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Copyright of Avian Conservation & Ecology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Populations of marsh‐breeding birds have declined throughout the southern Laurentian Great Lakes basin. To advance conservation of these species, we used occupancy modeling, a regional prioritization scheme, and data from Birds Canada's Great Lakes Marsh Monitoring Program (2016–2018) to describe species‐habitat relationships and identify priority habitat areas for 7 obligate marsh‐breeding bird species in southern Ontario, Canada: American bittern (Botaurus lentiginosus), common gallinule (Gallinula galeata), least bittern (Ixobrychus exilis), marsh wren (Cistothorus palustris), pied‐billed grebe (Podilymbus podiceps), sora (Porzana carolina), and Virginia rail (Rallus limicola). Given these species respond to land cover at widely varying spatial scales, we initially identified the most informative scale (buffer = 100 m, 200 m, 400 m, 800 m, 1,600 m, 3,200 m, or 6,400 m) for marsh, urban, agricultural, and forest cover to increase model performance. We also considered climate variables, whether sample sites were along a Great Lakes coastline or inland, and covariates influencing detection. Occupancy was best explained by land cover at a wide range of spatial scales depending on the species. All species except Virginia rail responded positively to marsh cover; American bittern and Virginia rail responded negatively to urban cover; least bittern, pied‐billed grebe, and Virginia rail responded negatively and sora responded positively to agricultural cover; and American bittern, common gallinule, marsh wren, and pied‐billed grebe responded negatively and Virginia rail responded positively to forest cover. Only American bittern responded negatively to mean May–June temperature; only pied‐billed grebe responded positively to start of growing season; and only Virginia rail had higher occupancy at inland marshes compared to coastal. We combined predictions from the best model for each of 5 species with reasonably good model fit (we excluded sora and Virginia rail) to identify priority habitat areas for marsh‐breeding birds. Expansion of wetland conservation work from existing priority areas based on waterfowl to also include these new additional priority areas based on marsh‐breeding birds will be an important step towards conservation of all birds, and will help slow or maybe even reverse declining population trends. Some restoration activities outside but adjacent to priority areas will also be important for rebuilding marshes for these species across this intensively farmed and developed region. © 2020 The Wildlife Society. We used occupancy modeling, a regional prioritization scheme, and data from Birds Canada's Great Lakes Marsh Monitoring Program to describe species‐habitat relationships and identify priority habitat areas for obligate marsh‐breeding bird species in southern Ontario, Canada. Expansion of wetland conservation work from existing priority areas based on waterfowl to also include these new additional priority areas based on marsh‐breeding birds will be an important step towards conservation of all birds in this intensively farmed and developed region. [ABSTRACT FROM AUTHOR]

Copyright of Avian Conservation & Ecology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• A simple biotic indicator framework for assessing the ecological condition of points or sites. • Weights for species/taxa are based on sensitivity to an explicit environmental gradient. • Example illustrated for birds of coastal wetlands in North America's Great Lakes. • The Index of Biotic Condition (IBC) framework is applicable to other taxa and ecosystems. To survive in an area, plant and animal species must confront many interacting environmental stressors at different spatial and temporal scales. Consequently, assemblages of resident species, which have successfully negotiated these stressors, are widely recognized as indicators of environmental quality. Many biotic variables have been employed as indicator metrics, but the simplest is presence/absence of sensitive species in a standardized field sample. We describe a multi-species ecological indicator, the Index of Biotic Condition (IBC), which overcomes key concerns with using indicator species or species assemblages to assess environmental quality. Developing an IBC requires substantial ecological knowledge and preliminary data to identify an appropriate set of species or species groups for the area and habitat(s) of interest and to quantify the sensitivity of these species to an explicit environmental reference gradient. Based on objective biotic response (BR) functions describing the relationship between species occurrences and the environmental gradient, we outline a method for deriving species weights (factors that determine the relative contributions of species / species groups), subsequently used to calculate the simple multispecies index. The IBC is more rigorous than structurally similar metrics like the Floristic Quality Index (FQI) and average Coefficient of Conservatism ( C ¯ ) and, at least for some applications, is more parsimonious than comprehensive metrics like the Index of Biotic Integrity (IBI) and our previously described Index of Ecological Condition (IEC). We apply information from standardized basin-wide bird surveys conducted between 2011 and 2022 (particularly a subset of data from 2011 to 2015) to develop an IBC for comparing and interpreting the environmental quality of 794 wetlands in the coastal zone of North America's Laurentian Great Lakes. Implicit in this formulation is the existence of a high-quality reference assemblage that includes 14 obligate or facultative bird species/species groups characteristic of these wetlands. The index ranges from 0 (worst condition) to 10 (best condition) and is correlated with species richness (r = 0.87), although the IBC provides additional information reflecting the taxon-specific environmental sensitivities. The distribution of IBC values for 4,359 point samples in Great Lakes coastal wetlands between 2011 and 2022 is strongly skewed right, with a median value of 2.31. Only 28 wetland points (<1%) yielded an IBC value of 8.0 or greater, suggesting that relatively complete coastal wetland bird assemblages rarely occur at specific points in today's Great Lakes coastal wetlands, consistent with the region's well-documented historical reduction in biological diversity. [ABSTRACT FROM AUTHOR]