Trent L. Mcdonald

McDonald Data Sciences

We conducted a range‐wide investigation of the dynamics of site level reproductive rate of northern spotted owls using survey data from 11 study areas across the sub‐species geographic range collected during 1993–2018. Our analytical approach accounted for imperfect detection of owl pairs and misclassification of successful reproduction (i.e., at l...

Effective conservation of at‐risk species presents a conundrum, often requiring rapid status assessments and timely actions regardless of the adequacy of best available information. Here, we present a case study on Humboldt martens (Martes caurina humboldtensis), a rare and cryptic carnivore listed as threatened in 2020 under the United States Enda...

The impacts of wind energy on bat populations is a growing concern because wind turbine blades can strike and kill bats, and wind turbine development is increasing. We tested the effectiveness of 2 management actions at 2 wind‐energy facilities for reducing bat fatalities: curtailing turbine operation when wind speeds were <5.0 m/second and combini...

Photographic identification is an essential research and management tool for marine mammal scientists. However, manual identification of individuals is time-consuming. To shorten processing times, we developed finFindR, an open-source application that uses a series of neural networks to autonomously locate dorsal fins in unedited field images, quan...

Significance Invasive species can cause extinctions of native species and widespread biodiversity loss. Invader removal is a common management response, but the use of long-term field experiments to characterize effectiveness of removals in benefitting impacted native species is rare. We used a large-scale removal experiment to investigate the demo...

The northern spotted owl (Strix occidentalis caurina) inhabits older coniferous forests in the Pacific Northwest and has been at the center of forest management issues in this region. The immediate threats to this federally listed species include habitat loss and competition with barred owls (Strix varia), which invaded from eastern North America....

Estimating bird and bat fatalities caused by wind‐turbine facilities is challenging when carcasses are rare and produce counts that are either exactly or very near zero. The rarity of found carcasses is exacerbated when live members of a particular species are rare and when carcasses degrade quickly, are removed by scavengers, or are not detected b...

Estimating bird and bat fatalities caused by wind-turbine facilities is challenging when fatalities are rare and the number of observed carcasses is either exactly zero or very near zero. The rarity of found carcasses is exacerbated when particular species are rare, when carcasses degrade quickly, when they are removed by scavengers, or when they a...

A spatial sampling design determines where sample locations are placed in a study area. The main objective is to select sample locations in such a way that valid scientific inferences can be made to all regions of the study area. A sample that is well-spread over the study area is called a spatially balanced sample. Spatially balanced sampling desi...

Photographic identification is an essential research and management tool for studying population size and dynamics of common bottlenose dolphins ( Tursiops truncatus ). Photographic identification involves recognizing individuals based on unique dorsal fin markings. Manual identification of dolphins, while successful, is labor-intensive and time-co...

Ranked set sampling is a design that can increase sample efficiency by forcing sample coverage over the range of response values in the population. Balanced acceptance sampling (BAS) has a similar aim, with sample efficiency coming from ensuring coverage, where coverage is considered in terms of spatial spread over the sample space. Here we describ...

1.Our knowledge of migration ecology has progressed quickly in concert with technological advances that collect fine‐scale movement data through time. We now know that migration plays a critical role in the annual nutritional cycle of large herbivores and that sustaining functional migratory routes is key to long‐term conservation. Yet, we lack bas...

Risso's dolphin (Risso's; Grampus griseus) behavior is little described given their typical offshore distribution where research access is inherently challenging. We conducted focal group behavior follows of 51 Risso's groups from a circling, small, fixed-wing Partenavia aircraft in the Southern California Bight from 2008 through 2012 (15 aerial su...

The original version of this article contained a misaligned equation. The following equation replaces the online printed on the 5th page of the article.

Surveys for long-term monitoring programs managing natural resources often incorporate sampling design complexity. However, design weights are often ignored in trend models of data from complex sampling designs. Generalized random tessellation stratified samples of a simulated population of lakes are selected with various levels of survey design co...

A new spatially balanced sampling design for environmental surveys is introduced, called Halton iterative partitioning (HIP). The design draws sample locations that are well spread over the study area. Spatially balanced designs are known to be efficient when surveying natural resources because nearby locations tend to be similar. The HIP design us...

The Aleutian Tern Technical Committee convened an Aleutian Tern Conservation Planning Meeting in Anchorage, Alaska, January 26-27, 2018. The meeting's overarching goal was to work towards methods for assessing statewide Aleutian Tern population size and trend. The primary question addressed at the meeting was whether and how within-year population...

Bottlenose dolphins along the northern Gulf of Mexico continue to be impacted by numerous stressors including harmful algal blooms, infectious disease epizootics, and oil exposure following the Deepwater Horizon (DWH) oil spill. Studies to assess the potential impacts of the DWH oil spill on dolphins in the northern Gulf of Mexico were initiated as...

After the Deepwater Horizon (DWH) oil spill began in April 2010, studies were initiated on northern Gulf of Mexico common bottlenose dolphins (Tursiops truncatus) in Mississippi Sound (MSS) to determine density, abundance, and survival, during and after the oil spill, and to compare these results to previous research in this region. Seasonal boat-b...

The intent of this work was to determine the amount and suitability of Golden Eagle habitat within federally designated Priority Areas for Conservation (PACs) managed for Greater Sage-Grouse, and to assess the extent to which the protection of PACs might reduce the risk of oil and gas development and wildfire faced by Golden Eagle habitats.

This article presents a modification of balanced acceptance sampling (BAS) that causes inclusion probabilities to better approximate targeted inclusion probabilities. A new sample frame constructor for BAS is also introduced from which equi-probable spatially balanced samples are drawn.

Increasing concern for environmental sustainability, the demand for domestic energy, and an impetus on reducing dependence on fossil fuels have led to substantial investment in renewable energies including wind energy over the last 2 decades. Increases in wind energy development are especially noticeable in prairie habitats with high wind capacity....

Wind energy development is an emerging source of anthropogenic disturbance that could affect greater sage-grouse (Centrocercus urophasianus; sage-grouse) populations. Our objective was to determine the response of male sage-grouse attending leks (lek counts) to wind energy development using a before/after– control/treatment study design. We counted...

To assess potential impacts of the Deepwater Horizon oil spill in April 2010, we conducted boat-based photo-identification surveys for common bottlenose dolphins Tursiops truncatus in Barataria Bay, Louisiana, USA (~230 km², located 167 km WNW of the spill center). Crews logged 838 h of survey effort along pre-defined routes on 10 occasions between...

Greater Sage-Grouse (Centrocercus urophasianus) have been the focus of an unparalleled conservation effort across the western United States (US) in recent years. Greater Sage-Grouse have been suggested as an umbrella species, meaning that management actions for Greater Sage-Grouse are likely to benefit a host of other species that use similar sageb...

Using high-resolution airborne measurements and more synoptic coverage of Landsat measurements, we estimated the total Sargassum coverage in the northeastern Gulf of Mexico (NE GOM) during 2010, with the ultimate purpose to infer how much Sargassum might have been in contact with oil from the Deepwater Horizon oil spill. Mean Sargassum coverage dur...

A seismic survey was conducted off the northeastern coast of Sakhalin Island, Russia in 2010. The survey area was adjacent to the only known near-shore feeding ground of the Critically Endangered population of western gray whales Eschrichtius robustus in the western Pacific south of the Aleutian Islands. This study examined the effectiveness of eff...

Knowledge of population size and trend is necessary to manage anthropogenic risks to polar bears ( Ursus maritimus ). Despite capturing over 1,025 females between 1967 and 1998, previously calculated estimates of the size of the southern Beaufort Sea (SBS) population have been unreliable. We improved estimates of numbers of polar bears by modelingh...

One of the most important needs for wildlife managers is an accurate estimate of population size. Yet, for many species, including most marine species and large mammals, accurate and precise estimation of numbers is one of the most difé cult of all research chal- lenges.Open-population capture- recapturemodelshaveprovenusefulinmanysituationsto esti...

Estimates of species' vital rates and an understanding of the factors affecting those parameters over time and space can provide crucial information for management and conservation. We used mark–recapture, reproductive output, and territory occupancy data collected during 1985–2013 to evaluate population processes of Northern Spotted Owls (Strix oc...

Federally listed as threatened in 1990 primarily because of habitat loss, the northern spotted owl (Strix occidentalis caurina) has continued to decline despite conservation efforts resulting in forested habitat being reserved throughout its range. Recently, there is growing evidence the congeneric invasive barred owl (Strix varia) may be responsib...

The Deepwater Horizon (DWH) oil spill was unprecedented in extent and duration, and affected marine natural resources, including sea turtles, throughout the northern Gulf of Mexico. Consequently, US federal and state Trustees documented and quantified oil exposure and resulting injuries to sea turtles under the DWH Natural Resource Damage Assessmen...

The 2010 Deepwater Horizon (DWH) oil spill posed a severe threat to surface-pelagic sea turtles because the surface convergence zones, which provide vital habitat by aggregating pelagic Sargassum and other floating material, also aggregated floating oil. Following the DWH spill, turtle rescue operations between 17 May and 9 September 2010 documente...

Following the Deepwater Horizon (DWH) oil spill, numerous studies were conducted to determine impacts on common bottlenose dolphins Tursiops truncatus. Common bottlenose dolphins are found in estuarine environments of the northern Gulf of Mexico which vary in salinity, depending on location (e.g. distance to freshwater source), season, and ocean ti...

Spatially balanced sampling is becoming a popular design for surveys in biological and environmental management. For large scale surveys, where the region of interest is too large to visit every site, a sample is taken from a selection of sites. The process used to select these sites is called the survey design. Spatially balanced designs ensure th...

Common bottlenose dolphins (Tursiops truncatus) inhabit bays, sounds and estuaries across the Gulf of Mexico. Following the Deepwater Horizon oil spill, studieswere initiated to assess potential effects on these ecologically important apex predators. A previous study reported disease conditions, including lung disease and impaired stress response,...

Rdistance is an R package that contains functions and associated routines to analyze line transect data, and functionality for point count data is forthcoming. A large suite of classical, parametric detection functions are included, and the package can also accommodate user-defined detection functions. Website: https://github.com/tmcd82070/Rdistanc...

In proximity to seismic operations, bowhead whales (Balaena mysticetus) decrease their calling rates. Here, we investigate the transition from normal calling behavior to decreased calling and identify two threshold levels of received sound from airgun pulses at which calling behavior changes. Data were collected in August-October 2007-2010, during...

In the southern Beaufort Sea of the United States and Canada, prior investigations have linked declines in summer sea ice to reduced physical condition, growth, and survival of polar bears (Ursus maritimus). Combined with projections of population decline due to continued climate warming and the ensuing loss of sea ice habitat, those findings contr...

Fifteen aerial surveys (72,667 km, 86 days) occurred in the Southern California Bight October 2008 - April 2012, spanning January-November, funded by the U.S. Navy as part of their marine mammal monitoring program. Behavior of cetaceans in this region is poorly known, particularly for Risso’s dolphins, and previous published surveys are >12 years o...

The Pacific walrus is a large benthivore with an annual range extending across the continental shelves of the Bering and Chukchi Seas. We used a discrete choice model to estimate site selection by adult radio-tagged walruses relative to the availability of the caloric biomass of benthic infauna and sea ice concentration in a prominent walrus winter...

This study assesses effects of airgun sounds on bowhead calling behavior during the autumn migration. In August–October 2007, 35 directional acoustic recorders (DASARs) were deployed at five sites in the Alaskan Beaufort Sea. Location estimates were obtained for >137,500 individual calls; a subsample of locations with high detection probability was...

Use-availability and presence-only analyses are synonyms. Both require two samples (one containing known locations, one containing potential locations), both estimate the same parameters, and both use the same fundamental likelihood. Use-availability and presence-only designs compare characteristics of points where an organism was located to those...

To design an efficient survey or monitoring program for a natural resource it is important to consider the spatial distribution of the resource. Generally, sample designs that are spatially balanced are more efficient than designs which are not. A spatially balanced design selects a sample that is evenly distributed over the extent of the resource....

The “occupancy problem” has also been called the “sequential occupancy problem” and the “coupon-collector's problem”. Although there exist many variations, one popular statement of the problem asks, “What is the probability that a set of n independent multinomial trials yield at least one member of y classes?” The answer to this question has direct...

Previous work has shown that bowhead whales cease calling when near (<40 km) seismic exploration activities involving airguns. The aim of this study is to estimate the received level threshold for the onset of this behavior (cessation of calling). The analysis relied on data collected during late summer of 2007-2010 by up to 40 Directional Autonomo...

Introduction The spatial survey component (i.e. sampling design, Chapter 2) of a long-term ecological monitoring study dictates where sample locations are placed in a study area. The primary purpose of the spatial design is to select a sample of locations in such a way that valid scientific inferences can be made to all geographic regions of intere...

An automated procedure has been developed for detecting and localizing frequency-modulated bowhead whale sounds in the presence of seismic airgun surveys. The procedure was applied to four years of data, collected from over 30 directional autonomous recording packages deployed over a 280 km span of continental shelf in the Alaskan Beaufort Sea. The...

Bowhead whales (Balaena mysticetus) migrate west parallel to the north coast of Alaska during the late summer and autumn. In 2000, BP Exploration (Alaska) Inc. (BPXA), Anchorage, AK, began constructing its Northstar oil production facility on an artificial gravel island 5 km seaward of the natural barrier islands in the Beaufort Sea, AK, and a few...

This paper describes an analysis approach designed to detect the effects of fluctuating anthropogenic underwater sound on the distribution of calling bowhead whales (Balaena mysticetus) during migration. The anthropogenic sounds in this case were associated with an offshore oil production island (Northstar Island) in the Beaufort Sea northwest of P...

California’s salmon and steelhead populations have experienced marked declines leading to California Endangered Species Act (CESA) and Federal Endangered Species Act (ESA) listings of almost all of California’s anadromous salmonids. These CESA and ESA listings require recovery plans that call for monitoring to provide some measure of progress towar...

Since 1993, rotary screw traps (RSTs) have been used to monitor the production or abundance of juvenile Chinook salmon at 37 locations in the Central Valley of California. Despite the expenditure of over $45,000,000 to operate these traps between 1993 and 2010, there has been no standardized, unified effort to store, analyze, and report RST data in...

Polar bears (Ursus maritimus) of the northern Beaufort Sea (NB) population occur on the perimeter of the polar basin adjacent to the northwestern islands of the Canadian Arctic Archipelago. Sea ice converges on the islands through most of the year. We used open-population capture-recapture models to estimate population size and vital rates of polar...