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Full-Text Articles in Ecology and Evolutionary Biology

Breeding Ecology And Nest- Site Selection Of Turtle Doves (Streptopelia Turtur) In Three New Orchard Habitats, Thilelli Aitouakli, Ettayib Bensaci Apr 2021

Breeding Ecology And Nest- Site Selection Of Turtle Doves (Streptopelia Turtur) In Three New Orchard Habitats, Thilelli Aitouakli, Ettayib Bensaci

Journal of Bioresource Management

The main aim of our work was to investigate the breeding parameters in three orchard types in Algeria (apple, cherry and nectarine) for better conservation of existing species. A total of 149 active Turtle dove nests were monitored in these man–made agro-systems. Egg laying occurred from early May and continued until mid-August. Egg laying started later in cherry trees and stopped earlier in nectarines. Nest density was higher in apple orchards. Nests were located higher in nectarine. Clutch size was similar among orchard types. Northeast was the dominant orientation in all orchards. Breeding success was higher than that recorded in …


Population Fluctuation And Diurnal Time Budgeting Of White-Headed Duck (Oxyura Leucocephala) During Winter At Garaet Hadj Tahar (Skikda, North East Algerian), Merzoug Seyf Eddine, Abdi Soumia, Bara Mouslim, Houhamdi Moussa Mar 2021

Population Fluctuation And Diurnal Time Budgeting Of White-Headed Duck (Oxyura Leucocephala) During Winter At Garaet Hadj Tahar (Skikda, North East Algerian), Merzoug Seyf Eddine, Abdi Soumia, Bara Mouslim, Houhamdi Moussa

Journal of Bioresource Management

This study was focused on the ecology and behavior of the White-headed Duck (Oxyura leucocephala) at Garaet Hadj Tahar (Guerbes-Sanhadja, North East of Algeria). Sampling was carried out during two wintering seasons (2017-2018 and 2018-2019). High number of this duck was recorded in 2018/19 (350 individuals). We observed two Oxyura population, the first sedentary, and the second, hosted the Garaet during the wintering season. Diurnal time budget was dominated by the comfort activities the sleeping with a rate of 39.13%. Following by swimming (37.76%), feeding (17.59%) grooming (4.58%), courtship ritual (0.56%) and flying (0.38%). The feeding of white-headed …


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 …


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; …


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 …


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 …


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 …


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 …


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 …