African fish eagles are diurnal birds, meaning they are active during the day and rest at night. They do not have the necessary adaptations to see clearly in low light conditions, such as large corneas or a tapetum lucidum, which is a layer of reflective cells at the back of the eye that reflects light back through the retina, increasing the light available to the photoreceptors. Therefore, African fish eagles are not able to see well at night.
Excellent Vision for Daytime Hunting
African fish eagles are known for their excellent vision, which they use to spot fish in the water from a distance. They have deep brown eyes and bare yellow mask-like skin on their faces that extends to their sharp hooked, black-tipped beak. Fish eagles have excellent color vision and are able to spot camouflaged prey from a distance. This is how they spot fish in water.
Habitat and Distribution
Image source: African fish eagle above water by Mehmet Karatay
African fish eagles are widely distributed across sub-Saharan Africa and are typically found near rivers, lakes, and streams. They also occur around estuaries and lagoons in coastal areas, as long as there is freshwater available. They are found in a wide variety of habitat types across the continent, including grasslands, wetlands, rainforests, fynbos, and even deserts close enough to a water source such as Namibia’s Skeleton Coast.
Mating and Nesting Behavior
African fish eagles usually mate for life and are territorial birds, typically occurring in pairs. They build their nests out of sticks and debris in large trees and may have a few nests within a nesting site, re-using them year after year while continuously expanding them. Ultimately, nests can reach up to two metres across.
Adaptations for Hunting
African fish eagles have several adaptations that make them excellent hunters during the day. Their sharp talons and hooked beak are well-suited for catching and tearing apart their prey, which consists mainly of fish, but they also hunt small mammals, birds, and reptiles. Their keen eyesight allows them to spot their prey from a distance, and their powerful wings enable them to swoop down and snatch their prey from the water or the ground.
Nocturnal Predators
While African fish eagles are not able to see well at night, there are other predators in their ecosystem that are adapted for nocturnal hunting. These include various species of owls, such as the Verreaux’s eagle-owl and the spotted eagle-owl, as well as some species of cats, such as the African leopard and the serval. These nocturnal predators use their excellent low-light vision and acute hearing to hunt at night, when the fish eagles are resting.
Conclusion
In conclusion, African fish eagles are diurnal birds and do not have the necessary adaptations to see clearly in low light conditions. They are known for their excellent vision and are able to spot fish in the water from a distance. They are widely distributed across sub-Saharan Africa and are typically found near bodies of water. While they are not able to hunt at night, there are other predators in their ecosystem that are adapted for nocturnal hunting.
References:
– Animalia.bio – African Fish Eagle
– Reddit – A Few Hawks and Eagles from a Uganda Trip
– The Peregrine Fund – Bateleur Eagle
– SA-Venues.com – African Fish Eagle
– Avibirds.com – African Fish Eagle
– Nature – Avian Photoreceptor Arrangement and Spectral Sensitivity in Relation to Foraging and Nesting Habitat
– Science Direct – Vision in Birds
– Research Gate – Vision in Birds
– NCBI – The Avian Retina: Oil Droplets, Cone Types, and Ganglion Cell Topography
– Science Direct – Retinal Specializations in the African Fish Eagle
