Spatial and Temporal Patterns in Debarking by Indian Crested Porcupine (Hystrix indica kerr) in Sariska National Park

Abstract

A study on debarking by porcupine was conducted in Sariska National Park form 6th May to 1Oth october 1989. The climate is semi-arid with mean annual rainfall 650 mm but most of it during monsoon (June-September). Rainfall is variable seasonally and spatially. 4021 trees of nineteen species were examined for debarking in six Intensive study Sites (ISS). Of these Anogeissus pendula (1932), Balanites aegyptica (174) and Capparis decidua (101) were not found debarked. Twelve species were rare «20). Remaining four species Acacia catechu, A. leucophloea , 'Butea monosperma and Zizyphus mauritiana provided the data to study spatial and temporal variations 1n debarking. Both old and new debarking evidences were recorded. In Zizyphus and mixed woodlands the intensity of debarking high. Anogeissus woodland (ISS-5) did not have any tree debarked.Debarking evidences were lower in Zizyphus scrubland, Butea woodland and degraded Zizyphus woodland. The overall difference in debarking in different sites was significant (p ( .0001). Percentage of different species debarked in each ISS varied greatly. This intensity of debarking was positively related to the overall density of trees that could be debarked in a site . A. catechu and Z. uauritiana were significantly more debarked (p ( .05) than other species in respective ISS. iii - The Less debarking was observed in lower and higher girth classes within 41-100 cm. were debarked girth classes. more than any other class. Of the 59 trees recorded debarked 58 were debarked in summer and only 1 was consumed in monsoon. Thus debarking of trees occurs mostly in Bummer when no other food is available for the porcupine. Microscopic analysis of porcupine faeces shows that 75-95% of the food in summer was bark and stem. In monsoon/post-monsoon season grass seeds and monocot formed 33% and 41% of food respectively. Average density of porcupine in Sariska valley based on direct counting was calculated to be 8+2 animals per km2. Debarking does not have 'severe effects on the life and phenology of the tree. From the total density of debarked trees (77 I ha) only 0.79% of the debarked trees were dead. Hence no special measure is required to control debarking but any occurrence of fire should be prevented. If there is fire , these trees will be most severely affected because of their exposed hardwood.