Tall Timbers Research Station and Land Conservancy is a research and learning facility located in northern Leon County, Florida, just off County Road 12 on the north side of Lake Iamonia. Tall Timbers researches the areas of fire ecology, resource management, forestry, game bird management, and vertebrate ecology.
Human disturbance on vegetation communities can result in alternative stable states in ecosystems, which often present animals with novel environments and may lead to evolutionary mismatches. The chestnut-bellied scaled quail (Callipepla squamata var. castanogastris; hereafter: “scaled quail”) is a shrubland-obligate subspecies of scaled quail native to South Texas, USA that has faced population declines in recent decades, despite increasing shrub cover across their distribution. These shrublands often arise after brush management and are structurally distinct from the Tamaulipan thornscrub it replaced, which may represent an alternative stable state changing functional responses of this species. Examine the movement and selection of scaled quail in response to combinations of vegetation community and vegetation structure (representing alternative stable states) across within-diel (4 hr) and across-diel (12 hr) cycle temporal grains. From 2022 to 2023, we fit individuals with GPS transmitters and subsequently used step selection functions (SSF) to estimate responses to changes in vegetation community states at two study sites in South Texas (one declining [peripheral] and one stable [core] population). Birds avoided disturbed shrubland communities (mesquite savanna and woodland), and avoidance became stronger in the presence of high herbaceous biomass, suggesting that a combination of vegetation community and structure associated with disturbed shrublands affects selection. This avoidance was strongest at the 12 h temporal grain and was largely driven by the presence of high herbaceous biomass. Structural differences between Tamaulipan thornscrub and disturbed shrublands may impact functional habitat connectivity for scaled quail, even if shrublands are still present.
Open forest ecosystems are considered one of the most imperiled ecosystems in North America and many associated avian species are experiencing population declines. Management at large and impactful scales is challenging on private lands due to fragmentation and resource limitations, but public lands are often larger in scale and offer opportunities for landscape‐level conservation of species of conservation concern. Northern bobwhite Colinus virginianus is a popular but declining game bird which is often considered an umbrella indicator species for pine savanna ecosystems in the southeastern USA. To evaluate the effects of tree canopy cover and prescribed fire frequency (1 Jan 2010–15 May 2024) on bobwhite occupancy we surveyed 144 sites 11 times during 15 May–17 June 2024 using acoustic recording units on the Sabine and Angelina National Forests of Texas. Probability of bobwhite occupancy decreased as canopy cover increased (β Tree = −0.74, 95% CrI: −1.29 to −0.28); occupancy was over 19 times higher when canopy cover was 44.0% versus the mean observed value of 80.8% (range: 38.0–96.0%). Despite a well‐established positive relationship of bobwhite and prescribed fire based on previous research, we found tree canopy obfuscated any effects of fire frequency on bobwhite occupancy (β Fire = −0.09, 95% CrI: −0.57 to 0.43). Only 2 of 144 sites were characterized by low–moderate canopy cover (< 50%) with a moderate fire frequency (burned 5 and 7 times since 2010). Our results underscore the importance of forest thinning in addition to prescribed fire for managing species which require savanna conditions.
Autonomoius 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. Received 28 Apr 2025, accepted 9 Sept 2025.
Ambiguity in sexually dimorphic characteristics can lead to inaccurate sex determination in some species. One such species is the scaled quail (Callipepla squamata). We collected DNA samples from scaled quail and compared the genetically confirmed biological sex to the sex assigned in the field. Sexing accuracy was significantly lower in the early-fall months (September-October) than in other months, coinciding with the annual molt. Accuracy tended to be higher for females than males and higher for adults than juveniles. Our results indicate that established field methods for sexing scaled quail are fairly accurate but may be unreliable during the early fall, before the annual molt is complete. Even when the early-fall months are excluded, disparities in sexing accuracy between females and males might bias reported sex ratios for this species.
