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Jane A. Fitzgerald

Publications and source records attributed to Jane A. Fitzgerald.

4 recordsLinked to original sources

Developing a decision-support process for landscape conservation design

Planning for sustainable landscapes is hampered by uncertainty in how species will respond to conservation actions amidst impacts from landscape and climate change. Planning decisions, including tradeoffs among competing species objectives, are complex. We developed a decision-support framework that integrates dynamic-landscape metapopulation models (DLMPs) and structured decision making (SDM) to help guide landscape conservation design. With this framework, we demonstrated that planning for viable populations across broad scales can be achieved under global change. Furthermore, the integration of DLMPs with SDM enabled decisions to be more objective and transparent, and thus, more defensible.

Report

Habitat and landscape effects on abundance of Missouri's grassland birds

Of 6 million ha of prairie that once covered northern and western Missouri, <36,500&thinsp;ha remain, with planted, managed, and restored grasslands comprising most contemporary grasslands. Most grasslands are used as pasture or hayfields. Native grasses largely have been replaced by fescue ( Festuca spp.) on most private lands (almost 7 million ha). Previously cropped fields set aside under the Conservation Reserve Program (CRP) varied from a mix of cool-season grasses and forbs, or mix of native warm-season grasses and forbs, to simple tall-grass monocultures. We used generalized linear mixed models and distance sampling to assess abundance of 8 species of breeding grassland birds on 6 grassland types commonly associated with farm practices in Missouri and located in landscapes managed for grassland-bird conservation. We selected Bird Conservation Areas (BCAs) for their high percentage of grasslands and grassland-bird species, and for <5% forest cover. We used an information-theoretic approach to assess the relationship between bird abundance and 6 grassland types, 3 measures of vegetative structure, and 2 landscape variables (% grassland and edge density within a 1-km radius). We found support for all 3 levels of model parameters, although there was less support for landscape than vegetation structure effects likely because we studied high-percentage-grassland landscapes (BCAs). Henslow's sparrow ( Ammodramus henslowii ) counts increased with greater percentage of grassland, vegetation height-density, litter depth, and shrub cover and lower edge density. Henslow's sparrow counts were greatest in hayed native prairie. Dickcissel ( Spiza americana ) counts increased with greater vegetation height-density and were greatest in planted CRP grasslands. Grasshopper sparrow ( A. savannarum ) counts increased with lower vegetation height, litter depth, and shrub cover. Based on distance modeling, breeding densities of Henslow's sparrow, dickcissel, and grasshopper sparrow in the 6 grassland types ranged 0.9&ndash;2.6, 1.4&ndash;3.2, and 0.1&ndash;1.5&thinsp;birds/ha, respectively. We suggest different grassland types and structures (vegetation height, litter depth, shrub cover) are needed to support priority grassland-bird species in Missouri.

Journal of Wildlife Management

Change in avian abundance predicted from regional forest inventory data

An inability to predict population response to future habitat projections is a shortcoming in bird conservation planning. We sought to predict avian response to projections of future forest conditions that were developed from nationwide forest surveys within the Forest Inventory and Analysis (FIA) program. To accomplish this, we evaluated the historical relationship between silvicolous bird populations and FIA-derived forest conditions within 25 ecoregions that comprise the southeastern United States. We aggregated forest area by forest ownership, forest type, and tree size-class categories in county-based ecoregions for 5 time periods spanning 1963-2008. We assessed the relationship of forest data with contemporaneous indices of abundance for 24 silvicolous bird species that were obtained from Breeding Bird Surveys. Relationships between bird abundance and forest inventory data for 18 species were deemed sufficient as predictive models. We used these empirically derived relationships between regional forest conditions and bird populations to predict relative changes in abundance of these species within ecoregions that are anticipated to coincide with projected changes in forest variables through 2040. Predicted abundances of these 18 species are expected to remain relatively stable in over a quarter (27%) of the ecoregions. However, change in forest area and redistribution of forest types will likely result in changed abundance of some species within many ecosystems. For example, abundances of 11 species, including pine warbler (Dendroica pinus), brown-headed nuthatch (Sitta pusilla), and chuckwills- widow (Caprimulgus carolinensis), are projected to increase within more ecoregions than ecoregions where they will decrease. For 6 other species, such as blue-winged warbler (Vermivora pinus), Carolina wren (Thryothorus ludovicianus), and indigo bunting (Passerina cyanea), we projected abundances will decrease within more ecoregions than ecoregions where they will increase.

Forest Ecology and Management

Application of models to conservation planning for terrestrial birds in North America

Partners in Flight (PIF), a public–private coalition for the conservation of land birds, has developed one of four international bird conservation plans recognized under the auspices of the North American Bird Conservation Initiative (NABCI). Partners in Flight prioritized species most in need of conservation attention and set range-wide population goals for 448 species of terrestrial birds. Partnerships are now tasked with developing spatially explicit estimates of the distribution, and abundance of priority species across large ecoregions and identifying habitat acreages needed to support populations at prescribed levels. The PIF Five Elements process of conservation design identifies five steps needed to implement all bird conservation at the ecoregional scale. Habitat assessment and landscape characterization describe the current amounts of different habitat types and summarize patch characteristics, and landscape configurations that define the ability of a landscape to sustain healthy bird populations and are a valuable first step to describing the planning area before pursuing more complex species-specific models. Spatially linked database models, landscape-scale habitat suitability models, and statistical models are viable alternatives for predicting habitat suitability or bird abundance across large planning areas to help assess conservation opportunities, design landscapes to meet population objectives, and monitor change in habitat suitability or bird numbers over time. Bird conservation in the United States is a good example of the use of models in large-scale wildlife conservation planning because of its geographic extent, focus on multiple species, involvement of multiple partners, and use of simple to complex models. We provide some background on the recent development of bird conservation initiatives in the United States and the approaches used for regional conservation assessment and planning. We focus on approaches being used for landscape characterization and assessment, and bird population response modeling.

Book chapter