Wednesday, December 03, 2025

New camera traps snap nearly three times more images of endangered Sumatran tigers than before

In Sumatra, researchers captured almost three times as many images of critically endangered tigers as during previous surveys, which shows the positive impact of conservation efforts even outside of national parks

Frontiers

video:
Tigress with cub in the Leuser ecosystem. Credit: Figel et al. 2025, BKSDA-Aceh, DLHK. Please write to press@frontiersin.org for higher resolution video.
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Credit: Figel et al. 2025, BKSDA-Aceh, DLHK

Destroyed habitats, poaching, and prey depletion have dramatically reduced tiger habitats around the world. Today, tigers occupy just 5 to 10% of their historical habitats. But on the Indonesian island of Sumatra, an important population of critically endangered Sumatran tigers may persevere, a new Frontiers in Conservation Science study showed.

Using infrared cameras, researchers working on the island, have set out to estimate sex-specific population densities and tigers’ movements during three surveys.

“We documented a robust tiger population, apparently among the healthiest on the island,” said Dr Joe Figel, a conservation biologist, who works with Indonesian wildlife and forestry agencies. “For those on the ground, the onus now falls on us to double down and adequately protect them.”

Long-time tenants

In many ways, the Leuser ecosystem is ideal habitat for Sumatran tigers. Three times the size of Yellowstone National Park, it is the largest contiguous tiger habitat remaining in Sumatra. It’s made up of lowland, hill, and montane forests, of which 44% are classified as intact forest landscape. “It’s also more thoroughly patrolled by rangers than nearly any other place on the island,” Figel said.

Working with local collaborators from communities at the edges of the study area, the team put up cameras in the northern stretches of Leuser, located in Aceh province, and kept them there for three monitoring periods: 34 cameras were installed during March to May 2023, 59 cameras between June and December 2023, and 74 cameras between May and November of 2024.

“Multi-year camera trap monitoring is critically important for estimating key tiger demographic parameters such as survival, recruitment, tenure, and population growth rate,” explained Figel. “With these data – and only with these data – can we even begin to evaluate conservation efforts.”

During the monitoring periods, the team captured a total of 282 sufficiently clear images of Sumatran tigers to allow for the identification of individuals. Analyzing stripe patterns, the team identified 27 individuals from camera-trap images, including 14 females, 12 males, and one tiger of unknown sex. The relatively high number of tigers suggests there is adequate prey in the area to support tiger presence. Over the study period, female and male individuals were photographed an average of 14 and 16 times, respectively. High densities of female tigers indicate a healthy tiger social system and high-quality habitats, where they can raise about three litters of cubs over a decade. During the six-month session in 2023, three different sets of cubs were documented. Two tiger brothers photographed together as cubs were later spotted individually as adults.

Thriving tigers

Inside the Leuser ecosystem lies Gunung Leuser Nation Park, however, the present study was conducted in forests provincially protected by the Aceh government. In Indonesia, provincially protected forests receive far fewer resources than national parks, which are supported and managed by the central government.

The camera traps placed by Figel and colleagues snapped nearly three times as many tiger images as during previous 90-day surveys at other sites in Sumatra, and the team was able to identify many more individuals than reported in earlier studies. Only three previous surveys – all carried out in protected national parks – documented more than 10 tigers in a single survey. Higher tiger density estimates than reported in the present study were only documented in an intensive protection zone in southern Sumatra.

The current study also provides valuable insights for future monitoring of tigers, the team said. The data on tiger movement collected here could, for example, inform survey protocols and optimal camera spacing.

The high numbers of tiger sightings reported here highlights a success story that is due to a multitude of factors, said the team. “Thanks to the work, activities, and support of government agencies, local Acehnese and Gayo communities, donors, and other researchers, Leuser has maintained important patches of lowland and hill forests where, in Sumatra, tiger prey densities reach their highest levels,” concluded Figel. “The persistence of these habitats and prey populations are the main reasons for our findings.”

Journal

Frontiers in Conservation Science

DOI

10.3389/fcosc.2025.1691233

Method of Research

Observational study

Subject of Research

Animals

Article Title

Sumatran tiger density estimates in the Leuser Ecosystem, Sumatra, Indonesia

Article Publication Date

4-Dec-2025

Lowland River valley in the Leuser Ecosystem.
Camera trap snapshot of tiger in the Leuser ecosystem.

Credit: Figel et al. 2025, BKSDA-Aceh, DLHK.

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Camera trap snapshot of tiger in the Leuser ecosystem.

A resident female Sumatran tiger grooming one of her two large male cubs in October 2023.
Credit
Figel et al. 2025, BKSDA-Aceh, DLHK

**Tigress with two cubs [VIDEO]**

Tigress with two of her cubs in the Leuser ecosystem. Credit: Figel et al. 2025, BKSDA-Aceh, DLHK. Please write to press@frontiersin.org for higher resolution video.
Credit
Figel et al. 2025, BKSDA-Aceh, DLHK

Survey: Nearly all Americans not aware midwives provide care beyond pregnancy, birth

The benefits of a certified nurse-midwife that most people don’t know

Ohio State University Wexner Medical Center

The Midwife Misconception — video:
A new survey by The Ohio State University Wexner Medical Center reveals 93% of people think midwives only deliver babies and are surprised to learn they can be a trusted partner in all aspects of women’s health.
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Credit: The Ohio State University Wexner Medical Center

According to the Department of Health and Human Services, the United States is expected to face a significant shortage of OB-GYNs in the next five years. It’s vital for women to have access to highly trained health care providers for all stages of their lives, from the first menstrual cycle to menopause and beyond. Certified nurse-midwives offer this kind of care, but most Americans don’t realize it.

A new survey by The Ohio State University Wexner Medical Center reveals 93% of people think midwives only deliver babies and are surprised to learn they can be a trusted partner in all aspects of women’s health.

“We take care of women across the lifespan,” said Michaela Ward, APRN-CNM, a certified nurse-midwife at Ohio State Wexner Medical Center. “We are highly trained and we're highly skilled. We can take care of you even if there is something more complex about you or your health.”

Survey results
The Ohio State survey of 1,006 Americans shows only 1 in 5 are aware midwives can provide women’s annual gynecology exams. The survey found that while some services, such as pregnancy and birth support and water births were identified correctly as midwife services by over half of adults, other services, like medication management, menopause care and annual women’s health exams are known by far fewer.

Among those lesser-known services, there are no significant differences by gender, meaning both men and women are equally unaware of the full breadth of women’s health services provided by midwives.

Survey respondents’ knowledge of women’s health services provided by midwives:

Pregnancy and birth support (93%)
Water births (69%)
Medication management, including birth control (26%)
Menopause care (23%)
Annual women’s health exams including pap smears and STI testing (20%)
C-sections (13%)
Don’t know (1%)

Ohio State has 17 certified nurse-midwives on staff, the largest midwife program in central Ohio. Maternal fetal medicine and obstetrics and gynecology specialists are only a phone call away from midwives to provide support and care to patients with complex pregnancies.

“If I need to consult with one of our physicians at Ohio State, I can call them right away and discuss the patient’s case,” said Ward. “We all work together to provide the best care possible for our patients.”

Multimedia elements available for download: https://bit.ly/3LtvNtM

Fearless frogs feast on deadly hornets

Kobe University

251204-Sugiura-Stings-Frog_eats_hornet — image:
Kobe University ecologist SUGIURA Shinji discovered that the black-spotted pond frog seems to be unharmed and undaunted by venomous stings from hornets such as the Asian giant hornet, the largest in the world.
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Credit: Shinji Sugiura, Ecosphere 2025 (DOI 10.1002/ecs2.70457)

A remarkable resistance to venom has been discovered in a frog that feasts on hornets despite their deadly stingers. This frog could potentially serve as a model organism for studies on mechanisms underlying venom tolerance.

While just the sight of a hornet’s stinger is enough to fill many of us with dread, some animals, such as some birds, spiders and frogs, are known to prey on adult hornets. The venom injected by their stingers can cause sharp, intense pain as well as local tissue damage and systemic effects such as destruction of red blood cells and cardiac dysfunction, which may even be fatal. But whether the animals that hunt hornets are able to tolerate the venomous stings, or just manage to avoid them, has remained unclear. “Although stomach-content studies had shown that pond frogs sometimes eat hornets, no experimental work had ever examined how this occurs,” says Kobe University ecologist SUGIURA Shinji.

To test whether frogs avoid or tolerate these potentially deadly hornet stings, Sugiura presented individual adult pond frogs with workers of three hornet species, Vespa simillima, V. analis, and V. mandarinia, under laboratory conditions. Each frog was used only once, and was matched to fit the size of their prospective hornet prey, with larger frogs preferentially matched with Asian giant hornet (V. mandarinia) prey.

In the journal Ecosphere, Sugiura submits striking evidence that adult pond frogs actively attacked workers of the three hornet species. What’s more, he also reports that 93%, 87%, and 79% of frogs ultimately consumed V. simillima, V. analis, and V. mandarinia, respectively, despite being stung into the mouth or even into the eyes. “While a mouse of similar size can die from a single sting, the frogs showed no noticeable harm even after being stung repeatedly. This extraordinary level of resistance to powerful venom makes the discovery both unique and exciting,” says Sugiura.

Previous studies have suggested that pain and lethality of venomous stings are not necessarily correlated, with some stinging bees, wasps and ants delivering extremely painful, non-lethal stings while others cause little pain despite high lethality. This could mean that the frogs in this study have developed a double tolerance to these stings, which has enabled them to successfully prey on hornet workers.

“This raises an important question for future work,” he adds, “namely whether pond frogs have physiological mechanisms such as physical barriers or proteins that block the pain and toxicity of hornet venom, or whether hornet toxins have simply not evolved to be effective in amphibians, which rarely attack hornet colonies.” These frogs could, therefore, also serve as valuable model organisms for studying the physiological mechanisms underlying venom tolerance and pain resistance in vertebrates moving forward.

This research was funded by the Japan Society for the Promotion of Science KAKENHI (grants JP23K18027 and JP24K02099).

Kobe University is a national university with roots dating back to the Kobe Higher Commercial School founded in 1902. It is now one of Japan’s leading comprehensive research universities with over 16,000 students and over 1,700 faculty in 11 faculties and schools and 15 graduate schools. Combining the social and natural sciences to cultivate leaders with an interdisciplinary perspective, Kobe University creates knowledge and fosters innovation to address society’s challenges.