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Owl Eye Spots

Bruce G. Marcot


Some species of small owls have eyes in the back of their heads!

OK, not literally ... but they have dark spots, on the back of their head or neck, that resemble eyes.

It is thought that this adaptation developed to thwart predator attacks from behind.  Some predators choose not to attack their prey if the prey is clearly watching them, because the attack would likely fail and the predator would merely use of valuable body energy.  

One study (Deppe et al. 2003) found that the presence of eye spots on pygmy-owls seemed to reduce mobbing of the owl by small forest birds.  

However, whether such eye spots might also play other roles is unknown.  Perhaps these owls might also use their eye spots as signals to each other, such as for territoriality, or mate recognition.  In the natural world, it is not unusual for one adaptation to take on additional uses or benefits.

Literature Cited

Deppe, C., D. Holt, J. Tweksbury, L. Broberg, J. Petersen, and K. Wood. 2003. Effect of northern pygmy-owl (Glaucidium gnoma) eyespots on avian mobbing. The Auk 120(3):765-771. 




The back of a Pearl-spotted Owlet (Glaucidium perlatum) in Zimbabwe, Africa.  The two dark spots ringed by white are clearly intended to resemble large, watchful eyes.

(Click on photo for larger version.)



Here is the back of an African Barred Owlet (Glaucidium capense), the same genus as the Pearl-spotted Owlet, above ... also found in the same general location, too (here, also in Zimbabwe, Africa).

But ... there are no eye spots on this species.  Why? 

Perhaps this species is more aggressive and does not need the eye spots to deter predators or mobbing forest birds.  But we just don't know.

(Click on photo for larger version.)

Here is the back of a Ridgeway's Pygmy Owl (Glaucidium ridgwayi) from Arizona, USA.  

Note the great similarity of the eyespots to those of the Pearl-spotted Owlet, above, even though these species are half a world apart.  Whether this similarity signals convergent evolution or some common evolutionary ancestry is unknown.

(Click on photo for larger version.)


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