Invasive owls

1. Invasive owls

4. “sparred owl”

5. Results There are clear differences between the “traditional” contact calls of allopatric barred owls and the calls of barred owls that are sympatric with spotted owls.

6. Hypothesis: In areas of overlapping range, differences in contact calls will reinforce species isolation. Allopatric barred owls will show changes in the contact call to differentiate more clearly from the contact call of the spotted owl.

7. Methods • Using sonograms from the Macaulay Library and GIS mapping, we identified sympatric and allopatric samples of barred owl contact calls as well as spotted owls. Representative calls from each group were analyzed [number of syllables, max and min frequency, and frequency range of call, presence or absence of a descending trill on final syllable]

10. Reinforcement of species isolation in invasive barred owls David Glick, Stacey Kiser, Linda Vick Barred owl Strixvaria Spotted owl Strixoccidentalis Hypothesis: In areas of overlapping range, differences in contact calls will reinforce species isolation. Allopatric barred owls will show changes in the contact call to differentiate more clearly from the contact call of the spotted owl. Using sonograms from the Macaulay Library and GIS mapping, we identified sympatric and allopatric samples of barred owl contact calls as well as spotted owls. Representative calls from each group were analyzed [number of syllables, max and min frequency, and frequency range of call, presence or absence of a descending trill on final syllable]