The relevance of the study is determined by the great public and scientific significance of the scientific creativity of M. O. Zarudnyi in the zoological science of the late 19th and early 20th centuries, the lack of a special comprehensive study of his life, scientific, scientific-organizational and pedagogical activities in the history of science, the need to create the most objective and complete scientific biography of the scientist, a comprehensive analysis of his creative output, as well as the importance of introducing a mass of new sources into wide scientific circulation. The purpose of the study is to reproduce a complete picture of the development of zoological science due to the comprehensive coverage of the life path, scientific, pedagogical and educational activities of M. O. Zarudnyi, his contribution to the development of biological science.

Simultaneously with the above, the analysis of the creative heritage of M. O. Zarudnyi allows us to trace the difficult paths of development of the theory and practice of rational nature management and nature protection in the Russian Empire, and therefore in the RSFSR and the Soviet Union at the end of the 19th – the first third of the 20th centuries. Knowledge of the history of the formation of the scientific and legal foundations of hunting science also gives reason to recognize the scientist's work as an important role in the achievements of the modern level by these branches of science and practical management.

The modern revival of naturalistic biology, the study of nature as a whole, make the scientific legacy of M. O. Zarudnyi is more significant for the study of modern natural science. His approach to considering nature as a whole and the desire to see phenomena as they actually occur in it, together with the works of other outstanding natural scientists, may facilitate finding answers to the complex unsolved tasks of modern natural sciences.

Mykola Oleksiiovych made a significant contribution to fundamental biological science and, in particular, to the study of fauna, bird ecology and zoology in general. With his direct participation and under his leadership, extensive theoretical and practical work was carried out in various areas of biological science: faunistics, ecology, systematics, zoogeography of birds and other terrestrial vertebrates (all classes of vertebrates) and other general problems of biology. This far from complete list of the scientist's scientific preferences indicates that he was a scientist with a very broad worldview and a large scope of scientific activity. In total, the list includes 218 printed works of M. O. Zarudnyi.

1. Mirzoyan, E. N. (2001). Fiziko-mekhanicheskaya model' zhivoj materii N. A. Umova [Physical and mechanical model of living matter of N. A. Umov]. Etyudy po istorii teoreticheskoj biologii – Etudes on the history of theoretical biology. Kiev, 256–265 [in Russian].
2. Rahilin, B. K. (1997). Ornitogeografiya Rossii [Ornitogeography of Russia]. Moskow [in Russian].
3. Borzenkov, Yа. P. (1881). Istoricheskij ocherk napravlenij, sushchestvovavshih v zoologicheskih naukah v ХІХ stoletii. Rech', proiznesennaya na torzhestvennom sobranii im.Moskovskogo universiteta 12-go yanvarya 1881 g. [Historical sketch of the trends that existed in the zoological sciences in the nineteenth century. Speech delivered at the solemn meeting of the Moscow University on January 12, 1881]. Moskow [in Russian].
4. Burdok-Sanderson, J. S. (1894). Adress by President. Report of the sixtythird Meeting of the British Association for the Advancement jf Science in September 1893. London, 3–31.
5. Zarudnyj, N., & Molchanov, I. (1914). K aviafaune Pamira [To the air fauna of the Pamirs]. Ezhegodnik Peterburgskoj Akademii nauk – Yearbook of the St. Petersburg Academy of Sciences, 19, 439–477 [in Russian].
6. Zarudnyj, N. A. (1912). Zametki po ornitologii Turkestana [Notes on the ornithology of Turkestan]. Ornitologicheskij vestnik – Ornithological Bulletin, 16–30, 111–123 [in Russian].
7. Zarudnyj, N. A. (1899). O gadah i rybah Vostochnoj Persii. Gerpetologicheskie i ihtiologicheskie rezul'taty ekskursii po vostochnoj Persii v 1898 g. [About reptiles and fishes of Eastern Persia. Herpetological and ichthyological results of a tour of eastern Persia in 1898] Zapiski Geologicheskogo obshchestva –Notes of the Geological Society, 3, 1–42 [in Russian].
8. Mirzoyan, Е. N. (2001). Evolyucionnaya biologiya. Etyudy po istorii teoreticheskoj biologii [Evolutionary biology Studies in the history of theoretical biology]. Kiev, 58–76 [in Russian].
9. Bobrinskij, N. A. (1940). Nikolaj Alekseevich Zarudnyj: zoolog i puteshestvennik (1859–1919) [Nikolai Alekseevich Zarudnyi: zoologist and traveler (1859–1919)]. Moskow [in Russian].
10. Zarudnyj, N. A. (1888). Ornitologicheskaya fauna Orenburgskogo kraya [Ornithological fauna of the Orenburg region]. Zapiski Peterburgskoj Akademii nauk – Notes of the St. Petersburg Academy of Sciences, 57, 1–333 [in Russian].
11. Zarudnyj, N. A. (1898). Neskol'ko slov o poezdke v Persiyu v 1896 g. [Some words about the trip to Persia in 1896]. Izvestiya Russkogo geograficheskogo obshchestva – News of the Russian Geographical Society, Vol. 34, 2, 209–216 [in Russian].
12. Shtil'mark, F. R. (1891). Principy zapovednosti (teoreticheskie, pravovye i prakticheskie aspekty) [The principles of reservation (theoretical, legal and practical aspects)]. Geograficheskoe razmeshchenie zapovednikov RSFSR i organizaciya ih deyatel'nosti. Moskva: Glavohota RSFSR – Geographical location of the reserves of the RSFSR and the organization of their activities. Moskow: Glavohota RSFSR, 60–76 [in Russian].
13. Zarudnyj, N. A. (1896). Otchet ob ornitologicheskih issledovaniyah, proizvedennyh v Pskovskoj gubernii letom 1895 g. [Report on ornithological researches made in the Pskov province in the summer of 1895]. Godichnyj otchet MOIP za 1894–1895 gg. – MOIP annual report for 1894–1895, 38–39 [in Russian].
14. Kozhevnikov, G. A. (1909). O neobhodimosti ustrojstva zapovednyh uchastkov dlya ohrany russkoj prirody [On the necessity of establishing protected areas for the protection of Russian nature]. Trudy Vserossijskogo biologicheskogo akklimatizacionnogo sezda 1908 g. v Moskve – Proceedings of the All-Russian Biological Acclimatization Congress of 1908 in Moscow. Moskow, Vol. 1, 34–37 [in Russian].
15. Zarudnyj, N. A. (1897). Dopolneniya k «Ornitologicheskoj faune Orenburgskogo kraya» [Additions to the «Ornithological fauna of the Orenburg region»]. Materialy k poznaniyu fauny i flory Rossii – Materials for the knowledge of the fauna and flora of Russia, Vol. 3, 171–312 [in Russian].