Changes in Nesting Habitat Availability for Piping Plovers at the John E. Williams Preserve, North Dakota, 1992–2021

ABSTRACT Habitat loss is a major threat to the conservation of endangered species. We measured changes in piping plover (Charadrius melodus) nesting habitat at five alkali wetlands in The Nature Conservancy's John E. Williams Preserve, McLean county, North Dakota, from 1992 to 2021. This site has supported nesting by federally threatened piping plovers for decades. We measured the amount of non-vegetated (open) shoreline, required nesting habitat for plovers, from photo plots at 34 sites historically occupied by plovers distributed across the five wetlands. Twenty-six of 34 plots had significant negative trends (95% credible intervals not including zero) in nesting area availability. Nesting habitat increased significantly at one plot. Seven other plots had no detectable trends (i.e., the 95% credible intervals included zero). Mean percent annual change was –1.2% (±0.17 SE) and estimated total loss of nesting habitat within plots was ∼42%. To assess whether plover nesting habitat might have been created at areas outside of our plots, we compared total open shoreline habitat over all five wetlands in 1992 to that in 2017. We detected a ∼42% decline in total open shoreline area. Although measurement methods differed between 1992 and 2017, we found no evidence that nesting habitat was created at non–photo plot areas. In the absence of habitat restoration and management the decline in piping plover nesting habitat is likely to continue. Climate change projections for North Dakota indicate increased annual rainfall, higher CO2 levels, and longer growing seasons, all factors likely to promote vegetative growth at alkali wetlands like those we studied.