Asio Research Articles

Видовой состав хищных птиц Бузулукского бора (Оренбургская и Самарская области, Россия) по результатам наблюдений в прошлом и настоящем

Buzuluk pine forest is a unique pine massif with a total area of 111,118 hectares, which is located entirely in the steppe biome on the border of the Orenburg and Samara regions, in the southeastern part of the Russian Plain. This report provides some information about threatened and endangered raptors of the Buzuluk pine forest for a relatively long period of time. It uses data by scientist and ornithologist E.P. Knorre collected between 1928 and 1941, present time observations carried out since 2000 to the present, and published data by other researchers who have visited Buzuluk pine forest starting from the beginning of the 21st century. Most observations by E.P. Knorre were associated with the Pine Barrens Experimental Forestry in the Orenburg region, where “Buzuluk pine forest” Nature Reserve (10,503 hectares) existed at the time. In his unpublished monumental report “Qualitative inventory of birds and animals of the Buzuluk Pine Forest State Nature Reserve”, discovered in the archive of the current “Buzuluk Pine Forest” National Park relatively recently, E.P. Knorre listed the following raptor species found in Buzuluk Pine Forest: Common Kestrel Falco tinnunculus (breeding) Red-Footed Falcon Falco vespertinus (breeding) Eurasian hobby Falco subbuteo (breeding) Saker Falcon Falco cherrug (breeding) Osprey Pandion haliaetus (highly likely breeding) European Honey-Buzzard Pernis apivorus (breeding) Black Kite Milvus migrans (breeding) White-Tailed Sea-Eagle Haliaeetus albicilla (breeding) Short-Toed Snake-Eagle Circaetus gallicus (breeding) Western Marsh-Harrier Circus aeruginosus (breeding) Pallid Harrier Circus macrourus (breeding) Eurasian Sparrowhawk Accipiter nisus (breeding) Northern Goshawk Accipiter gentilis (breeding) Eurasian Buzzard Buteo buteo (breeding) Rough-Legged Buzzard Buteo lagopus (wintering) Greater Spotted Eagle Aquila clanga (breeding) Eastern Imperial Eagle Aquila heliaca (breeding) Golden Eagle Aquila chrysaetos (breeding) Eurasian Scops Owl Otus scops (breeding) Eurasian Eagle Owl Bubo bubo (breeding) Tawny Owl Strix aluco (breeding) Ural Owl Strix uralensis (breeding) Little Owl Athene noctua (common in autumn, the status is unclear) Northern Long-Eared Owl Asio otus (breeding) Short-Eared Owl Asio flammeus (breeding) Since the beginning of the 21st century, occurrence of most raptor species listed in report by E.P. Knorre was confirmed in the modern period of observations in Buzuluk Pine Forest. Nevertheless, such raptor species as Common Kestrel, Red-Footed Falcon, Saker Falcon, Osprey, Short-Toed Snake-Eagle, and Pallid Harrier were not recorded. Western Marsh-Harrier that once bred here was not found on the internal water lakes and swamps of the Buzuluk Pine Forest. As for the Strigiformes, Tawny Owl, Ural Owl and Northern Long- Eared Owl were recorded more frequently today. The previously breeding Eurasian Scops-Owl and Short-Eared Owl in the inner sections of the pine forest were not recently found here. Present-day breeding of Eurasian Eagle Owl requires additional confirmation. The finds of Little Owl, included in the Knorre’s report as autumn migrant, have not been confirmed yet. At the same time, new raptor species have been registered in the Buzuluk Pine Forest. These include Peregrine Falcon (Falco peregrinus; single individual was observed in summer: Barabashin, 2001), Hen Harrier (Circus cyaneus; a pair of birds in May: our data), Montagu’s Harrier (Circus pygargus; single bird in May: our data), Levant Sparrowhawk (Accipiter brevipes; single bird in May: Morozov, Kornev, 2009). According to our observations, the wellbeing of such species as Greater Spotted Eagle, White-Tailed eagle, Golden Eagle, Short-Eared Owl, Western Marsh-Harrier, Montagu’s Harrier was influenced by the ongoing climate warming in the Buzuluk Pine Forest area, which was evident from raising average annual air temperatures and decreasing precipitation. According to observations by E.P. Knorre, another serious limiting factor in the past was transformation of the forest under the influence of extensive fires and uncontrolled logging of trees. Logging and fires in pre-Soviet times led to appearance of huge empty spaces, which were then penetrated by steppe vegetation from adjacent steppe areas. Steppe formation was responsible for the appearance of such species as Common Kestrel, Red-Footed Falcon, Pallid Harrier, Eastern Imperial Eagle across inner forest areas for some time. In the 1950s, the mass pine tree plantings and increased fire control led to restoration of the forest integrity and at the same time to disappearance of Common Kestrel, Red-Footed Falcon, Pallid Harrier, relocation of breeding pairs of Eastern Imperial Eagle to outer rims of the forest.

Breeding Bird Occurrence Across a Gradient of Graminoid- to Shrub-Dominated Fens and Fire Histories

Population declines of birds affiliated with grasslands and grass-shrub habitats have been identified as a critical conservation concern. The effects of woody encroachment into grassland-dominated systems, which may contribute to species declines, has been examined mainly in upland systems. We examined occurrence of bird species across a gradient of graminoid- to shrub-dominated wetlands in the Upper Peninsula of Michigan and describe the habitat characteristics associated with their probability of occurrence at segment (100 × 100 m) and landscape (200 m buffer) scales. Because fire can suppress woody encroachment, we also examined the role of fire history, extending from 50 y on birds and habitat characteristics. We focused on seven species closely affiliated with grassland and grass-shrub habitats, but also found in wetlands: Sedge Wren (Asio flammeus), LeConte's Sparrow (Ammodramus leconteii), Savannah Sparrow (Passerculus sandwichensis), Bobolink (Dolichonyx oryzivorus), Common Yellowthroat (Geothlypis trichas), Swamp Sparrow (Melospiza georgiana), and Alder Flycatcher (Empidonax alnorum). We used nonparametric, multiplicative regression models to relate habitat variables and fire history to probability of species occurrence. Unlike studies in upland grasslands, none of the top models included measures of litter or graminoid height, and the highest probability of occurrence often was where graminoid cover was at intermediate rather than highest levels. Measures of woody cover or structure were important to all seven species modeled. We observed few clear differences in habitat metrics across fire history categories beyond the first year of burning. Years since last burned was in the best model for four of the seven species, despite high variability of habitat metrics within fire history categories; those species were more likely to occur in segments burned 15–19 y earlier. Infrequent light- to moderate-severity fires in fens had little effect on focal species occurrence beyond the first year after burning and little long-term effect to suppress woody cover.

'Some like it alien': predation on invasive ring–necked parakeets by the long–eared owl in an urban area

Predation pressure by native species may limit the spread of alien invasive species, thus playing a pivotal role in the impact and implementation of management strategies. The ring–necked parakeet Psittacula krameri is one of the most widespread alien bird species in Europe, with nearly 70 established populations. Predators of this species include diurnal raptors, synanthropic corvids, and rodents. Here we report for the first time that long–eared owls Asio otus might have preyed upon parakeets in their night roosts. Analysis of 167 owl pellets showed that ring–necked parakeets made up over 10 % of the total volume of the diet of these owls in winter (32.93 % of absolute frequency), representing the most important prey species after murid rodents and passerine birds. Further studies are needed to investigate whether parakeet consumption by long–eared owls is only a local occurrence or whether it is widespread in European cities. If so, predation by long–eared owl may eventually lead to a form of parakeet control and may limit the impact of this introduced parakeet on native biodiversity.

‘Some like it alien’: predation on invasive ring–necked parakeets by the long–eared owl in an urban area

Predation pressure by native species may limit the spread of alien invasive species, thus playing a pivotal role in the impact and implementation of management strategies. The ring–necked parakeet Psittacula krameri is one of the most widespread alien bird species in Europe, with nearly 70 established populations. Predators of this species include diurnal raptors, synanthropic corvids, and rodents. Here we report for the first time that long–eared owls Asio otus might have preyed upon parakeets in their night roosts. Analysis of 167 owl pellets showed that ring–necked parakeets made up over 10 % of the total volume of the diet of these owls in winter (32.93 % of absolute frequency), representing the most important prey species after murid rodents and passerine birds. Further studies are needed to investigate whether parakeet consumption by long–eared owls is only a local occurrence or whether it is widespread in European cities. If so, predation by long–eared owl may eventually lead to a form of parakeet control and may limit the impact of this introduced parakeet on native biodiversity.

Aspects of the Breeding Ecology of Short-eared Owls (Asio flammeus) on Amherst and Wolfe Islands, Eastern Ontario

Aspectos de la Ecologia Reproductiva de Asio flammeus en las Islas Amherst y Wolfe, Este de Ontario A pesar de su estatus como una especie de preocupacion de manejo a traves de gran parte de Norte America, se conoce relativamente poco sobre la ecologia reproductiva de Asio flammeus. Estudiamos la ecologia reproductiva de siete territorios de cria en dos islas en el este de Ontario durante 2009 y 2010. Cada ano, los territorios de cria estuvieron agrupados en localizaciones distintivas en la Isla Amherst. Cinco de los siete territorios estuvieron ubicados en pastizales con pastoreo y proximos a cercas de postes de madera y cercas de alambre de rejilla. De los cuatro nidos encontrados, todos estuvieron a menos de 540 metros de un humedal y a 1500 metros de una vivienda humana. Al parecer, los nidos se ubicaron selectivamente en sitios con vegetacion que brindaba un alto grado de ocultamiento. Los pastos constituyeron el 70% de la vegetacion en estos nidos, con contribuciones menores de hierbas (25%) y suelo...

Probing the density of states of two-level tunneling systems in silicon oxide films using superconducting lumped element resonators

We have investigated dielectric losses in amorphous silicon oxide (a-SiO) thin films under operating conditions of superconducting qubits (mK temperatures and low microwave powers). For this purpose, we have developed a broadband measurement setup employing multiplexed lumped element resonators using a broadband power combiner and a low-noise amplifier. The measured temperature and power dependences of the dielectric losses are in good agreement with those predicted for atomic two-level tunneling systems (TLS). By measuring the losses at different frequencies, we found that the TLS density of states is energy dependent. This had not been seen previously in loss measurements. These results contribute to a better understanding of decoherence effects in superconducting qubits and suggest a possibility to minimize TLS-related decoherence by reducing the qubit operation frequency.

Wing Kinematics of Long Eared Owl and Sparrow Hawk in Flapping Flight

Many species of owl has ability of fly silently. To explore the mechanism of owl’s silent flight, the kinematic character of the silent flight owl have been studied preliminarily on 3D motion capture technology. The paper has compared the flight motion between the long eared owl(Asio otus) and sparrow hawk(Accipiter nisus). According to the kinematic data, the flight trajectory, flapping frequency, flapping cycle, wrist angle, upstroke and downstroke percentage of cycle were computed and analyzed. The results show that wing tip, wrist and primary feather P10 of long eared owl and the eagle owl have obvious trajectory in flapping flight. Especially the wing tip trajectory in upstroke shows double“8”type. However, the wing tip trajectory in upstroke of sparrow hawk shows single“8”type. The wrist angle of silent owl keeps in downstroke and decreases in upstroke. But the wrist angle of sparrow hawk has increased first and then kept in downstroke, and the angle has begun decrease in upstroke. The above results show the difference of wing kinematics between silent owl and sparrow hawk, and will be useful for bionic design and silent fly technology.

Predatory Bird Species Show Different Patterns of Hydroxylated Polychlorinated Biphenyls (HO-PCBs) and Polychlorinated Biphenyls (PCBs)

Hydroxylated metabolites of polychlorinated biphenyls (HO-PCBs) have previously been associated with endocrine disrupting effects. Since metabolic capacity may differ among species, we investigated the levels and profiles of HO-PCBs and PCBs in livers of four predatory bird species from Belgium. Maximum concentrations for sum HO-PCBs were found in the common buzzard (Buteo buteo) up to 13 700 pg/g wet weight (ww). The most prominent HO-PCB congener in all bird species was 4-HO-CB 187 (up to 6420 pg/g ww in buzzard liver), followed by 4-HO-CB148 in the buzzard (up to 1820 pg/g ww), sparrowhawk (Accipiter nisus), and grey heron (Ardea cinerea), and by 3'-HO-CB138 in long eared owl (Asio otus) and in one grey heron (up to 985 pg/g ww and 3450 pg/g ww, respectively). The mean profile of the grey heron differed from the other species with 3'-HO-CB138 and 4-HO-CB163 contributing more to the sum HO-PCBs. This indicates that aquatic and terrestrial predatory bird species may show differences in their HO-PCBs profiles. Variation in the diet and species-specific accumulation and metabolism of PCBs are probably the most important causes for these differences. Correlations between HO-PCBs and their parent PCBs were only found significant for buzzards.

Nest Defense and Some Rare Breeding Events in Long-eared Owls (Asio otus)

DEFENSA DEL NIDO Y ALGUNOS EVENTOS REPRODUCTIVOS INUSUALES EN ASIO OTUS Aproximadamente la mitad de las parejas reproductivas de Asio otus defendieron sus nidos ante intrusos humanos en Ljubljansko Barje, Eslovenia. Su actividad de defensa de los nidos incremento con el estadio del ciclo de nidificacion, siendo baja durante la etapa de huevos, e incrementalmente mas agresiva a medida que los pichones maduraron. Este incremento en el comportamiento defensivo podria explicarse por el incremento en el valor reproductivo y la vulnerabilidad de los pichones en crecimiento. En las regiones templadas de Europa y Norte America, los individuos de esta especie rara vez nidifican en el suelo (0.6–4% de todos los intentos de nidificacion), y rara vez desplazan a otras especies de aves de sus nidos activos. En Eslovenia, observe tres casos de nidos de A. otus que contenian huevos de otra especie, lo que representa evidencia indirecta que sugiere que los buhos podrian haber desplazado violentamente a los duenos origina...

Refugee Detained for Two Years on False ASIO Intelligence

Refugee Detained for Two Years on False ASIO Intelligence

Comparison of the Diet of Two Desert-living Owls, the Long-eared Owl(Asio otus) and Little Owl (Athene noctua) from Southern Mongolia

The diet of two sympatric owl species, the long-eared owl (Asio otus) and the little owl (athene noctua) was investigated in an arid area of southern Mongolia using pellet analysis. In total 334 pellets of long-eared owl and 52 pellets of little owl were analysed, revealing the presence of five small mammal species (Dipodidae, three Muridae and one Soricidae), small birds and invertebrate fragments. Accumulative composition plots indicated a batch size of 35-60 pellets was sufficient to reveal representative diet composition. Small mammals comprised the largest component of the diet of long eared owls with four species recorded, Phodopus was the most frequently occurring (85%) followed by Meriones (33%). Bird and invertebrate remains were also found in long-eared owl pellets but comprised less than 2%. In contrast, invertebrates were the highest occurring component of the diet of little owls (35%), with small mammals occurring in only 40% of pellets. Meriones was the most frequently recorded small mammal in owl pellets (23%) and contributed the greatest in terms of overall rodent biomass. There was a highly statistically significant difference in the diet of the two species (÷2 = 2043, d.f. = 4,P<0.001). Levin's measure of niche breadth was greater for little owls (0.71) than long-eared owls (0.51), but overall the two species had low niche overlap using Levin's index (0.22). These results are discussed in relation to previous findings of these two species.

Adaptive details in the comparison of predatory behaviourw of four owl species

The predatory behaviour of four owl species, tawny owl (Strix aluco), long‐eared owl (Asio otus), little owl (Athene noctua) and barn owl (Tyto alba), was compared. The birds were wild individuals temporarily in captivity for rehabilitation and were tested before release into an outdoor pen. Between four and ten birds per species were individually tested by offering a laboratory mouse used as prey. The resulting sequence of the predatory behaviour patterns was homogeneous among the species. The latency to attack was similar and there was a tendency to prefer direct attacks, i.e. landing onto the prey directly, instead of indirect ones, i.e. landing a few centimetres from the mouse. However, tawny owls used the former attack only. The various degrees of specialisation to hunt small mammals is reflected by the grip location: the barn owls strongly preferred to seize the mouse on the head, while the little owls preferred the trunk and the other species preferred either location. Similarly, after grasping the mouse tawny and long—eared owls struck it with the beak, while the little owls performed strikes similar to bites. In contrast, barn owls performed a peculiar torsion of the neck region, instead of a beak strike. We interpret this pattern difference within a basically homogeneous behaviour sequence as evolutionary radiation due to species‐specific specialisation of feeding and hunting behaviour.

Sex and Age Determination of Short- Eared Owl Nestlings

Abstract We studied plumage patterns of known-sex nestling and juvenile Short-eared Owls (Asio flammeus) to develop a sexing technique for nestlings in the field. Markings on the secondaries varied according to sex, and differences were apparent from about 10–15 days of age. We also provide aging formulas based on mass for nestlings up to 15 days of age and on wing length for nestlings older than that age. Finally, we evaluate growth parameters according to sex. The asymptotes of body mass, wing length, and tarsus length growth curves were higher in females than males. The inflexion point was attained earlier by males than by females.

Food Habits of Long-Eared Owls (Asio otus) at a Communal Roost Site during the Nesting Season

Le gite communal d'A.o. observe est situe dans le sud-est de l'Idaho. Liste commentee des proies

ASIO and Accountability

ASIO and Accountability

Some Comparisons of the Feeding Ecology of Four Owls in North-Central Colorado

Four species of owls (Great Homed Owl, Bubo virginianus; Long- eared Owl, Asio otus; Burrowing Owl, Speotyto cunicularia and Barn Owl, Tyto alba) which inhabit the same grassland habitats in northcentral Colorado were investigated to determine differences and similarities in feeding ecology. Consider- able overlap in prey species was found in the four owls. However, the average estimated prey weight was significantly different for each owl species. Differences in activity periods, foraging methods and predator-prey size relationships may all function in reducing interspecific competition among these owls. During 1967 observations were made on the feeding ecology of the Great Horned Owl (Bubo virginianus), Long-eared Owl (Asio otus), Burrowing Owl (Speotyto cunicularia) and Barn Owl (Tyto alba) on short-grass prairie or interspersed prairie and farmland in the eastern one-fifth of Larimer County, Colorado. Rock outcroppings, canyons and eroded ditches, all abundant in this area, provide nesting sites for Great Horned and Barn Owls. Small groups of trees along water- courses, wind breaks and orchards are utilized for nesting and roosting by Long-eared and Great Horned Owls. Both occupied and abandoned prairie dog towns attract Burrowing Owls during the nesting season. Blue grama (Bouteloua gracilis) and buffalo grass (Buchloe dacty- loides) are dominant grasses. On rocky soils where rock outcroppings appear, mountain mahogany (Cerocarpus montanus) is abundant. Cottonwoods (Populus spp.) are the most abundant trees and occur mostly along watercourses. Only a small percentage of the land at most of the areas studied was under cultivation. Very little published literature exists on the food habits of these owls in north-central Colorado. Reed (1957) examined Barn Owl pellets from Larimer County and Hamilton (1941) made observations on the food habits of Burrowing Owls in Denver County. Nothing, apparently, has been published on the food habits of the Great Horned and Long- eared Owls for this locality.