Dayawansa P. N. (2017) Kota’s Nature: A tribute to a great environmentalist Department of Zoology and Environment Sciences ISBN 978-955-41408-7-5

Dayawansa P. N. (2016) Bula Bebe- A beginners Guide to the Butterfly Watching in Fiji. Fiji National University ISBN 978-955-41801-5-1

http://www.fnu.ac.fj/new/media/com_acymailing/upload/fnu_newsletter_vol_8_no_20_19_may_2016.pdf

Dayawansa P. N. (2016) A Pocket Guide to the Butterflies of Fiji. Author Publication. ISBN 978-955-41801-5-2

http://www.fnu.ac.fj/new/2-uncategorised/1394-book-on-unique-role-of-butterflies

Dayawansa Nihal (2014) Guide for Student Counselors: Highlighting the use of nature for training, Kline Publishers ISBN 978-955-41408-3-7

Dayawansa P. N. (2014) Fieldcraft: Essential of Nature Interpretation for Nature Education and Environmental Studies, SLCSL Environment Education Guide 2-e-Book Sustainability Learning Centre Sri Lanka ISBN 978-955-41408-4-4

http://sustainability.sjp.ac.lk/wp-content/uploads/2017/11/Fieldcraft-e-Boo.pdf

Dayawansa P. N. (2014) Envitoons, An Inspirational Approach of Teaching and Awareness towards Nature Education and Environmental Studies. SLCSL Environment Education Guide 1- Sustainability Learning Centre Sri Lanka ISBN 978-955-590-035-3

Dayawansa, P. N. (2014) An Introductory Guide to the Study of Behaviour of wading birds Field Ornithology Group of Sri Lanka, University of Colombo ISBN 978-955-41408-2-0

Rathnayake P. Suranga, Mapatuna Y. and Dayawansa P. N. (2012) Restoration of deteriorated wetlands in Kumana (Yala East) National Park, Sri Lanka: A Pilot Project on mangrove restoration. In Sharing lessons on mangrove restoration (2012) Macintosh D.J. Mahindapala R, Markopoulos, M (Editors) IUCN, Gland ISBN 978-2-8317-1558-2

Dayawansa P. N. and Mapatuna Y. (2011) Manual for Ecosystem Conservation and Wildlife Protection in Tea Estates of Mild- and Upcountry of Sri Lanka, Praguna Educational Services Limited, ISBN 978-955-0836-05-3

M.D. Ajantha U. De Alwis, P. Nihal Dayawansa, Ric How, B.M.P. Singhakumara, Devaka Weerakoon, Mayuri R. Wijesinghe (2007) Biodiversity Baseline Survey: Ritigala Strict Nature Reserve, Editor: Michael J.B. Green: Protected Areas Management and Wildlife Conservation Project, Department of Wildlife Conservation, Sri Lanka

M.D. Ajantha U. De Alwis, P. Nihal Dayawansa, Ric How, B.M.P. Singhakumara, Devaka Weerakoon, Mayuri R. Wijesinghe (2007) Biodiversity Baseline Survey: Peak Wilderness Sanctuary, Editor: Michael J.B. Green: Protected Areas Management and Wildlife Conservation Project, Department of Wildlife Conservation, Sri Lanka

M.D. Ajantha U. De Alwis, P. Nihal Dayawansa, Ric How, B.M.P. Singhakumara, Devaka Weerakoon, Mayuri R. Wijesinghe (2007) Biodiversity Baseline Survey: Minneriya National Park, Editor: Michael J.B. Green: Protected Areas Management and Wildlife Conservation Project, Department of Wildlife Conservation, Sri Lanka

M.D. Ajantha U. De Alwis, P. Nihal Dayawansa, Ric How, B.M.P. Singhakumara, Devaka Weerakoon, Mayuri R. Wijesinghe (2007) Biodiversity Baseline Survey: Horton Plains National Park, Editor: Michael J.B. Green: Protected Areas Management and Wildlife Conservation Projected, Department of Wildlife Conservation, Sri Lanka

M.D. Ajantha U. De Alwis, P. Nihal Dayawansa, Ric How, B.M.P. Singhakumara, Devaka Weerakoon, Mayuri R. Wijesinghe (2007) Biodiversity Baseline Survey: Field Study Techniques Manual, Editor: Michael J.B. Green: Protected Areas Management and Wildlife Conservation Project, Department of Wildlife Conservation, Sri Lanka

http://www.dwe.gov.lk/Aoldsite/documents%20in%20word%20and%20pdf/BBS_Field_Manual.pdf

Jayantha D., and Dayawansa P. N. (2007) Behavioural Ecology of rehabilitated juvenile elephants- Phase 2- Airawana: Serial Publication of the project ELEMONI-SL; Juvenile Elephant Monitoring Project, Udawalawa National Park: University of Colombo and Department of Wildlife Conservation. ISBN 35-103-06

M.D. Ajantha U. De Alwis, P. Nihal Dayawansa, Ric How, B.M.P. Singhakumara, Devaka Weerakoon, Mayuri R. Wijesinghe (2007) A guide to the Horton Plains National Park: Michael J.B. Green: Protected Areas Management and Wildlife Conservation Project, Department of Wildlife Conservation, Sri Lanka ISBN 978-955-1580-30-08

http://2.3.143.23.34/BBS/bbs.html

Jayantha D., and Dayawansa P. N. (2006) Behavioural Ecology of rehabilitated juvenile elephants- Phase 1- Airawana: Serial Publication of the project ELEMONI-SL; Juvenile Elephant Monitoring Project, Udawalawa National Park: University of Colombo and Department of Wildlife Conservation. ISSN 35-103-06

Dayawansa, P. N. and Wijesinghe, Mayuri R. (2002) Waders in Sri Lanka: A guide to their identification and study. National Science Foundation. ISBN 955-590-035-3

http://dl.nsf.ac.lk/bitstream/1/5481/1/NA-258.pdf

Weerakoon, D. K., Goonathilake, W. L. D. P. T. S. de A., Dayawansa, P. N. and Wijesinghe Mayuri R. (1999) List of Threatened Fauna of Sri Lanka. In. The 1999 List of Threatened Fauna & Fauna of Sri Lanka, IUCN, Colombo, Sri Lanka pp 9-69. ISBN 955-8177-01-6

Lincoln, G. A., Dayawansa, N. and Ratnasooriya, W. D. (1994) Characteristics of the Antler Cycle in Male Axis Deer, Axis axis living in Sri Lanka close to the equator. In Recent Developments in Deer Biology, Milne J. A. (Editor) ISBN 0-7084-0598-3 Modern Research Institute, Edinburgh