1. The monarch has undergone considerable population declines over the past decade, and the governments of Mexico, Canada, and the United States have agreed to work together to conserve the species. 2. Given limited resources, understanding where to focus conservation action is key for widespread species like monarchs. To support planning for continental-scale monarch habitat restoration, we address the question of where restoration efforts are likely to have the largest impacts on monarch butterfly (Danaus plexippus Linn.) population growth rates. 3. We present a spatially explicit demographic model simulating the multi-generational annual cycle of the eastern monarch population, and use the model to examine management scenarios, some of which focus on particular regions of North America. 4. Improving the monarch habitat in the north central or southern parts of the monarch range yields a slightly greater increase in the population growth rate than restoration in other regions. However, combining restoration efforts across multiple regions yields population growth rates above 1 with smaller simulated improvements in habitat per region than single-region strategies. 5. Synthesis and applications: These findings suggest that conservation investment in projects across the full monarch range will be more effective than focusing on one or a few regions, and will require international cooperation across many land use categories.
Bibliographical noteFunding Information:
This work was conducted as part of the ?Animal Migration and Spatial Subsidies: Establishing a Framework for Conservation Markets and Monarch Butterfly Recovery? and the Department of Interior's Monarch Conservation Science Partnership working groups supported by the John Wesley Powell Center for Analysis and Synthesis, funded by the U.S. Geological Survey. We thank the members of these groups for their input, Steve Hilburger for his leadership, and Julie Beston for constructive comments. Any use of trade, firm or product names are for descriptive purposes only and do not imply endorsement by the U.S. Government. Oberhauser, Ries, and B. Semmens developed the original model following discussions with all authors. B. Semmens and Wiederholt coded the model. Oberhauser and Wiederholt wrote the initial draft of the paper, based on extensive discussion and subsequent editing by Diffendorfer, D. Semmens, Ries, Thogmartin, and Lopez-Hoffman. None of the authors have any conflicts of interest relevant to this paper. There are no disputes over the ownership of the data presented in the paper and all contributions have been attributed appropriately, via coauthorship or acknowledgement.
- Bayesian stage-based matrix model
- Danaus plexippus
- conservation prioritisation
- management strategies
- population dynamics