Short-term Response of Breeding Barred Owls to Forestry in a Boreal Mixedwood Forest Landscape

Olsen, Ben.; Hannon, Susan J.; Court, Gordon S.

doi:10.5751/ace-00065-010301

Cited by 4 publications

(12 citation statements)

References 26 publications

(23 reference statements)

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“…in contrast to other studies (Mazur et al 1997a;Postupalsky et al 1997;Olsen et al 2006), all nests (n = 9) located in the study were in tree cavities (Table 1). Mazur et al (1997a) reported that 5 of 15 Barred Owl nests (33%) in the study in the boreal forest of Saskatchewan were in structures other than tree cavities; in witch's broom (the dense branching caused by Arceuthobium spp.…”

Section: Nest Typecontrasting

confidence: 83%

“…128 haney 1997; Mazur et al 1997aMazur et al , 1997bPostupalsky et al 1997;Winton and leslie 2004;Olsen et al 2006;Grossman et al 2008;Singleton et al 2010) and general Barred Owl habitat associations (McGarigal and Fraser 1984;Booth and harrison 1997;Mazur et al 1998;hamer et al 2007;Russell 2008). These studies vary considerably, as described in more detail below, in the way study areas were selected, in the size and habitat fragmentation of the study areas, and in the size and measurement of nest habitat plots.…”

Section: Discussionmentioning

confidence: 99%

“…in a White Spruce tree), in Red Squirrel (Tamiasciurus hudsonicus) nests, or in stick nests. in a study in the boreal mixedwood forest in alberta (Olsen et al 2006), 9 of 10 nest sites (90%) were in tree cavities (one Barred Owl nested in a stick nest). in Michigan, in hardwood (deciduous) and mixed forest habitat, Postupalsky et al (1997) described 13 of 57 nests (23%) as being open sites, including hawk (Red-shouldered hawk (Buteo lineatus) or Broadwinged hawk (Buteo platypterus) and Northern Goshawk (Ac cipiter gentilis)) stick nests, a ground nest, a flat area in the fork of a Yellow Birch (Betula alleghaniensis), and a nest platform intended for Great horned Owls (Bubo virginianus); the remainder were in tree cavities (n = 26) or nest boxes (n = 18).…”

Section: Nest Typementioning

confidence: 99%

“…in Michigan, in hardwood (deciduous) and mixed forest habitat, Postupalsky et al (1997) described 13 of 57 nests (23%) as being open sites, including hawk (Red-shouldered hawk (Buteo lineatus) or Broadwinged hawk (Buteo platypterus) and Northern Goshawk (Ac cipiter gentilis)) stick nests, a ground nest, a flat area in the fork of a Yellow Birch (Betula alleghaniensis), and a nest platform intended for Great horned Owls (Bubo virginianus); the remainder were in tree cavities (n = 26) or nest boxes (n = 18). (Olsen et al 2006), none were found nesting on a cumulative total of 2527 natural and/or artificial open stick platform nests in a variety of habitats checked for raptors over a 27-year period in the same 25 000 km 2 study area in southeastern Manitoba (duncan 1992; JRd, unpublished data).…”

Section: Nest Typementioning

confidence: 99%

“…The aforementioned studies (Mazur et al (1997a), Postupalsky et al (1997), and Olsen et al (2006)) varied considerably in the way the study areas were selected or described, in the size of the study areas, in the methods used to find nests, in the forest habitat composition/ fragmentation, and in other quantified ways (i.e., prey density, human disturbance). For example, this study was larger (~25 000 km 2 ) with varied habitat, the study described in Mazur et al (1997a) was conducted within a 3 874 km 2 national park, the study described in Olsen et al (2006) was a 800 km 2 predetermined area, and two study areas (28 km 2 and an undefined larger area) were studied in Postupalsky et al (1997).…”

Section: Nest Typementioning

confidence: 99%

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Characteristics of Barred Owl (<em>Strix varia</em>) nest sites in Manitoba, Canada

Whiklo

Duncan²

2014

Can Field Nat

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Whiklo, Todd M., and James R. duncan. 2014. Characteristics of Barred Owl (Strix varia) nest sites in Manitoba, Canada.Canadian Field-Naturalist 128(1): 38-43.during 2009 and 2010, nine Barred Owl (Strix varia) nest sites were located in Manitoba, Canada, and data on nest trees, nest structure, and nest site habitat were collected. Nests were located in a variety of tree species, including Balsam Poplar (Populus balsamifera), Paper Birch (Betula papyrifera), Trembling aspen (Populus tremuloides) and Burr Oak (Quercus macrocarpa). all nests were in tree cavities, and the majority of nests were in dead trees (67%) and had lateral openings (67%). habitat surrounding nest trees and estimated canopy cover were highly variable. diameter at breast height of nest trees, cavity width, and cavity depth were consistent and were determined to be the most reliable indicators of nest suitability for breeding Barred Owls. We conclude that the distribution of nesting Barred Owls is influenced more by availability of suitable nest sites than by nest tree species or nest site habitat.

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Section: Nest Typecontrasting

confidence: 83%

Section: Discussionmentioning

confidence: 99%

Section: Nest Typementioning

confidence: 99%

Section: Nest Typementioning

confidence: 99%

Section: Nest Typementioning

confidence: 99%

See 3 more Smart Citations

Characteristics of Barred Owl (<em>Strix varia</em>) nest sites in Manitoba, Canada

Whiklo

Duncan²

2014

Can Field Nat

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Competitive interactions and resource partitioning between northern spotted owls and barred owls in western Oregon

Wiens

Anthony

Forsman

2014

Wildlife Monographs

121

239

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The federally threatened northern spotted owl (Strix occidentalis caurina) is the focus of intensive conservation efforts that have led to much forested land being reserved as habitat for the owl and associated wildlife species throughout the Pacific Northwest of the United States. Recently, however, a relatively new threat to spotted owls has emerged in the form of an invasive competitor: the congeneric barred owl (S. varia). As barred owls have rapidly expanded their populations into the entire range of the northern spotted owl, mounting evidence indicates that they are displacing, hybridizing with, and even killing spotted owls. The range expansion by barred owls into western North America has made an already complex conservation issue even more contentious, and a lack of information on the ecological relationships between the 2 species has hampered recovery efforts for northern spotted owls. We investigated spatial relationships, habitat use, diets, survival, and reproduction of sympatric spotted owls and barred owls in western Oregon, USA, during 2007USA, during -2009. Our overall objective was to determine the potential for and possible consequences of competition for space, habitat, and food between these previously allopatric owl species. Our study included 29 spotted owls and 28 barred owls that were radio-marked in 36 neighboring territories and monitored over a 24-month period. Based on repeated surveys of both species, the number of territories occupied by pairs of barred owls in the 745-km 2 study area (82) greatly outnumbered those occupied by pairs of spotted owls (15). Estimates of mean size of home ranges and core-use areas of spotted owls (1,843 ha and 305 ha, respectively) were 2-4 times larger than those of barred owls (581 ha and 188 ha, respectively). Individual spotted and barred owls in adjacent territories often had overlapping home ranges, but interspecific space sharing was largely restricted to broader foraging areas in the home range with minimal spatial overlap among coreuse areas. We used an information-theoretic approach to rank discrete-choice models representing alternative hypotheses about the influence of forest conditions, topography, and interspecific interactions on species-specific patterns of nighttime resource selection. Spotted owls spent a disproportionate amount of time foraging on steep slopes in ravines dominated by old (>120 yr) conifer trees. Barred owls used available forest types more evenly than spotted owls, and were most strongly associated with patches of large hardwood and conifer trees that occupied relatively flat areas along streams. Spotted and barred owls differed in the relative use of old conifer forest (greater for spotted owls) and slope conditions (steeper slopes for spotted owls), but we found no evidence that the 2 species differed in their use of young, mature, and riparian-hardwood forest types. Mean overlap in proportional use of different forest types between individual spotted owls and barred owls in adjacent territories was 81% (range ¼ 30...

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Responses of Great Horned Owls (Bubo virginianus), Barred Owls (Strix varia), and Northern Saw-whet Owls (Aegolius acadicus) to forest cover and configuration in an agricultural landscape in Alberta, Canada

2008

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Studies on the effects of forest fragmentation on birds have focussed primarily on passerines, with few studies on owls. We assessed the influence of forest amount and configuration on the abundance and distribution of three species of forest owls, Great Horned Owl (Bubo virginianus (Gmelin, 1788)), Barred Owl (Strix varia Barton, 1799), and Northern Saw-whet Owl (Aegolius acadicus (Gmelin, 1788)), in agricultural landscapes with varying amounts of forest cover in central Alberta, Canada. All three species were positively associated with forest cover: Barred Owls were most prevalent in landscapes with >66% forest cover, Great Horned Owls in landscapes with between 36% and 65% forest cover, and Northern Saw-whet Owls in landscapes with between 16% and 100% forest cover. Regression models containing configuration variables were chosen as best models using AIC for all three species. Great Horned Owls were most abundant in landscapes with high heterogeneity: more forest-nonforest edges and higher forest patch area variation. Barred Owls were more likely to occur in landscapes with larger forest patch areas and Northern Saw-whet Owls were more abundant in landscapes that were more connected. These relationships are consistent with predictions based on body size of owls and local habitat relationships described in the literature. Résumé :Les études des effets de la fragmentation des forêts sur les oiseaux se sont intéressées principalement aux passereaux, avec peu de travaux sur les hiboux. Nous évaluons l'influence de l'étendue et de la configuration de la forêt sur l'abondance et la répartition de trois espèces forestières de hiboux, le grand-duc d'Amérique (Bubo virginianus (Gmelin, 1788)), la chouette rayée (Strix varia Barton, 1799) et la petite nyctale (Aegolius acadicus (Gmelin, 1788)), dans des paysages agricoles possédant des étendues diverses de couverture forestière dans le centre de l'Alberta, Canada. Il existe une association positive entre les trois espèces et le couvert forestier : les chouettes rayées prédominent surtout dans les paysages qui présentent plus de 66 % de forêt, les grands-ducs d'Amérique dans les paysages à 36 % -65 % de forêt et les petites nyctales dans les paysages à 16 % -100 % de forêt. Nous avons choisi pour les trois espèces les meilleurs modèles de régression contenant les variables de configuration à l'aide du critère AIC. Les grands-ducs d'Amérique sont plus abondants dans les paysages de forte hétérogénéité avec plus de lisières forêt et non forêt et une variation plus grande des taches forestières. Les chouettes rayées ont plus de chances de se retrouver dans les paysages contenant des taches forestières plus étendues et les petites nyctales sont plus abondantes dans les paysages qui sont plus interconnectés. Ces relations s'accordent avec les prédictions basées sur la taille corporelle des hiboux et des relations d'habitat décrites dans la littéra-ture.[Traduit par la Rédaction]

show abstract

Short-term Response of Breeding Barred Owls to Forestry in a Boreal Mixedwood Forest Landscape

Cited by 4 publications

References 26 publications

Characteristics of Barred Owl (<em>Strix varia</em>) nest sites in Manitoba, Canada

Characteristics of Barred Owl (<em>Strix varia</em>) nest sites in Manitoba, Canada

Competitive interactions and resource partitioning between northern spotted owls and barred owls in western Oregon

Responses of Great Horned Owls (Bubo virginianus), Barred Owls (Strix varia), and Northern Saw-whet Owls (Aegolius acadicus) to forest cover and configuration in an agricultural landscape in Alberta, Canada

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