PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Spotted apex predator being pressured by spotted pack hunters – and it's our fault

Spotted apex predator being pressured by spotted pack hunters – and it's our fault
2024-07-02
(Press-News.org)

Who’s stronger? A solitary leopard or cackle of hyenas? And which is best at getting along with humans?

University of Copenhagen researchers closely studied this in a large East African natural area surrounded by rural settlements. The study demonstrates that the presence of humans has a direct impact on the competitive relationship between the two large predator species: leopards (Panthera pardus) – the iconic spotted feline and the spotted hyena (Crocuta crocuta) – a kleptoparasite and pack hunter known for its comical appearance and characteristic 'laugh'.

"We humans continue eating our way into the little bit of wilderness left in the world. As we do, we impact wildlife. This study demonstrates that human disturbance upsets the balance between competing species and that this advantages hyenas," says Rasmus W. Havmøller, the study’s first author and a postdoc at the University of Copenhagen’s Natural History Museum of Denmark.

For months, Havmøller have been using camera traps to observe the dynamics between hyenas and leopards living in Tanzania’s Udzungwa Mountains – an approximately 2,000 km2 national park that is completely surrounded by agricultural and populated areas. The study is the first to combine camera observations of large predators over both time and space in a single analysis.

While the hyena as a species seems to be increasing in numbers, the population of leopards has been in significant decline for decades, both in Africa and worldwide. Since hyenas are the leopards' only competitor in this particular natural area, the ability of the two species to coexist is important for their survival. And here, the local population is an important factor:

"As the local people definitely don’t' like leopards, the leopards retreat as far away from humans as possible. Hyenas, on the other hand, benefit from the fact that humans don’t feel threatened by or pursue them. Consequently, hyenas live in close to human populations and may even exploit humans as shields against the leopards," says Havmøller.

"But the areas nearest to humans are also the areas with the most prey. And as hyenas assert dominance over these areas, it increases their ability to outcompete leopards and potentially threaten the leopard's adaptability," adds Havmøller.

Size matters

The researchers' observations confirm that size matters. While male leopards, which are larger, retain their dominance over hyenas, the situation is different for female leopards, which are smaller.

"Even though the male leopards are the ones in charge, the hyenas aren’t exactly scared off by them. They simply hang out in the background – probably to follow the leopards and steal their prey. But the physical inferiority of the hyenas seems to be compensated for in the areas closest to humans, because male leopards pull out," says Rasmus W. Havmøller, who continues:

"Female leopards, on the other hand, completely change their behavior when hyenas are in the area. They become diurnal, whereas hyenas are primarily nocturnal. This is probably because female leopards are smaller than hyenas, and that they will likely lose in any fight over prey."

Overall, the study shows that the hyenas benefit from living near humans.

"This suggests that the hyena's ability to adapt to areas of human activity may strengthen their overall success as a species and their competitive advantage over other large predators as we humans disturb more and more nature," says Havmøller.

When leopards are pressured, cascade effects may follow

According to the researcher, the shift in female leopard hunting patterns may have negative consequences:

"If you open up for more tourism and build more roads in the national park, the female leopards will be pressured immediately. They aren’t able to differentiate between safari tourists – who are most active during the day – and poachers. In time, they will probably learn that safari guests aren’t dangerous. But if there is a large and rapid influx into the area, you will probably see a decline in their population," says Rasmus W. Havmøller.

If leopards are seriously pressured out of the food chain, one should expect the emergence of what are known as cascade effects in the ecosystem:

"Plucking a large predator like leopards out of a food chain, which can be the ultimate consequence of human disturbances, may have very violent effects. Populations of other species, such as certain monkeys, whose populations are kept in check by leopards, will suddenly become too large and change the balance of the entire ecosystem," says the researcher.

As such, Havmøller hopes that the study will serve to encourage restraint when it comes to managing wilderness areas.

"Our results clearly indicate that human disturbances can change the competitive relationship between important predators. So, I hope that considerations will be made when expanding activities in wilderness areas, so as to roll them out slowly and give animals a chance to adapt. Furthermore, it would be good if the effects of human disturbances were monitored in more places using camera traps," concludes Rasmus W. Havmøller.

 

 

HYENAS VS. LEOPARDS  Leopards are unpopular among local people in many places because they may hunt livestock and attack humans. Hyenas, on the other hand, "clean up" by eating sick or dead livestock and don’t pose a problem for humans. Female leopards (approx. 20-43 kg.) are about half the size of male leopards (approx. 51-72 kg). Hyenas are in the middle in terms of weight (approx. 48-56 kg). Leopards are solitary hunters, whereas hyenas hunt in large cackles (clans), which can be an advantage for hyenas in confrontations with leopards. Hyenas are kleptoparasites that regularly steal the prey of other carnivores – including leopards. Leopards on the other hand, are masterful tree-climbers, which allows them to protect their prey from hyenas.  

ABOUT THE STUDY The researchers behind the study are: Rasmus W. Havmøller and Linnea W. Havmøller from the Natural History Museum of Denmark, University of Copenhagen; Arielle W. Parsons from Lincoln Park Zoo, USA and Roland Kays from North Carolina State University, USA. The study has been published in the scientific journal Ecosphere. The research is supported by the ERC under the EU’s Horizon 2020 programme.  

END


[Attachments] See images for this press release:
Spotted apex predator being pressured by spotted pack hunters – and it's our fault Spotted apex predator being pressured by spotted pack hunters – and it's our fault 2

ELSE PRESS RELEASES FROM THIS DATE:

True scale of carbon impact from long-distance travel revealed

2024-07-02
The reality of the climate impact of long-distance passenger travel has been revealed in new research from the University of Leeds. Despite only accounting for less than 3% of all trips by UK residents, journeys of more than 50 miles (one way) are responsible for 70% of all passenger travel-related carbon emissions. The disparity is even greater when international travel is singled-out: international journeys are only 0.4% of total trips but are responsible for 55% of emissions. The new research, published today in the journal Nature Energy, also shows ...

Cutting-edge genomic test can improve care of children with cancer

2024-07-02
Whole genome sequencing has improved clinical care of some children with cancer in England by informing individual patient care. New research from the Wellcome Sanger Institute, Cambridge University Hospitals NHS Trust, Great Ormond Street Hospital, and the University of Cambridge, supports the efforts to provide genome sequencing to all children with cancer and shows how it can improve the management of care in real-time, providing more benefits than all current tests combined. The study, published today (2 July) in Nature Medicine, ...

Drugs that kill "zombie" cells may benefit some older women, but not all, Mayo Clinic study finds

2024-07-02
ROCHESTER, Minn. — Drugs that selectively kill senescent cells may benefit otherwise healthy older women but are not a "one-size-fits-all" remedy, Mayo Clinic researchers have found. Specifically, these drugs may only benefit people with a high number of senescent cells, according to findings publishing July 2 in Nature Medicine. Senescent cells are malfunctioning cells in the body that lapse into a state of dormancy. These cells, also known as "zombie cells," can't divide but can drive chronic inflammation and tissue dysfunction linked to aging and chronic ...

New lab test to detect persistent HIV strains in Africa may aid search for cure

New lab test to detect persistent HIV strains in Africa may aid search for cure
2024-07-02
New Lab Test to Detect Persistent HIV Strains in Africa May Aid Search for Cure A multinational team led by Weill Cornell Medicine investigators developed a test that will help measure the persistence of HIV in people affected by viral strains found predominantly in Africa—a vital tool in the search for an HIV cure that will benefit patients around the world. The study, published in Nature Communications on July 2, helps fill a major gap in human immunodeficiency virus (HIV) research. Most HIV studies have focused on strains circulating in Western countries, predominantly ...

RecombinHunt: predicting new pandemics through data analysis

2024-07-02
Milan, July 2, 2024 - Combating future pandemics through data analysis of recombinant virus genomes. A study published in the prestigious journal Nature Communication presents the promising results of RecombinHunt, a new data-driven method developed by the Department of Electronics, Information and Bioengineering of the Politecnico di Milano and the University of Milan, which can identify, with high accuracy and computational efficiency, recombinant SARS-CoV-2 genomes with one or two breakpoints. Recombination, that is, the composition of two or more viral genomes to form a new genome, is an efficient molecular mechanism ...

A new breakthrough in understanding regeneration in a marine worm

A new breakthrough in understanding regeneration in a marine worm
2024-07-02
The sea worm Platynereis dumerilii is only a few centimetres long but has a remarkable ability: in just a few days, it can regenerate entire parts of its body after an injury or amputation. By focusing more specifically on the mechanisms at play in the regeneration of this worm’s tail, a research team led by a CNRS scientist1 has observed that gut cells play a role in the regeneration of the intestine as well as other tissues such as muscle and epidermis. Even more surprising, the team found that this ability of gut cells to regenerate other tissue varies according to their location: the closer they are to the posterior end of the ...

New molecules to modulate gene expression

New molecules to modulate gene expression
2024-07-02
Genoa (Italy)/Grenoble (France) – 2nd July, 2024 - The correct functioning of cells relies heavily on the ability to finely control gene expression, a complex process by which the information contained in DNA is copied into RNA to eventually give rise to all the proteins and most of the regulatory molecules in the cell. If DNA can be imagined as a dense technical manual, gene expression is the method by which the cell extracts useful information from it. Researchers at the Istituto Italiano di Tecnologia (IIT) in Genoa and the European Molecular Biology Laboratory (EMBL) in ...

Study shows hairy skin does not become less sensitive with age

Study shows hairy skin does not become less sensitive with age
2024-07-02
Like most primates, humans are remarkably touchy-feely. Starved of touch, we release more of the stress hormone cortisol, which causes the immune system to be down-regulated and the heart rate and blood pressure to go up. On the other hand, touch causes the brain to be flooded by natural opioids, the ‘bonding hormone’ oxytocin, and the ‘feel-good’ neurotransmitters dopamine and serotonin. It is generally assumed that our sense of touch worsens with age, just like our vision and sense of hearing. However, new results are good news for those who wished they could stave off age-related decline forever: they show for the first time that a deterioration ...

Safer, swifter, smaller scar: new brain surgery approach targets difficult tumors at skull base

Safer, swifter, smaller scar: new brain surgery approach targets difficult tumors at skull base
2024-07-02
Tumors arising in the base of the skull are among the most difficult to remove in neurosurgery. The current treatment method is to perform surgical removal by what is known as the microscopic anterior transpetrosal approach (ATPA). Seeking to lessen the risk of damage and postoperative complications, as the skull base is densely packed with nerves, blood vessels, and other tissues, not to mention the brain stem, an Osaka Metropolitan University medical research team is taking a new approach. Led by Dr. Hiroki Morisako, a lecturer in ...

Barriers to care: transgender and gender-diverse peoples’ health care experiences

2024-07-02
Transgender, nonbinary, and gender-diverse people face barriers to accessing surgery and to the health system in general, describe authors in two new research papers published in CMAJ (Canadian Medical Association Journal). In many areas of life, people who identify as transgender, nonbinary, and gender diverse experience discrimination even where there are laws to protect transgender human rights. Health systems also pose barriers for transgender, nonbinary, and gender-diverse people, who are more likely to delay obtaining ...

LAST 30 PRESS RELEASES:

Being consistently physically active in adulthood linked to 30–40% lower risk of death

Nerve pain drug gabapentin linked to increased dementia, cognitive impairment risks

Children’s social care involvement common to nearly third of UK mums who died during perinatal period

‘Support, not judgement’: Study explores links between children’s social care involvement and maternal deaths

Ethnic minority and poorer children more likely to die in intensive care

Major progress in fertility preservation after treatment for cancer of the lymphatic system

Fewer complications after additional ultrasound in pregnant women who feel less fetal movement

Environmental impact of common pesticides seriously underestimated

The Milky Way could be teeming with more satellite galaxies than previously thought

New study reveals surprising reproductive secrets of a cricket-hunting parasitoid fly

Media Tip Sheet: Symposia at ESA2025

NSF CAREER Award will power UVA engineer’s research to improve drug purification

Tiny parasitoid flies show how early-life competition shapes adult success

New coating for glass promises energy-saving windows

Green spaces boost children’s cognitive skills and strengthen family well-being

Ancient trees dying faster than expected in Eastern Oregon

Study findings help hone precision of proven CVD risk tool

Most patients with advanced melanoma who received pre-surgical immunotherapy remain alive and disease free four years later

Introducing BioEmu: A generative AI Model that enables high-speed and accurate prediction of protein structural ensembles

Replacing mutated microglia with healthy microglia halts progression of genetic neurological disease in mice and humans

New research shows how tropical plants manage rival insect tenants by giving them separate ‘flats’

Condo-style living helps keep the peace inside these ant plants

Climate change action could dramatically limit rising UK heatwave deaths

Annual heat-related deaths projected to increase significantly due to climate and population change

Researchers discover new way cells protect themselves from damage

Rivers choose their path based on erosion — a discovery that could transform flood planning and restoration

New discovery reveals dopamine operates with surgical precision, not as a broad signal

New AI tool gives a helping hand to x ray diagnosis

New Leicester study reveals hidden heart risks in women with Type 2 Diabetes

Over 400 different types of nerve cell have been grown – far more than ever before

[Press-News.org] Spotted apex predator being pressured by spotted pack hunters – and it's our fault