Ruscena Wiederholt James E. Diffendorfer Darius J. Semmens Leslie Ries Wayne E. Thogmartin Laura Lopez-Hoffman Brice Semmens Karen Oberhauser 2017 <p>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.</p><p>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 (<i>Danaus plexippus</i> Linn.) population growth rates.</p><p>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.</p><p>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.</p><p>5. <i><strong>S</strong><strong>ynthesis and applications:</strong></i> 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.</p> application/pdf 10.1111/een.12351 en Wiley A trans-national monarch butterfly population model and implications for regional conservation priorities article