Important Bird Areas (IBAs) are key sites for bird conservation, so it is important to carefully document the birds they contain, and subsequently monitor the sites to assess the efficacy of management and to detect early signals of trouble. In this post, we explore the possibility of using eBird lists as a way of documenting and monitoring birds in Indian IBAs.
eBird now contains roughly 1.5 million observations of Indian birds, organised into over 70,000 birdlists. These lists have accompanying information on date, time, location and effort (eg distance covered and duration spent). To examine how much of this information comes from IBAs, we used shapefiles kindly provided by the Indian Bird Conservation Network and BNHS-India to identify lists from within IBAs. The maps below show the locations of eBird lists from India (left) and the boundaries of Indian IBAs (right).
Roughly 300,000 bird observations from within Indian IBAs are contained in the eBird database. These are from c.11,300 birdlists. A listing of the 10 IBAs with the highest birding effort (total number of birding hours) is given below.
This table shows that a large volume of information is being uploaded from IBAs by birders and tourists visiting these birding hotspots. But clearly the effort is highly skewed. For example these IBAs are represented in eBird by only two records or fewer: Kalesar Wildlife Sanctuary, Tirthan Wildlife Sanctuary, and Kumbalgarh Wildlife Sanctuary, among others.
To examine the feasibility in using eBird data to monitor changes in species sightings over time, we looked at birdlists from Thattekad Wildlife Sanctuary, Kerala. In all, 254 ‘complete’ lists have been uploaded from Thattekad to eBird. A complete list is one in which the observer has included all identifiable species, and these allow one to calculate the frequency with which a species is seen (eg, a common species might occur in 90% of lists and a rare one in only 5% of lists). For the period 1999-2013, 97 complete lists exist in eBird and for 2014-215, 157 lists are on eBird from Thattekad.
Extracting only birds endemic to South Asia, the table below shows the change in the frequency of sighting of the most common 10 endemics in Thattekad between the two time periods.
Note that the calculations for Thattekad have been made with all ‘complete’ lists in the eBird database. It is likely that the reason for the apparent decline in reporting rate for all the species in Table 2 is that the duration of lists has reduced over time. Indeed, the median duration of birdlists in 2014-2015 was c.60min, while in 1999-2013 it was 180min. Shorter lists mean fewer species on each list.
The purpose of making these calculations is not to accurately assess changes in status of birds; this would require more detailed analysis and more data. Rather our intention is to illustrate the possibility of using lists from birders to monitor, in a crude way, possible changes in the status of bird populations over yearly (or longer) durations.
Some other countries (for example, Canada) use eBird as a data gathering platform for their IBA monitoring through a specific protocol, and this is a model that we could think of adapting for India.