EPA Science Inventory

Mapping sources, sinks, and connectivity using a simulation model of Northern Spotted Owls

Citation:

Schumaker, N., A. Brookes, J. Dunk, B. Woodbridge, J. Heinrichs, J. Lawler, C. Carroll, AND D. LaPlante. Mapping sources, sinks, and connectivity using a simulation model of Northern Spotted Owls. LANDSCAPE ECOLOGY. Springer, New York, NY, 29:579-592, (2014).

Description:

This is a study of source-sink dynamics at a landscape scale. In conducting the study, we make use of a mature simulation model for the northern spotted owl (Strix occidentalis caurina) that was developed as part of the US Fish and Wildlife Service’s most recent recovery planning effort for the species. Our spotted owl model was constructed with the HexSim life history simulator, and we take advantage of features in HexSim to develop maps of source and sink strength at multiple different scales across the range of the species. We also use HexSim to produce matrix model representations of the full, mechanistic simulation, and extract information about the fluxes of owls across the landscape from those simple models. We describe a quantity “net flux” that turns out to be well correlated with the importance of movement pathways based on an analysis of dominant eigenvalues (λ).

Purpose/Objective:

The US Fish and Wildlife Service (FWS) is developing a new recovery plan for the Northern Spotted Owl. One key part of the recovery planning process involves the development of an individual-based simulation model for the spotted owl. This simulation model was built inside the HexSim modeling environment, which was designed and constructed at EPA. In this paper, the authors use the computer model to develop a better understanding of source-sink dynamics across the range of the owl. This work extends this traditionally theoretical concept in ways that make it much more useful and assessable to managers and the public.

URLs/Downloads:

ABSTRACT - SCHUMAKER - SOURCE-SINK.PDF   (PDF,NA pp, 62.702 KB,  about PDF)

Record Details:

Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Start Date: 03/18/2014
Completion Date: 03/18/2014
Record Last Revised: 08/13/2014
Record Created: 03/18/2014
Record Released: 03/18/2014
OMB Category: Other
Record ID: 271195

Organization:

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF RESEARCH AND DEVELOPMENT

NATIONAL HEALTH AND ENVIRONMENTAL EFFECTS RESEARCH LAB

WESTERN ECOLOGY DIVISION

ECOLOGICAL EFFECTS BRANCH