A TWO-DAY PARTICIPATORY OBSERVATIONAL BIRD SURVEY AT BRT WILDLIFE SANCTUARY. NOVEMBER 2006.
Krishna MB and Prashanth MB. 2007.
Draft: not formally edited; citation expected if used.
Survey dates: November 18th and 19th 2006.
Participants: There were five teams, each with both new and experienced birdwatchers. The details of the survey programme, the organizations and people involved, with the list of participants would be available elsewhere.
Methodology: Each of the five teams was asked to make a new list for every ten minutes of observation. The teams were asked to keep to the trail or road, and were accompanied by a forest department guard to ensure compliance. The areas visited were Team A: Tourism zone; K'gudi to Chamarajnagar checkpost; Team B: Burde to Gundal (3 kms); Burde to BRT road; Burde to Dodda Sampige mara; Team C: Mulki gate/Sampige mara cross to Thondekere (base of Mulki betta); Lingana katte trail to Guruvina gadde; Gavibore-Kumbaranakola-Jadeswamygudi Stream; Team D: MPC game road to Ganhalli road; Forest IB to K'gudi road; Purani road cross; Team E: Bedagully and K'gudi; near K'gudi lake; Mulki gate/Sampige mara cross to base of Mulki betta.
Objective: Mere bird lists done for any area have a limited value. The idea of the exercise was to encourage and demonstrate a very simple technique of quantifying observational data, which could, if done over time, help monitor the changes in birdlife better. The idea was to convey that getting occurrence frequencies would in turn give an indication of relative abundance of the species. This would bring observations more towards the realm of ecological studies, rather than mere ornithological listing as has happened over the years.
Outcome: A cumulative number of 157 ten-minute lists were obtained from the five teams. Since this is an amateur exercise and more of a training effort, a great deal of scientific importance cannot be assigned to the outcome. But the effort has its value. A major limitation is that it has been done just over two days, and in inclement weather on the first day.
The Relative Frequencies of Species’ Encounters
A look at the above table shows that there are many-more rarer species than those that are frequently come across. This is the same as seen in densities and populations. The distribution is highly skewed. Usually, a rank order comparison of encounter frequencies and abundance shows a high correlation.
It can be seen from the list that the top fifteen species are all usually found on canopies of trees or as in the case of the Jungle fowl, on the ground. All those species preferring the canopy or are aerial in their habits are marked in green. Shrub zone species (and under storey birds in suitable habitat) occur quite low in the ranking and are marked in purple. Are shrub zone species so rare in BR hills or are they not easily seen? Or are observers predisposed to see birds on trees? Grassland and wetland birds are in blue. Ground birds are in grey. The number of species and their encounter rates progressively decrease as we move down from the highly productive canopy layer of the forest. This is excluding the water, wetland and grassland birds.
A look at the data sequence in which species once seen are seen again shows that sightings are not random (not shown here). Except for a few species, the likelihood of seeing a species again is more, when it is closer to the first sighting.
The Performance of the Teams and the Birds they encountered
This dendrogram shows how the different teams fared. The birds and their frequencies were most similar between team C and team D. Teams B and E were also similar. What team A encountered was inbetween what the other teams encountered. Since this is a reflection of what they saw in each habitat/place, it would indicate the similarity of the habitats too.
Team A went to the tourism zone, and the road going to the Chamarajanagar edge of the Sanctuary..
Team B went to Burde and covered the three roads: Burde to Gundal (3 kms), Burde to BRT road and Burde to Dodda Sampige mara.
Team E went to Bedagully and K'gudi; near K'gudi lake; Mulki gate/Sampige mara cross to base of Mulki betta.
Team C went to Mulki gate/Sampige mara cross to Thondekere (base of Mulki betta); Lingana katte trail to Guruvina gadde; and Gavibore-Kumbaranakola-Jadeswamygudi Stream.
Team D went to MPC game road to Ganhalli road; Forest IB to K'gudi road and Purani road cross.
Conclusion
The purpose of this exercise has been quite limited and to that extent the purpose has been satisfied.
Frequency of occurrence in the same spot gives a good indication of the occupancy of that patch by the species. This is a good indicator of habitat suitability and should be an important consideration for conservation efforts.
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