Population Biology Commons^™

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

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 …

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 …

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

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

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 …

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

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 …

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

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; …

A Preliminary Study On The Small Population Paradigm And Nesting Biology Of Rose-Ringed Parakeets (Psittacula Krameri) In Gujar Khan, Pakistan, Muhammad Bilal, Muhammad Huzaifa Zahid, Khalid Mahmood, Abdullah Ibrahim, Ali Hasnain Mosvi, Amir Naseer, Sadia Munir

Journal of Bioresource Management

Rose-ringed parakeet (P. krameri) is commonly found native psittacid in Pakistan. It is most popular companion bird in Pakistan. It is an unprotected species as per The Punjab Wildlife Act, 1974. The objectives of the present study were to study its population paradigm and basic nesting biology in the Gujar Khan, Punjab, Pakistan. Previously, no studies were carried out to assess its live and vacant nest cavities, nesting site, nest height, cavity position on substrate, and potential roosts in the area. Moreover, this study also assesses the potential threats and factors in this area and conservation of the …

Modeling Migratory Nongame Birds: A Plea For Data, George M. Linz

Human–Wildlife Interactions

The Bird Damage Management Conference held February 10–13, 2020 in Salt Lake City, Utah, USA provided a forum for professionals from across the United States to discuss and share management approaches, research strategies, policy, and messaging regarding the management of blackbirds (Icteridae), starlings (Sturnus vulgaris), corvids (Corvidae), and vultures (Cathartidae). Mathematical models were presented at the conference and subsequently discussed in a special issue of Human–Wildlife Interactions. Rapidly changing landscape variables point to the need for detailed systematic population monitoring programs with specific objectives. Nationwide periodic monitoring would provide data about changes not only in bird populations …

The Nebraska Bird Review, Volume 88 December 2020 Number 4

Nebraska Bird Review

Fall Field Report, August - November 2020, by W. Ross Silcock …13.8

History of the Seward - Branched Oak Christmas Bird Count, 1993-2020, by Joseph Gubanyi …162

Index to Volume 88 … 173

Subscription and Organization Information …187

Fall Field Report, August-November 2020, W. Ross Silcock

Nebraska Bird Review

Two issues were of concern this fall, and both appeared to have consequences or at least similarities in Nebraska. A major die-off in New Mexico made national news: https://www.aba.org/the-data-behind-mysterious-bird-deaths-in-new-mexico/. On Sep 9, 2020, the temperature dropped from 96°F to 40°F in the Albuquerque area, a record low, winds reached 70 mph, and several inches of snow fell, killing large numbers of birds directly. Over the next few days, hundreds more dead birds were picked up. Some have linked this high mortality to birds displaced from the mountains due to fire and unfortunately being caught in the severe weather. While fire …

History Of The Seward-Branched Oak Lake Christmas Bird Count, 1993-2020, Joseph A. Gubanyi

Nebraska Bird Review

The Seward-Branched Oak Lake Christmas Bird Count (Seward-BOL CBC) began in 1993 and has been conducted every year since then except for 2010 for a total of 27 counts. Weather conditions prevented the count on the selected date in 2010 and a backup date could not be set up. The count was started for several reasons. The area west of Lincoln has a diversity of habitats including all or part of four public lakes (Branched Oak, Pawnee, Twin Lakes, and Meadowlark) as well as a diversity of terrestrial habitats on both public and private land. The circle is close to …

Index To Volume 88

Nebraska Bird Review

Index to The Nebraska Bird Review, Volume 88 (2020)

From: Aden, Scott 95

to: Zonotrichia leucophrys gambelii 158 leucophrys 70, 158 oriantha 70

Summer Field Report, June-July 2020, W. Ross Silcock

Nebraska Bird Review

Overall, this was a fairly routine summer although birders in Nebraska know that “routine” still holds promise of a few happenings out of the ordinary. The summer season primarily examines new breeding records, range expansions, and changes in numbers, up or down. Mississippi Kites were conspicuous, a pair providing Scottsbluff’s first breeding record, but a repeating pair in Lincoln, Lancaster lost its nest in a windstorm. The first nesting record for Violet-Green Swallow for Sheridan, 7th nesting for White-winged Dove, and 9th for Short-eared Owl were all encouraging, as was an apparent family group of Northern Saw-whet Owls in Sioux. …

Robert Wolcott And The Art Of Nest Records, Thomas E. Labedz

Nebraska Bird Review

The autumn of 1894 was fortuitous for Nebraska ornithology because it is when Robert Henry Wolcott accepted an assistantship at the University of Nebraska, moving to Lincoln from the University of Michigan (Swenk 1935). Wolcott, from that point onward, made significant contributions to our knowledge of Nebraska birds (Bruner et al. 1903, Wolcott 1909, 1919), was a founding member of the Nebraska Ornithologists’ Union (NOU), and was editor for the first three Proceedings of the NOU from 1899-1902. His work expanded beyond local focus and he eventually authored a text on animal biology (Wolcott 1933). The topic of this paper, …

The Nebraska Bird Review, Volume 88 September 2020, Number 3

Nebraska Bird Review

Summer Field Report, June - July 2020, by W. Ross Silcock …94.

Robert Wolcott and the Art of Nest Records, by Thomas E. Labedz …112

2019 (31st) Report of the NOU Records Committee, by Mark A. Brogie …124

Subscription and Organization Information …135

2019 (31st) Report Of The Nou Records Committee, Mark A. Brogie

Nebraska Bird Review

The functions and methods of the Nebraska Ornithologists’ Union Records Committee (NOURC) are described in its bylaws (NOURC 2010). The committee’s purpose is to provide a procedure for documenting unusual bird sightings and to establish a list of all documented birds for Nebraska. Species for which the NOURC seeks documentation (NOURC Review List) can be found at the NOU website www.NOUbirds.org. Starting in 2020, the NOURC will deal mainly with those species deemed as Accidental on the “Official List of the Birds of Nebraska”. Casual species and out-ofrange species will continue to be summarized in the “Seasonal Reports” of the …

Window Strike Bird Mortality On The University Of Nebraska – Lincoln City Campus, Thomas E. Labedz

Nebraska Bird Review

On May 25, 1915, in Lincoln, Lancaster County, Nebraska, a Gray-cheeked Thrush was “killed by flying against the library building on city campus” and was found by Robert H. Wolcott and prepared as a scientific study skin by Leroy M. Gates. This thrush is now ZM-6674 in the University of Nebraska State Museum (UNSM) Zoology collections. Birds are typically killed at low level buildings by flying into windows. This thrush is the first documented window strike death for what is now the University of Nebraska – Lincoln city campus. Based upon the UNSM bird collections I report on the last …

The Nebraska Bird Review, Volume 88 June 2020 Number 2

Nebraska Bird Review

Spring Field Report, March - May 2020, by W. Ross Silcock …46

Window Strike Bird Mortality on the University of Nebraska - Lincoln City Campus, by Thomas E. Labedz …75

Subscription and Organization Information…91

Prey Selection By Birds Of Prey, Anisha Pokharel

School of Biological Sciences: Dissertations, Theses, and Student Research

Prey selection is key to determine predator prey interaction and understanding the complexity of food web structure. In this thesis, we used two different approaches to understanding prey selection by North American birds of prey. Using a conventional method, in Chapter 1 we compared pellet analysis and trapping data to assess patterns of prey selection of barn owls in western Nebraska. Microtus spp. comprised 55.8% of the prey items in the barn owl’s diet. The proportion of several prey types in the diet were significantly different from the expected proportion based on trapping. This pattern may indicate barn owls actively …

The Nebraska Bird Review, 2020 Annual Color Section

Nebraska Bird Review

Our theme this year is Odd Couples: two or more different species captured in the same photo frame. Examples appear on the first three pages of photos.

Blue Jay with Great Horned Owl in Plum Creek SRA, Dawson Co., 23 Dec. 2019. Photo by Elizabeth Winter.

Green Heron with Baltimore Oriole on Dark Island Trail, Merrick Co., June 2020. Photo by Colleen Childers.

Wilson’s Phalarope surrounded by Longbilled Dowitchers and Stilt Sandpipers along highway 30 east of North Platte, Lincoln Co., 12 May 2020. Photo by Boni Edwards.

Downy Woodpecker with Carolina Wren on suet feeder in photographer’s yard, La …

Winter Field Report, December 2019-February 2020, W. Ross Silcock

Nebraska Bird Review

As with any of these Seasonal Reports, there was plenty to entertain us and to contemplate this winter. The most obvious feature of this winter’s reports was the taxonomically widespread incidence of midwinter occurrences of species normally absent at that time. Snow, Ross’s, and Greater White-fronted Geese occurred in good numbers, and Jan to early Feb reports of dabbling and diving ducks often far from expected winter occurrence locations were notable. Among passerines, notable midwinter reports were of Gray Catbird, Brown Thrasher, and Northern Mockingbird, Nebraska’s first record for Feb of American Pipit, and 6th winter record of Lesser Goldfinch. …

2019-2020 Christmas Bird Counts, Don Paseka

Nebraska Bird Review

Mergansers reached a new high of 104 counted in nine circles, which topped the count of 97 from 2017. A single Surf Scoter was found in the Lower Platte circle, which was only the fourth time that this species has been found on a Nebraska CBC. Lone birds were also found at Lake McConaughy in 1999, 2010 and 2015. A good North Platte find were two Barrow’s Goldeneye. Several species, however, were counted in numbers much below the norm. The lone Wood Duck found at Branched Oak was the lowest count for that species since 2004, when they were missed …

Assessing Population Genetic Structure Of Eastern Phoebes At A Migratory Stopover Site, Daniel Jones

Biology Theses

Migration is an energetically costly and stressful event and migratory stopover sites are important areas along the migratory route that birds stop at to rest and refuel. Migration timing and routes vary across and even within species, including differences between sexes, ages and populations. Most genetic studies of migratory birds occur on breeding grounds, but when breeding locations are not known, it is likely that genetic patterns can be assessed accurately at migratory stopover sites if certain conditions exist. First, if a species is philopatric – where individuals return to the same sites every year, gene flow across geographically separated …

Proceedings Of The Fifteenth North American Crane Workshop, Jane E. Austin, Richard P. Urbanek, Megan E. Brown

Proceedings of the North American Crane Workshop

Proceedings of the Fifteenth North American Crane Workshop (2020) edited by Jane E. Austin, Richard P. Urbanek, and Megan E. Brown.

Spring Field Report, March-May 2020, W. Ross Silcock

Nebraska Bird Review

Although there were numerous early arrival dates, most were in the range of historically earliest expected dates; notable, however, was a lone record-early Whiterumped Sandpiper, nicely photographed. Record late by a month was a juvenile Redtailed (Harlan’s) Hawk, also confirmed by photo. Perhaps most prominent this spring were the large numbers of several species. Most eye-popping were record spring totals of 22 Glossy Ibises, 11 Yellow-bellied Flycatchers, 14 Veeries, including five in the Panhandle, 48 Gray-cheeked Thrushes, 20 Bay-breasted Warblers, not long ago a rare bird in spring, 45 Golden-winged Warblers and 27 Canada Warblers, both of which were about …

The Nebraska Bird Review, Volume 88 March 2020 Number 1

Nebraska Bird Review

Winter Field Report, Dec. 2019 - Feb. 2020, by W. Ross Silcock …2

2019-2020 Christmas Bird Counts …18, 27-41

Annual Color Photo Section …19-26

Annual Treasurer's Report for 2019, by Jan Johnson …42

Subscription and Organization Information …43