Department of Biology, Lund University, Sölvegatan 35, Lund S-22362, Sweden.
Les Ailes de l'Urga, 72 rue de la vieille route, 27320 Marcilly la Campagne, France.
Proc Biol Sci. 2023 Oct 25;290(2009):20230664. doi: 10.1098/rspb.2023.0664. Epub 2023 Oct 18.
The binocular field of vision differs widely in birds depending on ecological traits such as foraging. Owls (Strigiformes) have been considered to have a unique binocular field, but whether it is related to foraging has remained unknown. While taking into account allometry and phylogeny, we hypothesized that both daily activity cycle and diet determine the size and shape of the binocular field in owls. Here, we compared the binocular field configuration of 23 species of owls. While we found no effect of allometry and phylogeny, ecological traits strongly influence the binocular field shape and size. Binocular field shape of owls significantly differed from that of diurnal raptors. Among owls, binocular field shape was relatively conserved, but binocular field size differed among species depending on ecological traits, with larger binocular fields in species living in dense habitat and foraging on invertebrates. Our results suggest that (i) binocular field shape is associated with the time of foraging in the daily cycle (owls versus diurnal raptors) and (ii) that binocular field size differs between closely related owl species even though the general shape is conserved, possibly because the field of view is partially restricted by feathers, in a trade-off with auditory localization.
鸟类的双眼视野差异很大，这取决于觅食等生态特征。猫头鹰（Strigiformes）被认为具有独特的双眼视野，但这种视野是否与觅食有关尚不清楚。在考虑到体型大小和系统发育的情况下，我们假设昼夜活动节律和饮食都会影响猫头鹰的双眼视野大小和形状。在这里，我们比较了 23 种猫头鹰的双眼视野结构。虽然我们没有发现体型大小和系统发育的影响，但生态特征强烈影响双眼视野的形状和大小。猫头鹰的双眼视野形状与昼行猛禽明显不同。在猫头鹰中，双眼视野形状相对保守，但不同物种的双眼视野大小因生态特征而异，生活在密集栖息地和以无脊椎动物为食的物种具有较大的双眼视野。我们的结果表明：（i）双眼视野形状与昼夜活动节律中的觅食时间有关（猫头鹰与昼行猛禽）；（ii）即使一般形状保持不变，密切相关的猫头鹰物种之间的双眼视野大小也存在差异，这可能是因为视野部分受到羽毛的限制，与听觉定位存在权衡。
