Born on 10 April 1943 in the village of Kalniškių (Kelmė district).
In 1965 he graduated from the Faculty of Agronomy of the Lithuanian Academy of Agriculture with a diploma of scientific agronomist. Since 1981. Member of the Lithuanian Union of Journalists, later the Society of Journalists, long-standing member of the "Valstiečių laikrašt'" (State newspaper), "Moksleivis" (Student newspaper), "Dienovidis" (Daily newspaper), "Liaudies kultūros" (People's Culture newspaper), "Merkio krašto" (Merkias krašto newspaper), "Zelaliojas pasaulio" (Green World newspaper), "Nemunas" (Nemunas newspaper), "Literature and Art newspaper", and "Metai" (Year), Correspondent of "Dainava", publishing essayistic prose texts, articles on nature, landscape, ethnic heritage, agriculture, gardening, rural life and preservation of the countryside, in periodical weeklies and monthlies. Gudavičius' texts are often read on the Lithuanian Radio in nature and literature and culture programmes.