Bird community structure in the sacred groves of northern kerala

Abstract

A study on the ‘Bird community structure in the sacred groves of northern Kerala’ was carried out during 2011-2014. Fifteen sacred groves, eight from Kannur and seven from Kasargod districts were selected for the study. The bird community was studied at each of these sacred groves. The bird study was done for three hours from 7h to 11h and 15h to 18h in each of the fifteen sacred groves. The study was repeated once in every two months in each of the sacred groves between March 2012 to December 2013. Thus a total of 168 visits and 1008 h of field work is done during the study period. The bird diversity was then correlated with various variables such as the size of the sacred grove, distance of the sacred grove to the nearest forest, altitude of the area and tree density. Tree diversity in the sacred groves was also studied and was correlated to bird diversity. Ten quadrats of 10x10m were taken in each of the sacred groves and trees having more than 10 cm girth was selected and GBH and height was measured. Socio-economic study was undertaken to know the awareness about the birds of the sacred grove and the perception about the significance of sacred grove among villagers. Ten respondents from each of the sacred groves were interviewed. A total of 111 bird species, belonging to 15 orders, 47 families and 90 genera were recorded from the sacred groves of northern Kerala. The species richness per sacred grove ranged from maximum of 55 to minimum 23. And the number of individuals of birds per sacred grove ranged from 576 to 203 birds. The bird diversity was highest in the Cheemeni Kavu, while the bird species richness was highest in the Verikkara Kavu. Sacred groves of northern Kerala supported 86.48 per cent of resident birds and 14.52 per cent of migratory birds. Twenty five percent of the birds found in the sacred groves were found to be forest-dependent birds. Two species of birds that are endemic to Western Ghats viz., Malabar Grey Hornbill (Ocyceros griseus) and Rufous Babbler (Turdoides subrufa) were recorded from sacred groves of northern Kerala. The bird community of the Kammadam Kavu and Thazhe Kavu was found to be distinct among the 15 sacred groves studied using the Correspondence analysis. Dendrogram based on Bray-Curtis similarity matrix identified broadly three clusters viz. Karaka Kavu to Cheemeni Kavu, Edapara Kavu to Kuduvakolangara Kavu and Thazhe Kavu to Kammadam Kavu. The numbers of endemic birds were found to be greatly influenced by the extent of the sacred grove. However number of forest birds was influenced by the altitude and tree density. A total of 130 tree species were reported from the sacred groves of northern Kerala. 14 species of trees were endemic to Western Ghats and seven were threatened, this includes one Critically Endangered (Vateria indica) and four Endangered (Hopea ponga, Hopea parviflora and Chionanthus mala-elengi, Evodia lunu-anekanda) and two Vulnerable tree (Cinnamomum perrottetii, Santalum album) species. Respondents in the sacred groves of northern Kerala had medium awareness about the birds and perception about the significance of the sacred groves of northern Kerala. Awareness was found to be influenced by caste, gender, education, knowledge about bird diversity in sacred grove and understanding the beneficial effect by birds among the respondents. The perception was influenced by occupation of the respondent, knowledge about bird diversity in sacred grove and understanding of beneficial effect by birds among the respondents. Important threats faced by sacred groves in northern Kerala were encroachment, degradation of vegetation in the sacred grove, dumping of waste into the sacred groves, deposition of solid waste through contaminated water, passages within the sacred grove, use of sacred grove for anti-social activities like for consumption of liquor, playing cards etc, and various construction activities taking places in some of the sacred groves. The Government should step in and take some bold initiatives for the conservation of the sacred groves. Incentives should be provided for the owners of the sacred groves for preserving these important biodiversity repositories outside the reserved forests and protected areas. Restoration planting should be taken up in the degraded sacred groves with community participation.