Vitaly Aleksandrovich Nikolayenko (Russian: Виталий Александрович Николаенко, transliteration: Vitálij Aleksándrovich Nikoláyenko, 1938 - December 2003) was a Russian self-educated natural scientist and photographer notable for his extensive research on the ethology of Russian bears. He spent 33 years living with the brown bears (Ursus arctos) native to the Kamchatka peninsula. He was found dead in December 2003 at the Kronotsky state reserve, one of two managed by the federal government, 177 km (110 mi) north of Petropavlovsk. Authorities concluded that the cause of death was an apparent bear mauling.