Removal of barred owls slows decline of iconic spotted owls in Pacific Northwest, study finds
(Press-News.org) CORVALLIS, Ore. - A 17-year study in Oregon, Washington and California found that removal of invasive barred owls arrested the population decline of the northern spotted owl, a native species threatened by invading barred owls and the loss of old-forest habitats.
The conservation and management of northern spotted owls became one of the largest and most visible wildlife conservation issues in United States history after the U.S. Fish and Wildlife Service listed the spotted owl as threatened under the Endangered Species Act in 1990 because of rapid declines in the owl's old-forest habitats. Four years later, the Northwest Forest Plan was adopted and reduced the rate of logging of old-growth forests on federal lands.
Despite more than 30 years of protection, spotted owl populations have continued to decline, with steepest declines observed in the past 10 years. Long-term monitoring of spotted owl populations across the species' range identified rapid increases in the population of invasive barred owls as a primary reason for those declines, the researchers said.
The study published this week in PNAS by scientists at the U.S. Geological Survey, Oregon State University, and several other entities is the first to look at the wide-scale impact of barred owls on populations of spotted owls in the Pacific Northwest.
The study focused on two sites in northern California, two in Oregon and one in Washington and found that spotted owl populations stabilized in all study areas where the researchers lethally removed barred owls (0.2% decline per year on average) but continued to decline sharply in areas without removals (12.1% decline per year on average.)
The findings in the new paper inform future management decisions about the spotted owl population.
"This study is a promising example of successful removal and suppression of an invasive and increasingly abundant competitor, with a positive demographic response from a threatened native species," said David Wiens, the lead author of the paper who is a wildlife biologist with the USGS Forest and Rangeland Ecosystem Science Center in Corvallis and a courtesy faculty member with Oregon State's Department of Fisheries, Wildlife, and Conservation Sciences.
As a species native to eastern North America, barred owls began expanding their populations westward in the early 1900s. The newly extended range now completely overlaps that of the northern spotted owl.
While barred owls look similar to spotted owls, they are larger, have a stronger ecological impact and outcompete spotted owls for habitat and food. This competition exacerbated spotted owl population declines, which were historically triggered by loss of old-forest habitat.
Mounting concerns about the threat of barred owls prompted a barred owl removal pilot project from 2009 to 2013 in California that concluded removal of barred owls, coupled with conservation of old forest, could slow or reverse population declines of spotted owls.
The research outlined in the PNAS paper expanded the pilot project to cover a much wider geographic range and a longer time period. The new research showed that barred owl removal had a strong, positive effect on survival and population trends of spotted owls that was consistent across all five study areas.
The conservation and restoration of old forests, which has been a chief focus of recovery strategies for the northern spotted owl, is a major source of controversy in the Pacific Northwest. The barred owl invasion has exacerbated this issue, placing an even higher premium on remaining old conifer forests.
"While suppression of barred owls can be difficult, costly, and ethically challenging, improvements in vital rates and population trends of spotted owls, and perhaps other threatened wildlife, can be expected when densities of barred owls are reduced from current levels," the researchers write in the paper. "Alien predators are considered to be more harmful to prey populations than native predators, and the dynamic interactions between invasive and native predators can lead to profound changes in ecosystems, often with considerable conservation and economic impacts."
ELSE PRESS RELEASES FROM THIS DATE:
Tsukuba, Japan - Scientists from the department of Anatomy and Embryology at the Faculty of Medicine of the University of Tsukuba created a computer model to simulate the development of complex structures based on the Delta-Notch signaling pathway. This work may lead to a more comprehensive picture of the process that results in the formation of organs and other physiological systems.
The development of a tiny embryo consisting of undifferentiated cells into a healthy fetus with spatially defined organs depends on the complex interplay between genetic instructions and signaling molecules. For example, "Notch" genes are ...
Berkeley -- More than 700 imaging satellites are orbiting the earth, and every day they beam vast oceans of information -- including data that reflects climate change, health and poverty -- to databases on the ground. There's just one problem: While the geospatial data could help researchers and policymakers address critical challenges, only those with considerable wealth and expertise can access it.
Now, a team based at the University of California, Berkeley, has devised a machine learning system to tap the problem-solving potential of satellite imaging, using low-cost, ...
CATONSVILLE, MD, July 20, 2021 - Uber and Lyft are popular on-demand ways to travel, but does that mean trains and buses are a thing of the past? Travelers prefer different modes of transportation at different times. So how can all these modes co-exist and do so successfully? New research in the INFORMS Journal Transportation Science has created a model and an algorithm to redistribute transit resources based on commuter preferences resulting in millions in savings.
"Based on case study experiments in New York City, our optimized transit schedules consistently lead to 0.4%-3% system-wide cost reduction. This amounts to rush hour savings of millions of dollars per day, while simultaneously reducing costs to passengers and transportation service ...
A team of chemists from the Croatian Ruđer Bošković Institute (RBI) described a new, easy-to-use method for uninterrupted monitoring of mechanochemical reactions. These reactions are conducted in closed milling devices, so in order to monitor the reaction one has to open the reaction vessel, thus interfering with the process. The new method uses Raman spectroscopy to get deeper insight into solid-state milling reactions, without the usual interruption of the chemical reaction process.
Mechanochemical synthesis by milling is used today to prepare all ...
High school students who participated in summer programs about public health increased their interest in pursuing careers in science, technology, engineering and mathematics (STEM), according to a Rutgers study.
Published in the journalPedagogy in Health Promotion, the study explored whether increasing public health awareness would motivate high school students to pursue public health careers.
Researchers found that the summer program, Public Health: Outbreaks, Communities, and Urban Studies (PHocus) offered in 2018 and 2019 increased the students' knowledge in public health, epidemiology, urban public health and global public health.
"Including interdisciplinary, authentic ...
ROCHESTER, Minn. ? Using data from 9,859 COVID-19 infections, Mayo Clinic researchers have new insights into risk factors for younger populations, some of which differ significantly from their older counterparts. People younger than 45 had a greater than threefold increased risk of severe infection if they had cancer or heart disease, or blood, neurologic or endocrine disorders, the research found. These associations were weaker in older age groups. The study was published in Mayo Clinic Proceedings.
The research team studied people living in a 27-county region of Southeast Minnesota and West Central Wisconsin surrounding Mayo Clinic in Rochester diagnosed with COVID-19 between March and ...
In the largest study of its kind, an investigation by UC San Francisco has found no evidence that moderate coffee consumption can cause cardiac arrhythmia.
In fact, each additional daily cup of coffee consumed among several hundred thousand individuals was associated with a 3 percent lower risk of any arrhythmia occurring, including atrial fibrillation, premature ventricular contractions, or other common heart conditions, the researchers report. The study included a four-year follow up.
The paper is published July 19, 2021, in JAMA Internal Medicine.
"Coffee is the primary source of caffeine for most people, and it has a reputation for causing or exacerbating arrhythmias," said senior and corresponding author Gregory Marcus, MD, professor ...
It is a scenario familiar to anyone who has driven down a crowded, narrow street. Parked cars line both sides, and there isn't enough space for vehicles traveling in both directions to pass each other. One has to duck into a gap in the parked cars or slow and pull over as far as possible for the other to squeeze by.
Drivers find a way to negotiate this, but not without close calls and frustration. Programming an autonomous vehicle (AV) to do the same -- without a human behind the wheel or knowledge of what the other driver might do -- presented a unique challenge ...
Wind energy is of outstanding importance to the energy transition in Germany. According to the Federal Statistical Office, its share in total gross electricity production of about 24% is far higher than those of all other renewable energy sources. "To reach our climate goals, it is important to further expand these capacities and to replace as much coal-based power as possible," says Professor Wolf Fichtner from KIT's Institute for Industrial Production (IIP). "However, there is considerable resistance, especially in beautiful landscapes." A team of researchers from KIT, the University of Aberdeen, and the Technical University of Denmark has now calculated what this means for the costs ...
The photovoltaic effect of ferroelectric crystals can be increased by a factor of 1,000 if three different materials are arranged periodically in a lattice. This has been revealed in a study by researchers at Martin Luther University Halle-Wittenberg (MLU). They achieved this by creating crystalline layers of barium titanate, strontium titanate and calcium titanate which they alternately placed on top of one another. Their findings, which could significantly increase the efficiency of solar cells, were published in the journal Science Advances.
electric crystals do not require a so-called pn junction to create the photovoltaic effect, in other words, no positively and negatively doped layers. This makes it much easier to produce ...
LAST 30 PRESS RELEASES:
[Press-News.org] Removal of barred owls slows decline of iconic spotted owls in Pacific Northwest, study finds