6 February 2013

How do you survey a population of owls that are afraid to make noise?  Dogs to the rescue!

In 1990 northern spotted owls were listed as Threatened under the Endangered Species Act.  Since then their population has been surveyed year after year, but despite changes in logging practices northern spotted owls continue to decline 3.7% per year.

Part of the problem could be that some owls have fallen silent and are impossible to count.   The typical survey method is to play an owl recording and listen for the owl to respond.  But barred owls have infiltrated the old growth forest, displaced northern spotted owls, and sometimes killed them.  Some northern spotted owls would rather not respond when the tapes are played.  They don’t want to give themselves away.

So how do you count these owls?

Researchers at the University of Washington trained two dogs, Max and Shrek, to identify owl pellets by species!   Amazingly, the dogs can smell the difference in regurgitated mouse bones from a barred owl versus a northern spotted owl.

The team takes the dogs out for a spin in the forest.  They don’t use recordings at all.  The dogs sniff for pellets below owl roosts and are so good at identifying the species that they have a 30% better success rate at finding northern spotted owls than the recordings do.

Here’s Max triumphant.  See the northern spotted owl in the tree above him?

Good dog!

Read more about Max in the Science Daily press release.

(photo of  Max, a member of the University of Washington’s Conservation Canines program, by Jennifer Hartman, Univ of Washington)