The past and future roles of competition and habitat in the range-wide occupancy dynamics of Northern Spotted Owls

Authors

Charles B. Yackulic, Southwest Biological Science CenterFollow
Larissa L. Bailey, Colorado State University
Katie M. Dugger, Oregon State UniversityFollow
Raymond J. Davis, Forestry Sciences Laboratory
Alan B. Franklin, USDA APHIS National Wildlife Research CenterFollow
Eric D. Forsman, Pacific Northwest Research Station, Forestry Sciences Laboratory
Steven H. Ackers, Oregon State University
Lawrence S. Andrews, Oregon State University
Lowell V. Diller, Green Diamond Resource Company
Scott A. Gremel, Olympic National Park
Keith A. Hamm, Green Diamond Resource Company
Dale R. Herter, Raedeke Associates
J. Mark Higley, Hoopa Tribal Forestry
Rob B. Horn, Roseburg District Office
Christopher McCafferty, Oregon State University
Janice A. Reid, Roseburg Field Station
Jeremy T. Rockweit, Colorado State University
Stan G. Sovern, Oregon State University

ORCID IDs

https://orcid.org/0000-0001-9661-0724

https://orcid.org/0000-0002-8109-0532

Document Type

Article

Date of this Version

1-7-2019

Citation

Yackulic, C.B., L.L. Bailey, K.M. Dugger, R.J. Davis, A.B. Franklin, E.D. Forsman, S.H. Ackers, L.S. Andrews, L.V. Diller, S.A. Gremel, K.A. Hamm, D.R. Herter, J.M. Higley, R.B. Horn, C. McCafferty, J.A. Reid, J.T. Rockweit, and S.G. Sovern. 2019. The past and future roles of competition and habitat in the range‐wide occupancy dynamics of northern spotted owls. Ecological Applications 29(3):e01861. doi: 10.1002/eap.1861

Comments

U.S. Government Work

Abstract

Slow ecological processes challenge conservation. Short-term variability can obscure the importance of slower processes that may ultimately determine the state of a system. Furthermore, management actions with slow responses can be hard to justify. One response to slow processes is to explicitly concentrate analysis on state dynamics. Here, we focus on identifying drivers of Northern Spotted Owl (Strix occidentalis caurina) territorial occupancy dynamics across 11 study areas spanning their geographic range and forecasting response to potential management actions. Competition with Barred Owls (Strix varia) has increased Spotted Owl territory extinction probabilities across all study areas and driven recent declines in Spotted Owl populations. Without management intervention, the Northern Spotted Owl subspecies will be extirpated from parts of its current range within decades. In the short term, Barred Owl removal can be effective. Over longer time spans, however, maintaining or improving habitat conditions can help promote the persistence of northern spotted owl populations. In most study areas, habitat effects on expected Northern Spotted Owl territorial occupancy are actually greater than the effects of competition from Barred Owls. This study suggests how intensive management actions (removal of a competitor) with rapid results can complement a slower management action (i.e., promoting forest succession).