Monarch Butterfly Distribution and Breeding Ecology in Idaho and Washington

Studies of monarch butterflies (Danaus plexippus) and their milkweed (Asclepias spp.) host plants in North America have focused primarily on monarch populations ranging east of the Rocky Mountains. We report the first systematic assessment of monarch butterfly and milkweed populations in the western states of Idaho and Washington, states at the northern tier of western monarch breeding range. Results of our 2-year study (2016–2017) offer new insights into monarch breeding habitat distribution, characteristics, and threat factors in our 2 states. We documented milkweeds and breeding monarchs in all 16 climate divisions in our study area. Milkweed and breeding monarch phenologies were examined with evidence supporting 2, and possibly 3 monarch generations produced in Idaho and Washington. Key monarch breeding habitats were moist-soil sites within matrices of grasslands, wetlands, deciduous forest, and shrub-steppe supporting large, contiguous, and high-density milkweed stands. Co-occurrence of showy milkweed (A. speciosa) and swamp milkweed (A. incarnata) was an important indicator of productive monarch breeding habitat in Idaho. Nectar plants were generally limited in quantity and richness across the study area, particularly in late summer, and included frequently-used non-native, invasive species. Primary threats at milkweed sites were invasive plant species, herbicide application, and mowing, followed by secondary threats of recreational disturbance, livestock grazing, insecticide application, loss of floodplain function, and wildfire. We provide management recommendations and research needs to address ongoing stressors and knowledge gaps in Idaho and Washington with the goal of conserving monarchs and their habitats in the West

Modeling Current and Future Potential Distributions of Milkweeds and the Monarch Butterfly in Idaho

Monarch butterflies (Danaus plexippus) are widespread in North America but have experienced large rangewide declines. Causes of recent declines likely involve multiple biotic and abiotic stressors including climate change and loss and degradation of native milkweed (Asclepias spp.), monarchs' obligate larval host plant. Recent broad-scale modeling efforts suggest milkweed and monarch distributions in the eastern United States will expand northward during summer months while fine-scale modeling of western population overwintering sites in California indicate shifts inland and upward in elevation. However, species' response to climate measures varies at sub-regional scales across its range and both the impacts of climate change and potential adaptation measures may be sensitive to the spatial scale of climate data used, particularly in areas of complex topography. Here, we develop fine-scale models of monarch breeding habitat and milkweed distributions in Idaho, an area at the northern extent of the monarch breeding range in North America and important in western overwintering population recruitment. Our models accurately predict current distributions for showy milkweed (A. speciosa), swamp milkweed (A. incarnata), and monarch with AUC (area under the receiver operating characteristic curve) = 0.899, 0.981, and 0.929, respectively. Topographic, geographic, edaphic, and climatic factors all play important roles in determining milkweed and, thus, monarch distributions. In particular, our results suggest that at sub-regional and fine-scales, non-climatic factors such as soil depth, distance to water, and elevation contribute significantly. We further assess changes in potential habitat across Idaho under mid-21st century climate change scenarios and potential management implications of these changing distributions. Models project slight decreases (−1,318 km2) in potential suitable habitat for showy milkweed and significant increases (+5,830 km2) for swamp milkweed. Projected amounts of suitable habitat for monarch are likely to remain roughly stable with expansion nearly equal to contraction under a moderate scenario and slightly greater when under the more severe scenario. Protected areas encompass 8% of current suitable habitat for showy milkweed, 11% for swamp milkweed, and 9% for monarch. Our study shows that suitable habitat for monarchs and/or milkweeds will likely continue to be found in managed areas traditionally seen as priority habitats in Idaho through mid-century

Ecological content and context of the National Park System /by Leona K. Svancara.

Our goal was to assess the current level of representation and redundancy of natural features within the National Park Service (NPS) System, the spatial distribution of parks, the integrity of the surrounding landscape, and the resilience of parks to 21st century threats such as climate change and land use change. Although the System has been considered one of """"America's best ideas"""" and held up as an example for the world, our results indicate that it is neither representative, nor redundant, nor resilient in the face of modern threats. Our analyses show that parks are too small to support viable populations of mammals over the long term, are not representative with biases in geology, topography, climate, and land cover, and are geographically biased with great variability in redundancy across the coterminous U.S. These biases in representation and redundancy of resources, together with the skewed size distribution, leave biodiversity in the System vulnerable to stochastic events and, in the absence of compatible management on surrounding lands, hamper the ability of the NPS to fulfill its mission to conserve natural and historical resources within the park system and manage so to """" ... leave them unimpaired for the enjoyment of future generations."""";As climate change impacts become more pronounced, the ecological content and context of parks will become even more important. Although counties around parks tend to be more natural, more intact, and more protected than other counties, they are possibly at risk due to higher human population density, increases in human population, and decreases in natural land cover. Our climate change analyses indicate that, even under the lower greenhouse-gas emission scenario, species and communities in the System will likely undergo substantial changes in the next 60-90 years. Strategic growth of protected area systems will be needed to account for shifts in species distribution and areas highlighted in our analyses are natural targets for mitigation efforts and regional collaborations aimed at improving connectivity through matrix management.Thesis (Ph. D., Natural Resources)--University of Idaho, January 2010

By the Numbers

The current endangered species list has its administrative beginnings in 1964 when the Department of the Interior\u27s Committee on Rare and Endangered Wildlife Species published a preliminary list of 62 species at risk of extinction (Goble, forthcoming). Following the enactment of the Endangered Species Preservation Act of 1966 (ESPA), the secretary of the interior in 1967 published the first official list of 78 native fish and wildlife threatened with extinction (ESPA sec. l(c); U.S. Department of the Interior 1967; Wilcove and McMillan, this volume). By the time the Endangered Species Act (ESA) was adopted in 1973, there were 392 species on the list (Yaffee 1982). These first lists included only vertebrate species. On the thirtieth anniversary of the ESA, the number stood at 1,260 domestic species and 558 foreign species (USFWS 2003a), with plant and invertebrate species outnumbering vertebrates. This chapter presents a graphical summary encapsulating thirty years of species protection and restoration under the ESA. The summary reveals both gains and losses. For some species, such as the Aleutian Canada goose (Branta canadensis leucopareia), the process worked as it was meant to, reversing decline and restoring populations to healthy levels (USFWS 2001a); for others, such as the dusky seaside sparrow (Ammodramus maritimus nigrescens), the process failed, and despite being listed the species continued to spiral toward eventual extinction (USFWS 1983; Walters 1992). What follows is an assessment of the state of species protection as it has evolved under the ESA. This includes the taxonomie and demographie distribution of listed species, and the number of critical habitat designations. We also examine newer legal tools for conserving habitat on private land (such as habitat conservation plans), various measures of the act\u27s success, and funding levels for species protection

Policy-Driven Versus Evidence-Based Conservation: A Review Of Political Targets And Biological Needs

How much is enough? is a question that conservationists, scientists, and policymakers have struggled with for years in conservation planning. To answer this question, and to ensure the long-term protection of biodiversity, many have sought to establish quantitative targets or goals based on the percentage of area in a country or region that is conserved. In recent years, policy-driven targets have frequently been faulted for their lack of biological foundation. In this manuscript, we reviewed 159 articles reporting or proposing 222 conservation targets and assessed differences between policy-driven and evidence-based approaches. Our findings suggest that the average percentages of area recommended for evidence-based targets were nearly three times as high as those recommended in policy-driven approaches. Implementing a minimalist, policy-driven approach to conservation could result in unanticipated decreases in species numbers and increases in the number of endangered species. © 2005 American Institute of Biological Sciences

Endangered Species Time Line

The Endangered Species Act (ESA) is embedded in a web of statutes designed to regulate relationships between humans and other species that stretch back nearly a millennium (Goble, this volume; Goble and Freyfogle 2002). This chapter presents a time line of federal actions taken to protect wildlife beginning with passage of the Land and Water Conservation Fund Act in 1963 (Act of May 28, 1963). Earlier laws to protect wildlife are discussed elsewhere (Goble, this volume). The time line emphasizes federal actions that conserve species at risk of extinction and significant events in the course of implementing the Endangered Species Act. The story is one of expanding protection, moving from the Land and Water Conservation Fund Act\u27s recognition of species threatened with extinction, through the protection of migratory birds, to the first federal statutes to protect endangered species-the Endangered Species Preservation Act (Act of October 15, 1966a), the Endangered Species Conservation Act (Act of December 5, 1969), and the Endangered Species Act itself in 1973. In this progression, federallaw has moved from protection of only fish and game to include nearly all at-risk plants and animals. The enactment of the ESA in 1973 was not the end of the story, however. The act has been amended several times over the past thirty years and administrative actions have also modified its on-the-ground application. The original ESA embodied a top-down regulatory approach but the subsequent amendments have increased incentives that would encourage private landowners, government agencies, and other organizations to collaborate in recovery efforts for endangered species

Understanding the spatiotemporal distribution of snow refugia in the rain-snow transition zone of north-central Idaho

Knowledge of snow cover distribution and disappearance dates over a wide range of scales is imperative for understanding hydrological dynamics and for habitat management of wildlife species that rely on snow cover. Identification of snow refugia, or places with relatively late snow disappearance dates (SDDs) compared to surrounding areas, is especially important as climate change alters snow cover timing and duration. The purpose of this study was to increase understanding of snow refugia in complex terrain spanning the rain-snow transition zone at fine spatial and temporal scales. To accomplish this objective, we used remote cameras to provide relatively high temporal and spatial resolution measurements on snowpack conditions. We built linear models to relate SDDs at the monitoring sites to topoclimatic and canopy cover metrics. One model to quantify SDDs included elevation, aspect, and an interaction between canopy cover and cold-air pooling potential. High-elevation, north-facing sites in cold-air pools (CAPs) had the latest SDDs, but isolated lower-elevation points also exhibited relatively late potential SDDs. Importantly, canopy cover had a much stronger effect on SDDs in CAPs than in non-CAPs, indicating that best practices in forest management for snow refugia could vary across microtopography. A second model that included in situ hydroclimate observations (December – February (DJF) temperature and March 1 snow depth) indicated that March 1 snow depth had little impact on SDD at the coldest winter temperatures, and that DJF temperatures had a stronger effect on SDD at lower snow depths, implying that the relative importance of snowfall and temperature could vary across hydroclimatic contexts in their impact on snow refugia. This new understanding of factors influencing snow refugia can guide forest management actions to increase snow retention and inform management of snow-dependent wildlife species in complex terrain

Virtual snow stakes: a new method for snow depth measurement at remote camera stations

Abstract Remote cameras are used to study demographics, ecological processes, and behavior of wildlife populations. Cameras have also been used to measure snow depth with physical snow stakes. However, concerns that physical instruments at camera sites may influence animal behavior limit installation of instruments to facilitate collecting such data. Given that snow depth data are inherently contained within images, potential insights that could be made using these data are lost. To facilitate camera‐based snow depth observations without additional equipment installation, we developed a method implemented in an R package called edger to superimpose virtual measurement devices onto images. The virtual snow stakes can be used to derive snow depth measurements. We validated the method for snow depth estimation using camera data from Latah County, Idaho, USA in winter 2020–2021. Mean bias error between the virtual snow stake and a physical snow stake was 5.8 cm; the mean absolute bias error was 8.8 cm. The mean Nash Sutcliffe Efficiency score comparing the fit of the 2 sets of measurements within each camera was 0.748, indicating good agreement. The edger package provides researchers with a means to take critical measurements for ecological studies without the use of physical objects that could alter animal behavior, and snow data at finer scales can complement other snow data sources that have coarser spatial and temporal resolution