Geology topics

Auriel M.V. Fournier

Publications and source records attributed to Auriel M.V. Fournier.

3 recordsLinked to original sources

USGS2026

King Rails in southeastern Arkansas are majority resident

King Rails ( Rallus elegans ), a declining species of secretive marsh bird, have a mixed migratory strategy, with some individuals migrating and some being year-round residents. Determining the distribution of migratory versus resident King Rails is critical to guiding habitat management and assessing risks to populations. We examined the migratory status of adult King Rails at the Choctaw West Wildlife Management Area in southeastern Arkansas, the only known site in Arkansas with multiple breeding pairs. Of the 23 adult King Rails we tagged in 2022 and 2023, two birds migrated away from the local area, one in each year. One migrated 145 km, and the other 450 km. Our findings suggest that the line between the migratory and resident range of Arkansas King Rails could be north of our site.

Arkansas↗

USGS2025

Rallus elegans (King Rail) occupancy is stable, but habitat is in short supply in the Arkansas Delta

Secretive marsh birds experienced precipitous declines due to losses in wetland habitat across North America. However, from 1998 to 2004, wetland area increased, and between 2009 and 2019, the extent of emergent wetlands did not significantly decrease. This raises the question: how did secretive marsh birds, which are tied to emergent wetlands, respond to this period of relative stability in wetland area? Here, we use Rallus elegans (King Rail) occurrence data collected in 2005, 2006, 2012, and 2017 in the Arkansas Delta in the United States to test the hypothesis that a period of stability in wetland vegetation is linked to stable Rallus elegans occupancy. Specifically, we sought to (1) quantify relationships between R. elegans occupancy and land cover, (2) quantify temporal trends in R. elegans occupancy, and (3) characterize changes in land cover types linked to R. elegans occupancy. We developed spatial multi-season occupancy models, and our top model contained the categorical year effect but showed no trend in R. elegans occupancy between 2005 and 2017, instead showing high interannual variation in occupancy. We found strong associations between R. elegans occupancy and emergent wetlands (positive) and elevation (negative). From 2005 to 2017 in the ∼3.7 million ha Arkansas Delta, rice crop cover decreased by 294,750 ha, emergent wetlands increased by 6,719 ha, and all other cover types increased or decreased by < 7,500 ha. Thus, although emergent wetlands did increase, the total area of emergent wetlands in 2016 (22,262 ha) comprised <1% of the Arkansas Delta. Our results support the hypothesis that R. elegans occupancy stabilized during a time when the main habitat type R. elegans depend on, emergent wetlands, also stabilized in spatial extent. There is an opportunity to turn the tide in R. elegans declines by conserving extant emergent wetlands and creating new emergent wetlands.

Arkansas↗

USGS2025

Variation in detection distance of Eastern Black Rail (Laterallus jamaicensis jamaicensis) vocalizations by autonomous recording units

Autonomous recording units (ARUs) are an emerging technology that allows for passive monitoring of soniferous animals and soundscapes. Over the past decade, ARUs have become a popular tool for monitoring birds for their potential to reduce the labor and costs of traditional in-person sampling procedures. However, uncertainty surrounding factors affecting detection of avian taxa using ARUs can inhibit their monitoring efficacy. Eastern Black Rails ( Laterallus jamaicensis jamaicensis ) are a secretive marsh bird listed as a federally threatened species in the U.S.A. Eastern Black Rail vocalizations are difficult to detect by field personnel, and numerous in-person surveys can be required to confirm their presence at a site. While ARUs are an alternative for detecting Eastern Black Rails, it is unknown at what maximum distance an ARU can detect their vocalizations. We evaluated factors affecting the detection distance of simulated vocalizations for ARUs in four marsh vegetation types under a range of environmental conditions. Detection distances varied across models, vocalization and vegetation types, and call volume. Kickeedo vocalizations were detected at greater distances, and detection distances increased for all vocalization types in open vegetation. High relative humidity increased detection distances, while louder background noise decreased detection distances. High wind speeds in cordgrass ( Spartina spp .) decreased detection probability disproportionately relative to other vegetation types. Based on these results, considerations of survey area, vegetation type, and site condition can allow land managers and researchers to optimize Eastern Black Rail monitoring using ARUs. Given the substantial staff time needed to monitor this species, ARUs may increase the likelihood of detection and provide an efficient alternative to in-person monitoring.

Waterbirds↗