The Baya Weaver bird, Ploceus philippinus utilizes the well developed leaves of Cycas sphaerica for nest construction and offspring production. It constructs nest on the leaf tips of this species; the nest material used is exclusively Dendrocalamus strictus. This bird species does not utilize Cycas beddomei for nest construction and offspring production. The Plains Cupid butterfly, Chilades pandava utilizes the newly emerging leaves of both C. sphaerica and C. beddomei for raising its offspring. In both the Cycas species, the new leaves emerge as a crown at the top of the plant; the larvae of C. pandava feed on these leaves and make the plant as leafless until the next leaf flushing season. New leaf production occurs after coning event in Cycas species; coning is not annual event. In consequence, the plants utilized by C. pandava for the production of its offspring remain leafless until the next coning season and their survival during this period depends on the nutrient status within the shoot system and in the soil system. The study suggests that there is no direct or indirect interaction between C. pandava and P. philippinus. C. sphaerica serves as a host plant for these two animal species at different times; but the interaction of these animal species is dependent on the leaves only; C. pandava on newly emerging leaves while P. philippinus on well developed leaves.