Fishing owls, really?

[It’s been a quiet winter on my pond. It had still not fully frozen over when I left last weekend, so the otters cannot rest out on the ice.They are there, but far off in the distance. So I am showing you some posts from various past trips that I stockpiled for moments like these!]

When I think of an owl, I think of the night: a shadow with huge eyes, and a silent ghostly flight through the trees and grasslands in the pursuit of mice. But not all owls are like that. There are four species of owl that hunt fish, not mice. They hunt by day as well as by night, by sight not sound, and their own flight is not silent.

The best known is probably Pel’s Fishing Owl, Scotopelia peli, which I have seen in Zambia.

They still have large eyes because they are mostly nocturnal, but they sometimes hunt during the day. They snatch prey from the surface of shallow water, using surface ripples as cues (though I don’t understand how they can do this at night!).

Our more familiar prototypical owls have a facial disc, which serves to collect and concentrate the sound of their prey in the dark, like this Barred Owl:

Fishing owls more or less lack this, because transmission of sound from water to air is too poor to be useful. Here is a Brown Fish Owl, Ketupa zeylonensis, from India, also lacking that dramatic facial disc.

Just as they cannot hear the fish, the fish can’t hear them, so the owls don’t need and don’t have the specialized feathers that make flight silent in most owls.

Another adaptation is beak position. Fishing owls’ beaks are longer than most other owls, better for holding slippery fish, and more or less between their eyes, higher on the face than in other owls.

Again, the reason for this is unclear. They catch their prey by dangling their talons in the water from flight, not with their beaks. This Brown Fish Owl is coming in to land, not fishing, but you can get the idea.

PS The world’s very largest fishing owl is the endangered Blakiston’s Fish Owl, and I highly recommend Jonathan Slaght’s thrilling book on his quest for this owl in Siberia, “Owls of the Eastern Ice: A Quest to Find and Save the World’s Largest Owl”.