He was recently diagnosed with cancer and died at 10 PM, BNHS sources told PTI.
This is another loss to the conservation movement in India after the demise of BNHS President B G Deshmukh on August 7.
Daniel was associated with BNHS as a researcher since the 1950s. He had worked as the director of the Society and later as head of various sub-committees.
He was the mentor at BNHS in many ways and had worked on various projects involving conservation at various levels including for elephants and the big cats.
He has authored various books such as 'The Book of Indian Reptiles and Amphibians', 'Cassandra of Conservation', 'Petronia', 'A Week with Elephants' and the recently released 'Birds of the Indian subcontinent – A field guide'.
He had also initiated various pioneering activities such as recording and documenting old trees in the Mumbai region with the help of nature lovers and BNHS members.
Conservation and BNHS have once again lost one of their greatest supporters in his death, BNHS officials said.