Photos like these hardly look real, but this one is, and it was taken just a few minutes ago at feeding time. This big female GHO is on the mend and about ready to get back to the wild. She came to us from the Woodbury area suffering from secondary poisoning back on July 12th. What a difference eight days of supportive care has made!
What she's doing here is called a deimatic display. She's trying to frighten me away by making herself look bigger than she is and not worth attacking. What you can't hear in this photo is the hissing and beak clapping warnings. This is a good thing to see for a rehabber. We want that fear of humans to remain strong while we have them so they stay wild when released. She's been outside regaining flight strength for two days now, so she won't need much longer with us before back to the forest she goes!
Animal defenses can be diematic (from the Greek deimatόo, meaning "to frighten") or aposematic (from the Greek apo, "away" and sēma, "sign").
Diematic displays are something done to surprise a predator to momentarily distract them so the prey can escape. The owl rapidly puffing up and making sharp noises, or an octopus changing colors and squirting ink are diematic behaviors. They offer no actual defensive capability, but their sudden appearance offers a chance to get away.
Aposematic displays are warning signs that tell a predator there is an actual danger present. Brightly colored frogs are highly poisonous, so animals learn to avoid eating them. Animals like certain insects or opossums can emit very foul smelling secretions, making themselves into something the predator would not want to eat.
Some displays serve both functions, like the rattle of a rattlesnake. The sudden sharp sound can help them avoid being trampled or startle away a would-be predator, but to experienced predators, it is also aposematic, as it indicates the snake has a deadly bite.
