Explore the vast range of titles available.

Raptors, including eagles, are geographically widespread and sit atop the food chain, thereby serving an important role in maintaining ecosystem balance. After facing population declines associated with exposure to organochlorine insecticides such as dichlorodiphenyltrichloroethane (DDT), bald eagles ( Haliaeetus leucocephalus ) have recovered from the brink of extinction. However, both bald and golden eagles ( Aquila chrysaetos ) are exposed to a variety of other toxic compounds in the environment that could have population impacts. Few studies have focused on anticoagulant rodenticide (AR) exposure in eagles. Therefore, the purpose of this study was to determine the types of ARs that eagles are exposed to in the USA and better define the extent of toxicosis (i.e., fatal illness due to compound exposure). Diagnostic case records from bald and golden eagles submitted to the Southeastern Cooperative Wildlife Disease Study (University of Georgia) 2014 through 2018 were reviewed. Overall, 303 eagles were examined, and the livers from 116 bald eagles and 17 golden eagles were tested for ARs. The percentage of AR exposure (i.e., detectable levels but not associated with mortality) in eagles was high; ARs were detected in 109 (82%) eagles, including 96 (83%) bald eagles and 13 (77%) golden eagles. Anticoagulant rodenticide toxicosis was determined to be the cause of mortality in 12 (4%) of the 303 eagles examined, including 11 bald eagles and 1 golden eagle. Six different AR compounds were detected in these eagles, with brodifacoum and bromadiolone most frequently detected (81% and 25% of eagles tested, respectively). These results suggest that some ARs, most notably brodifacoum, are widespread in the environment and are commonly consumed by eagles. This highlights the need for research to understand the pathways of AR exposure in eagles, which may help inform policy and regulatory actions to mitigate AR exposure risk.

While native grass and shrub restoration is often promoted for bird conservation, evaluations are necessary to understand the effects of habitat change on songbird vital rates and migratory stopover use. We evaluated the effects of native vegetation restoration on the species richness, productivity, and capture rate of breeding and fall migrating songbirds at the Shaker Village of Pleasant Hill, in central Kentucky, USA. From 2009 to 2022, we conducted constant effort mist netting, resulting in 8418 captures of 110 bird species. In 2012–2013, we implemented management in the study area, which began as an old field, to restore native grasses, forbs, and shrubs. Effects on the vital rates of breeding species included higher Spizella pusilla (field sparrow) and Spinus tristis (American goldfinch) productivity post restoration. Restoration of native vegetation also led to significantly higher fall capture rates for pooled cohorts of both long-distance and medium-distance migrants. Our results demonstrate that the restoration and management of native vegetation can enhance stopover habitats for fall migrating songbirds including neotropical migrants and the field sparrow, a common bird in steep decline. We recommend prioritizing areas for native grass and shrub restoration that initially lack structural heterogeneity (a well-developed grass component with diverse forbs and interspersed shrubs).

Haliaeetus leucocephalus (Bald Eagle) is a well-studied species, and information on their nest abundance and population trends is widely available. However, research on the movements and home range of nesting Bald Eagles in the interior US is lacking. In this study, we used a solar-powered Argos platform transmitter terminal (PTT) with global positioning system (GPS) capabilities to monitor the movements of an adult, breeding male Bald Eagle, captured at Ballard Wildlife Management Area, KY, from 29 April 2012 to 23 October 2013. We generated minimum convex polygons (MCP) for comparisons to previous studies and used 95% and 50% fixed kernel density estimators (KDE) to estimate home-range size and core-use areas, respectively, during nesting and non-nesting periods. Estimates of home range and core-use areas were slightly larger during the non-nesting period (MCP = 420.0 km2, 95% KDE = 1.6 km2, 50% KDE = 0.2 km2) when compared to the nesting period (nesting MCP=415.0 km2, 95% KDE =1.3 km2, 50% KDE = 0.01 km2). Our home range and core-use estimates were smaller than previous studies using comparable methods, suggesting that habitat quality at this site may be high.

The number of telecommunication towers (TCTs) throughout the United States has and continues to increase exponentially. Increased TCT placement has been implicated in local population increases in platform nesting birds such as ospreys (Pandion haliaetus). However, osprey use of artificial structures can cause conflicts with humans because of economic costs and risks to human safety. Managers require better information regarding the effect of artificial nesting surfaces, such as TCTS, on osprey reproduction to make informed decisions regarding species conservation and to mitigate potential conflicts. The objective of our study was to evaluate the influence of TCTs on osprey productivity and adult nesting behaviors. From March to July 2019, we monitored 30 osprey nests located in western Kentucky, USA, on TCTs (n = 11), navigation channel markers (NCMs; n = 10), and natural surfaces (NATs; n = 9). We found no differences in nest success, productivity, or the proportion of male ospreys perched at the nest between surface types. Nests on NCMs received 1.9-2.1 times more fish than nests on NATs and TCTs, respectively. Moreover, NCMs experienced 5.4-8.0 times more disturbances per hour compared to NATs and TCTs, respectively. Our data suggest ospreys nesting on TCTs are productive contributors to local populations. We recommend deterrence of osprey nesting should be focused on locations that are unsafe for ospreys and/or pose insurmountable problems for communication infrastructure.

Immature raptors often travel long distances and move nomadically from the time they leave their natal area to the time they are recruited into the breeding population. Emphasis on identifying the nesting and winter habitat of Bald Eagles (Haliaeetus leucocephalus) has overshadowed the need to understand the habitat and spatial use of young eagles prior to reaching maturity. We used satellite telemetry to track the movements of immature Bald Eagles hatched in western Kentucky during 2010–2016. We analyzed movement data to identify high-use areas for eagles in their first and second years during warm and cool periods. Five out of seven eagles migrated north to the Great Lakes region during their first year. Using Brownian Bridge Movement Modelling, we identified 47 noncontiguous high-use areas during the warm period and 67 during the cool period. Public lands comprised 17% of warm period high-use areas and 43% of cool period high-use areas. High-use areas were located in Illinois, Indiana, Kentucky, Arkansas and Tennessee, and were often near federally-owned dams, rivers with sandbars, or areas with abundant waterfowl. Our small sample of tracked eagles correctly identified known Bald Eagle concentration areas within the study area; thus, we infer that previously unrecognized high-use areas identified by this study are likely to be concentration areas important to the larger population. We further suggest remote sensing data, even in limited datasets, as an efficient way to identify Bald Eagle concentration areas.

Peregrine falcons (Falco peregrinus) often nest on bridges over rivers and other waterways, resulting in the need for mitigation planning for bridge maintenance and reconstruction. However, mitigation guidelines for peregrine falcon nests during bridge reconstruction are lacking in the literature. In this paper, we describe the monitoring, spatial, and temporal buffers, nest box installation, and other methods that allowed peregrine falcons to nest successfully on the Milton-Madison (US-421) Bridge during demolition and reconstruction. Construction activities occurred overa 4-year period (2011-2014), and coordination with local road departments and contracted engineers was necessary to accommodate the falcon nest. Nonetheless, construction activities were able to progress without causing major construction expense or delays, and the nesting falcons were able to fledge 14 young during the project.

We evaluated the effects of native-grass restoration on the spatial distribution and density of raptors, vegetative characteristics, and small-mammal communities at Peabody Wildlife Management Area, a large reclaimed surface-coal mine in western Kentucky. We surveyed raptors from 2008 to 2012 via distance sampling at roadside points, and conducted vegetation and small-mammal surveys. We found no associations between total small-mammal relative abundance and native-grass restoration or vegetative characteristics. However, management for native grass positively affected the density of Circuscyaneus (Northern Harrier) and influenced the local distribution of Northern Harriers and Buteo jamaicensis (Red-Tailed Hawk). These results suggest that restoration and management of native grass on reclaimed mine lands can enhance habitat for grassland raptors, including the Northern Harrier, a species of conservation concern throughout its range.