Thick-billed Longspur (Rhynchophanes mccownii) reproduction shows minimal short-Term response to conservation-based program

Abstract

The Thick-billed Longspur (Rhynchophanes mccownii) is a bird species of conservation concern that relies on shortgrass prairies and steppes of western North America. These habitats have been greatly altered from expansive and diverse ecosystems into small patches of homogeneous pastures interspersed with agricultural lands, yet little information exists on how land use affects Thick-billed Longspur demography. This study evaluates the benefits of an incentivized private land conservation-based program (CBP) on Thick-billed Longspur reproduction. We compared Thick-billed Longspur nest success and density on data collected on pastures enrolled in CBP with pastures not enrolled. CBP pastures experienced a rest-rotation specified grazing regime, while there were no requirements for the pastures outside the program. We use a time-To-event state-space superpopulation model that accounts for the availability of nests when estimating detection. We detected and monitored 74 Thick-billed Longspur nests over 2 breeding seasons, including 28 nests in CBP pastures. Our results suggest similar estimates of nest success and nest density between nests in CBP pastures and nests in pastures not participating in the conservation program. Our estimates of nest success and nest density advance our understanding of the influence of an incentivized conservation program on songbirds and give insight into 2 metrics of Thick-billed Longspur reproduction.