
Roost tree species (common or scientific name)
Height of roost (range)
Photographs of the roost (showing details as well as surrounding area)
If roost is remote, directions from nearest village
Distance to nearest forest and directions
Threat information (e.g., disturbance, killings, habitat loss)
Protection information (e.g., temple, sacred groves, sanctuary)
Notes and comments (include any anecdotal information about history of roost)
Observer's Email and Phone number

Measuring the population
Each roost should be measured by means of one of two methods, an exact count or an estimated count. The choice of methodology should be noted on the data sheet.

Bats tend to be more active during dusk and dawn hours, often flying around the roost and changing their location. It is therefore best to conduct the count during the day (not dusk or dawn) as this minimizes the chance of missing a bat in the count or multiple counts of the same individual.
1. Exact Method: This method should be used for small roosts (300 or less) where individuals can be easily distinguished and counted. Counts should be conducted by enumerating the number of bats on individual branches to create a tree total and then summing bats across all trees.
2. Estimation Method: If there are too many bats to count each and every bat, one can use an estimation method. It is important to note that no one method is suitable for all situations. Here we present a few methods that are commonly used to estimate populations. If you use your own estimation method, or a variation of one of these, please describe in detail on the form.
a. Branch Estimates: Identify all the major branches on the tree that have bats on them. Pick a branch that has an average number of bats on it (i.e., don't pick one that has just a few, or the branch that has the most). Count the number of bats on this branch and multiply that number by the total number of branches that are occupied by bats.
  1. You can make this estimate more precise by counting a few branches and taking the average, and also by ensuring that the branches are of roughly equal length.
  2. Additionally you could count the actual number of bats on branches where they are sparse, and then use the estimation methods for the heavily populated branches.
b. Tree Estimates: In situations where the roost is spread out across many trees, one can count the number of bats on a tree and then multiply by the number of trees. You can increase the accuracy by following the same suggestions above.
c. Flight Estimates: If it is not possible to count the bats while they are on the trees, one can count the number flying from the roost. This is suitable for small roosts where visibility is not a problem. This methods is not recommended as many factors can affect this count (bats flying in different directions, darkness affecting visibility, inaccuracy of counting many flying bats concurrently, etc.)

Other Considerations
Sampling Periods
Ideally, censuses should be done once a month. At a minimum a census should be done annually. However, annual censuses will not provide useful information on seasonal patterns of movement, changes in roost size or reproductive cycles.

Roost ID numbers
Each roost will be assigned a unique roost ID - preferably based on a GPS location but if not possible then by using the detail directions to and description of the roost. Once your roost site has been given a number, you may use this reference number in subsequent surveys and not have to fill in the location information every time.

Disturbance at Roosts
It is important that the monitoring activity of the researcher not disturb the bats at their roost. One should avoid any activity, such as getting too close to the trees or talking too loud, which may disturb the bats.

Additional Information
There are many other studies that can be done at the roost site, and much depends on the time and inclination of the participant. Some of the possible topics worth studying include monitoring roosts for sex ratios, age structure, reproductive status, threats, social behavior, sleeping activity, social structure, foraging activity, movement between trees/roosts, direction that bats fly at sunset, etc. Those interested in studying such aspects of the roost may wish to contact the group organizers for details.

The data collected will be analyzed for patterns and changes in populations. Annual reports will be sent to each participant in the network as well as published online. The summary information, but not the details of each site, will also be available at any time via the internet. The network will periodically publish summaries of the information collected so as to distribute the information to the scientific community and also inform policy.

Ownership of Data / Copyright Issues
Ownership of Data
The data collected belong to the researcher and the group. Thus, the individual volunteer may use their site data to publish in any way they wish and the Programme may use the data from multiple sites for "Programme scale" publications.

Thus, by participating in this group, the volunteer agrees to help the Programme to
Add their data to the Programme database
Present summaries of the data on the website as well as in annual printed summaries
(Note: at no point will the Programme release actual location information or details of a study to others without the participant's permission)
Publish papers based on the information collected by the Programme. These papers would be at the scale of the entire Programme and not the individual sites. Thus there should be no overlap between these publications of those of individual researchers. If anything, they will compliment each other. Since we anticipate that there will be many individuals taking part in this collaborative project, it would be difficult to list all as authors.



Ptero Count

Sanjay Molur and Shahroukh Mistry, Coordinators
Sally Walker, Convenor / Administrative Chair, CCINSA
Sripathi Kandula, Scientific Chair, CCINSA

CCINSA - Zoo Outreach Organization
3A2, Varadharajulu Nagar, FCI Road
Ganapathy, Coimbatore, Tamil Nadu 641006, India
Ph: +91 9385339862 and 9385339863