Population Biology Commons^™

Impulse Vaccination Model For The Control Of Devil Facial Tumor Disease, Zachary Bobbitt, Timothy Comar, Megan O. Powell, Catherine Roberts, Nicholas Schneider, Teagen Smith

Spora: A Journal of Biomathematics

Devil facial tumor disease (DFTD) is a cancer that affects Tasmanian devils and that has caused the devil population to grossly decline since 1996. We present an SEIVR model to explore if recent advances in DFTD vaccines can help the wild population recover. Considering both and bi-annual impulse of vaccinating wild devils through food drops and introducing vaccinated captive-bred devils into the population, we explore the vaccine efficacy, percent of healthy devils receiving the vaccine, and years of campaign necessary for the devil population to have a long-term recovery. Based on our initial parameter estimations, we find a stable population …

Data From: Recovery From Discrete Wound Severities In Side-Blotched Lizards (Uta Stansburiana): Implications For Energy Budget, Locomotor Performance, And Oxidative Stress, Susannah S. French, Spencer B. Hudson

Browse all Datasets

Wounding events (predation attempts, competitive combat) result in injuries and/or infections that induce integrated immune responses for the recovery process. Despite the survival benefits of immunity in this context, the costs incurred may require investment to be diverted from traits contributing to immediate and/or future survival, such as locomotor performance and oxidative status. Yet, whether trait constraints manifest likely depends on wound severity and the implications for energy budget. For this study, food intake, body mass, sprint speed, and oxidative indices (reactive oxygen metabolites, antioxidant capacity) were monitored in male side-blotched lizards (Uta stansburiana) healing from cutaneous wounds of discrete …

Production Of Embryos And A Live Offspring Using Post Mortem Reproductive Material From Bison (Bison Bison Bison) Originating In Yellowstone National Park, Usa, Hayley M. Benham, Matthew P. Mccollum, Pauline Nol, Rebecca K. Frey, P. Ryan Clarke, Jack C. Rhyan, Jennifer P. Barfield

United States Department of Agriculture Wildlife Services: Staff Publications

Bison from Yellowstone National Park (YNP) have an important genetic history. As one of the few wild herds of bison with no evidence of cattle DNA introgression and a large enough population to maintain genetic diversity, they are considered a conservation priority for the species. Unfortunately, there is a high prevalence of the zoonotic disease brucellosis in the herd. Part of the management strategy for controlling the disease and herd size in YNP is to remove bison from the population during the winter migration out of the park. This interagency management cull provides an opportunity to collect a large number …

A New Vine Snake (Reptilia, Colubridae, Oxybelis) From Peru And Redescription Of O. Acuminatus, Robert C. Jadin, Michael J. Jowers, Sarah A. Orlofske, William E. Duellman, Christopher Blair, John C. Murphy

Publications and Research

The Brown Vine Snake, Oxybelis aeneus, was until recently considered a single species, distributed from southern Arizona through the Neotropics into southeastern Brazil. However, newly conducted research restructured the species with a substantial taxonomic revision, recognizing five additional taxa (i.e. O. koehleri, O. microphthalmus, O. potosiensis, O. rutherfordi, O. vittatus) in this species complex. This revision focused on populations in North America, Central America, and northern South America while neglecting the southern portion of its distribution. Here, we examine the taxonomic history of the complex and use it along with specimen data to resurrect O. acuminatus from southeastern Brazil. Finally, …

Dispersal And Land Cover Contribute To Pseudorabies Virus Exposure In Invasive Wild Pigs, Felipe A. Hernandez, Amanda N. Carr, Michael P. Milleson, Hunter R. Merrill, Michael L. Avery, Brandon M. Parker, Cortney L. Pylant, James D. Austin, Samantha M. Wisely

United States Department of Agriculture Wildlife Services: Staff Publications

We investigated the landscape epidemiology of a globally distributed mammal, the wild pig (Sus scrofa), in Florida (U.S.), where it is considered an invasive species and reservoir to pathogens that impact the health of people, domestic animals, and wildlife. Specifically, we tested the hypothesis that two commonly cited factors in disease transmission, connectivity among populations and abundant resources, would increase the likelihood of exposure to both pseudorabies virus (PrV) and Brucella spp. (bacterial agent of brucellosis) in wild pigs across the Kissimmee Valley of Florida. Using DNA from 348 wild pigs and sera from 320 individuals at 24 sites, we …

Ovarian Dynamics And Fecundity Regulation In Blueback Herring, Alosa Aestivalis, From The Connecticut River, Us, Foivos Alexandros Mouchlianitis, Eric T. Schultz, Thassya C. Dos Santos Schmidt, Justin P. Davis, Kostas Ganias

EEB Articles

We analyzed ovarian dynamics of anadromous blueback herring, Alosa aestivalis, in Connecticut River with the principal aim of exploring oocyte recruitment and how it shapes the fecundity pattern. We examined the oocyte release strategy and analyzed spawning cyclicity by linking oocyte growth to the degeneration of postovulatory follicles. Females were accordingly classified as pre-spawners, early and late active spawners, and oocyte recruitment intensity was compared among the different spawning phases. Oocyte recruitment occurred continuously and in parallel with spawning activity, a pattern which is diagnostic of indeterminate fecundity. However, both fecundity and oocyte recruitment intensity progressively decreased (tapered) throughout …

Red Drum And Spotted Seatrout Live-Release Tournament Mortality And Dispersal, T. Reid Nelson, Crystal Hightower, Sean P. Powers

University Faculty and Staff Publications

Although catch-and-release fishing tournaments undoubtedly reduce mortality of target species, postrelease mortality and fish stockpiling at release sites remain common concerns related to these tournaments. The impacts of liverelease tournaments on freshwater species have been widely studied. However, research on estuarine sport fishes is lacking even though catch-and-release tournaments targeting these species are prevalent and popular recreational fisheries exist. Therefore, we estimated the post-weigh-in mortality and dispersal of Red Drum Sciaenops ocellatus and Spotted Seatrout Cynoscion nebulosus released from the 2016–2018 Alabama Deep Sea Fishing Rodeo live-weigh-in categories using acoustic telemetry. To concurrently estimate overall post-weigh-in mortality and dispersal, we …

Data Repository For "Use Of Redwood Basal Hollows By Bats: A Focus On The Townsend’S Big-Eared Bat On The North Coast Of California", Amon J. Armstrong

Research Data Sets

Loss of roosting resources, either through disturbance or removal, negatively affects bats. Identifying sensitive species and determining roost requirements are critical components in conserving their habitat. Cavity roosting bats on the North Coast of California are known to use hollows in large redwood trees. In this study, we examined the factors determining the use of basal tree hollows by different bat species at eight redwood forest sites in Del Norte, Humboldt, and Mendocino Counties, California. Bat guano was collected from 179 basal hollow roosts from 2017 to 2018, and guano mass was used as an index of roosting activity. Nine …

Age, Growth, And Mortality Of Atlantic Tripletail In The North-Central Gulf Of Mexico, Amanda E. Jefferson, Matthew B. Jargowsky, Meagan N. Schrandt, Pearce T. Cooper, Sean P. Powers, John Dindo, J. Marcus Drymon

University Faculty and Staff Publications

In the southeastern USA and the Gulf of Mexico (GOM), Atlantic Tripletail Lobotes surinamensis are increasingly targeted by recreational anglers, indicating that stock status should be assessed. A critical need for such assessments is age-specific data; however, previous studies have drawn conflicting conclusions regarding the most appropriate structure for aging. Moreover, growth parameters and mortality rates for GOM Atlantic Tripletail are unknown. Therefore, the goals of this study were to (1) evaluate sagittal otoliths and first dorsal spines as aging structures; (2) model combined and sex-specific growth; and (3) estimate mortality rates for GOM Atlantic Tripletail. From 2012 to 2019, …

Documentation Of Atlantic Tarpon (Megalops Atlanticus) Space Use And Move Persistence In The Northern Gulf Of Mexico Facilitated By Angler Advocates, J. Marcus Drymon, Matthew B. Jargowsky, Michael A. Dance, Mitchell Lovell, Crystal L. Hightower, Amanda E. Jefferson, Andrea M. Kroetz, Sean P. Powers

University Faculty and Staff Publications

Atlantic tarpon (Megalops atlanticus, hereafter tarpon) are facing a multitude of stressors and are considered Vulnerable by the IUCN; however, significant gaps remain in our understanding of tarpon space use and movement. From 2018 to 2019, citizen scientists facilitated tagging of 23 tarpon with SPOT tags to examine space use and movement across the northern Gulf of Mexico. Movement-based kernel densities were used to estimate simplified biased random bridge-based utilization distributions and a joint move persistence model was used to estimate a behavioral index for each fish. Tarpon showed consistent east–west movement from the Alabama/Florida border to Louisiana, and utilization …

Evaluating Potential Effects Of Solar Power Facilities On Wildlife From An Animal Behavior Perspective, Rachel Y. Chock, Barbara Clucas, Elizabeth K. Peterson, Bradley Blackwell, Daniel T. Blumstein, Kathleen Church, Esteban Fernández-Juricic, Gabriel Francescoli, Alison L. Greggor, Paul Kemp, Gabriela M. Pinho, Peter M. Sanzenbacher, Bruce A. Schulte, Pauline Toni

United States Department of Agriculture Wildlife Services: Staff Publications

Solar power is a renewable energy source with great potential to help meet increasing global energy demands and reduce our reliance on fossil fuels. However, research is scarce on how solar facilities affect wildlife. With input from professionals in ecology, conservation, and energy, we conducted a research-prioritization process and identified key questions needed to better understand impacts of solar facilities on wildlife. We focused on animal behavior, which can be used to identify population responses before mortality or other fitness consequences are documented. Behavioral studies can also offer approaches to understand the mechanisms leading to negative interactions (e.g., collision, singeing, …

Temporal And Spatial Blood Feeding Patterns Of Urban Mosquitoes In The San Juan Metropolitan Area, Puerto Rico, Matthew W. Hopken, Limarie J. Reyes-Torres, Nicole Scavo, Antoinette J. Piaggio, Zaid Abdo, Daniel Taylor, James Pierce, Donald A. Yee

United States Department of Agriculture Wildlife Services: Staff Publications

Simple Summary: Understanding the biodiversity of urban ecosystems is critical for management of invasive and pest species, conserving native species, and disease control. Mosquitoes (Culicidae) are ubiquitous and abundant in urban ecosystems, and rely on blood meals taken from vertebrates. We used DNA from freshly blood-fed mosquitoes to characterize the diversity of vertebrate host species in the San Juan Metropolitan Area, Puerto Rico. We collected two mosquito species that fed on a variety of vertebrates. Culex quinquefasciatus fed on 17 avian taxa (81.2% of blood meals), seven mammalian taxa (17.9%), and one reptilian taxon (0.85%). Aedes aegypti blood meals were …

Best Management Practices For Trapping Furbearers In The United States, H. Bryant White, Gordon R. Batcheller, Edward K. Boggess, Clifford L. Brown, Joseph W. Butfiloski, Thomas A. Decker, John D. Erb, Michael W. Fall, David A. Hamilton, Tim L. Hiller, George F. Hubert Jr., Matthew J. Lovallo, John F. Olson, Nathan M. Roberts

United States Department of Agriculture Wildlife Services: Staff Publications

Humans have used wild furbearers for various purposes for thousands of years. Today, furbearers are sustainably used by the public for their pelts, leather, bones, glands, meat, or other purposes. In North America, contemporary harvest of furbearers has evolved along with trap technologies and societal concerns, and is now highly regulated and more closely coupled with harvest analysis and population monitoring. Traps and regulated trapping programs provide personal or cultural rewards that can also support conservation, and can assist with advancing ecological knowledge through research, protecting endangered species, restoring populations or habitats, protecting personal property, and enhancing public health and …

Strategic Considerations For Invasive Species Managers In The Utilization Of Environmental Dna (Edna): Steps For Incorporating This Powerful Surveillance Tool, Jeffrey Morisette, Stanley Burgiel, Kelsey Brantley, Wesley M. Daniel, John Darling, Jeanette Davis, Thomas Franklin, Keith Gaddis, Margaret Hunter, Richard Lance, Tracy Leskey, Yale Passamaneck, Antoinette Piaggio, Brian Rector, Adam Sepulveda, Melissa Smith, Carol A. Stepien, Taylor Wilcox

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive species surveillance programs can utilize environmental DNA sampling and analysis to provide information on the presence of invasive species. Wider utilization of eDNA techniques for invasive species surveillance may be warranted. This paper covers topics directed towards invasive species managers and eDNA practitioners working at the intersection of eDNA techniques and invasive species surveillance. It provides background information on the utility of eDNA for invasive species management and points to various examples of its use across federal and international programs. It provides information on 1) why an invasive species manager should consider using eDNA, 2) deciding if eDNA can …

Reproductive Trade-Offs In The Colorado Checkered Whiptail Lizard (Aspidoscelis Neotesselatus): An Examination Of The Relationship Between Clutch And Follicle Size, Hannah E. Caracalas, S. S. French, S. B. Hudson, B. M. Kluever, A. C. Webb, D. Eifler, A. J. Lehmicke, Lise M. Aubry

United States Department of Agriculture Wildlife Services: Staff Publications

Life history theory predicts that there should be an inverse relationship between offspring size and number, because individuals cannot simultaneously maximize both when resources are limited. Although extensively studied in avian species, the occurrence and determinants of reproductive tradeoffs in oviparous reptiles are far less understood, particularly in parthenogenetic species. We studied this trade-off in the Colorado Checkered Whiptail, Aspidoscelis neotesselatus, a female-only parthenogenetic lizard. Using data previously collected in 2018 and 2019, we tested for clutch and egg size trade-offs and determined whether this relationship could be influenced by female size and aspects of physiological condition. Physiological condition …

Modelling The Factors Affecting The Probability For Local Rabies Elimination By Strategic Control, Johann L. Kotzé, John Duncan Grewar, Aaron M. Anderson

United States Department of Agriculture Wildlife Services: Staff Publications

Dog rabies has been recognized from ancient times and remains widespread across the developing world with an estimated 59,000 people dying annually from the disease. In 2011 a tri-partite alliance consisting of the OIE, the WHO and the FAO committed to globally eliminating dog-mediated human rabies by 2030. Regardless of global support, the responsibility remains with local program managers to implement successful elimination programs. It is well known that vaccination programs have a high probability of successful elimination if they achieve a population-coverage of 70%. It is often quoted that reducing population turnover (typically through sterilizations) raises the probability for …

Comparing The Condition Of Deformed And Non-Deformed Walleyes In Long Lake, Mn, Clayton Beck

Journal of Earth and Life Science

Walleye Sander vitreus is a popular game fish in Minnesota. Walleye’s have become such a popular game fish for anglers that it has led agencies to raise Walleye in rearing ponds. Farm raised fish can show deformities due to environmental, genetic, nutritional, infectious, and toxic factors. Due to this phenomenon, the purpose of this study was to determine if the condition of the Walleye differed between those with and without deformities in Long Lake, MN. Angling was the method of capture during the months of September 2020 through July 2021. There was no evidence to suggest condition differed between non-deformed …

Jaguars And Pumas Exhibit Distinct Spatiotemporal Responses To Human Disturbances In Colombia’S Most Imperiled Ecoregion, Joe J. Figel, Sebastián Botero-Cañola, Juan David Sánchez-Londoño, Javier Racero-Casarrubia

University of Nebraska State Museum: Mammalogy Papers

Abstract

Coexistence of sympatric felids is facilitated by mutual avoidance and the partitioning of habitats, prey, and time. Anthropogenic disturbances disrupt this coexistence in fragmented landscapes, potentially triggering cascading influences in ecological communities. We used photographic data from 8,717 trap nights (November 2014–June 2016) at 87 camera trap sites in Colombia’s middle Magdalena River basin to compare spatiotemporal overlap among jaguars (Panthera onca), pumas (Puma concolor), their prey, and humans, at sites of high and low disturbance, as determined by the human influence index. Human disturbance events (e.g. domestic dogs, livestock, and humans, including armed hunters) …

Using Audio Recording Devices And Multiseason Occupancy Modelling To Evaluate Clark's Nutcracker (Nucifraga Columbiana) Occurrence In Whitebark Pine Habitats Of Washington's Cascade Mountains, Lauren Taracka

Undergraduate Honors Theses

The Clark’s nutcracker (Nucifraga columbiana) and whitebark pine (Pinus albicaulis), both native to the harsh subalpine habitats of Washington’s Cascade Mountains, are being negatively impacted by white pine blister rust (Cronartium ribicola), the mountain pine beetle (Dendroctonus ponderosae), and climate change. As temperatures continue to warm, while many species at lower elevations can move upward in elevation to suit their temperature needs, subalpine species do not have that option. Whitebark pine is a keystone tree species - numerous animals consume its high fat, high energy seeds; it’s a nurse tree, providing shelter …

Genetic Diversity & Connectivity Of Chasmanthium Latifolium (Poaceae) In Pennsylvania & The Effect On Conservation Status Of A Rare Species, Jonathan D. Hayes

Honors Theses

Chasmanthium latifolium (Michx.) Yates (Poaceae) is a loosely colonial, rhizomatous, perennial grass species that lives in riparian habitats, making it fittingly referred to as river oats. Native to the southern Midwest and the eastern half of the United States, C. latifolium reaches the northeastern edge of its range in Pennsylvania. Within Pennsylvania, eleven extant C. latifolium populations are found along four waterways: the Monongahela River, the Susquehanna River, and two tributaries to the Susquehanna River. This limited state distribution exhibits an east-west disjunct distribution, where western populations are largely separated from eastern populations with one centrally located population. Between the …

Distribution And History Of The Roseate Spoonbill (Platalea Ajaja) In Arkansas, C. Renn Tumlison, Grace Wills, Karen Rowe

Journal of the Arkansas Academy of Science

The Roseatte Spoonbill (Platalea ajaja) is a rare bird in Arkansas and was not reported from the state until 1959, when it was seen in southwestern Arkansas. By use of online sources for citizen science, we elucidate the history of occurrence and present analysis of seasonal distribution of this bird in Arkansas. Individuals arrive in Arkansas as early as April, observations peak in August, and the birds may remain to late October when colder weather promotes southward migration. Most observations are of a few birds, but a maximum of 128 has been counted at one location and time. …

History, Distribution, And Reproduction By The Swallow-Tailed Kite (Elanoides Forficatus) In Arkansas, Grace Wills, C. Renn Tumlison

Journal of the Arkansas Academy of Science

The Swallow-tailed Kite (Elanoides forficatus) is a rare bird in Arkansas, and its historical populations are believed to have declined over much of the last century due to loss of bottomland hardwood forests and associated wetlands. However, sightings have increased in the recent 2 decades. By use of online sources for citizen science, we elucidate the current distribution of this bird in Arkansas, and comment on the status of reproduction. Swallow-tailed Kites arrive in Arkansas as early as March and remain to mid-September, but numbers of reported sightings have a bimodal occurrence with peaks in May and August.

Continental-Scale Dynamics Of Avian Influenza In U.S. Waterfowl Are Driven By Demography, Migration, And Temperature, Erin E. Gorsich, Colleen T. Webb, Andrew A. Merton, Jennifer A. Hoeting, Ryan S. Miller, Matthew Farnsworth, Seth R. Swafford, Thomas J. Deliberto, Kerri Pedersen, Alan B. Franklin, Robert G. Mclean, Kenneth R. Wilson, Paul Doherty

United States Department of Agriculture Wildlife Services: Staff Publications

Emerging diseases of wildlife origin are increasingly spilling over into humans and domestic animals. Surveillance and risk assessments for transmission between these populations are informed by a mechanistic understanding of the pathogens in wildlife reservoirs. For avian influenza viruses (AIV), much observational and experimental work in wildlife has been conducted at local scales, yet fully understanding their spread and distribution requires assessing the mechanisms acting at both local, (e.g., intrinsic epidemic dynamics), and continental scales, (e.g., long-distance migration). Here, we combined a large, continental-scale data set on low pathogenic, Type A AIV in the United States with a novel network-based …

Avian Use Of Exotic Street Treescapes In Metropolitan Areas Of Phoenix, Arizona, Brian E. Washburn, Karen Hoss, David L. Bergman

United States Department of Agriculture Wildlife Services: Staff Publications

Urban areas are highly modified environments that are strongly influenced by a variety of anthropogenic factors. Consequently, these areas contain unique wildlife communities typically dominated by species that are generalist in nature or highly adaptable. We examined the use of five species of exotic treescapes by exotic and native birds in metropolitan areas of Phoenix, Arizona. House Sparrows [Passer domesticus (37%)], European Starlings [Sturnus vulagris (27%)], Mourning Doves [Zenaida macroura (11%)], and Great-tailed Grackles [Quiscalus mexicanus (7%)] were the most frequently observed species during the study. Approximately two-thirds (67%) of the birds observed during the study were exotic species. Avian …

Table Of Contents

Human–Wildlife Interactions

This is the table of contents.

Efficacy Of Manipulating Reproduction Of Common Ravens To Conserve Sensitive Prey Species: Three Case Studies, Corina A. Sanchez, Brianne E. Brussee, Peter S. Coates, Kerry L. Holcomb, Seth M. Harju, Timothy A. Shields, Mercy Vaughn, Brian G. Prochazka, Steven R. Mathews, Steffen Cornell, Chad V. Olson, David J. Delehanty

Human–Wildlife Interactions

Expansion of human enterprise across western North America has resulted in an increase in availability of anthropogenic resource subsidies for generalist species. This has led to increases in generalists’ population numbers across landscapes that were previously less suitable for their current demographic rates. Of particular concern are growing populations of common ravens (Corvus corax; ravens), because predation by ravens is linked to population declines of sensitive species. Ecosystem managers seek management options for mitigating the adverse effects of raven predation where unsustainable predator–prey conflicts exist. We present 3 case studies examining how manipulating reproductive success of ravens influences …

Diets Of Double-Crested Cormorants In The Lake Winnebago System, Wisconsin, Ryan P. Koenigs, Daniel J. Dembkowski, Charles D. Lovell, Daniel A. Isermann, Adam D. Nickel

United States Department of Agriculture Wildlife Services: Staff Publications

Double-crested cormorant Phalacrocorox auritus Lesson (cormorant) populations have increased throughout the Great Lakes region of North America causing concern related to the impact of cormorant predation on fish communities. A recent decline in yellow perch Perca flavescens (Mitchill) abundance within the Lake Winnebago System, Wisconsin, USA, prompted an assessment of cormorant diets to evaluate potential effects of cormorant predation on the sportfish community. Diets were collected from 883 cormorants (417 from Lake Winnebago and 466 from Lake Butte des Morts) between 2015 and 2017. Cormorant diets on both waterbodies consisted mostly of freshwater drum Aplodinotus grunniens Rafinesque and gizzard shad …

Evaluation Of A Warfarin Bait For Controlling Invasive Wild Pigs (Sus Scrofa), James C. Beasley, Lindsay M. Clontz, Allison Rakowski, Nathan P. Snow, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

BACKGROUND: Wild pigs (Sus scrofa) cause widespread environmental and economic damage, and as a result are subjected to extensive control. Current management strategies have proven insufficient, and there is growing interest in use of toxicants to control invasive populations of this species. In 2017 a low-dose warfarin bait was federally approved for use in controlling wild pigs in the United States. However, no states have allowed use of this bait due to unanswered questions regarding welfare concerns, field efficacy, and non-target impacts.

RESULTS: All captive wild pigs fed 0.005% warfarin baits in no choice feeding trials succumbed in an average …

Effects Of Salt Runoff On Aquatic Macroinvertebrate Colonies, Kendra Fink

Journal of Earth and Life Science

Aquatic macroinvertebrates bridge the gap in part between primary and secondary consumers, making them ecologically important for most aquatic systems. They are used as biotic indicators for water quality due to their sensitivity to pollutants and may be affected, specifically, by chloride ion concentrations in the water. Water quality can be evaluated by looking at species compositions and their respective tolerance values. To determine long-term effects of road salt on macroinvertebrate colonies, a total of 338 identified macroinvertebrates of 10 families (two generalized to class) at 9 sites were collected from before, after, and between three bridges on Turtle River …

Common Raven Impacts On Nesting Western Snowy Plovers: Integrating Management To Facilitate Species Recovery, Cheryl Strong, Kriss K. Neumann, Jenny L. Hutchinson, Jamie K. Miller, Amber L. Clark, Lena Chang, Joanna Iwanicha, Elizabeth Feucht, Matthew J. Lau, David J. Lauten, Sarah Markegard, Benjamin Pearl, David L. Sherer, Rachel Tertes, Susie Tharratt, Travis Wooten

Institute for Natural Resources Publications

The U.S. Pacific coast population of the western snowy plover (Charadrius nivosus nivosus; plover) has declined due to loss and degradation of coastal habitats, predation, and anthropogenic disturbance. The U.S. Fish and Wildlife Service listed the subspecies in 1993 as threatened under the Endangered Species Act due to the population declines and habitat loss. Predation of nests and chicks has been identified as an important cause of historic population declines, and thus, most predator management actions for this subspecies are focused on reducing this pressure. In recent years, common ravens (Corvus corax; ravens) have become the most common and pervasive …