Research interests

Biology of owls and birds of prey (lifespan, survival, age in the population, dispersal distances), biometrics (sexual dimorphism, individual parameters, color variations), abundance and territorial distribution, breeding (incubation, breeding success), autumn and winter ecology, nutrition, behavior, threats and protection.
The main tasks of working with the house owl include the development of both conventional and remote research methods during autumn and winter, studies of hibernation ecology, dynamics of pair formation and dissolution, diversity of phenotypes, distribution in habitats, short-term and long-term changes of phenotypes in the population, and the effect of phenotypic plasticity on demographic indicators of the population.

Annotation of the dissertation

Anthropogenic activities induced global and local changes drive ecosystems. Individuals of resident species, which spend the complete annual cycle in the same ecosystem, are affected by the different driving factors simultaneously. Phenotypic plasticity is a mechanism providing opportunity for the species to cope with environmental changes. Therefore, research of resident organisms allows us to study responses and adaptation mechanisms to rapid changes in environments inhabited by the species.
Tawny Owl (Strigiformes, Strix aluco) – is a resident and territorial species for which characteristic colour polymorphism. This species is suitable to study phenotypic plasticity because of life-history traits. Although different aspects of Tawny Owl ecology and demography were widely covered by early research, previous studies were mainly focused on different patterns or responses during the breeding season, which covers only part of the annual cycle. Research outside the breeding season was mainly restricted by the lack of suitable methods resulting in limited understanding even of mechanisms of phenotypic plasticity described previously.
The aims of this PhD study are mainly related to development of conventional and telemetry methods suitable for research of Tawny Owl during autumn and winter seasons, various aspects of ecology outside the breeding season, pair formation and break-up, phenotypic diversity and spatial distribution, spatial and temporal phenotypic changes, and consequences to population demography.

Scientific articles published in journals (books), indexed in „Clarivate Analytics Web of Science“ database (without citation index):

Rumbutis, S. 1997. Long-term observations on breeding biology of the Tawny Owl (Strix aluco) female. Acta Zoologica Lituanica 6: 131132.

Rumbutis, S. 1990. Spring arrival date, breeding biology and breeding success of the Long – eared Owl (Asio otus L.) in central Lithuania. Acta Ornithologica Lituanica 2: 117121.

Other reviewed scientific publications (books, books‘ chapters, collections of articles, articles, textbooks and etc.):

Rumbutis, S., Blaževičius, P., Piličiauskienė, G. Birds in the castles of Vilnius. In the monograph: Blaževičius, P., Dambrauskaitė, N., Luik, H., Piličiauskienė, G., Rumbutis, S., Zarankaitė-Margienė, T. Fauna of Vilnius castles from steak to friend. – Vilnius: Vilnius University Publishing House, 2018, – 328 p.: illustration. Bibliogr.: 293-323.

Blaževičius, P., Rumbutis, S., Zarankaitė, T. 2012. The latest research on hunting, game and domestic birds in the Vilnius Lower Castle in the 14th–15th century. Chronicle of the Grant Duces Lithuania vol. II, p. 299-319.

Mammen, U. and Stubbe, M. 2009. Monitoring of European Raptors and Owls: Annual Report for 2003 and 2004. Monitoring of European Raptors and Owls Annual Report 16–17: 1–118.

Mammen, U. and Stubbe, M. 2003. Monitoring of Raptors and Owls in Europe: Annual Report 2002. Monitoring of Raptors and Owls in Europe 15: 1–101.

Mammen, U. and Stubbe, M. 2002. Monitoring of Raptors and Owls in Europe: Annual Report 2001. Monitoring of Raptors and Owls in Europe 14: 1–111.

Rumbutis S. 1988. Changes in nesting sites by female Tawny Owl (Strix aluco). Edited by R. Budris and others. Abstracts of the XII Baltic Ornithological Conference. Vilnius. 201-202. In Russian.

Žebelis G., Rumbutis S. 1986. Ecology of birds of prey nesting in Dotnuva forests. Ecology of birds of the Lithuanian SSR. Vilnius. 111-117. In Russian.

Rumbutis S. 1986. Breeding success of the Tawny Owl (Strix aluco) in the Dotnuva Forest (Central Lithuania) in 1976-1985. Study of birds of the USSR, their protection and rational use. Edited by V.D. Ilyichev et al. Abstracts of reports of the 1st Congress of the All-Union Ornithological Society and the IX All-Union Ornithological Conference. Leningrad. 201-202. In Russian.

Rumbutis S. 1983. Defensive behavior of the Tawny Owl (Strix aluco) during the nesting period. Edited by E. Kumari and others. Abstracts of the XI Baltic Ornithological Conference. Tallinn. 185-186. In Russian.

Rumbutis S. 1982. Data on the diet of the Long-eared Owl (Asio otus) and the Tawny Owl (Strix aluco) in the Central Lithuanian lowland. Ecological research and protection of birds of the Baltic republics. Edited by R. Budris et al. Abstracts of the Baltic Conference of Young Ornithologists. Kaunas. 69-73. In Russian.

International scientific conferences:


  1. Dementavičius, D., Rumbutis, S., Vaitkuvienė, D., Dagys, M. and Treinys, R. Does a Lesser Spotted Eagle suffers fitness costs in a high-density area of the White-tailed Eagle? SEA EAGLE 2017 CONFERENCE, 5–7 October, Roosta, Estonia.
  2. Dementavičius, D., Rumbutis, S., Vaitkuvienė. D., Dagys, M. and Treinys, R. Does mesopredator Lesser Spotted Eagle suffers breeding costs in a high-density area of the White-tailed Eagle? The Lesser Spotted Eagle Conference, Burgas, Bulgaria, 11-14 of October, 2017.
  3. Dementavičius, D., Rumbutis, S., Vaitkuvienė, D., Dagys, M., Treinys, R. Does the Whitetailed Eagle predation on the intraguild and internationally protected bird species presents a sharp conservation dilemma? SEA EAGLE 2017 CONFERENCE, 5–7 October, Roosta, Estonia.
  4. Dementavičius, D., Rumbutis, S., Vaitkuvienė, D., Dagys M., Treinys, R. Are geese an important       component of diet for the White-tailed Eagle nestlings in Lithuania? THE 18TH CONFERENCE OF GOOSE SPECIALIST GROUP, 27–30 March 2018, Klaipėda.

National scientific conferences:

Rumbutis S. 2019. Bird collection and ornithological research in Kaunas Tadas Ivanauskas Zoological Museum 1989-2019. The conference of the Lithuanian Ornithological Society “Ornithological research in Lithuania”, which was intended to mark the 30th anniversary of the independent Lithuanian Ornithological Society and the 35th anniversary of the establishment of the society itself. Kaunas, Lithuania.

Grigonis R., Rumbutis S. 2023. Development of zoological research in Kaunas Tadas Ivanauskas Museum of Zoology. A conference dedicated to the 140th anniversary of the birth of Academician Tadas Ivanauskas (1882–1970) Legacy of Academician Tadas Ivanauskas: established institutions and their departments and their activities today. Kaunas, Lithuania.