The future of North American grassland birds: Incorporating persistent and emergent threats into full annual cycle conservation priorities

Abstract

North American grasslands are one of the most threatened ecosystems in the world, and grassland bird populations have experienced drastic declines over the past half century. Land‐use change is widely accepted as the most persistent threat, and climate change is expected to further compromise grassland integrity. The limited consideration of projected future threats is a significant gap in existing conservation priorities for North America's central grasslands. We identified Grassland Climate Strongholds (predicted to have high climate suitability for grassland birds both today and under 21st century climate change scenarios) and Grassland Climate and Land‐use Strongholds (predicted to have high climate and land‐use suitability for grassland birds today and under 21st century climate change scenarios). Strongholds were mainly distributed across southern Canada, the Dakotas, Montana, Wyoming, Colorado, New Mexico, the Oklahoma Panhandle, Texas, and the Chihuahuan Desert. Strongholds vulnerable to land‐use conversion included the Prairie Pothole region and surrounding areas, much of the eastern‐central Plains, the Texas Blackland Prairie, the Western Gulf Coastal Plain, and areas west of the Chihuahuan Desert. A maximum of only 9% of strongholds were protected. Strongholds are critical for full annual cycle conservation of declining grassland birds in North America and complement existing grassland priorities.

Metrics for conservation success: using the ‘Bird-Friendliness Index’ to evaluate grassland and aridland bird community resilience across the Northern Great Plains ecosystem

“…Conversely, the lowest BFI values were found in the southwestern regions of the study area, notably southern Montana, Wyoming, and southern South Dakota. This finding is consistent with a recent grasslands prioritization based primarily on climate suitability (Grand et al, 2019). These regions tend to be drier with more sparse vegetation, as well as lower soil moisture and productivity.…”

“…Similarly, many Grassland Priority Conservation Areas (Pool & Panjabi, 2011) were identified across the Prairie Potholes, Dakotas, as well as in a few isolated pockets in northeastern Wyoming coinciding with top-priority areas identified by the BFI. A recent spatial prioritization analyzing current and future climate suitability also identified the Prairie Potholes and North Dakota as high-priority areas, similar to our findings (Grand, Wilsey, Wu, & Michel, 2019).…”

Metrics for conservation success: Using the “Bird‐Friendliness Index” to evaluate grassland and aridland bird community resilience across the Northern Great Plains ecosystem

“…Prairie Pothole regions with concentrations of high BFI values coincide with Grassland Potential Conservation Areas identified in the N Great Plains Fescue Mixed‐grass and NW Great Plains Mixed‐grass Prairie grasslands (Comer et al., 2018). Similarly, many Grassland Priority Conservation Areas (Pool & Panjabi, 2011) and Climate and Land Use Strongholds (Grand et al., 2019) were identified across the US and Canadian Prairie Potholes, coinciding with areas of high BFI values. BFI values were significantly higher where there was consensus across one or more of these prioritizations and increased further with growing consensus.…”

“…We used the Consensus Priorities identified by Grand et al. (2019), which identified overlaps between five prioritization scenarios: Grassland Climate Strongholds, Grassland Climate and Land use Strongholds, Vulnerable Grassland Climate Strongholds (all from Grand et al., 2019), Grassland Priority Conservation Areas (Pool & Panjabi, 2011) and Grassland Potential Conservation Areas (Comer et al., 2018; Figure c). There were no overlaps between all five prioritizations; therefore, we compared mean BFI values among areas included in 0–4 prioritizations using a beta regression in betareg (Cribari‐Neto & Zeileis, 2010) with the number of prioritizations used as a categorical fixed effect, and conducted Tukey's post hoc evaluations using emmeans (Lenth, 2020).…”

Extent of similarity between agricultural and natural land covers shapes how biodiversity responds to agricultural expansion at landscape scales

“…Prairie Pothole region) it requires practices that do not endanger ecosystem services, avoid overexploitation of the natural resource base and manage for native species intolerant of the production system (Cunningham et al 2013). We emphasize this latter point in particular because prairie grasslands are among the most threatened ecosystems in North America (With et al 2008, Grand et al 2019). While a number of species in the prairie community tolerate some agriculture, several endemic species sensitive to agriculture are in serious decline with some such as Chestnut-collared Longspur and Lark Bunting ( Calamospiza melanocorys ) declining by more than 80% since the 1970s (Wilson et al 2018).…”