The Experts below are selected from a list of 726 Experts worldwide ranked by ideXlab platform
Erin L.r. Simons - One of the best experts on this subject based on the ideXlab platform.
-
Microstructure and Cross-Sectional Shape of Limb Bones in Great Horned Owls and Red-Tailed Hawks: How Do These Features Relate to Differences in Flight and
2016Co-Authors: Hunting Behavior, Crystal A Marelli, Erin L.r. SimonsAbstract:The Red-tailed Hawk and Great Horned Owl are two species of raptor that are similar in body size, diet, and habitat. Both species use their hindlimbs during hunting, but differ in foot morphology, how they approach and immobilize prey, and the average size of prey captured. They also differ in primary flight style: the Red-tailed Hawk uses static soaring and the Great Horned Owl uses flap-gliding. The objectives of this study were to characterize the microstructure and cross-sectional shape of limb bones of these species and examine the relationship with flight and hunting behaviors. The mid-shaft of six limb bones from six individuals of each species was sampled. The degree of bone laminarity (proportion of circular primary vascular canals) and cross-sectional geometric parameters were calculated. In both species, the humerus and femur exhibited features that suggest high resistance to torsional loading, whereas the tibiotarsus and phalanges had a shape more likely to resist compression and bending in a specific plane. The femur of the Red-tailed Hawk exhibited higher laminarity and larger polar moment of area than that of the Great Horned Owl. The tibiotarsus was more elliptical than that of the Great Horned Owl. The hawk approaches prey from a more horizontal axis, takes prey of Greater mass, and is more likely to pursue prey on the ground, which could potentially be causing more torsional loads on the femur and bending loads on the tibiotarsus. In addition, differences in polar moment of area of the phalanges between the species could relate to differences in foot morphology or digit length. The humerus and ulna of the flap-gliding Great Horned Owl are mor
-
microstructure and cross sectional shape of limb bones in Great Horned Owls and red tailed hawks how do these features relate to differences in flight and hunting behavior
PLOS ONE, 2014Co-Authors: Crystal A Marelli, Erin L.r. SimonsAbstract:The Red-tailed Hawk and Great Horned Owl are two species of raptor that are similar in body size, diet, and habitat. Both species use their hindlimbs during hunting, but differ in foot morphology, how they approach and immobilize prey, and the average size of prey captured. They also differ in primary flight style: the Red-tailed Hawk uses static soaring and the Great Horned Owl uses flap-gliding. The objectives of this study were to characterize the microstructure and cross-sectional shape of limb bones of these species and examine the relationship with flight and hunting behaviors. The mid-shaft of six limb bones from six individuals of each species was sampled. The degree of bone laminarity (proportion of circular primary vascular canals) and cross-sectional geometric parameters were calculated. In both species, the humerus and femur exhibited features that suggest high resistance to torsional loading, whereas the tibiotarsus and phalanges had a shape more likely to resist compression and bending in a specific plane. The femur of the Red-tailed Hawk exhibited higher laminarity and larger polar moment of area than that of the Great Horned Owl. The tibiotarsus was more elliptical than that of the Great Horned Owl. The hawk approaches prey from a more horizontal axis, takes prey of Greater mass, and is more likely to pursue prey on the ground, which could potentially be causing more torsional loads on the femur and bending loads on the tibiotarsus. In addition, differences in polar moment of area of the phalanges between the species could relate to differences in foot morphology or digit length. The humerus and ulna of the flap-gliding Great Horned Owl are more elliptical than the static soaring Red-tailed Hawk, a shape that may better resist the bending loads associated with a larger amount of flapping.
Crystal A Marelli - One of the best experts on this subject based on the ideXlab platform.
-
Microstructure and Cross-Sectional Shape of Limb Bones in Great Horned Owls and Red-Tailed Hawks: How Do These Features Relate to Differences in Flight and
2016Co-Authors: Hunting Behavior, Crystal A Marelli, Erin L.r. SimonsAbstract:The Red-tailed Hawk and Great Horned Owl are two species of raptor that are similar in body size, diet, and habitat. Both species use their hindlimbs during hunting, but differ in foot morphology, how they approach and immobilize prey, and the average size of prey captured. They also differ in primary flight style: the Red-tailed Hawk uses static soaring and the Great Horned Owl uses flap-gliding. The objectives of this study were to characterize the microstructure and cross-sectional shape of limb bones of these species and examine the relationship with flight and hunting behaviors. The mid-shaft of six limb bones from six individuals of each species was sampled. The degree of bone laminarity (proportion of circular primary vascular canals) and cross-sectional geometric parameters were calculated. In both species, the humerus and femur exhibited features that suggest high resistance to torsional loading, whereas the tibiotarsus and phalanges had a shape more likely to resist compression and bending in a specific plane. The femur of the Red-tailed Hawk exhibited higher laminarity and larger polar moment of area than that of the Great Horned Owl. The tibiotarsus was more elliptical than that of the Great Horned Owl. The hawk approaches prey from a more horizontal axis, takes prey of Greater mass, and is more likely to pursue prey on the ground, which could potentially be causing more torsional loads on the femur and bending loads on the tibiotarsus. In addition, differences in polar moment of area of the phalanges between the species could relate to differences in foot morphology or digit length. The humerus and ulna of the flap-gliding Great Horned Owl are mor
-
microstructure and cross sectional shape of limb bones in Great Horned Owls and red tailed hawks how do these features relate to differences in flight and hunting behavior
PLOS ONE, 2014Co-Authors: Crystal A Marelli, Erin L.r. SimonsAbstract:The Red-tailed Hawk and Great Horned Owl are two species of raptor that are similar in body size, diet, and habitat. Both species use their hindlimbs during hunting, but differ in foot morphology, how they approach and immobilize prey, and the average size of prey captured. They also differ in primary flight style: the Red-tailed Hawk uses static soaring and the Great Horned Owl uses flap-gliding. The objectives of this study were to characterize the microstructure and cross-sectional shape of limb bones of these species and examine the relationship with flight and hunting behaviors. The mid-shaft of six limb bones from six individuals of each species was sampled. The degree of bone laminarity (proportion of circular primary vascular canals) and cross-sectional geometric parameters were calculated. In both species, the humerus and femur exhibited features that suggest high resistance to torsional loading, whereas the tibiotarsus and phalanges had a shape more likely to resist compression and bending in a specific plane. The femur of the Red-tailed Hawk exhibited higher laminarity and larger polar moment of area than that of the Great Horned Owl. The tibiotarsus was more elliptical than that of the Great Horned Owl. The hawk approaches prey from a more horizontal axis, takes prey of Greater mass, and is more likely to pursue prey on the ground, which could potentially be causing more torsional loads on the femur and bending loads on the tibiotarsus. In addition, differences in polar moment of area of the phalanges between the species could relate to differences in foot morphology or digit length. The humerus and ulna of the flap-gliding Great Horned Owl are more elliptical than the static soaring Red-tailed Hawk, a shape that may better resist the bending loads associated with a larger amount of flapping.
Grzegorz Kopij - One of the best experts on this subject based on the ideXlab platform.
-
food niche overlap in co existing barn Owl tyto alba scopoli 1769 and Great Horned Owl bubo virginianus gmelin 1788 in intensively used farmland
Polish Journal of Ecology, 2013Co-Authors: Grzegorz KopijAbstract:The study was conducted at a site where the Great Horned Owl and the Barn Owl nested in a close proximity to each other in an intesivelly managed farmland in north-eastern Oregon. By the means of pellet content analysis it has been shown that food niches of both species almost totally overlapped. Their main diet was composed of Microtus voles (numerically: 79% in Great Horned Owl and 86% in Barn Owl) which were probably superabundant in this site.
Matt J. Griffin - One of the best experts on this subject based on the ideXlab platform.
-
New data on Neodiplostomum americanum Chandler and Rausch, 1947 (Digenea: Diplostomidae), in the Great Horned Owl Bubo virginianus Gmelin, 1788 and the Eastern Screech Owl Megascops asio Linnaeus, 1758 in Mississippi, USA
Parasitology Research, 2017Co-Authors: Ethan T Woodyard, Thomas G. Rosser, Matt J. GriffinAbstract:Neodiplostomum americanum Chandler and Rausch, 1947 has been reported from six species of Owls in North America. At present, there are no molecular data for this species and gene sequence data from Neodiplostomum Railliet, 1919 are limited. A freshly deceased specimen of the Great Horned Owl Bubo virginianus Gmelin, 1788 and a freshly deceased specimen of the Eastern Screech Owl Megascops asio Linnaeus, 1758 were collected in Oktibbeha County, Mississippi in 2014 and 2016, respectively. Neodiplostomum americanum were recovered from both hosts. Herein, updated morphological descriptions are supplemented with gene sequence data from conserved (18S, ITS1-5.8S, ITS2, and 28S rRNA) and fast-evolving (cytochrome c oxidase subunit 1 mtDNA) regions. Preliminary phylogenetic analysis of the genus based on cytochrome c oxidase subunit 1 gene sequence data supports the placement of N. americanum within a discrete phylogroup of the family Diplostomidae. The life history of N. americanum is unknown and currently limited to the description of the adult stage in avian hosts. The molecular data generated in this study offer insight into the phylogenetic placement of N. americanum within the Diplostomatidae and will aid in identifying different life stages in putative intermediate hosts.
Ethan T Woodyard - One of the best experts on this subject based on the ideXlab platform.
-
redescription of eimeria megabubonis upton campbell weigel mckown 1990 apicomplexa emeriidae from the Great Horned Owl bubo virginianus gmelin
Systematic Parasitology, 2019Co-Authors: Ethan T Woodyard, Scott A Rush, Graham T RosserAbstract:While nine nominal species of Eimeria Schneider, 1875 have been described from strigiform birds, molecular sequence data are not available for any of these species. In the present study, oocysts of a coccidian were isolated by faecal flotation from the lower intestinal contents of an opportunistically collected, recently deceased Great Horned Owl Bubo virginianus (Gmelin), sporulated in potassium dichromate, and subjected to morphological and molecular characterisation. Comparisons of morphological data with previous accounts of Eimeria spp. from Owls were consistent with Eimeria megabubonis Upton, Campbell, Weigel & McKown, 1990. Novel molecular data for the 18S ribosomal RNA gene region and the mitochondrial cytochrome c oxidase subunit 1 gene are provided. The results of phylogenetic analysis based on concatenated sequence data from these regions are presented and implications for the evolutionary history of Eimeria are discussed.
-
New data on Neodiplostomum americanum Chandler and Rausch, 1947 (Digenea: Diplostomidae), in the Great Horned Owl Bubo virginianus Gmelin, 1788 and the Eastern Screech Owl Megascops asio Linnaeus, 1758 in Mississippi, USA
Parasitology Research, 2017Co-Authors: Ethan T Woodyard, Thomas G. Rosser, Matt J. GriffinAbstract:Neodiplostomum americanum Chandler and Rausch, 1947 has been reported from six species of Owls in North America. At present, there are no molecular data for this species and gene sequence data from Neodiplostomum Railliet, 1919 are limited. A freshly deceased specimen of the Great Horned Owl Bubo virginianus Gmelin, 1788 and a freshly deceased specimen of the Eastern Screech Owl Megascops asio Linnaeus, 1758 were collected in Oktibbeha County, Mississippi in 2014 and 2016, respectively. Neodiplostomum americanum were recovered from both hosts. Herein, updated morphological descriptions are supplemented with gene sequence data from conserved (18S, ITS1-5.8S, ITS2, and 28S rRNA) and fast-evolving (cytochrome c oxidase subunit 1 mtDNA) regions. Preliminary phylogenetic analysis of the genus based on cytochrome c oxidase subunit 1 gene sequence data supports the placement of N. americanum within a discrete phylogroup of the family Diplostomidae. The life history of N. americanum is unknown and currently limited to the description of the adult stage in avian hosts. The molecular data generated in this study offer insight into the phylogenetic placement of N. americanum within the Diplostomatidae and will aid in identifying different life stages in putative intermediate hosts.
