For thirty years, he was the chief of the ornithological station "Rybachy" (literally "Fishers'" - after the village where it was situated).
Dolnik was chief research fellow at Zoological institute of Russian Academy of science.
Kozlov, he was the author of a textbook on zoology for secondary schools.
He was best known to the general public for a series of articles concerning human ethology (1980-1990s).
These articles later were compiled into a book "Disobedient Child of Biosphere" (1994).