Journals publish Montana State ecologist’s studies on the effects of prey depletion on populations of large African carnivores

Montana State University

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By Diana Setterberg, MSU News Service

BOZEMAN – Two recently published studies by a Montana State University ecologist reveal new findings about the relationship between population dynamics of two species of large African carnivores and the availability of their prey.

“The studies are related in a lot of ways,” said Scott Creel, lead author of a paper about the effects of prey depletion on endangered African wild dogs that was published this week in the journal Proceedings of the National Academy of Sciences, and co-lead author of another paper about the effects of poaching controls on African lion demographics that was featured on the cover of the Jan.11 issue of Conservation Science and Practice. 

“The common denominator is that across sub-Saharan Africa, populations of animals like wildebeest and impala are declining pretty dramatically almost everywhere as a consequence of habitat loss and bushmeat poaching,” Creel said. “The densities of those animals, which are prey for species like African wild dogs and lions, are a tiny fraction of what they would have been 40 or 50 years ago.”

The two papers document studies by Creel and his students of the relationship between prey depletion and population decline of large carnivores. For several decades, Creel, a Distinguished Professor in the Department of Ecology in MSU’s College of Letters and Science, has studied the behavior, ecology and conservation of large mammals, with particular emphasis on African carnivores. 

For each study, the researchers monitored groups of animals in Zambia between 2013 and 2021, including prides of lions living in the massive Kafue ecosystem. The area is located in an economically depressed area of the country that has experienced significant declines in prey animals due to poaching.

“For very understandable reasons, the people living in villages next to the protected areas turn to bushmeat poaching as a way to get food and make money,” Creel explained. 

The researchers monitored the lions through both visual observation and data from collars worn by at least one animal in each group. During the first five years of the study, the lion population in the ecosystem declined by 3% per year, and Creel said there was debate among ecologists about whether that trend could be reversed. Some advocated for fencing to deter poachers, while others suggested employing other means of protecting the lions. In 2018, patrols were systematically increased to curb poaching in several well-defined areas of the ecosystem. 

That’s when the researchers started to see growth of the lion populations in those areas – most notably, a 29% increase in the number of cubs produced.

“More prey means it’s easier for a female lion to raise her cubs,” Creel said. “What used to be a litter of three cubs is now four cubs, and that will change population growth rate pretty dramatically.”

Also in the patrolled areas, the survival rate of the lions rose by about 8%, partly because fewer of them were being killed by snares in the patrolled areas, but also because more prey translates into better odds of survival. However, Creel said, the most significant benefit for lions was that fewer animals they hunt for food were dying in those snares. Overall, the study showed that in protected areas, the lion population grew by about 8% annually, while in unprotected areas, the population continued to decline.

“That’s a good news story in the face of these problems. It definitely shows that even in a big ecosystem that potentially can hold a huge population, increased investment works,” he said. “With 8% annual growth, a population will double in just 10 years.” 

The wild dog study told a different story, Creel said.

African wild dogs, about half the size of hyenas, are pack animals that typically live in groups of eight to 10 adults. They were listed as endangered in 1990, and fewer than 1,500 breeding adults remain in the world among a total population of about 6,500 individuals. The dogs hunt in teams, allowing them to prey upon the same species as larger carnivores, but their kills are often stolen by hyenas. And hyenas aren’t the only thing they have to worry about, because lions kill African wild dogs.

“They really are between a rock and a hard place,” Creel said. “In places with low prey density, they die at higher rates and reproduce at lower rates but they still have to avoid places with high lion density, because they’re just so dangerous.”

Creel and his team tested the physical effects of prey depletion on African wild dogs, focusing on two populations in ecosystems where prey and competitor densities varied. One or two adult members in each of 16 packs were fitted with collars that measured their energy expenditures, which provided researchers with highly detailed data about the animals’ activities.

“You can tell when they make a kill, you know how far they’ve run, you know how much energy they’ve burned,” Creel said. “It’s crystal clear.”

Combined with direct observation, the data revealed that the energy costs of hunting were higher and the benefits lower for wild dogs in prey-depleted areas, regardless of the number of competitors present – a fundamental change from past studies that showed the most important factor limiting population size was the presence of dominant competitors, Creel said.

“Wild dogs were always limited from the top down by their competitors. They’re limited now from the bottom up by their food supply,” Creel said. “The reason they do badly in those places is they have to go farther to find an opportunity to hunt, and they usually kill a smaller thing when they succeed. They burn much more energy and get less in return.

“That they switched from being limited by their competitors to being limited by food is a new thing, and unfortunately, very worrisome,” he said.

Both studies were conducted in coordination with the Zambia Department of National Parks and Wildlife and the Zambian Carnivore Programme. Matthew Becker, the co-lead author of the PNAS article, is CEO and program manager of the Zambian Carnivore Programme, an MSU alumnus and an affiliate faculty member in the Department of Ecology. Creel said the cooperation of those agencies made it possible to conduct the years of intensive field research that enabled scientists to become familiar with the lives of each individual animal and understand very well the factors that affect them.

“We’ve now shown that even in a huge, unfenced ecosystem that’s already heavily affected by humans, we can reverse the decline by increasing the investment in protection – we just need the will to do it,” Creel said. “We know what works, and it’s a pretty simple thing.”

He said he is encouraged that the Zambia Department of National Parks and Wildlife allows research and data to guide decision making, and by the potential economic benefits from tourism that could result from investing in protecting animals.

“I think the lion study is really exciting, in that if we can do it for lions, we can do it for all wildlife,” he said. “All boats are going to rise on the same tide if you increase the protection.”

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Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2414772122 

Method of Research

Observational study

Subject of Research

Animals

Article Title

Prey depletion, interspecific competition, and the energetics of hunting in endangered African wild dogs, Lycaon pictus

Article Publication Date

27-Jan-2025

 

Study of basic training of new police hires shows resistance to change

Academies focus on police as “warriors” instead of “guardians”

American Society of Criminology

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For the past 60 years, concerns over U.S. police officers’ excessive use of force and race-based targeting of citizens, and deteriorating relations between police and communities of color have spurred calls to change the focus of officers’ preservice basic training. Yet research suggests that few of the recommendations proposed have taken root.

In a new panel study, researchers assessed basic training of new police hires in hundreds of U.S. police academies. The study showed continuity over time in total required hours of training and a disproportionate distribution of total training hours for areas central to the crime fighting role of police, highlighting strong intransigence in the field.

The study was conducted by researchers at the University of Alabama at Birmingham (UAB) and the University of Central Florida (UCF). It is published in Criminology and Public Policy, a publication of the American Society of Criminology.

“We found strong evidence of long-term resistance to change in police basic training given the continuing overemphasis of traditional, crime fighting ‘warrior’ aspects of basic training over ‘guardian’ aspects such as community partnerships,” explains John Sloan, emeritus professor of criminal justice at UAB, who co-authored the study. “These findings, combined with recent qualitative analyses of police basic training, suggest that decades of efforts to get the occupation to change what new police officers learn during basic training have failed.”

Despite concerns by national level commissions, scholars, and practitioners about the substance of police academy basic training, this study is the first since the 1980s to examine the content of basic training at multiple police academies over an extended period that included two eras of policing: community-oriented and post-9/11 or evidence-based. Using secondary data from a census of 421 police academies across the United States that operated continuously between 2002 and 2018, the study assessed continuity and change in six core areas of basic law enforcement training of new police hires:

• Operations: first aid/CPR, computers and information systems, operation of emergency vehicles, investigations, and patrol procedures),
• Weapons/defensive tactics (non-lethal weapons, self-defense tactics, and firearms skills),
• Legal training (juveniles/juvenile justice procedure, criminal law, and constitutional law),
• Self-improvement: stress prevention and management, ethics and integrity, acquisition of a foreign language, and health and fitness,
• Community-oriented policing: mediation and conflict management, and cultural diversity, and
• Special topics: hate crimes and bias crimes, domestic preparedness and terrorism, and domestic violence.

The study showed continuity over time in total required hours of basic law enforcement training, including required hours of core curriculum training, with training averaging roughly 11 weeks of 40-hour weeks. In addition, across the six areas, prioritization of instruction remained relatively unchanged. Finally, within each of the six core training areas, the average amount of time allocated to each of the topics in the core curriculum varied considerably.

Police operations and weapons and defensive tactics received the greatest allotment of academy training time, while time spent on legal training declined. Moreover, training devoted to special topics, which have grown in importance in the last half century, received just over half a week on average. The fewest hours of training were devoted to community-oriented policing.

“Our findings reinforce the idea that the ‘warrior content’ of academy training takes precedence over training that supports police officers’ role as guardians,” suggests Eugene Paoline, professor of criminal justice at UCF, who coauthored the study.

“Recruiters, academy administrators and instructors, and agency leaders must take steps toward a complete and comprehensive reorientation of police recruitment and basic training that stresses the importance of new hires acquiring a toolkit that has a guardian-based foundation and emphasis but allows for the far fewer instances when officers need to use warrior tools,” adds Matt Nobles, professor of criminal justice at UCF, who coauthored the study.

These goals could be achieved, the authors say, by proportionally reducing the total required hours devoted to training in select operations, weapons and defensive tactics, and related topics, while proportionally increasing total required hours of training in guardian-related topics (e.g., interpersonal communication, conflict management, de-escalation, cultural diversity, community partnerships).

Among the limitations of their study, the authors note that they did not assess the specific content of the training, their data represent self-report surveys, and they did not consider potential sources of variation in training curricula (e.g., academies’ affiliation with different law enforcement agencies or educational institutions or regional location).

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Journal

Criminology & Public Policy

DOI

10.1111/1745-9133.12691 

Article Title

The more things change, the more they stay the same: A multi-wave national assessment of police academy training curricula

 AMERIKA

Using machine learning, study developed models to predict high-risk gun dealers

Results can help target enforcement to disrupt flow of firearms used in crimes

American Society of Criminology

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Federally licensed firearm dealers are an important target of regulatory and enforcement efforts aimed at reducing the supply of firearms diverted to the illicit market, but the extent of dealers’ involvement in the illegal diversion of firearms is hard to measure.

In a new study using machine learning, researchers examined firearm transaction and crime gun recovery records from California from 2010 to 2021 to identify dealers selling the highest number and largest proportion of guns recovered in crimes within a year of sale, a well-established indicator of possible illegal activity by dealers or traffickers. The prediction models have the potential to support targeted enforcement, helping disrupt the flow of firearms to offenders.

The study, by researchers at the University of California (UC), Davis, appears in Criminology & Public Policy, a publication of the American Society of Criminology.

“Although most gun offenders do not get their firearms directly from licensed dealers and most dealers abide by laws, even a few negligent or corrupt dealers can contribute significantly to the supply of firearms used in crimes,” explains Hannah Laqueur, associate professor of emergency medicine at UC Davis, who led the study.

Firearms dealers can facilitate the diversion of guns to the criminal market through practices such as selling to straw purchasers or failing to conduct required background checks. Prior studies have shown that enforcement actions and lawsuits targeting law-evading dealers can deter these behaviors and reduce the flow of firearms into criminal markets.

In this study, researchers used machine learning techniques to develop two prediction models. The first classifies dealer-years in the top 5% of one-year crime gun sales volume (the number of sales of guns recovered in crimes within a year of sale); the second identifies dealer years in the top 5% based on the fraction of sales recovered within a year. Both models had strong discriminative performance, with the first model particularly effective at identifying the highest-risk dealers.

The models generally outperformed simpler regression and rule-based approaches, underscoring the value of data-adaptive models for prediction. Key predictors included prior-year crime gun sales, the average age of purchasers, the proportion of “cheap” handgun sales, and the local gun robbery and assault rate.

Many of the dealers with the highest predicted probabilities not only sold a large volume of guns with very short “time-to-crime” but also consistently sold crime guns over multiple years. This suggests that a relatively small group of dealers could be targeted for enforcement, offering the potential for outsized impact. More consistent and targeted inspections of high-risk dealers, along with citations or license revocations, could strengthen deterrence and promote compliance, helping reduce the supply of guns to offenders.

“Our findings show how machine learning techniques, combined with California’s comprehensive firearm transaction and crime gun recovery data, could help identify potentially high-risk retailers,” says Laqueur. “This type of identification can improve the efficiency and effectiveness of inspections and enforcement efforts aimed at interdicting negligent or corrupt dealers.”

Among the study’s limitations, the authors note that dealers selling many short time-to-crime guns may not have violated the law and conversely, non-compliant dealers may not be reflected in short time-to-crime statistics. They also point out that because California is a state with stringent gun laws and extensive dealer regulations, the number of negligent or law-evading dealers in the study may be lower than in states with fewer regulations. However, while the study’s findings are specific to California, consistency of risk factors across different jurisdictions and regulatory contexts suggests that the models could inform approaches in other states, the authors say.

The study was supported by the National Collaborative on Gun Violence Research.

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Journal

Criminology & Public Policy

DOI

10.1111/1745-9133.12692 

Article Title

Identifying high-risk firearms dealers: A machine learning study of rapidly diverted firearm sales in California

Article Publication Date

28-Jan-2025\

Standardizing provider assessments reveals important information about gun and opioid access for US veterans at risk of suicide

Study of nearly 39,000 health records is the first to examine access to firearms and opioids, and completion of related interventions, among veterans at risk for suicide receiving care at the VA

University of Pennsylvania School of Medicine

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PHILADELPHIA—Standardizing an assessment process currently used by doctors during care discussions with veterans at risk for suicide in other context could shed more light on the risks related to firearms and opioids.  

The findings from researchers at the Perelman School of Medicine at the University of Pennsylvania were reported today in JAMA Network Open. They found that fewer veterans reported having access to firearms than expected—either because some didn't mention it to their doctor, it wasn't recorded by the provider, or because the true prevalence is lower among this high-risk group.

The research was led by Gabriela Khazanov, PhD, a research associate with the Penn Center for Mental Health and research psychologist with the Corporal Michael J. Crescenz VA Medical Center (VA). 

“Veterans have high rates of firearm ownership but may not always share this with their provider as part of suicide safety planning,” Khazanov said. “Some may worry, incorrectly, that their firearms would be confiscated, or their care would be impacted in some way, highlighting the importance of explaining the rationale for these discussions and describing any potential consequences, however unlikely, of firearm disclosure.”  

Among veterans, firearm injury accounts for 72 percent of suicides and poisoning, typically by overdose, accounts for 8 percent of suicides among veterans, respectively, with suicides due to opioid overdose nearly tripling over the last 20 years.  

The team reviewed health records of 38,454 veterans at risk for suicide receiving suicide safety plans in the VA—a brief, evidence-based intervention that helps patients identify strategies to prevent or de-escalate suicidal crises. One-third of veterans with access to firearms reported storing at least one firearm insecurely and only one-third of veterans with access to opioids accepted naloxone, an overdose-reversing drug. In addition, researchers found that only 5 percent of veterans included reported having access to opioids. 

Doctors did report addressing firearm safety with 98 percent of veterans with access to firearms and discussing overdose risks with 79 percent of veterans with access to opioids. 

“Veterans may have underreported access to opioids when discussing higher suicide risk due to concerns that their access to prescribed opioids would be limited,” Khazanov said.  

Researchers noted that while the study’s relative size was a strength, further study and discussion is necessary on socioeconomic and demographic differences when leading these discussions.  

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Penn Medicine is one of the world’s leading academic medical centers, dedicated to the related missions of medical education, biomedical research, excellence in patient care, and community service. The organization consists of the University of Pennsylvania Health System and Penn’s Raymond and Ruth Perelman School of Medicine, founded in 1765 as the nation’s first medical school.

The Perelman School of Medicine is consistently among the nation's top recipients of funding from the National Institutes of Health, with $550 million awarded in the 2022 fiscal year. Home to a proud history of “firsts” in medicine, Penn Medicine teams have pioneered discoveries and innovations that have shaped modern medicine, including recent breakthroughs such as CAR T cell therapy for cancer and the mRNA technology used in COVID-19 vaccines.

The University of Pennsylvania Health System’s patient care facilities stretch from the Susquehanna River in Pennsylvania to the New Jersey shore. These include the Hospital of the University of Pennsylvania, Penn Presbyterian Medical Center, Chester County Hospital, Lancaster General Health, Penn Medicine Princeton Health, and Pennsylvania Hospital—the nation’s first hospital, founded in 1751. Additional facilities and enterprises include GSPP Rehabilitation, Penn Medicine at Home, Lancaster Behavioral Health Hospital, and Princeton House Behavioral Health, among others.

Penn Medicine is an $11.1 billion enterprise powered by more than 49,000 talented faculty and staff.

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Journal

JAMA Network Open

Article Title

Access to Firearms and Opioids Among Veterans at Risk for Suicide

Article Publication Date

28-Jan-2025

 

Can you really have it all? New study reveals how to succeed at work without sacrificing your free time

Research highlights the benefits of integrating professional growth into leisure activities – but warns of the need for balance

Institute for Operations Research and the Management Sciences

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New INFORMS Organization Science Study Key Takeaways:

• Integrating work-related learning into leisure activities can enhance confidence, build new skills and support professional growth.

• Leisure-work synergizing is most effective for individuals who prefer blending work and personal life rather than keeping them separate.

• Overdoing leisure-work synergizing may lead to fatigue, emphasizing the importance of balance to maintain its benefits.

BALTIMORE, MD, January 28, 2025 – Could your favorite hobbies help you get ahead at work? New research published in the INFORMS journal Organization Science explores “leisure-work synergizing,” a novel strategy for integrating professional development into leisure activities. The findings suggest that this approach can help employees thrive in their careers while enjoying their personal lives – but only if used in moderation.

“We found that employees who intentionally integrate professional growth into their free time – like listening to leadership podcasts, watching TED Talks or reading engaging business books – report feeling more confident, motivated and capable at work,” says Kate Zipay, one of the study authors and professor at Purdue University. “This innovative approach allows individuals to build skills and thrive professionally without sacrificing the enjoyment of leisure activities.”

The study, “Have Your Cake and Eat It Too? Understanding Leisure-Work Synergizing and Its Impact on Employee Thriving,” also highlights potential challenges. For employees who prefer strict boundaries between work and personal life, blending the two may feel overwhelming and lead to fatigue.

“Employees who prefer a clear separation between work and personal life might struggle with this approach, highlighting the importance of tailoring the practice to individual preferences,” says Zipay.

For others, leisure-work synergizing offers a way to make downtime more fulfilling while advancing professional goals. “This isn’t about making your free time feel like work,” says Zipay. “It’s about leveraging activities you already love in a way that fuels your professional growth. Done right, it’s a game-changer for employees and employers alike.”

Zipay and co-author Jessica Rodell, professor at the University of Georgia, emphasize that these insights have far-reaching implications. As more employees seek ways to balance demanding careers with meaningful personal lives, leisure-work synergizing offers a fresh, practical solution. Employers can also use these findings to support skill development and employee well-being, creating a win-win for both sides.

 

Link to full study.

 

About INFORMS and Organization Science
INFORMS is the world’s largest association for professionals and students in operations research, AI, analytics, data science and related disciplines, serving as a global authority in advancing cutting-edge practices and fostering an interdisciplinary community of innovation.  Organization Science, a leading INFORMS journal, publishes innovative research on strategy, management and organizational theory. INFORMS empowers its community to enhance organizational performance and drive data-driven decision-making through its journals and resources. Learn more at www.informs.org or @informs.

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Journal

Organization Science

Method of Research

Observational study

Subject of Research

People

Article Title

Have Your Cake and Eat It Too? Understanding Leisure-Work Synergizing and Its Impact on Employee Thriving