Temporal validation of an estimator for successful breeding pairs of wolves Canis lupus in the U.S. northern Rocky Mountains
Michael S. Mitchell, Douglas W. Smith, Justin A. Gude, David E. Ausband, Carolyn A. Sime, Edward E. Bangs, Michael D. Jimenez, Curt M. Mack, Thomas J. Meier & M. Steven Nadeau
Model-based predictors derived from historical data are rarely evaluated before they are used to draw inferences. We performed a temporal validation, (i.e. assessed the performance of a predictive model using data collected from the same population after the model was developed) of a statistical predictor for the number of successful breeding pairs of wolves Canis lupus in the northern Rocky Mountains (NRM). We predicted the number of successful breeding pairs, β, in Idaho, Montana and Wyoming based on the distribution of pack sizes observed through monitoring in 2006 and 2007 (^β), and compared these estimates to the minimum number of successful breeding pairs, bMIN, observed through intensive monitoring. βMIN was consistently included within the 95% confidence intervals of ^β for all states in both years (except for Idaho in 2007), generally following the pattern ^βL (lower 95% prediction interval for ^β) , ^βMIN , ^β. This evaluation of ^β estimates for 2006 and 2007 suggest it will be a robust model-based method for predicting successful breeding pairs of NRMwolves in the future, provided influences other than those modeled in ^β (e.g. disease outbreak, severe winter) do not have a strong effect on wolf populations. Managers can use ^β models with added confidence as part of their post-delisting monitoring of wolves in NRM.
Michael S. Mitchell, U.S. Geological Survey, Montana Cooperative Wildlife Research Unit, 205 Natural Sciences Building, University of Montana, Missoula, Montana 59812, USA - e-mail: mike.mitchell@umontana.edu
Justin A. Gude & Carolyn A. Sime, Montana Fish, Wildlife & Parks, 1420 E. 6th Avenue, Helena, Montana 59620, USA - e-mail addresses: jgude@nt.gov (Justin A. Gude); casime@mt.gov (Carolyn A. Sime)
David E. Ausband, Montana Cooperative Wildlife Research Unit, 205 Natural Sciences Building, University of Montana, Missoula, Montana 59812, USA - e-mail: david.ausband@mso.umt.edu
Edward E. Bangs, U.S. Fish and Wildlife Service, 585 Shepard Way, Helena, Montana 59601, USA - e-mail: ed_bangs@fws.gov
Michael D. Jimenez, U.S. Fish and Wildlife Service, P.O. Box 2645, Jackson, Wyoming 83001, USA - e-mail: mike_ jimenez@fws.gov
Curt M. Mack, Gray Wolf Recovery Project, Nez Perce Tribe, P.O. Box 1922, McCall, Idaho 83638, USA - e-mail: cmack@nezperce.org
Thomas J. Meier, National Park Service, Denali National Park and Preserve, Denali Park, Alaska 99755, USA - e-mail: tom_meier@nps.gov
M. Steven Nadeau, Idaho Department of Fish and Game, 600 S. Walnut, Boise, Idaho 83707,USA- e-mail: snadeau@idfg.idaho.gov
Douglas W. Smith, Yellowstone Center for Resources, P.O. Box 168, Yellowstone National Park, Wyoming 82190,USA e-mail: doug_smith@nps.gov
