Publications

This report describes a compilation of brood observations for Anatidae species breeding in Maine during an 18-year period (1977–94) that were made by the U.S. Geological Survey’s Patuxent Wildlife Research Center while it was operated by the U.S. Fish and Wildlife Service. During four focused studies, variables affecting the declining Anas rubripes (Brewster, 1902) (American black duck...

Population estimates are often required for identifying relationships between predators and their prey and to inform conservation and management actions. The random encounter model (REM) estimates population density of wildlife lacking individually unique markings, based on photographs or videos from remote camera-traps. However, the REM has strict sampling and input requirements that...

We assessed amphibian diversity, rarity, and threats across the National Park System (U.S.A.), which covers 3.5% of the country and 12% of federal lands. At least 230 of 354 (65%) amphibian species documented in the country occur on National Park Service lands. Of species in parks, 17% are at-risk globally and 20% are uncategorized, reflecting still-widespread data deficiencies. National...

1. Benthic fishes are a common target of scientific monitoring but are difficult to quantify because of their close association to bottom habitats that are hard to access. Advances in image-acquisition technologies, machine vision, and deep learning have made capturing and quantifying fishes with cameras increasingly feasible. We present a method and open-source software called...

Background: Desert tortoise (Gopherus agassizii) populations have continued to decline due to infectious and other diseases, predation, and habitat alteration. The potential contribution of minerals and heavy metals to tortoise health and susceptibility to disease remains uncertain. Objective: The objective of this study was to evaluate the results of elemental analysis of trace minerals...

Effective waterfowl management relies on the collection of relevant demographic data to inform land management decisions; however, some types of data are difficult to obtain. For waterfowl, brood surveys are difficult to conduct because wetland habitats often obscure ducklings from being visually assessed. Here, we used Unoccupied Aerial Systems (UAS) to assess what wetland habitat...

The Chicago Area Waterway System (CAWS) is a potential route for the migration of aquatic invasive species from the Mississippi River Basin into the Great Lakes. Electric dispersal barriers were installed in the Chicago Sanitary Ship Canal, within CAWS, to prevent invasive fish from reaching the Great Lakes. Despite the high efficiency of these barriers, occasional maintenance events...

Flooding rice (Oryza sativa) agricultural fields during winter to facilitate rice straw decomposition has mitigated the loss of some of the natural wetlands in California’s Central Valley. We conducted bird surveys in 253 rice checks (2,158 ha) within 177 rice fields in the Sacramento Valley during the fall and winter of 2021-2022 and 2022-2023 to evaluate factors influencing bird use of...

Pesticide formulations containing the active ingredient antimycin–a (ANT–A) have been used by fisheries and aquaculture managers for several decades to remove nuisance fish species. Analytical methods for measuring ANT–A during pesticide treatments have been done using high performance liquid chromatography (HPLC) paired with multiple detection methods (for example, electrochemical...

Stony coral tissue loss disease (SCTLD) was first documented in Florida in 2014 and has since spread through the Caribbean causing unprecedented mortality in more than 20 species of corals. The cause of SCTLD is unknown, but bacteria are suspected based on regression of gross lesions in some corals treated with antibiotics. Limited pathology studies on SCTLD exist, but it is likely that...

Introduction: The long-distance, seasonal migrations of birds make them an effective ecological bridge for the movement of ticks. The introduction of exotic tick species to new geographical regions can cause the emergence of novel tick-borne pathogens. This study examined the prevalence of exotic tick species parasitizing migratory songbirds at stopover sites along the northern Gulf of...

Crude oil toxicity to early life stage fish is commonly attributed to polycyclic aromatic hydrocarbons (PAHs). However, it remains unclear how the polar unresolved complex mixture (UCM), which constitutes the bulk of the water-soluble fraction of crude oil, contributes to crude oil toxicity. Additionally, the role of photomodification-induced toxicity in relation to the polar UCM is not...