Sensory capacities and the nocturnal habit of owls (Strigiformes)

Martin, Graham R.

doi:10.1111/j.1474-919x.1986.tb02674.x

Cited by 53 publications

(31 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An earlier report (Ramanujam, 2003) documented the use of the tape playback method (Bergerhausen & Willelms, 1988;Falls, 1982;Martin, 1986) to determine the territorial boundaries of each pair of owls in the study area, which was imperative to this study. Intensive pellet and carcass gathering exercises were simultaneously undertaken with bird watching sessions.…”

Section: Methodsmentioning

confidence: 99%

On the prey of the Indian Eagle Owl Bubo bengalensis (Franklin, 1831) in and around Pondicherry, southern India

Ramanujam¹

2006

Zoos Print J.

View full text Add to dashboard Cite

Section: Methodsmentioning

confidence: 99%

On the prey of the Indian Eagle Owl Bubo bengalensis (Franklin, 1831) in and around Pondicherry, southern India

Ramanujam¹

2006

Zoos Print J.

View full text Add to dashboard Cite

“…Owls flying at night also might collide with power lines, tree branches, or other obstacles. This might be particularly true for birds migrating or dispersing through unfamiliar terrain (Martin 1986). Little information is available either on how frequently this might occur, or when it occurs.…”

Section: Mortality Factorsmentioning

confidence: 99%

Status and ecology of Mexican spotted owls in the Upper Gila Mountains recovery unit, Arizona and New Mexico

Ganey¹,

Ward²,

Willey³

2011

View full text Add to dashboard Cite

This report summarizes current knowledge on the status and ecology of the Mexican spotted owl within the Upper Gila Mountains Recovery Unit (UGM RU). It was written at the request of U.S. Forest Service personnel involved in the Four Forests Restoration Initiative (4FRI), a collaborative, landscape-scale restoration effort covering approximately 2.4 million ac (1 million ha) across all or part of four National Forests (Apache-Sitgreaves, Coconino, Kaibab, and Tonto National Forests) located within the UGM RU. The UGM RU supports >50% of the known population of Mexican spotted owls, and the central location of the UGM RU within the overall range of the owl appears to facilitate gene flow throughout that range. Consequently, the UGM population is viewed as important to stability within the overall range of the owl, and management that impacts owls within the UGM RU could affect owl populations beyond that RU. The UGM RU supports >50% of the known population of Mexican spotted owls. KeywordsHabitat connectivity within the UGM RU is high relative to other RUs, allowing high levels of owl movements and gene flow, and the central location of the UGM RU within the overall range of the owl appears to facilitate gene flow throughout that range. Consequently, the UGM population is viewed as important to stability within the overall range of the owl, and management that impacts owls within the UGM RU could affect owl populations beyond that RU.We have little information on historical distribution of Mexican spotted owls within the RU. This owl currently is distributed widely in mountains and canyons featuring mixed-conifer, ponderosa pine-Gambel oak, and/or riparian forests. In other parts of the range, they occur in rocky canyons lacking extensive forest cover, but this appears atypical within the UGM RU.Mexican spotted owls in the UGM RU occupy large (up to 2,500 ac [1,012 ha]) home ranges. They typically concentrate use in smaller portions of this larger home range, with these "activity centers" typically comprising <50% of homerange area. Most radio-marked owls remain near their breeding areas year-round, but some migrate during winter. This migration, which has been observed in all populations studied, typically entails movement to lower elevations. Resident owls greatly expand their home range during the non-breeding season, but areas used during the breeding and non-breeding seasons overlap spatially. Thus, protection of breeding-season home ranges protects habitat that is used throughout the year.All studies in the UGM RU indicate that home ranges are located in areas containing greater amounts of mature forest than surrounding areas, or sometimes in areas of younger forest containing relatively large trees (>18 in [45.7 cm] diameter at breast height [dbh]). Differences between owl home ranges and randomly located areas are most pronounced near the nest area and decline as areas farther from nests and range centers are included.ii Mexican spotted owls appear to be more selective for habitat used for roostin...

show abstract

“…Although other avian taxa could also be examined, owls are ideal for such comparisons for two primary reasons. First, unlike many other avian orders, they exhibit variation in both activity pattern and habitat preference [Martin, 1986;Voous, 1988;del Hoyo et al, 1999;König and Weick, 2008] such that comparative analyses can be conducted. Second, much is known about the structure, organization and physiology of the owl visual system.…”

Section: Introductionmentioning

confidence: 99%

“…Second, much is known about the structure, organization and physiology of the owl visual system. Owls have large, frontally oriented eyes [Oehme, 1961;Fite, 1973;Martin, 1977Martin, , 1986Hall and Ross, 2007;Hall, 2008] characterized by high visual sensitivity [Martin, 1977], poor visual acuity [Fite, 1973;Martin and Gordon, 1974;Harmening and Wagner, 2011] and a higher proportion of rods to cones than other birds [Walls, 1942;Hocking and Mitchell, 1961;Oehme, 1961Oehme, , 1962Fite, 1973;Martin, 1982;Braekevelt, 1993;Braekevelt et al, 1996].…”

Section: Introductionmentioning

confidence: 99%

Eye Shape and Retinal Topography in Owls (Aves: Strigiformes)

Lisney¹,

Iwaniuk

Bandet

et al. 2012

Brain Behav Evol

View full text Add to dashboard Cite

The eyes of vertebrates show adaptations to the visual environments in which they evolve. For example, eye shape is associated with activity pattern, while retinal topography is related to the symmetry or ‘openness’ of the habitat of a species. Although these relationships are well documented in many vertebrates including birds, the extent to which they hold true for species within the same avian order is not well understood. Owls (Strigiformes) represent an ideal group for the study of interspecific variation in the avian visual system because they are one of very few avian orders to contain species that vary in both activity pattern and habitat preference. Here, we examined interspecific variation in eye shape and retinal topography in nine species of owl. Eye shape (the ratio of corneal diameter to eye axial length) differed among species, with nocturnal species having relatively larger corneal diameters than diurnal species. All the owl species have an area of high retinal ganglion cell (RGC) density in the temporal retina and a visual streak of increased cell density extending across the central retina from temporal to nasal. However, the organization and degree of elongation of the visual streak varied considerably among species and this variation was quantified using H:V ratios. Species that live in open habitats and/or that are more diurnally active have well-defined, elongated visual streaks and high H:V ratios (3.88–2.33). In contrast, most nocturnal and/or forest-dwelling owls have a poorly defined visual streak, a more radially symmetrical arrangement of RGCs and lower H:V ratios (1.77–1.27). The results of a hierarchical cluster analysis indicate that the apparent interspecific variation is associated with activity pattern and habitat as opposed to the phylogenetic relationships among species. In seven species, the presence of a fovea was confirmed and it is suggested that all strigid owls may possess a fovea, whereas the tytonid barn owl (Tyto alba) does not. A size-frequency analysis of cell soma area indicates that a number of different RGC classes are represented in owls, including a population of large RGCs (cell soma area >150 µm²) that resemble the giant RGCs reported in other vertebrates. In conclusion, eye shape and retinal topography in owls vary among species and this variation is associated with different activity patterns and habitat preferences, thereby supporting similar observations in other vertebrates.

show abstract

Sensory capacities and the nocturnal habit of owls (Strigiformes)

Cited by 53 publications

References 54 publications

On the prey of the Indian Eagle Owl Bubo bengalensis (Franklin, 1831) in and around Pondicherry, southern India

On the prey of the Indian Eagle Owl Bubo bengalensis (Franklin, 1831) in and around Pondicherry, southern India

Status and ecology of Mexican spotted owls in the Upper Gila Mountains recovery unit, Arizona and New Mexico

Eye Shape and Retinal Topography in Owls (Aves: Strigiformes)

Contact Info

Product

Resources

About