Rodent species in mangosteen intercropped with coconuts and their bait preferences

C. H. Lee and H. S. Goh

Abstract

A study on the rodent species composition, sex and bait preferences was undertaken in a coconut-mangosteen plot in Kluang that had relatively severe mangosteen fruit damage. Three rodent species namely the red-bellied squirrel (Callosciurus notatus), the wood rat (Rattus tiomanicus) and the ground squirrel (Rhinosciurus laticaudatus) were trapped and identified present in the field plot. A high number of red-bellied squirrels was trapped with jackfruit baits with a lesser number caught using ripe bananas and the least trapped with fresh coconut pieces. In contrast more wood rats were trapped using fresh coconut pieces and a lesser number caught with ripe bananas and jackfruit baits. The dominant species was the red-bellied squirrel with 56 animals trapped, followed by 35 wood rats and 13 ground squirrels. The animals caught were studied on their damage potential and their pattern and mode of damage. Mangosteen fruits that were light greenish, unripe and developing to matured purplish, almost ripe fruits were attacked. Damaged fruits in the field were found to have holes bored, with striation teeth marks on the fruit husk, the white succulent pulp in side fed upon and small size husk chippings below the fruit. Such damage symptoms in the laboratory were noted to be caused by the red-bellied squirrel which had a damage potential of 0.5 mangosteen fruit/animal/day. The wood rat and the ground squirrel were noted not able to gnaw through any mangosteen fruit provided and thus are not likely to cause any fruit damage in the field. These two animal species would likely feed upon mangosteen fruits already damaged by the red-bellied squirrel and are thus secondary feeders. At the end of the two weeks trapping period there was no more fresh mangosteen fruit damage and it was apparent trapping can be an effective means of squirrel control.

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