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2021

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Articles 61 - 90 of 94

Full-Text Articles in Ornithology

2021 Annual Color Photo Section Mar 2021

2021 Annual Color Photo Section

Nebraska Bird Review

Our photo theme this year is species with the word “red” in their common names. For this "Red Challenge", "red" must be used to mean the color red, but the birds don't actually have to display any red to qualify. Examples appear on the next five pages of photos.

Redheaded Woodpecker in Knox Co., 28 July 2020. Photo by Mark Brogie.

Rednaped Sapsucker male at Plum Creek Valley WMA, Brown Co., 16 Sept. 2018. Photo by Mary Clausen.

Redbellied Woodpecker female, photographer's yard, Wahoo, Saunders Co., 14 Feb. 2021. Photo by Joe Freeborn.

Northern Flicker male, western "redshafted" subspecies, Seward …


The Nebraska Bird Review, Volume 89 March 2021 Number 1 Mar 2021

The Nebraska Bird Review, Volume 89 March 2021 Number 1

Nebraska Bird Review

Winter Field Report, Dec. 2020 - Feb. 2021, by W. Ross Silcock …2-17

2020-2021 Christmas Bird Counts …18, 29-40

Annual Color Photo Section …21-28

Apparent Townsend’s x Black-throated Green Warbler (Setophaga townsendi x virens) hybrids in Kansas and Nebraska, by Jon C. King, Terry Swope, Kevin Groeneweg, Pete Janzen, & Mark A. Brogie … 41

Annual Treasurer's Report for 2020, by Jan Johnson …46.

Subscription and Organization Information …47


2020-2021 Christmas Bird Counts, Don Paseka Mar 2021

2020-2021 Christmas Bird Counts, Don Paseka

Nebraska Bird Review

Fourteen counts were run during the 2020-2021 CBC season, ten of which were run in the period December 14 through December 22. The other four were done December 28 or later. The weather was generally cooperative with little snow cover and some open water. While there were no weather issues that resulted in cancellation or postponement, four counts, Crawford, Harrison, Harlan County, and Omaha, were cancelled over concerns for the Covid situation. It would be expected that running fewer counts would have a noticeable negative impact on this year’s species count and overall numbers. The Harrison and Crawford counts usually …


Apparent Townsend’S X Black-Throated Green Warbler (Setophaga Townsendi X Virens) Hybrids In Kansas And Nebraska, Jon C. King, Terry Swope, Kevin Groeneweg, Pete Janzen, Mark A. Brogie Mar 2021

Apparent Townsend’S X Black-Throated Green Warbler (Setophaga Townsendi X Virens) Hybrids In Kansas And Nebraska, Jon C. King, Terry Swope, Kevin Groeneweg, Pete Janzen, Mark A. Brogie

Nebraska Bird Review

The Townsend’s Warbler (Setophaga townsendi), Hermit Warbler (Setophaga occidentalis), Golden-cheeked Warbler (Setophaga chrysoparia), and Black-throated Green Warbler (Setophaga virens) are similar in appearance and vocalizations. Evaluation of mtDNA suggests that these four species diverged about 1 million years ago during the mid-Pleistocene (Lovette et al. 2010), at which time glaciation separated ancestral forms thus allowing for speciation (Morse and Poole 2020). Under the environmental conditions prevalent today, however, the breeding distribution of Townsend’s Warbler now overlaps to a limited extent with those of the Hermit and Black-throated Green Warblers, and hybridization occurs …


Estimating The Size Of Georgia's Resident Canada Goose Population, Gregory D. Balkcom Feb 2021

Estimating The Size Of Georgia's Resident Canada Goose Population, Gregory D. Balkcom

Georgia Journal of Science

Canada geese (Branta canadensis) are an important waterfowl species in Georgia, and are hunted across the state. To meet management objectives, managers need to understand the impacts of hunting regulations on the population of interest. Therefore, reliable population estimates are necessary. Population size can be estimated by various methods, including aerial surveys, ground surveys, or population indices such as the Lincoln Estimator. I used annual estimates of resident Canada goose harvest in Georgia from the U.S. Fish and Wildlife Service’s Harvest Information Program along with banding and recovery data from the Bird Banding Laboratory in a bias-adjusted version …


Occurrence Of Ticks (Acari: Ixodidae) On Birds In Northwestern Lower Michigan, 2011-2019, William C. Scharf, Lisa Aukland, Gary W. Shugart, Sarah A. Hamer Feb 2021

Occurrence Of Ticks (Acari: Ixodidae) On Birds In Northwestern Lower Michigan, 2011-2019, William C. Scharf, Lisa Aukland, Gary W. Shugart, Sarah A. Hamer

The Great Lakes Entomologist

Abstract

Monitoring tick infestation of wildlife provides baseline tick

occurrence data that may have human or animal health implications. We collected 312 ticks of four species from 5,122 birds of 93 species while monitoring bird migration during 15 fall and spring seasons between 2011 and 2019 in the northern Lower Peninsula of Michigan. Twenty-seven of 93 bird species hosted ticks with an overall prevalence (=at least one tick) of 3.6% (185/5,122). Median burden was one tick/per infested bird with a range of 1-16 ticks per infested bird. Tick species collected were primarily Haemaphysalis leporispalustris (Packard) and Ixodes scapularis Say, with …


Kentucky Warbler (Vol. 97, No. 1), Kentucky Library Research Collections Feb 2021

Kentucky Warbler (Vol. 97, No. 1), Kentucky Library Research Collections

The Kentucky Warbler

No abstract provided.


Spatio-Temporal Variation Patterns Of Bird Community In The Oasis Ecosystem Of The North Of Algerian Sahara, Lasad Chiheb, Bensaci Ettayib, Nouidjem Yassine, Hadjab Ramzi Jan 2021

Spatio-Temporal Variation Patterns Of Bird Community In The Oasis Ecosystem Of The North Of Algerian Sahara, Lasad Chiheb, Bensaci Ettayib, Nouidjem Yassine, Hadjab Ramzi

Journal of Bioresource Management

The spatial and temporal variation patterns of birds were investigated in the Oasis ecosystem of the North of Algeria Sahara. This contribution aimed to investigate the poorly studied bird fauna of Bousaâda oasis. The direct observation method was used for bird counts, adopted only during the breeding period. A total of 53 species of birds from 29 families and 16 orders were assessed in the different habitats of the Oasis (palm, fruit trees and, cultivated crops). The Passeriformes order was the most abundant represented by 35 species and 16 families. The relative abundance and species richness were recorded during our …


Wpa News 116 (2021), World Pheasant Association Jan 2021

Wpa News 116 (2021), World Pheasant Association

Galliformes Specialist Group and Affiliated Societies: Newsletters

WPA News (Winter 2021), number 116

Published by the World Pheasant Association


Diverse Demographic Factors Influence Apparent Juvenile Survival In A Migratory Songbird, Emma M. White, Noah G. Perlut, Steven E. Travis, Allan Strong Jan 2021

Diverse Demographic Factors Influence Apparent Juvenile Survival In A Migratory Songbird, Emma M. White, Noah G. Perlut, Steven E. Travis, Allan Strong

Environmental Studies Faculty Publications

To better understand the dynamics of avian populations and their role in population trends, we require an in-depth understanding of the factors influencing the survival of adults and juveniles. How-ever, assessing survival in juveniles is often challenging, especially in small, migratory species where individuals typically disperse from the study area and are not available for recapture in subsequent years. Bobolinks (Dolichonyx oryzivorus) are a long-distance migrant that exhibits natal philopatry in at least one population, allowing for more comprehensive juvenile survival analyses than in many other long-distance avian migrants. Using a 17-yr dataset from two sites representing a …


Management Schemes, Not Philopatry Or Breeding Experience, Affect Nest Success Of Two Songbirds In Vermont Hayfields, Kylie Denny, Noah G. Perlut, Allan Strong Jan 2021

Management Schemes, Not Philopatry Or Breeding Experience, Affect Nest Success Of Two Songbirds In Vermont Hayfields, Kylie Denny, Noah G. Perlut, Allan Strong

Environmental Studies Faculty Publications

Songbirds can benefit from natal philopatry through prior knowledge about site‐specific resources and local adaptation to environmental conditions. Likewise, breeding experience may also play a role in reproductive success. However, for birds that breed in managed habitats, management activities may overwhelm any potential benefits of philopatry or breeding experience. We examined the effect of site fidelity on reproductive success in 1,823 bobolink and Savannah sparrow nests in agricultural grasslands in Vermont, USA. From 2003–2019 we monitored the nests of 51 female Savannah sparrows and 72 female bobolinks that returned to breed on or near fields in which they hatched between …


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 Jan 2021

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 …


Energy Content Of Seeds Of Palmer’S Pigweed (Amaranthus Palmeri) In The Diet Of Scaled Quail (Callipepla Squamata) In Southeastern New Mexico, John L. Hunt, Matthew E. Grilliot, Troy L. Best, Isaac C. Castillo, Paige E. Eddington, Faith A. Johnson, Tyneshia L. Kilgore, Jacob H. Courson Jan 2021

Energy Content Of Seeds Of Palmer’S Pigweed (Amaranthus Palmeri) In The Diet Of Scaled Quail (Callipepla Squamata) In Southeastern New Mexico, John L. Hunt, Matthew E. Grilliot, Troy L. Best, Isaac C. Castillo, Paige E. Eddington, Faith A. Johnson, Tyneshia L. Kilgore, Jacob H. Courson

Journal of the Arkansas Academy of Science

Palmer’s pigweed (Amaranthus palmeri) is a common grassland plant that occurs across much of North America. It is often considered a weed but is an important source of food for many game birds. We analyzed the energy content of seeds of Palmer’s pigweed obtained from the crops of scaled quail (Callipepla squamata) collected from plains-mesa sand-scrub habitat in Eddy and Lea counties, New Mexico. Seeds were dried for 48 hours at 60°C to remove moisture and then analyzed for gross caloric value (i.e., energy content) in an oxygen bomb calorimeter. Energy content of seeds of Palmer’s …


Bird Usage Of Black Marasmius Fibers As Nest Material, Haris Rana, Shayla Smithson, Jack Jackson, Ragupathy Kannan Jan 2021

Bird Usage Of Black Marasmius Fibers As Nest Material, Haris Rana, Shayla Smithson, Jack Jackson, Ragupathy Kannan

Journal of the Arkansas Academy of Science

Black Marasmius fungal fibers have been frequently observed in neotropical bird nests. We tested to determine if superior tensile strength and temperature moderation contributes to why these fibers are preferred by some species over other available nesting materials. Marasmius fibers from nests of Yellow-olive Flycatchers (Tolmomyias sulphurescens) were compared to grass fibers from a Yellow-tailed Oriole (Icterus mesomelas) nest from the same area in Belize, Central America. We measured tensile strengths by a universal strength tester which stretched the fibers to their breaking point. We also used HOBO data loggers to compare the temperature differential between …


Common Ravens Disrupt Greater Sage-Grouse Lekking Behavior In The Great Basin, Usa, Joseph L. Atkinson, Peter S. Coates, Brianne E. Brussee, Ian A. Dwight, Mark A. Ricca, Pat J. Jackson Jan 2021

Common Ravens Disrupt Greater Sage-Grouse Lekking Behavior In The Great Basin, Usa, Joseph L. Atkinson, Peter S. Coates, Brianne E. Brussee, Ian A. Dwight, Mark A. Ricca, Pat J. Jackson

Human–Wildlife Interactions

Expansion of human enterprise has contributed to increased abundance and distribution of common ravens (Corvus corax; ravens) across sagebrush (Artemisia spp.) ecosystems within western North America. Ravens are highly effective nest predators of greater sage-grouse (Centrocercus urophasianus; sage-grouse), a species of high conservation concern. Sage-grouse population trends are estimated using count survey data of males attending traditional breeding grounds, known as leks. We sought to investigate associations of ravens to sage-grouse lek sites and document interactions between the sage-grouse and ravens as well as those between sage-grouse and other animals observed around leks. First, we …


Grouse News 61-67 (2021-2024), Iucn/Ssc Galliformes Specialist Group Jan 2021

Grouse News 61-67 (2021-2024), Iucn/Ssc Galliformes Specialist Group

Galliformes Specialist Group and Affiliated Societies: Newsletters

Issue 61 (May 2021)

From the Editor

From the Chair

News from the Galliformes Specialist Group

News from the Grouse Group Conservation News

Grouse in Estonia

Endangered Species Act Protections for Southern White-Tailed Ptarmigan Found to be Not Warranted

A Remarkable Return. The Attwater’s prairie-chicken is bouncing back

Research Reports

Fluctuations and trends in tetraonid populations of the “Bryansky Les” Nature Reserve (southwest Russia)

Evaluation of the durability and longevity of lesser prairie-chicken fence tags in Kansas and Colorado

Longevity of the Lesser Prairie-Chicken

Conferences

Conferences postponed

New Books

European Breeding Bird Atlas 2: Distribution, Abundance and Change

Recent grouse …


Effects Of Predator Management And Parasitism On Over-Water Nesting Diving Duck Production In Southwestern Manitoba, Trenton E. Rohrer Jan 2021

Effects Of Predator Management And Parasitism On Over-Water Nesting Diving Duck Production In Southwestern Manitoba, Trenton E. Rohrer

Electronic Theses and Dissertations

Nest survival of upland nesting waterfowl (e.g., mallard [Anas platyrhynchos], blue-winged teal [Anas discors]) has been studied extensively in the Prairie Pothole Region (PPR) of North America. Conversely, over-water nesting diving ducks’ nest survival is poorly understood, likely because over-water nests are more challenging to find, may be less concentrated, and searching for these nests is physically demanding. Nest depredation is considered a leading cause of duck nest failure and is considered a limiting factor on upland nesting waterfowl production in the PPR. Similar factors limiting upland nesting duck production may limit over-water nesting duck productivity, but studies of this …


Bird Abundance And Diversity And The Impact Of Oyster Reef Restoration On The Bird Community In Mosquito Lagoon, Florida, Usa, Jessica Copertino Jan 2021

Bird Abundance And Diversity And The Impact Of Oyster Reef Restoration On The Bird Community In Mosquito Lagoon, Florida, Usa, Jessica Copertino

Electronic Theses and Dissertations, 2020-2023

Birds are often used as indicators for biodiversity and ecosystem health. While birds have been monitored in other parts of the Indian River Lagoon (IRL), there has been little research on birds in Mosquito Lagoon (ML, the northernmost portion of the IRL). This thesis first examines the abundance and diversity of birds in ML by using two years of photographic observations to assess seasonal variations and the use of various habitat features by specific bird taxa. Abundance and species richness were highest in winter, while evenness and Simpson's diversity were highest in summer. Moreover, natural and artificial habitat features were …


Non-Lethal Predictors Of Organ Level Metal Contaminants In Central Florida Red-Shouldered Hawks, Jennifer Bouchenot Jan 2021

Non-Lethal Predictors Of Organ Level Metal Contaminants In Central Florida Red-Shouldered Hawks, Jennifer Bouchenot

Electronic Theses and Dissertations, 2020-2023

Elemental contaminants aggregate in the environment due to human activity and can induce detrimental physiological effects within organisms. Birds exhibit exceptional susceptibility to many pollutants and are popular biomonitoring agents throughout the world. Birds of prey are of special interest due to their substantial biomagnification potential. Lethal sampling of internal organs yields accurate contaminant measurements, but recent sampling trends are endeavoring towards non-destructive sampling such as feathers. This methodological shift stems from researchers' preference for less-regulated samples, enhanced animal welfare, and broadening the possible collaborative audience with simpler protocols. Unfortunately, investigations of feathers have shown that their accuracy is capricious …


Common Raven Nesting And Spatial Distancing On Power Lines In Southeast Idaho, Usa, Quinn R. Shurtliff, Jericho C. Whiting Jan 2021

Common Raven Nesting And Spatial Distancing On Power Lines In Southeast Idaho, Usa, Quinn R. Shurtliff, Jericho C. Whiting

Human–Wildlife Interactions

Common raven (Corvus corax; raven) abundance and distribution have increased in western North America in recent decades, facilitated by anthropogenic subsidies and other environmental changes. Electrical power transmission line structures provide nesting substrates for ravens. When these structures transect landscapes where natural nest substrates are limited, they may facilitate raven predation on eggs and juveniles of sensitive avian and reptile species. Little information is available regarding raven nest density trends on adjacent power lines or how raven territorial behavior influences spatial partitioning of nests, and hence, nest density. This knowledge would be valuable for managers of sensitive prey …


Synthesis Of Nest Predation Impacts Of Common Ravens On Sensitive Avian Species, Peter S. Coates, William C. Webb, Seth J. Dettenmaier, Seth M. Harju, David J. Delehanty Jan 2021

Synthesis Of Nest Predation Impacts Of Common Ravens On Sensitive Avian Species, Peter S. Coates, William C. Webb, Seth J. Dettenmaier, Seth M. Harju, David J. Delehanty

Human–Wildlife Interactions

Decades of mounting scientific evidence have revealed that common raven (Corvus corax; raven) population numbers have been increasing across nearly all regions of their geographic range in North America. Concomitantly, numerous native wildlife species have experienced elevated predation rates from ravens as populations have increased and expanded their range. Managers are concerned that increased raven predation of many threatened and endangered avian species in the U.S. and Canada during nesting periods may be hampering species recovery. We explored the literature to aggregate existing knowledge and evaluate the impacts of raven predation on nests and young of sensitive avian …


A Decision Tool To Identify Population Management Strategies For Common Ravens And Other Avian Predators, Andrea F. Currylow, Brenda J. Hanley, Kerry L. Holcomb, Timothy Shields, Stephen Boland, William I. Boarman, Mercy Vaughn Jan 2021

A Decision Tool To Identify Population Management Strategies For Common Ravens And Other Avian Predators, Andrea F. Currylow, Brenda J. Hanley, Kerry L. Holcomb, Timothy Shields, Stephen Boland, William I. Boarman, Mercy Vaughn

Human–Wildlife Interactions

Some avian species have developed the capacity to leverage resource subsidies associated with human manipulated landscapes to increase population densities in habitats with naturally low carrying capacities. Elevated corvid densities and new territory establishment have led to an unsustainable increase in depredation pressure on sympatric native wildlife prey populations as well as in crop damage. Yet, subsidized predator removal programs aimed at reducing densities are likely most effective longer-term when conducted in tandem with subsidy control, habitat management, and robust assessment monitoring programs. We developed decision support software that leverages stage structured Lefkovitch population matrices to compare and identify treatment …


Searching For Gold: Using A Novel Land Cover Classification To Identify Multiscale Drivers Of Site Occupancy By A Flagship Species For Early-Successional Habitat Conservation, Baron Lin Jan 2021

Searching For Gold: Using A Novel Land Cover Classification To Identify Multiscale Drivers Of Site Occupancy By A Flagship Species For Early-Successional Habitat Conservation, Baron Lin

Theses and Dissertations

Understanding habitat selection at multiple scales is an important step in guiding conservation programs and reversing species declines. This, however, is difficult for species that occupy early-successional habitats (ESH) due to a lack of accurate representation of shrub cover in publicly available land cover data. The Golden-winged Warbler (Vermivora chrysoptera; GWWA) is a threatened species of conservation concern and a flagship for ESH conservation. We used a novel, LIDAR-derived land cover classification that accurately identifies shrubs at a fine resolution (1m) to investigate how habitat composition and configuration influence GWWA site occupancy. We aggregated this same land cover …


Inter- And Intra-Annual Effects Of Lethal Removal On Common Raven Abundance In Nevada And California, Usa, Shawn T. O'Neil, Peter S. Coates, Julia C. Brockman, Pat J. Jackson, Jack O. Spencer Jr., Perry J. Williams Jan 2021

Inter- And Intra-Annual Effects Of Lethal Removal On Common Raven Abundance In Nevada And California, Usa, Shawn T. O'Neil, Peter S. Coates, Julia C. Brockman, Pat J. Jackson, Jack O. Spencer Jr., Perry J. Williams

Human–Wildlife Interactions

Populations of common ravens (Corvus corax; ravens) have increased rapidly within sagebrush (Artemisia spp.) ecosystems between 1960 and 2020. Although ravens are native to North America, their population densities have expanded to levels that negatively influence the population dynamics of other wildlife species of conservation concern, such as greater sage-grouse (Centrocercus urophasianus) and desert tortoises (Gopherus agassizii). For this reason, lethal removal, such as the application of the avicide DRC-1339, has been used to manage raven numbers at local scales and under certain circumstances. Because the relative effectiveness of DRC-1339 in reducing raven …


Common Raven Impacts On The Productivity Of A Small Breeding Population Of Snowy Plovers, Matthew J. Lau, Benjamin H. Becker, David T. Press Jan 2021

Common Raven Impacts On The Productivity Of A Small Breeding Population Of Snowy Plovers, Matthew J. Lau, Benjamin H. Becker, David T. Press

Human–Wildlife Interactions

Common ravens (ravens; Corvus corax), an adaptable, synanthropic generalist, have thrived coincident with increasing human landscape modifications and fragmentation, consequently affecting their prey, which are often sensitive native and protected species. Ravens are a conservation concern for the protected western snowy plover (plover; Charadrius nivosus nivosus), causing low nest and chick survival in some breeding areas along the Pacific coast of North America. We used a long-term dataset from a breeding snowy plover monitoring program in Point Reyes National Seashore (PRNS) to investigate potential impacts of ravens on snowy plover nest and fledging success. Between 2002 and 2020, …


Increased Abundance Of The Common Raven Within The Ranges Of Greater And Gunnison Sage-Grouse: Influence Of Anthropogenic Subsidies And Fire, Jonathan B. Dinkins, Lindsey R. Perry, Jeffrey L. Beck, Jimmy D. Taylor Jan 2021

Increased Abundance Of The Common Raven Within The Ranges Of Greater And Gunnison Sage-Grouse: Influence Of Anthropogenic Subsidies And Fire, Jonathan B. Dinkins, Lindsey R. Perry, Jeffrey L. Beck, Jimmy D. Taylor

Human–Wildlife Interactions

The common raven (Corvus corax; raven) is native to North America and has increased in abundance, especially throughout western North America, during the last century. Human subsidies have facilitated raven dispersal into less suitable habitats and enabled these populations to maintain higher annual survival and reproduction. Concomitantly, overabundant raven populations are impacting other native at-risk species such as the greater sage-grouse (Centrocercus urophasianus) and potentially the Gunnison sage-grouse (C. minimus). Using Breeding Bird Survey data from 1995–2014, we evaluated raven count data to quantitatively describe changes in abundance and expansion into sagebrush (Artemisia …


Thinking Like A Raven: Restoring Integrity, Stability, And Beauty To Western Ecosystems, John M. Marzluff, Matthias-Claudio Loretto, Cameron K. Ho, Georgia W. Coleman, Marco Restani Jan 2021

Thinking Like A Raven: Restoring Integrity, Stability, And Beauty To Western Ecosystems, John M. Marzluff, Matthias-Claudio Loretto, Cameron K. Ho, Georgia W. Coleman, Marco Restani

Human–Wildlife Interactions

Common ravens (Corvus corax; ravens) are generalist predators that pose a threat to several rare wildlife species in the western United States. Recent increases in raven populations, which are fueled by increased human subsidies—notably food, water, and nest sites—are concerning to those seeking to conserve rare species. Due to the challenges and inefficiencies of reducing or eliminating subsidies, managers increasingly rely on lethal removal of ravens. Over 125,000 ravens were killed by the U.S. Government from 1996 to 2019, and annual removals have increased 4-fold from the 1990s to mid-2010s. We contend that lethal removal of ravens, while capable …


Estimating Trends Of Common Raven Populations In North America, 1966–2018, Seth M. Harju, Peter S. Coates, Seth J. Dettenmaier, Jonathan B. Dinkins, Pat J. Jackson, Michael P. Chenaille Jan 2021

Estimating Trends Of Common Raven Populations In North America, 1966–2018, Seth M. Harju, Peter S. Coates, Seth J. Dettenmaier, Jonathan B. Dinkins, Pat J. Jackson, Michael P. Chenaille

Human–Wildlife Interactions

Over the last half century, common raven (Corvus corax; raven) populations have increased in abundance across much of North America. Ravens are generalist predators known to depredate the eggs and young of several sensitive species. Quantifying raven population increases at multiple spatial scales across North America will help wildlife resource managers identify areas where population increases present the greatest risk to species conservation. We used a hierarchical Bayesian modeling approach to analyze trends of standardized raven counts from 1966 to 2018 using Breeding Bird Survey data within each Level I and II ecoregion of the United States and Canada. …


A Rapid Assessment Function To Estimate Common Raven Population Densities: Implications For Targeted Management, Brianne E. Brussee, Peter S. Coates, Shawn T. O'Neil, Seth J. Dettenmaier, Pat J. Jackson, Kristy B. Howe, David Delehanty Jan 2021

A Rapid Assessment Function To Estimate Common Raven Population Densities: Implications For Targeted Management, Brianne E. Brussee, Peter S. Coates, Shawn T. O'Neil, Seth J. Dettenmaier, Pat J. Jackson, Kristy B. Howe, David Delehanty

Human–Wildlife Interactions

Common raven (Corvus corax; raven) populations have increased over the past 5 decades within the western United States. Raven population increases have been largely attributed to growing resource subsidies from expansion of human enterprise. Concomitantly, managers are becoming increasingly concerned about elevated adverse effects on multiple sensitive prey species, damage to livestock and agriculture, and human safety. Managers could benefit from a rapid but reliable method to estimate raven densities across spatiotemporal scales to monitor raven populations more efficiently and inform targeted and adaptive management frameworks. However, obtaining estimates of raven density is data- and resource-intensive, which renders …


Evaluating Common Raven Take For Greater Sage-Grouse In Oregon’S Baker County Priority Conservation Area And Great Basin Region, Frank F. Rivera-Milán, Peter S. Coates, Jacqueline B. Cupples, Michael Green, Patrick K. Devers Jan 2021

Evaluating Common Raven Take For Greater Sage-Grouse In Oregon’S Baker County Priority Conservation Area And Great Basin Region, Frank F. Rivera-Milán, Peter S. Coates, Jacqueline B. Cupples, Michael Green, Patrick K. Devers

Human–Wildlife Interactions

The common raven (Corvus corax; raven) is a nest predator of species of conservation concern, such as the greater sage-grouse (Centrocercus urophasianus). Reducing raven abundance by take requires authorization under the Migratory Bird Treaty Act. To support U.S. Fish and Wildlife Service’s take decisions (e.g., those that authorize killing a specified proportion or number of individuals annually in a defined area), including the most recent one for Oregon’s Baker County Priority Area for Conservation (PAC), we modeled raven population dynamics under hypothetical scenarios with take rates ranging from below to above the maximum sustained yield (MSY; …