Perera H.I.T., Yapa W.B. and Perera H.K.K. (2016). Isolation of Salmonella species in Fulvous fruit bat (Rousettus leschenaulti) in Sri Lanka. Proc. of the 36th Annual Sessions of the Institute of Biology, Sri Lanka. P 33.

Ratnayake, H.U., Weerakoon, D.K., Yapa W.B. and Udagama P.V. (2014). Electrophoretic patterns of serum proteins of Rousettus leschenaulti (Fulvous fruit bat) in Sri Lanka. Proc. of the 34th Annual Sessions of the Institute of Biology, Sri Lanka. P 41.

Yapa, W.B. (2012). A preliminary study on the Ecosystem Services of four species insectivorous bats in two natural caves, Wavulpena and Wavulgalge in Sri Lanka. Proceedings of IOB 32nd Sessions. P17.

Chandima V.K. and W. B. Yapa. (2009) Effect of manual turning on the rate of degradation of household composting. Proceedings of the Sri Lanka Association for the Advancement of Science, 65th Annual Sessions.

Wijesinghe, M. R., W. B. Yapa, P. M. C. Digana, P. Gamage (2009). An assessment of mammalian diversity of the Wasgamuwa NP and the Ritigala SNR. Proc. of the 29th Annual Sessions of the Institute of Biology, Sri Lanka.

Harischandra, I. N., C.P. Adikaram, W.B. Yapa. and D.D. Wickramasinghe. (2008). Developmental Plasticity of Polypedates crusiger (Ranidae: Racophorinae) tadpoles to crowding. Proc. of the 28th Annual Sessions of the Institute of Biology, Sri Lanka. P49.

Kumara, M. V. T., W.B. Yapa and Ratnasooriya, W.D. (2007). Preliminary Investigations on the roost selection and population size of the common flying fox, Pteropus giganteus iIn the Viharamahadevi Park, Colombo. Proc. of the 27th Annual Sessions of the Institute of Biology, Sri Lanka. P38.

Goonatilake, M.R.M.P.N., Yapa, W.B., Schmidt, S. and Ratnasooriya, W.D. (2004). Activity budget in a diurnal roost of the Indian False vampire bat, Megaderma lyra Geoffrey, 1810 (Chiroptera, Megadermatidae) in Sri Lanka. Proc. of the 24th Annual Sessions of the Institute of Biology, Sri Lanka. P12.

Goonatilake, M.R.M.P.N., Yapa, W.B., Schmidt, S. and Ratnasooriya, W.D. (2002). Diet of the Greater False Vampire bat, M. lyra Geoffrey, 1810, (Chiroptera; Megadermatidae) in Sri Lanka determined by fecal analysis. Proc. of the 22nd Annual Sessions of the Institute of Biology, Sri Lanka. P 41.

Digana, P. M. C. B., Yapa,W.B., Randeniya, P. V. and Ratnasooriya,W D. (2001). Present status of Sri Lankan bats. Proceedings of the 21st Annual Sessions of the Institute of Biology, Sri Lanka. P21.

Nandasena, M.R.N.P., Yapa, W.B. , Schmidt, S. and Ratnasooriya, W.D. (2001). Are bats cannibalistic? Evidence from the Indian False Vampire bat, Megaderma lyra. Proceedings of the 21st Annual Sessions of the Institute of Biology, Sri Lanka. P 19.

Digana, P.M.C.B., Yapa,W.B., Randeniya, P.V. and Ratnasooriya, W. D. (2000). Roost selection of Sri Lankan bats. Proceedings of the 1st Annual Sessions, University of Colombo, Sri Lanka, P39.

Nandasena, M., Yapa, W.B., Schmidt, S. and Ratnasooriya, W.D. (2000). Diet composition of greater false vampire bat, Megaderma lyra at Baddegama, Sri Lanka. Proc. of the 20th Annual Ses. of the Institute of Biology, Sri Lanka. P38.

Kumarasinghe, J., Digana, P.M.C.B., Yapa, W.B., Randeniya, P.V. and Ratnasooriya, W. D. (1998). Food preference of short nosed fruit bat Cynopterus sphinx (Chiroptera). Proceedings of the 18th Annual Sessions of the Institute of Biology, Sri Lanka. P20.

Yapa, W.B., Digana, P.M.C.B., Ratnasooriya, W.D., Rübsamen, R., Costa, H.H. and Randeniya, P.V. (1998) Breeding associated migration of Miniopterus schreibersii between two natural caves in Sri Lanka. Proceedings of the 19h Annual Sessions of the Institute of Biology, Sri Lanka. P21.

C. M. Edirisinghe, D. U. J. Sonnadara and W. Yapa (1998). An Electronic Surveillance System for Night-Flying Birds. Proceedings of the 14th Technical Session, Institute of Physics, Sri Lanka.

Digana, P.M.C.B., Yapa, W.B., Randeniya, P.V. and Ratnasooriya, W. D. (1997). Neonatal mortality of rufous horse shoe bat Rhinolophus rouxii, (Chiroptera) in a maternity colony Wavul-Galge in Sri Lanka. Proceedings of 17th Annual Sessions of the Institute of Biology, Sri Lanka. P17.

Digana, P.M.C.B., Yapa, W.B., Randeniya, P.V. and Ratnasooriya, W. D. (1997). Breeding pattern of Schneiders Leaf nosed bat Hipposideros speoris (Microchiroptera) in Sri Lanka. Proceedings of the Sri Lanka Association for the Advancement of Science, 53rd Annual Sessions. P243.

Yapa, W.B., Digana, P.M.C.B., Randeniya, P.V. and Ratnasooriya, W. D. (1996). Some observations on the distribution and abundance of the microchiropteran bats in the wet zone of Sri Lanka. Proceedings of the 16th Annual Sessions of the Institute of Biology, Sri Lanka. P4.

Digana, P.M.C.B., Yapa, W.B., Randeniya, P.V. and Ratnasooriya, W. D. (1996) Roosting pattern of some Sri Lankan bats. Proceedings of the Sri Lanka Association for the Advancement of Science, 52nd Annual Sessions. P149.

Yapa, W.B., R., Ratnasooriya, W.D., Rübsamen, and Costa, H.H. (1990). Factors affecting the flight activity pattern of cave dwelling bats in Sri Lanka. Proceedings of the Physiological Society of Sri Lanka. P3.

Yapa, W.B., Rübsamen, R., Ratnasooriya, W.D. and Costa, H.H. (1989). The pattern of reproduction of some cave dwelling bats in Wavul Galge, a natural cave in Uva province of Sri Lanka. Proceedings of the 45th Annual Sessions of the Sri Lanka Association for the Advancement of Science. P84.