5 interesting things I learned:
- Raptors, like this Swainson’s hawk, have the most acute avian vision, relying on sight to spot and capture prey from altitude. While most birds have laterally positioned eyes, giving them a broader field of view, raptors have eyes set frontally to give them increased binocular vision and depth perception.
-Diurnal birds tend to have increased ultraviolet sensitivity, with far more cones than rods, while nocturnal species such as owls tend towards sensitivity in the infrared end of the spectrum and have a relatively high proportion of rods.
-One possible advantage of ultraviolet vision is in spotting the traces left by prey. The urine and feces of mice are visible in the ultraviolet range, so they stand out against the uniform color of a cultivated field to the eyes of a hunting kestrel.
-Some species we see as having identical male and female plumage differ when seen in the ultraviolet range - a difference apparent to the birds themselves.
-Migrating birds that fly at night need different navigational equipment. When compared to daytime flyers, songbirds that migrate nocturnally have an enlarged section of the brain, which apparently controls this aspect of migration.
