https://journals.lub.lu.se/os/issue/feedOrnis Svecica2024-03-10T16:02:46+01:00Martin Stervanderos@birdlife.seOpen Journal Systems<p><strong>Ornis Svecica</strong> is an online scientific journal issued by BirdLife Sweden. All contributions are published as open access, available to anyone, and with no publication fee for the authors. The aims and scope of the journal are to provide a forum for full-length or short original research reports, including descriptive ones, and reviews, communications, debate, and letters concerning all fields of ornithology. Ornis Svecica publishes contributions irrespective of the geographic origin of authors and subject, and we welcome submissions not only from professional researchers but from laymen as well. We assume a particular responsibility to offer a process and a forum for the latter, and encourage their submission of results and ideas. The journal language will be English or Swedish with a comprehensive summary in the other language (assistance is offered to authors with insufficient knowledge in the language for the summary).</p>https://journals.lub.lu.se/os/article/view/26038Casting anchor2024-03-10T16:02:44+01:00Jonas Waldenströmjonas.waldenstrom@lnu.seMartin Stervandermartin@stervander.com2024-03-08T00:00:00+01:00Copyright (c) 2024 Jonas Waldenström, Martin Stervanderhttps://journals.lub.lu.se/os/article/view/23521Breeding ecology of Boreal Owl Aegolius funereus in Jämtland, central Sweden, 1976–19852024-03-10T16:02:46+01:00Thomas Holmbergthho46@gmail.com<p><span class="Apple-converted-space">A long-term </span>Boreal Owl <em>Aegolius funereus </em>nest box project ran 1976–1985 in central Sweden. Average occupancy among 200 nest boxes was 16% (range 0–54%) with average clutch size 6.0 eggs and number of fledged per successful breeding 4.6, while 41% of breeding attempts failed, primarily due to predation by pine marten <em>Martes martes </em>or desertion by the female. The highest observed breeding density was 0.9 breedings/km<sup>2</sup>. Five cases of bigamy were observed. Females weighed 50% more than males during egg laying and incubation, probably because of pre-emptive weight gain to compensate for the risk of subsequent changes to food availability. The male provisioned both the female and chicks for most of the breeding period, mainly with small rodents (87%). Population sizes of small rodents fluctuated in 3–4-year cycles. Reproduction was successful during phases of increasing rodent density (1977–1978, 1980–1981, and 1984–1985), while almost no breedings were initiated during nadir years (1976, 1979, and 1982–1983). Ringing recoveries suggested that juveniles recruited into the local population in years with abundant food resources, but dispersed if food availability was declining. Adult females were often nomadic, while most males were resident.</p>2024-03-08T00:00:00+01:00Copyright (c) 2024 Thomas Holmberg