Molecular Identification of Sarcocystis sp. (Apicomplexa, Sarcocystidae) in Offspring of Tengmalm's Owls, Aegolius funereus (Aves, Strigidae)

Background: Birds act as intermediate or definitive hosts of cyst-forming coccidia parasites of the genus Sarcocystis Lankester, 1882. However, the spectrum of species of Sarcocystis in birds and the role of the latter in the transmission of coccidia are still incomplete for many avian species, including the Tengmalm's owl Aegolius funereus (Linnaeus, 1758). During the research on Tengmalm's owls in Finland, some fledglings were found dead and subsequently parasitologically examined. Therefore, this study is focused on the morphological and molecular description of a Sarcocystis species found in the intestine of the Tengmalm's owl and its possible role as a definitive host.Methods: Eleven fledgling owls in the Kauhava region of west-central Finland were found dead and subsequently were submitted for necropsy and parasitologically examined through the flotation–centrifugation coprological technique for the presence of oocysts/sporocysts of the genus Sarcocystis by light microscopy. Wet mounts were used for the examination of muscle samples (breast, legs, and heart). Polymerase chain reaction (PCR) and nested-PCR were carried out using primers for 18S rRNA, 28S rRNA, ITS1 region, and CO1 genes.Results: All 11 examined owls were parasitized by numerous sporocysts and oocysts in the intestinal mucosa scrapings (prevalence, 100%). Sporulated oocysts and sporocysts measured 16.34–16.96 × 11.47–12.09 μm and 11.85–13.52 × 7.77–9.25 μm, respectively. The skeletal and heart muscles were negative for sarcocysts. Sarcocystis sp. ex Aegolius funereus (hereafter Sarcocystis sp. Af) is closely related to Sarcocystis strixi in the barred owl (Strix varia Barton, 1799) from the USA and Sarcocystis sp. isolate 5 in the European shrew (Sorex araneus Linnaeus, 1758) from the Czech Republic. Phylogenetic analysis allowed determining the relationship of the herein reported Sarcocystis sp. with its congeners.Conclusions: This work provided the first and most comprehensive record on Sarcocystis from owls obtained in Finland, thus highlighting the importance of molecular data in species identification.

Molecular identification of Sarcocystis funereus sp. nov. (Apicomplexa, Sarcocystidae) in offspring of Tengmalm’s owls Aegolius funereus (Aves, Strigidae)

The spectrum of species of Sarcocystis in birds and the role of the latter in the transmission of coccidia are still incomplete for many avian species including Tengmalm’s owl Aegolius funereus (Linnaeus, 1758). Therefore, this study is focused on the morphological and molecular description of a new Sarcocystis species found in the intestine of the Tengmalm’s owl and its possible role as definitive host. Ten fledgling owls from the Kauhava region of west-central Finland were parasitized by numerous sporocysts and oocysts in the intestinal mucosa scrapings (prevalence 100%). Sporulated oocysts and sporocysts measured 16.34−16.96 × 11.47−12.09 µm and 11.85−13.52 × 7.77−9.25 µm, respectively. Skeletal and heart muscles were negative for sarcocysts. Sarcocystis funereus sp. nov. is closely related to Sarcocystis strixi from the barred owl (Strix varia Barton, 1799) from the USA and Sarcocystis sp. isolate 5 from the European shrew (Sorex araneus Linnaeus, 1758) from the Czech Republic. This is the first and most comprehensive record on Sarcocystis from owls obtained in Finland, thus highlighting the importance of molecular data in the species identification.

High prevalence of Sarcocystis funereus sp. nov. (Apicomplexa, Sarcocystidae) in offspring of Tengmalm’s owls Aegolius funereus (Aves, Strigidae)

Background Birds act as intermediate or definitive hosts of cyst-forming coccidia parasites of the genus Sarcocystis Lankester, 1882. However, the spectrum of species of Sarcocystis in birds and the role of the latter in the transmission of coccidia are still incomplete for many avian species including Tengmalm’s owl Aegolius funereus (Linnaeus, 1758). During a research of Tengmalm’s owls in Finland some fledglings were found dead and subsequently parasitologically examined. Therefore, this study is focused on the morphological and molecular description of a new Sarcocystis species found in the intestine of the Tengmalm’s owl and its possible role as definitive host. Methods Eleven fledgling owls from the Kauhava region of west-central Finland were found dead and subsequently were submitted for necropsy, parasitologically examined through flotation-centrifugation coprological technique for the presence of oocysts/sporocysts of genus Sarcocystis by light microscopy. Wet mounts were used for the examination of muscle samples (breast, legs, heart). Polymerase chain reaction and nested-PCR were carried out by using primers for 18S rRNA, 28S rRNA, ITS1 region and cox1 genes. Results All eleven examined birds were parasitized by numerous sporocysts and oocysts in the intestinal mucosa scrapings (prevalence 100%). Sporulated oocysts and sporocysts measured 16.34 − 16.96 × 11.47 − 12.09 µm and 11.85 − 13.52 × 7.77 − 9.25 µm, respectively. Skeletal and heart muscles were negative for sarcocysts. The phylogenetic analysis revealed that Sarcocystis funereus sp. nov. is closely related to Sarcocystis strixi from the barred owl (Strix varia Barton, 1799) from the USA and Sarcocystis sp. isolate 5 from the European shrew (Sorex araneus Linnaeus, 1758) from the Czech Republic, but a valid species. Conclusions This work provided the first and the most comprehensive record on Sarcocystis from owls obtained in Finland, thus highlighting the importance of molecular data in the species identification.

Modélisation de la distribution des petites chouettesde montagne dans les Alpes du Nord françaises

Les petites chouettes de montagne (Chouette de Tengmalm, Aegolius funereus (Linnaeus, 1758) et Chevêchette d’Europe, Glaucidium passerinum (Linnaeus, 1758)) sont représentées en France par quelques centaines à quelques milliers de couples. Elles font l’objet d’une attention particulière au regard de leur rareté et en tant qu’espèces emblématiques des écosystèmes forestiers de montagne, qui sont particulièrement affectés par les changements globaux. Améliorer la connaissance de leur distribution, notamment dans les Alpes du Nord, est une nécessité pour préserver les milieux qui constituent leur habitat préférentiel. Issue d’une collaboration entre l’INRAE, l’Office national des Forêts et la Ligue pour la Protection des Oiseaux, nous présentons une approche par modélisation dans laquelle des données d’occurrence des deux espèces sur la période 2007-2014 ont été reliées à six variables environnementales potentiellement explicatives pour prédire leur répartition. Les résultats montrent que la distribution des deux espèces est principalement liée d’une part à l’altitude, facteur déterminant au plan régional, et d’autre part au type d’occupation du sol, meilleur prédicteur à l’échelle locale, alors que les autres facteurs (topographie, proximité de lisières) sont moins explicatifs. Ces prédictions ont été utiles aux naturalistes de terrain, qui ont pu utiliser ces données pour mieux structurer leurs campagnes d’observations. Il serait désormais intéressant d’étendre la démarche à d’autres zones biogéographiques et d’intégrer à la modélisation des données permettant d’évaluer les effets de la gestion forestière sur ces espèces.

Win – and stay, but not too long: cavity selection by Boreal Owls to minimize nest predation by Pine Marten

Site fidelity after successful nesting and site shift after nest predation (win–stay, lose–shift) is a well-documented adaptation to spatially heterogeneous and temporally auto-correlated predation risk. However, site shift even after a successful nesting (win–shift) may become a better tactic than site fidelity (win–stay), if a successful nest site becomes more risky until the next nesting opportunity, and if new low-risk nest sites regularly appear. Correspondingly, selecting a new non-used nest site may become a better tactic than selecting one previously used successfully by a conspecific. I studied this dynamic by focusing on nest cavities that may be available for many years, and using nest boxes to allow an experimental design. At localities where Boreal Owls (Aegolius funereus) had nested successfully, a dyad of nest boxes was made available each year, one box in the original nest tree and one in a new tree for the season, each containing either old nest material from the successful nesting or new wood shavings. Boreal owls were more likely to select the box in the new tree when more years had elapsed since the successful nesting and since a box was installed in the original nest tree, independent of box content. The pattern of selection differed between young and old individuals for males, but not females. Young males based their selection of nest tree mainly on box content, while old males based it on time elapsed since the successful nesting in the original nest tree and how long a box had been present there. The probability of depredation of Boreal Owl nests by Pine Marten (Martes martes) has previously been found to increase with cavity age and number of nesting seasons elapsed since the previous successful nesting. This pattern of nest predation thus predicted the pattern of nest site selection found.

Interactive influences of fluctuations of main food resources and climate change on long-term population decline of Tengmalm’s owls in the boreal forest

Recent wildlife population declines are usually attributed to multiple sources such as global climate change and habitat loss and degradation inducing decreased food supply. However, interactive effects of fluctuations in abundance of main foods and weather conditions on population densities and reproductive success have been studied rarely. We analysed long-term (1973–2018) data on Tengmalm’s owl (Aegolius funereus) and the influence of prey abundance and weather on breeding densities and reproductive success in western Finland. We found that fledgling production per breeding attempt declined and laying date of the owl population delayed during the period between 1973 and 2018. The breeding density of the owl population decreased with increasing temperature in winter (October–March), fledgling production increased with increasing temperature and precipitation in spring (April–June), whereas the initiation of egg-laying was delayed with increasing depth of snow cover in late winter (January–March). The decreasing trend of fledgling production, which was mainly due to starvation of offspring, was an important factor contributing to the long-term decline of the Tengmalm’s owl study population. Milder and more humid spring and early summer temperatures due to global warming were not able to compensate for lowered offspring production of owls. The main reason for low productivity is probably loss and degradation of mature and old-growth forests due to clear-felling which results in loss of coverage of prime habitat for main (bank voles) and alternative foods (small birds) of owls inducing lack of food, and refuges against predators of Tengmalm’s owls. This interpretation was also supported by the delayed start of egg-laying during the study period although ambient temperatures increased prior to and during the egg-laying period.

Monopis jussii, a new species (Lepidoptera, Tineidae) inhabiting nests of the Boreal owl (Aegolius funereus)

Monopis jussii Kaila, Mutanen, Huemer, Karsholt & Autto, sp. nov. (Lepidoptera, Tineidae) is described as a new species. It is closely related to the widespread and common M. laevigella ([Denis & Schiffermüller], 1775), but differs in its distinct COI DNA barcode sequences, four examined nuclear loci as well as details in forewing coloration and pattern. Most reared specimens of M. jussii have emerged from the nest remnants of the Boreal owl (Aegolius funereus (Linnaeus, 1758)), but also nests of the Ural owl (Strix uralensis Pallas, 1771) and the Great tit (Parus major Linnaeus, 1758) have been observed as suitable habitats. Based on the present knowledge, the new species has a boreo-montane distribution as it is recorded only from northern Europe and the Alps. Several extensive rearing experiments from Strix spp. nest remnants from southern Finland did not produce any M. jussii, but thousands of M. laevigella, suggesting that the species is lacking in the area or, more unlikely, that the nest of these owl species do not serve as good habitat for the new species. This unexpected species discovery highlights, once again, the usefulness of DNA barcoding in revealing the cryptic layers of biodiversity. To serve stability we select a neotype for Tinea laevigella [Denis & Schiffermüller], 1775, and discuss the complicated synonymy and nomenclature of this species.