The palm squirrel in coconut plantations: ecosystem services by therophily

Abstract

Palm squirrels, Funambulus palmarum, were believed and reported to inflict nut damage resulting in economic losses to coconut, Cocos nucifera, growers in South India. However, the current study, using field observations, pollination studies, gut content analyses, laboratory feeding tests, and exclusion experiments, established that Funambulus squirrels in cultivated coconut patches do not feed on nuts and hence do not generate economic losses. Squirrels cause male flower drop and feed on few male flowers without any negative impact on palm productivity or other aspects of the plantation ecosystem. Instead, squirrels pollinate (therophily) flowers, feed on insect pests, regulate vegetation at the microhabitat level as seed consumers and dispersers, and thus are an ecologically important component of cultivated coconut patches. Squirrels were found to be the most effective pollinators (85.70% nut formation in Arsikere and 94% at Madenur, Hassan). Fruit set was reduced by 19% when squirrels were prevented from pollinating coconut palms. Palm squirrel may also have myriad important roles to play in wild and cultivated patches in South India. Hence, the beneficial activities of F. palmarum must be sustained in cultivated coconut patches.