Researchers say the Indochinese leopard is functionally extinct in Cambodia after a 2021 camera-trap survey failed to capture a single individual from what was once thought to be the country’s last viable population of the big cat.
The study points to hunting as the most significant contributor to the decline of the subspecies, noting that the number of snares and traps observed in the study area increased despite years of law enforcement efforts.
Experts have called for focused conservation measures in the critically endangered subspecies’ remaining strongholds in Peninsular Malaysia, Myanmar and Thailand.
Years of law enforcement to tackle rampant snaring and poaching have failed to halt the loss of Cambodia’s last remaining Indochinese leopard population, according to a recent study.
The researchers believe that while a few individual Indochinese leopards (Panthera pardus delacouri) may still linger in Cambodia’s forests, the country no longer has a viable population of the subspecies.
“Given the current population status and myriad of threats, it is pretty certain that the Indochinese leopard now is functionally extinct in Cambodia,” study author Susana Rostro-Garcia, a scientist with the University of Oxford’s Wildlife Conservation Research Unit (WildCRU) and the NGO Panthera, told Mongabay in an email. “Regrettably, the population status and trajectory of the Critically Endangered Indochinese Leopard in the [Eastern Plains Landscape] suggest that population recovery in this priority site is unlikely to occur.”
Researchers conducted seven camera-trap surveys in Cambodia’s Eastern Plains between 2009 and 2019, revealing that the leopard population declined by 82% during that time. A further survey in 2021 found no leopards. (Individual leopards were caught on camera in Cambodia’s eastern highlands in 2022.)
The Indochinese leopard is critically endangered and its range has shrunk massively to as little as 2-6% of its former size. Cambodia’s population was considered a priority for conservation as one of the last viable, breeding populations, leaving remaining strongholds in Peninsular Malaysia, Thailand and Myanmar.
A massive increase in traps and hunting is the most likely cause of the Indochinese leopard’s demise in Cambodia, the researchers say; the discovery of lethal traps substantially increased during the study period. Other factors, including infrastructure development and illegal logging, compounded the threat.
Populations of other species, such as sun bears (Helarctos malayanus) and hog badgers (Arctonyx collaris) — both known to be sensitive to snaring — also declined during the study period and were not found in the final camera-trap survey in 2021, according to the study.
Emiel de Lange, a technical adviser with the Wildlife Conservation Society, Cambodia, who was not involved in the study, agreed that snaring is likely the main cause of the leopard’s population decline. “Data from other [protected areas] show similar trends for species vulnerable to snaring, while other drivers like land use change are less significant in the study area,” he told Mongabay.
“This is a big deal, because now both tigers and leopards are extirpated from Cambodia, Laos and Vietnam, and more species will soon follow if nothing is done to address the snaring,” said Jan Kamler, a co-author on the paper with WildCRU.
Law enforcement increases, leopard numbers decrease
Leopard numbers in Cambodia’s Eastern Plains dwindled despite increasing law enforcement efforts to remove snares and increase patrols, the researchers say, with interventions either too late or insufficient to halt the scale of the threat.
“Regular law enforcement” alone can’t stem the snaring crisis and protect Cambodia’s wildlife, Rostro-Garcia said, noting that efforts to reduce hunting pressure by tightening enforcement also failed to halt the decline of leopards in Laos and Vietnam.
WCF’s de Lange agreed that “more of the same” conservation enforcement-focused action is unlikely to work. “Decades of effort by NGOs to encourage and support law enforcement effort have sadly had little effect, as these efforts do not address the root social issues contributing to biodiversity loss,” he wrote in an email.
“Conservationists need to look at and work with other actors to address the root drivers of poaching, such as poverty, indebtedness, land insecurity, and market demand for wildlife products,” de Lange continued, adding that Indigenous peoples should be involved as equal partners on conservation projects.
Law enforcement is vital, experts say, but it should be part of a “multi-faceted approach” to reduce the number of snares and prohibit their use and possession. “These should be combined with long-term proactive efforts such as education campaigns, community outreach, engagement of local people and programs that reduce consumption of wildlife meat and products by the general public at the provincial, national, and regional levels,” Rostro-Garcia said.
In light of the study’s findings, researchers say the outlook for the survival of the Indochinese leopard subspecies has significantly worsened, and conservation action should focus on areas in Thailand, Myanmar and Peninsular Malaysia where viable populations remain.
“Alarmingly, there are no current conservation measures specifically focused on this Critically Endangered subspecies,” Rostro-Garcia said. “This unique subspecies is on the brink of extinction and requires that we take immediate action to stem the current trend.”
At least four people have been killed in wild elephant attacks in Bangladesh in the last few weeks, three of them in the northern Sherpur district.
At least one elephant was also killed by locals via electrification after a herd of wild elephants roamed the area for food.
Of the 12 elephant corridors in Bangladesh, Sherpur is the only corridor that has seen a rise in attacks, as the government and other conservation organizations focused their efforts in the southern zone, where the other 11 corridors are located.
Conservationists blame the scarcity of adequate resources and funding for proper management of conservation activities, resulting in the continuation of conflicts and killings.
For the last couple of decades, Bangladesh has been taking on several projects with an aim to protect the wild Asian elephant (Elephas maximus indicus), which is critically endangered in the country. However, the conflict between humans and the wild pachyderms, consisting of both migratory and resident population, is yet to be controlled.
An example is the recent clashes between humans and elephants which resulted in the death of at least four people and one elephant.
On May 6, a wild elephant was found dead in a paddy field in the Jhenaigati area of Sherpur district in northern Bangladesh. This happened as the locals had baited electric cables inside the field so the roaming elephant could not enter.
In Bangladesh, conflicts arise mainly during paddy harvesting when wild elephants come into human settlements to feed on the crop. To save their crops from the elephants, the locals use different elements, including fire, to spark fear in the animals. Sometimes, locals use high-voltage electric cables, a weapon that can kill wild animals.
Earlier — on May 1, April 14 and April 26 — three people lost their lives in Sherpur district in a similar incident. The most recent incident happened on May 7 in the southeastern Bandarban Hill district, where a wild elephant attack killed a local.
M. Monirul H. Khan, a professor of zoology at Jahangirnagar University, said elephants have huge food demands, but their habitat continues to deteriorate in the country.
Farmers are cultivating crops near the natural habitats of elephants. It’s due to this drastic habitat loss the wild elephants enter the croplands, accelerating human-elephant conflicts, he said. He added that, sometimes, people cultivate crops on encroached forestlands. “Certainly, wild elephants will invade these croplands for ample food. Farmers often kill this flagship animal of the forest to save their crops,” he said.
Unprotected northern corridor
Among the 12 declared elephant corridors along the Bangladesh, India and Myanmar borders, the one located in the northern part of the country — Sherpur, adjacent to the Indian state of Assam — is mostly unprotected. This is where most of the recent incidents have happened.
“To be frank, the funds coming for elephant conservation are very limited,” said Raquibul, and they don’t cover all the issues. For example, IUCN Bangladesh is running activities to reduce conflicts in Cox’s Bazar, where funds are geared toward humanitarian needs. The conservation activities here mainly help with reducing damages to the Rohingya community settlement located in an elephant corridor, Raquibul said.
The northern corridor is often neglected, where conflict between humans and elephants frequently arises, resulting in both human and pachyderm losses.
Elephant status and conservation in Bangladesh
According to the Bangladesh Forest Department, there were only 268 resident elephants in Bangladesh in 2016, all residing in its southeastern forest areas. Meanwhile, during the period of 2017-21, at least 50 elephants were killed in human-elephant conflicts and electrification by humans. Of them, 34 were killed in 2021 alone.
Currently, there are some projects, mainly in the southwestern Chittagong Hill district and Cox’s Bazar district, aimed at reducing clashes between humans and elephants.
Nature Conservation Management (NACOM) is one of the implementing partners working on creating an elephant response team and other activities. S.M. Munjirul Hannan Khan, NACOM executive director, said the funds they get are not enough to run the whole conservation initiative.
For example, he said that under the project, they are supposed to form Elephant Response Teams (ERTs) that will create awareness among locals and inform the people of practices to avoid conflict. However, the teams are not functioning properly, he said, as they work voluntarily without any financial or other benefits.
He expressed the need to deploy resources to the people involved to handle the situation in the field.
Considering the recent rise in elephant killings, the Forest Department has planned a new conservation project to save the endangered species by minimizing elephant-human conflicts and reviving their habitats. However, the planning commission recently rejected a proposal for a project that would cost BDT 500 million ($4.6 million).
Under the new elephant conservation project, orchards growing plants that elephants prefer to eat, such as calamus palms and bamboo gardens, would be introduced to ensure their safe habitat, breeding and food security.
Regarding the project’s rejection, Raquibul Amin said that the government should approve the project as it would help to take the next step in conservation.
An online tool maps and predicts the presence of black-backed woodpeckers (Picoides arcticus) in newly burned forests in California.
The tool aims to aid fire managers in incorporating the protection of these birds into their efforts to revive burned forests.
Black-backed woodpeckers thrive in the diverse ecosystem left behind by wildfires, but fire suppression efforts and salvage logging often disturb their habitats.
Through the case study of black-backed woodpeckers, the tool aims to illustrate how wildlife conservation and pyrodiversity (the variation in which fires burn landscapes) should be incorporated into fire management efforts around the world.
Imagine a burned forest in California. The charred remains of trees, the soot on the forest floor and the smoke in the air might make it seem like all is lost.
Far from it.
While fires negatively affect many species of animals, they also spawn new and complicated ecosystems with rich biodiversity.
In California, the black-backed woodpeckers (Picoides arcticus) are a ubiquitous presence in burned-over forests. The birds, in fact, capitalize on the diverse landscape left behind by the fires; they feed on beetles that infest burnt trees and make nests by drilling holes in dead ones. Their contributions are also significant. Once they are finished, these woodpeckers make way for other species — birds as well as small mammals — that use their nesting sites. Research has shown that these animals then go on to serve important functions such as repopulating the forests, dispersing seeds and keeping a check on insect populations.
Despite black-backed woodpeckers playing a pivotal role in post-fire regeneration of forests in California, their protection doesn’t often take precedence during fire recovery operations. In a scramble to make rapid decisions on how to better protect and revive burned forests, fire managers and authorities find it difficult to get data on where the birds are. Oftentimes, fire suppression efforts, cutting off of snags and salvage logging (the practice of logging trees in burned forests to minimize economic loss) impact these birds and disturb their habitats.
“In many ecosystems, animals have evolved alongside fire and actually benefit from it,” Andrew Stillman, a postdoctoral fellow at the Cornell Lab of Ornithology and the Cornell Atkinson Center for Sustainability, told Mongabay in a video interview.
A new online tool, developed by Stillman and his team, aims to help these birds and aid authorities in incorporating wildlife conservation into post-fire management.
The tool maps and predicts the presence of black-backed woodpeckers in forests after fires. Through this data, the tool enables land managers and authorities to identify and estimate areas with a higher abundance of woodpeckers and subsequently avoid those areas for post-fire management efforts. For example, if an area is estimated to have a larger population of birds, authorities can choose to leave that area out for salvage logging in order to save the birds and their habitats.
Stillman worked in partnership with the Joint Fire Science Program of the U.S. Department of the Interior, the U.S. Forest Service, the Institute for Bird Populations and the University of California, Los Angeles, to collect the data and develop the tool.
The tool hinges on the concept of pyrodiversity, which is the variation in the way fires burn landscapes, and the relationship that wildlife has with fires. While the tool monitors only black-backed woodpeckers in California, the scientists behind its development say they want it to serve as a case study to illustrate the importance of incorporating pyrodiversity into fire management efforts.
“Pyrodiversity is very important for wildlife and we need a pathway to adapt our toolbox for biodiversity conservation in the face of forest fire,” Stillman said. “The goal of this tool is to give us the ability to make more informed decisions about wildlife management immediately after fires burn.”
Different animals and birds react differently to fires. A study, co-authored by Stillman and published in the journal Ecological Applications in March 2023, found, for example, that black-backed woodpeckers not only like burned forests, but also need a good mix of different degrees of burn. The study found that the birds were more likely to occupy areas “with greater diversity in burn severity.”
“Adult woodpeckers were placing their nests near the edges of high-severity patches where there’s low-severity and high severity close together,” Stillman said. “We learned that adult woodpeckers forage in areas that burned at high-severity with lots of dead trees, but the juveniles forage and spend time in areas that are low-severity.”
The study also found that the survival of juveniles was much lower if they spend all their time in areas with high-severity burns.
“What we have is a species that requires both high-severity burns with snags and low-severity burns with live trees,” he said. From their findings, Stillman said, they concluded that authorities can manage burned forests to benefit black-backed woodpeckers by prioritizing the retention of areas with a high density of dead trees that are located right next to areas burned at low-severity.
The tool incorporates these findings to make estimations about where the birds might be.
The platform uses data derived from satellite imagery along with information from field surveys to make the predictions. Over 11 years, the Institute for Bird Populations and the USDA Forest Service collected data that gave them a sense of how the woodpeckers are using fires to form their habitats. They also collected data from radio transmitters attached to the birds to track their movements around the burned forests.
“That gave us a view of home range size, and we found that the density of dead trees is a really important factor that determines the size of the home range. This means that we can use snag density to actually estimate the density of home ranges on the landscape,” Stillman said.
In the tool, users are required to input some information based on their needs, such as year of the fire and the location they want to focus on. The tool then runs mathematical models to come up with three maps: one showing woodpecker density in the area, a second map that displays the estimated number of woodpecker pairs living in the area and another one that quantifies the uncertainties in those estimates. “It’s really important for managers to incorporate uncertainty into their decisions,” Stillman said.
While it is built specifically for black-backed woodpeckers in California, Stillman says the model could be adapted for other species in other places.
“The methods that we use, the model we use and the general framework that we are using to engage in adaptive management can be applied to any system anywhere,” he said.
What’s important, he said, is to learn how to start incorporating pyrodiversity to better manage and protect wildlife after fires, especially in the face of increasing temperatures and frequent droughts around the world.
“Fire is a natural part of California’s ecology, and it’s ingrained in the history of that landscape,” Stillman said. “This tool is about ways that we can live with the fire and manage fire in smarter ways.”
Virunga is known for its fauna and landscapes, but also for serving as a base for a number of armed groups for more than two decades [File: Baz Ratner/Reuters]
Two guards at Virunga National Park have been killed in the Democratic Republic of Congo, the latest bloodshed to rock the preserve designated as a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Site.
In a statement on Sunday, the park said the two guards “were shot and succumbed to their injuries” in Nyamusengera, a section near the Edward River, which marks the frontier with Uganda.
The Congolese Institute for Nature Conservation (ICCN) said the attack was likely to be blamed on the Mai-Mai, an armed group.
Kambale Muhindo, a worker in Vitshumbi, a fishing village 5 km (3 miles) from the scene of the attack, told the AFP news agency that “a group of poachers wanted to kill a hippopotamus and to protect themselves they ambushed the guards.”
Blaise Kalisha, a human rights activist, said that “six guards have been injured and sent to the Vitshumbi Catholic hospital”.
Since 2020, different armed groups have carried out attacks and ambushes targeting guards in the park.
On May 18 this year, four park employees, of whom three were guards, were killed. The authorities blamed the same armed group.
The ICCN warned of a resurgence of violence in February, after suspected Mai-Mai fighters killed a ranger in a third attack.
Founded in 1925, Virunga National Park has been recognised as a UNESCO World Heritage Site since 1979.
It is known for its fauna and landscapes as it’s a vast expanse of deep forests, glaciers and volcanos, with more species of birds, reptiles and mammals than any other protected area in the world. But it is also known to serve as a base for a number of armed groups for more than two decades.
The park has been caught in the middle of militia activity that has destabilised surrounding regions since civil wars fought around the turn of the century.
European eels (Anguilla anguilla) are critically endangered, their population having plummeted by 97% since 1980.
Illegal fishing, dams and other barriers to their migration, droughts, pollution and habitat changes are putting the eels’ survival at risk.
These eels reproduce once in their lifetime, only in the Sargasso Sea, where they die. Their unique lifecycle and migratory pattern further complicates conservation efforts.
In Italy’s Po River Basin, researchers are working to conserve eels through interventions including the construction of fish passages to defragment rivers, reproduction in captivity and teaching fishers to recognize and release the likeliest breeders.
OASI DI CANNEVIÉ, Italy — In the early morning haze, Luca Bellini steered his green boat through the web of canals and lagoons of the Po River Delta. He had just pulled the fyke nets after 12 hours in the water so biologist Mattia Lanzoni could check for baby eels entering the Po from the sea. Sifting through the catch in water-filled basins, Lanzoni looked for the 6-centimeter- (2.4-inch-) long babies, called glass eels for their transparent bodies.
Their work is part of the monitoring efforts of LIFEEL, a public-private project focused on the long-term conservation of European eels (Anguilla anguilla) in the Adriatic Sea, with efforts on the Po in Italy and the Nestos River in Greece.
The Po Delta, located where the Italian boot meets mainland Europe, is one of the most important habitats for European eels and the longtime heartland of eel fishing, a practice that is now slowly fading. For centuries, fishers have trapped adult eels heading out to sea and other migratory fish in the delta’s brackish waters, using massive V-shaped weirs called lavorieri. They also trap juvenile migratory fish to raise to adulthood in lagoons, a practice known as valliculture.
“The elderly used to say that by placing a trap made of rushes in the water you would catch hundreds of glass eels,” Bellini said from his boat. “Now you struggle to see them.”
Since 1980, the European eel population has declined dramatically, by 97%. In 2008 the species joined IUCN’s Red List as “critically endangered”. Other species of Anguilla are under threat worldwide.
On the day of Mongabay’s visit in March, Lanzoni found no glass eels. Overall, the monitoring, which takes place from February to April, portrays a bleak picture. “The density of the upriver ascent of juveniles is drastically decreasing,” Lanzoni said, carefully checking the basins.
In spring 2021, after 33 days of monitoring with two nets, Lanzoni’s team recorded only 24 glass eels; recruitment was two orders of magnitude lower than in 2014 and 2015. In 2022, 23 days of monitoring with four nets turned up only 34.
Habitat loss due to fragmented riverways, climate change, drought and pollution are among the causes of the eels’ population collapse. Some legal fishing of glass and silver eels still occurs. But above all, illegal fishing of glass eels is to blame. According to Europol, the smuggling of live glass eels to Asia for aquaculture purposes is one of the most lucrative illegal wildlife trades, with around 100 metric tons of glass eels smuggled annually out of Europe at prices of several thousand euros per kilogram. While they can’t stop the smuggling, LIFEEL researchers are working to reduce other anthropogenic threats to eels.
Feeling the call of water
The eels’ lifecycle covers thousands of miles underwater. In winter, sexually mature eels migrate from European rivers across the Atlantic Ocean to the Sargasso Sea in the Antilles to spawn and die. The resulting eggs drift eastward across the Atlantic, changing over a period of six months to one year into larvae called leptocephali, and reaching Europe after around three years.
“They feel the ‘call’ of the fresh water of fluvial transition areas,” Lanzoni said. “Instinctively, following the historical routes of the currents, of terrestrial magnetism, eels enter fresh waters.”
Growing in brackish and freshwater habitats where they spend most of their life, glass eels undergo another metamorphosis, taking on a yellow pigmentation. Then, after an average of 15 years, they metamorphose into silver-bodied adults, called silver eels, and feel another “call.” This time it’s seawater beckoning them to their last migration, westbound to the Sargasso.
Because eels live in several habitats — the sea, brackish waters, lagoons and rivers — they experience environmental pressures in each one. In 2022, the worst drought in 70 years gripped the Po River, and it has persisted at least until devastating floods hit northern Italy in May 2023. Riverside refuges and nurseries, usually flooded and lush with aquatic vegetation, were dry.
“Lacking the buffer zones used during their ascent, eels are pushed into the central section of the river where there is no vegetation and are further exposed to predators, with greater biological stress,” Lanzoni said.
While the delta is naturally in constant flux, the persistence of the drought led to habitat changes. From his boat, Bellini pointed at seaweeds that shouldn’t be growing in the riverine canals and at the water, too clean. He is a vallante, employed by LIFEEL to manage 70 hectares (173 acres) of marshy territory. He keeps watch over the seasonal fish movements and is the first to spot any signs of stress. In part of his territory where the land is lower than the sea, he also manages the fragile equilibrium between fresh water and salt water by regulating sluice gates and siphons. But droughts and the intrusion of salt water from the sea into the river have made his job increasingly difficult.
“The right salinity in the environment must be kept, but too little fresh water comes down from the Po,” Bellini said. Last year and this winter were “a disaster,” he added.
Saltwater intrusion is natural in the river delta. While seawater pushes inland, fresh water flows toward the sea, remaining above the denser seawater. When hit by drought, the river flow slows, letting the seawater push farther upriver and into the water table.
In the 1950s, saltwater extended about 3 kilometers (1.9 miles) upriver from the delta’s mouth. In 2022, however, it reached 30 km (19 mi) upriver in some areas. Entering the aquifers, saltwater burns the land, curtailing agricultural production. It also impoverishes the diversity of habitats the eels need. Spending more time in saline environments is altering eels’ development and increasing their exposure to marine predators, Lanzoni said.
Reconnecting fragmented rivers
As eels at various life stages move through the river system, they encounter other obstacles. The Po and its tributaries are broken with dams and other barriers: 79 along 10 of the Po’s main catchments, of which 48 were impassable to eels, according to a 2013 assessment by GRAIA, a Varese-based hydrological research company and LIFEEL project partner. The problem goes far beyond the Po. There are at least 1.2 million instream blockages in 36 European countries, according to a 2020 paper.
In fragmented rivers, eels can’t reach habitats they use to feed and grow, escape from predators or when they are sexually mature, return to the sea. “Transversal infrastructures lacking adequate artificial fish passages fragment the river network,” Cesare Puzzi, a veterinarian with GRAIA, told Mongabay. Puzzi is working to restore connectivity by coordinating the construction of six passages at key points on the Po and its first tributary in from the sea, the Panaro River.
Five of these passages will allow eels and other fish to migrate past barriers via a system of pools and weirs. A sixth passage at the Chiusa di Valpagliaro sluice gate will use a plastic rug-covered climbing ramp designed specifically for juvenile eels. The passages are in various stages of tendering and early construction.
The biggest of the Po’s existing fish ladders sits at the Isola Serafini hydroelectric dam, 300 km (186 mi) inland. After its construction in 1960, the dam divided the waterway, compromising riverine biodiversity for decades. Opened in 2017 as part of an earlier defragmentation project GRAIA supported, a 645-meter- (2,116-foot-) long passage lets fish surmount the 20-meter- (66-foot-) high dam by passing through a series of large basins, each stepped 25 cm (10 in) higher than the one before.
“We saw adult eels descending,” Puzzi said, but it will take time for young eels to ascend upstream again after decades of interruption.
Hydroelectric dams pose other risks, too. Their turbines are death traps for eels, which get caught in the whirl and chopped apart. Because eels don’t like light, Puzzi’s team plans to place submerged strobe lights near the turbines of the Creva dam, between Lake Maggiore and Lake Lugano in Switzerland, hoping to reroute the animals away from danger.
Watch out for the eel eye
Fishing of both glass eels for aquaculture and adults further decreases eels’ natural stock. So researchers at the University of Bologna are working to complete the reproduction cycle in captivity to reduce or eliminate the need for wild harvest. But it’s a difficult task because of these animals’ unique lifecycle.
During spring, in the Adriatic coastal town of Cesenatico, the laboratory led by Oliviero Mordenti at Bologna University becomes a sort of maternity ward for gravid eels. The laboratory is one of the few worldwide to achieve artificial reproduction. Adult eels mate in special tanks and lay eggs, resulting in an annual average of between 217,000 and 440,800 larvae.
“A pregnant eel has never been seen in the wild,” Mordenti told Mongabay. Last year his team and another together released 2 million larvae in the Adriatic Sea to supplement the wild stock. Mordenti’s lab is also working toward breeding a second generation of eels in captivity and developing food that can help the young survive and mature in aquaria.
Back in the Po Delta, researchers also work to identify the best breeders ready to start their migration journey. After analyzing around 20,000 morphometric measurements, Bologna University researchers with LIFEEL settled on two — body length and eye diameter — that can distinguish two groups of female silver eels: pre-migrant eels that aren’t quite sexually mature and tend to remain around the delta and fully mature migrants ready to travel to the Sargasso Sea.
They created and disseminated a protocol to help fishers and valliculturists on the Adriatic coast recognize animals with the best chances of reaching the Sargasso and let them live.
To check the accuracy of the protocol and see whether the mature migrants are heading south, LIFEEL researchers free silver eels raised in valliculture lagoons into the Adriadic each winter. They carry tags so fishers can release any that get caught in nets. Others carry an implanted sonic chip that emits signals tracked by five hydrophones placed along the Italian coast.
In 2022, the researchers released 707 silver eels, 50 of them carrying sonic chips. Two weeks later, the hydrophones detected some of them 130 km (81 mi) to the south, all migrating at a similar rate and right on track for their last journey toward the Sargasso Sea.
Researchers have found that bats specialized to feed on insects within the dense canopy of tropical forests are disproportionately affected by hydropower development.
The study in Peninsular Malaysia adds to a growing body of evidence demonstrating how hydropower developments impoverish tropical ecosystems.
Although forest-specialist bats were lost from the flooded landscape, bats that forage along forest edges and in open space were still present.
To minimize localized extinctions, the researchers advocate a preventive rather than mitigative approach to hydropower planning that prioritizes habitat connectivity and avoids creating isolated forest patches.
Flitting through the forest foliage, darting between branches and flawlessly negotiating their way around gargantuan tree trunks, bats have evolved exquisite adaptations to their forest homes. Although inaudible to human ears, the tropical forest canopy is abuzz every night with the tiny mammals’ echolocating calls as they pinpoint and gobble up their insect prey with deft precision.
But these high-performance adaptations, evolved over millions of years, could be the undoing of many species in the face of unprecedented human development pressures, according to new research.
Scientists studying insect-eating bats in Peninsular Malaysia have demonstrated that forest-specialist species are particularly prone to local extinction following flooding of the landscape for hydropower development. In contrast, species that find their meals along forest edges or clear above the canopy — which typically have a larger body size, are slower-moving and capable of flying longer distances — were less affected by the development. The team published their results recently in the journal Biological Conservation.
Although biologists have long sounded the alarm that hydropower dams pose greater risks to tropical biodiversity than solar or wind power, biodiverse waterways and forests continue to be dammed and flooded in many parts of Southeast Asia.
“River damming, by favoring the creation of a myriad of small islands of poor habitat quality, triggered a wave of insectivorous bat extirpations,” Ana Filipa Palmeirim, a tropical forest biologist at the Research Center for Biodiversity and Genetic Resources (CIBIO) at the University of Porto in Portugal and co-author of the new study, told Mongabay in an email.
The finding that forest fragmentation due to hydropower development can essentially restructure bat communities is “fundamental” information that will help conservation planners design effective management plans aimed at minimizing biodiversity losses, Palmeirim said.
The researchers studied bats at the 260,000-hectare (642,500-acre) Kenyir Lake, a waterbody created in 1986 when the Kenyir River was blocked for a hydropower project. The damming transformed the terrain of forested peaks into more than 340 islands of varying size and suitability for the animals and plants that suddenly found themselves stranded.
Since bats zip through the air at tremendous speed, making them all but impossible to identify by eye, the researchers set up acoustic recorders to monitor their echolocation calls. Between September and October 2019, they gathered 9,360 hours of recordings from 26 separate islands and two nearby control sites on the mainland.
Bat calls are closely associated with their foraging activity and have a distinct “signature” that enabled the researchers to assign the calls to one of three categories depending on whether the bat foraged in the forest interior, stuck close to forest edges, or searched for prey in open space.
Edge and open-space bats were detected at every site, but the more isolated islands in the middle of the lake were unsuitable for the forest-specialist bats, the study says. Forest species were, however, still present on islands that retained dense forest cover, an insight that the researchers say demonstrates the importance of preserving good-quality forest corridors in all development projects.
The reason for the varied responses among bats could come down to their basic biology, according to Quentin Hazard, a master’s student at CIBIO at the time of the research and study lead author. “Forest bats are not adapted to fly across water matrixes because they don’t have the wing morphology or call structure to cope with that sort of environment,” he told Mongabay. “They need clutter to know where they are, so in these open spaces full of water they’re not going to do well.”
The localized loss of forest-specialist bats from isolated and degraded islands are indicative of wider patterns across the region. Insect-eating bats are thought to be particularly prone to extinction due to deforestation, with a 2003 study forecasting that if the rate of forest loss in the region persists, nearly one-quarter of Southeast Asia’s bat species will be extinct by 2100.
Peninsular Malaysia is home to roughly 50 species of insectivorous bats. Given their vital ecological role in pollination, pest control and the food chain, any widespread losses would be a devastating and irreversible blow not only to the health of tropical forests, but also to the region’s agricultural output, Hazard said. “A ton of studies show that bats save farmers billions of dollars by just eating pests, so losing bats would be a nightmare.”
The study adds to the growing body of evidence demonstrating how patterns of biodiversity are affected by flooding-induced forest fragmentation. Previous studies in other parts of Southeast Asia and from the Brazilian Amazon, for instance, show that the composition of reptile, bird, and ground- and tree-dwelling mammal communities shifts following inundation of forested landscapes for hydropower.
Heightened awareness of the impacts of development on bats is timely in fast-developing mainland Southeast Asia, a part of the world that has experienced spillover of viruses from animals to humans following disturbance of bat habitats in the past. Pandemic experts are increasingly concerned, for instance, about rampant Chinese development in Laos that they say overlooks the risk of bringing bat populations and humans into closer proximity.
Palmeirim is involved in many similar studies that gauge the biodiversity impacts of hydropower in other parts of Southeast Asia, China and the Brazilian Amazon. “We are now reaching a good understanding on how biodiversity is generally affected by [hydroelectric dams],” she said.
According to Palmeirim, the key to sustainability lies in the planning process. Hydroelectric developers should apply a “preventive rather than mitigative” approach to their projects, she said. Crucial considerations include preserving habitat connectivity by preserving areas of structurally complex forest, avoiding the creation of isolated pockets of forest, and protecting surrounding mainland forests to ensure that displaced species continue to survive.
The ideal situation, she added, would be for hydropower projects to be completely clear of any areas of intact tropical forest.
Small wildcat species suffer from habitat loss, hunting and human conflicts, just like better-known big cats. But some small wildcat populations also face threats from other felines: hybridization.
Interbreeding with domestic cats (Felis catus), and also with other wildcat species, can alter the outward appearance, behaviors and genetic profiles of wildcats, and create conservation dilemmas about how best to define and protect a species.
In Scotland, hybridization caused the functional extinction of a subpopulation of European wildcat (Felis silvestris), but scientists and conservationists are collaborating to rebuild the genetically distinct wild population with kittens reared from selectively bred wildcats.
To protect the African wildcat (Felis lybica) in South Africa, international partners are working to reduce interbreeding by sterilizing domestic and feral cats near the borders of Kruger National Park. Hybridization can also occur between wildcat species and raises questions about preserving genetic purity vs. ecosystem function.
Charismatic big cats (think tigers and leopards) get the lion’s share of conservation attention, while their close relatives — 33 species of small wildcats roaming five continents — get far less notice. Yet they too often urgently need protection.
Like their larger counterparts, these felids suffer from habitat loss, hunting and human conflicts. But some face a less-known feline threat: hybridization with Felis catus, the domestic cat — darling to cat lovers the world over and YouTube superstars.
In Europe and South Africa, interbreeding by small wildcats with housecats or feral domestic cats has altered the genetic makeup of wild species and created conservation dilemmas.
To preserve the genetic integrity of these wildcats, conservationists plan to boost dwindling populations with wild-bred kittens, ramp up sterilization of feral domestic cats, and find better ways to study these elusive wild felids.
Doing so is important not only for individual species, but for protecting ecosystems from instability. “Small wildcats are habitat specialists and their losses can have wide impacts,” says Wai-Ming Wong, director of NGO Panthera’s small cats program. “Given the current biodiversity crisis, it’s really important to maintain ecosystem balance.”
Hybrids have always posed a conundrum for conservationists. Admixing “domestic” genes with the DNA of wild species through crossbreeding — a process known as introgression — can increase genetic diversity and even improve a species’ ability to prevail in a changing landscape. But the distinct genetic heritage of wild species can be lost via intermating.
Wild-domestic hybrid cats, for example, may display different behaviors from those in the wild, alter their use of habitat, or be more susceptible to disease. These crossbred cats also might not meet the specific genetic and taxonomic criteria that form the basis of legal protections for wildcats.
“Hybridization is a tricky issue,” says Helen Senn, head of conservation at the Royal Zoological Society of Scotland (RZSS) in Edinburgh and project lead for Saving Wildcats, an NGO. That’s especially the case for a subpopulation of European wildcat (Felis sylvestris) that once roamed Scotland, but which has been hit hard by wild-domestic hybridization.
Today, studies show that few of Scotland’s remaining wildcats (outside of zoos) display enough of the distinct genetic markers and physical traits to be defined as the “Highland tiger.” Although domestic cats were likely introduced to the United Kingdom in Roman times, whole genome studies point toward hybridization as “a recent phenomenon that probably only happened within the last 60 or so years,” Senn says.
That’s an important point for conservationists because “that tells us something changed to create a breakdown between these two species,” she explains. As habitat loss and persecution of Scotland’s wildcats escalated in recent decades, the dwindling population of Felis sylvestris likely mated with the more available domestic cat, Felis catus.
“Then things rapidly descended into what we call a ‘hybrid swarm,’” says Senn. “Which just means that everything is very mixed up [genetically].” In other European countries, analyses find that interbreeding with domestic felines affects anywhere from 3-21% of wildcat populations. But in Scotland, all of the wild-living cats in study samples show evidence of hybridization.
Today, Senn leads a European partnership tasked with rebuilding Scotland’s wildcat population. The collaborators plan to reintroduce wildcats into remote areas where the organization can still monitor the more isolated cats’ welfare.
Over the next three years, conservationists plan on annually releasing about 20 kittens from breeding pairs of captive (zoo) and wild-caught felines that scored at least 75% on a combination of specific wildcat genetic markers and pelage characteristics.
“The genetics are very important to helping us resolve taxonomy and understand what we’re trying to conserve,” said Senn, a conservation genetics specialist whose work ranges from the reintroduction of pond mud snails in Scotland to the scimitar-horned oryx in Chad.
Earlier this year, the first cohort of young wildcat kittens were old enough to move into individual enclosures at the Highland Wildlife Park, where they can continue to mature and work on their survival skills. They should be ready to release by the middle of the year.
After release, the young cats will be tracked using GPS collars and camera traps. Senn also wants to monitor the genetics of subsequent generations through fecal samples, hair traps and camera images. The scientist will also be comparing the DNA profiles of the wildcats with samples from the feral domestic felines that roam the same general area.
Studies on the rebound of the European wildcats in the Swiss Alps have modeled the size of wildcat populations needed to preserve the species’ genetic legacy, but Senn doesn’t know exactly how many cats need to be reintroduced to keep the Scottish wildcat from being overwhelmed by domestic cat DNA.
“We want to see a population of wildcats which are basically fit, with healthy numbers, that are reproducing with each other, and not breeding with domestic cats,” she says. “If we can do that, then we are onto a winner.”
Saving the African wildcat in South Africa
Hybridization is also a concern in South Africa, where the dust-colored, long-legged African wildcat (Felis lybica) roams. Although a 2016 IUCN survey found that F. lybica interbreeding with domestic cats has been fairly low across Africa’s broader landscape, the threat to the wildcat tends to be highest in parts of South Africa where human populations (and domestic cat numbers) are highest — especially near the borders of national parks.
One key recommendation coming out of the IUCN survey is to actively neuter domestic cats in these border areas to create buffer zones that reduce crossbreeding, says Louise Holton, president of Alley Cat Rescue (ACR), a U.S.-based nonprofit. Local veterinarians were already taking this approach, but ACR funding has helped ramp up trap-neuter-return (TNR) capacity around Kruger National Park. This approach takes care to return sterilized cats to the areas where they were found so that established cat populations are maintained, and there’s no “vacancy” created for an influx of new cats.
“The [feral cat] problem is enormous and ACR was able to help [veterinarians] scale up,” says Holton, who is originally from South Africa.
More than 5,000 feral and stray domestic cats have been sterilized and vaccinated against rabies since 2019, at a cost of around $45 per cat. The project has expanded its capacity to include three additional organizations, but Holton estimates there are still at least 3,500 unneutered cats around Kruger National Park, and thousands more near other parks. She especially wants to get blood samples for genetic analysis from hybrid-looking cats undergoing sterilization to get more DNA data on hybridization.
Holton notes that African wildcats and brown domestic tabbies share some similarities, but the wildcats have long front legs and an orange tinge to the ears, while hybrids have lost the long front legs and always have white spots somewhere — small but important visual distinctions when trying to identify and maintain the integrity of a wild species.
In addition to fieldwork, Holton is working rigorously to obtain more funding to keep these projects going. “African wildcats are amazing creatures,” she says. “And that’s where our beloved domestic cats started 10,000 years ago. Why not use a sterilization program that will stop the hybridization, yet keep the [wildcat] population doing what they should do?”
Reducing human-wildcat conflicts
Domestic cats aren’t the only threat to the pure genetic lineages of various small wildcat species. In southern Brazil, for example, researchers found at least 40% hybridization between two wild species, Geoffroy’s cat (Leopardus geoffroyi) and the southern tiger cat (Leopardus guttulus), when they analyzed DNA samples in Rio Grande do Sul state.
The main “hybrid zone” was at the southern extent of the much-fragmented, very ecologically stressed Atlantic Forest and the northern extent of pampas grassland where the two wildcats’ ranges overlap.
The hybrids aren’t easy to distinguish by looks alone: purebred Geoffroy’s cats are generally more robust and spotted with non-remarkable tails; southern tiger cats are typically lithe with long tails, stripes or open spots, and larger ears.
But looks aren’t the key issue, says Jim Sanderson, founder and director of the nonprofit Small Wild Cat Conservation Foundation (SWCCF) and an IUCN small cat specialist. “I think it’s more important to [maintain a specific] ecological role in nature than to be fixated on hybrid [looks],” Sanderson says. “Functional extinction is a terrible loss. So I’d rather have a weird-looking cat than no cat at all.”
In the increasingly human-dominated landscapes where he works, Sanderson focuses on finding ways to mitigate the conflicts with people that get wildcats killed. In Chile, for example, the diminutive güiña (Leopardus guigna) often preys on chickens raised by local farmers. The Pampas cat (Leopardus colocolo) has a similar penchant.
Fewer felines suffer from retaliatory killings when henhouses are repaired and cat-fortified, or when people are supplied with tailless chickens that are harder for wildcats to catch.
Other practical conservation approaches include equipping rural herders with guard dogs to stop wildcat-associated predation of alpacas, llamas and goats. Protecting bigger cats, such as mountain lions, can also help the small cats because the big cats can reduce populations of feral dogs that threaten smaller felids. “I just want to keep cats in the game,” says Sanderson.
Small wildcat future
A major hurdle to understanding the impacts of hybrids on the ecological roles played by small wildcats is the lack of studies to determine what these species need to thrive. That’s partly because small cats are incredibly elusive, with many conservationists having rarely — if ever — seen the cats they’re trying to save. And also because research into the 33 species of small wildcats isn’t funded at anywhere near the levels of their big cat relatives.
“We have thousands of detections of tigers on camera traps, even though they are a critically endangered species,” notes Wai-Ming Wong of Panthera. “But we have maybe 15 or 20 of the clouded leopard [Neofelis nebulosa] which occupies the same habitat.” With so few detections, the usual statistical analyses can’t be applied to these smaller species, explains Wong.
One solution for building knowledge of small cat species is the collection of environmental DNA samples from soils or waterbodies. To get population baselines — and detect hybridization — scientists need to analyze genetic materials at the species and individual level, and compare genetic relatedness.
Although big cats have long captured the public’s imagination, Wong thinks small wildcats are charismatic and capable of capturing people’s hearts. At his conservation talks, every time people see pictures of Asia’s Pallas’s cat (Otocolobus manul) — dubbed “the original grumpy cat” — he says they’re immediately captivated and want to know all about it.
With their mid-level trophic role in ecosystems, acting as both predator and prey, small wildcats are important sentinels for detecting ecosystem degradation. They can also be vital for rodent and small mammal control (critical to balanced ecosystems and to helping farmers protect crops at no cost). Perhaps, with some creative public relations work, small wildcats could become ambassadors for threatened habitats the world over.
Wong sees hybridization as an emerging threat to small cat species — occurring naturally in some populations and catalyzed by humans in others. One thing that’s clear, says Wong, is that each small wildcat species has its own unique set of challenges. “That means there’s no one-size-fits-all approach to their conservation,” he says.
The endangered golden-rumped elephant shrew has seen its population in a Kenyan forest reserve increase by 52% in a decade, upending researchers’ fears of extinction due to hunting and habitat loss.
The latest population survey credits the rabbit-sized mammal’s high adaptability to human-disturbed landscapes, including plantations of exotic tree species.
They also appear to be thriving amid Kenya’s long-running drought, which has caused trees to shed their leaves in large volumes, thus creating the thick carpets of leaf litter that are the animal’s favored habitat.
Researchers say the increase may also reflect the gains made by conservation measures within the forest reserve, including a community-based conservation system known as participatory forest management (PFM) that has the support of NGOs and the government.
A population of endangered elephant shrews has rebounded in a threatened coastal forest reserve in Kenya, suggesting the rabbit-sized mammals with endearingly long snouts could be adapting to both human disturbance and drought, researchers say.
Rael Ondoro, a Kenyan-trained ecologist, told Mongabay she was inspired to carry out a population assessment of the endangered golden-rumped elephant shrew (Rhynchocyon chrysopygus), also known as the sengi, after she heard that villagers in communities surrounding Arabuko Sokoke Forest Reserve ate them.
“I thought, ‘Let me check and see what’s happening now. Was the sengi going extinct?’ I think curiosity was a major motivation.”
To gather her data, Ondoro and her team spent three months in 2019 doing transects in the 40,000-hectare (99,000-acre) forest reserve to estimate the abundance of the sengis based on the number of nests they found. Sengis belong to an ancient African lineage whose members include hyraxes, aardvarks and elephants. They use their long snouts to rifle through leaf litter for insects and to scrape nests in the sandy soil which they then line and cover up with dry leaves.
According to Ondoro’s findings, published recently in the African Journal of Ecology, the population rose to 19,423 in 2019, from 12,750 in 2009. This represents an increase of more than 52%.
Previous studies had shown population declines of up to 30%.
“My expectation was that maybe the numbers would have reduced further,” Ondoro said, citing the negative impacts of illegal hunting and firewood harvesting.
While Ondoro said the previous studies may have underestimated the abundance of the sengis by using narrower transects, she has an intriguing theory as to what may be driving an increase: the sengis’ successful adaptation to human disturbance.
One of the transects she and her team did was in a plantation of exotic trees planted by the Kenya Forest Research Institute next to Arabuko Sokoke. The area had a high density of sengi nests.
Until now, 90% of the known sengi population was found within Arabuko Sokoke Forest Reserve, which is a mix of open- and closed-canopy woodland comprising native Brachystegia and Cynometra trees. The fact that sengis can make a home in a human-altered landscape of exotic trees and bamboo is a positive sign, Ondoro said.
“Even though there is disturbance, they are still able to thrive,” she said.
The disturbances, however, are also occurring in the heart of the sengis’ core habitat.
Francis Kagema, a regional manager with Nature Kenya, a conservation NGO, said disturbance surveys carried out within Arabuko Sokoke Forest Reserve in 2006, and again in 2017, showed that the number of tree cuttings and poaching incidents had increased significantly over that period.
Since those surveys were done, things have only gotten worse, he noted.
Nearly three years of drought have driven up food insecurity, increasing dependence on the forest by some people who raise money by illegally felling logs for home building or wood for charcoal burning.
Kagema also estimated that the forest currently contains up to 100,000 wire snares set to trap anything from sengis to buffaloes.
“The forest is in general decline, in terms of its ecological condition,” Kagema said. “We would expect that to go in tandem with the reduction of many species in the forest.”
The long-running drought in Kenya has, however, done something else, which might be aiding the sengis’ recovery. It has led to extraordinarily high levels of leaf shedding. Sengis thrive in leaf litter: they build their nests from it and find their food in it.
“If every tree is shedding its leaves, we have a huge layer, which is habitat for this species,” Kagema said. “Maybe it is being favored by climate change. You never know. These are things that need to be checked and researched, then we can confirm that.”
Ondoro and her co-authors say they’re hopeful the increase in sengi numbers may also reflect the gains made by conservation measures within the forest reserve, including a community-based conservation system known as participatory forest management (PFM) that has the support of NGOs and the government.
Under PFM, groups of people from surrounding communities are allowed to sustainably extract resources from the forest to supplement their livelihoods: there are groups dealing in firewood, those who farm butterflies, and others who nurture honey bees. Others collect material for basket weaving, or fodder for livestock.
Researcher Paul Matiku, who is also executive director of Nature Kenya, has published widely on the role of PFM in stemming biodiversity loss in the forest.
“Where PFM was implemented, the local people’s attitudes changed from a case where they wanted the forest turned into farmland to wanting it being conserved,” he told Mongabay.
“Areas where PFM was implemented had higher forest quality and forest specialist species.”
One of those specialists is the East Coast akalat (Sheppardia gunningi sokokensis), a shy robin with a bright orange breast that is also an indicator species for forest health.
A paper Matiku published in 2011 showed that parts of the forest that were under PFM harbored a higher number of the birds, which prefer quiet, undisturbed areas with deep shade and thickets.
During her fieldwork to assess the sengi population, Ondoro personally witnessed the positive impact that these conservation efforts with their focus on supplying alternative livelihoods was having.
“Some of the research assistants who were helping me were also from the community,” she said. “One of them said he used to do poaching within the forest. Now he’s using his efforts to help students doing research because he understands the forest so well.”
But Kagema, the Nature Kenya area manager who has spent nearly two decades working in and around Arabuko Sokoke, said he believes the pressures on the forest by an estimated 150,000 people who surround it are still too great.
He points to the harvesting of poles needed to build huts as just one example. The poles get devoured by termites and need to be replaced every two to four years. That leads to the overharvesting of young trees that represent the future of the forest.
Kagema said he believes only better law enforcement against illegal timber harvesting and animal poaching can ensure the forest and its rich biodiversity survives, but added he’s also willing to take some reassurance from signs of a sengi recovery.
“For now it gives us hope that some species have adapted to disturbance and are doing well,” he said. “If we improve on protection, then the forest can be there forever.”
Scientists described 380 new-to-science species from the Greater Mekong region of Southeast Asia between 2021 and 2022.
Researchers working in Cambodia, Laos, Myanmar, Thailand and Vietnam identified 290 plant, 19 fish, 24 amphibian, 46 reptile and one mammal species, including a thick-thumbed bat, a color-changing lizard, and a Muppet-looking orchid.
However, many of these species already face the threat of extinction due to human activity, prompting advocates to call for increased protection of their habitats by regional governments.
The most urgent threats to the region’s wildlife and habitats include the construction of hydropower dams, climate change, illegal wildlife trade, and loss of natural habitats.
A thick-thumbed bat, a color-changing lizard, and a Muppet-looking orchid are just a few of the 380 new-to-science species found and described in the Greater Mekong region of Southeast Asia between 2021 and 2022.
In a report released this week by WWF, researchers highlight the remarkable diversity in this underexplored hotbed of life. The report documents the collaborative efforts of hundreds of scientists who ventured into Cambodia, Laos, Myanmar, Thailand and Vietnam to survey the biodiversity there in what is sometimes called the Indo-Burma hotspot. They identified 290 plant, 19 fish, 24 amphibian, 46 reptile and one mammal species.
“These remarkable species may be new to science but they have survived and evolved in the Greater Mekong region for millions of years, reminding us humans that they were there a very long time before our species moved into this region,” said K. Yoganand, WWF-Greater Mekong regional wildlife lead. “We have an obligation to do everything to stop their extinction and protect their habitats, and help their recovery.”
The report highlights several notable new species, including the Cambodian blue-crested agama (Calotes mystaceus), an aggressive lizard known for changing color to defend itself against predators.
The Suzhen’s krait (Bungarus suzhenae), an extremely venomous snake named after Bai Su Zhen, a snake goddess from a popular traditional Chinese myth, the Legend of White Snake, was described in 2021.
Another find is the Hayes’ thick-thumbed myotis (Myotis hayesi), a bat with unique fleshy thumbs that distinguish it as a separate species. A preserved specimen of the bat had been stored in a Hungarian museum for 20 years before its identification.
The report also mentions Khoi’s mossy frog (Theloderma khoii), so named for its mossy-green skin that allows it to blend in with lichens and moss. Additionally, scientists described the miniature orchid Dendrobium fuscifaucium, which displays vibrant pink and bright yellow colors reminiscent of the Muppets who sang the song “Mah na mah na.”
However, many of these newly described species already face the threat of extinction due to human activity, prompting WWF to call for increased protection of their habitats by regional governments.
For instance, Cleyera bokorensis, an evergreen shrub, is threatened by the development of a Cambodian casino. Likewise, the Thai crocodile newt (Tylototriton thaiorum) in Vietnam is threatened by agricultural encroachment, logging, and its use in traditional medicine.
“To reverse the rapid biodiversity loss in the region, more concerted, science based, and urgent efforts need to be made, and conservation measures need more attention from governments, NGOs and the public,” said Truong Q. Nguyen, one of the report authors from the Institute of Ecology and Biological Resources at the Vietnam Academy of Science and Technology.
Nguyen emphasized the need for immediate action and the adoption of advanced technologies like bioacoustics and genetic sequencing to learn what lives in this biodiversity hotspot.
The Greater Mekong region is a vast area that straddles six countries in Asia: China, Myanmar, Laos, Thailand, Cambodia and Vietnam. The region covers an area of 81 million hectares (200 million acres), an area roughly the size of Texas and Arkansas.
The Mekong River is at the heart of the region, stretching some 4,900 kilometers (3,000 miles) from the Tibetan Plateau to the South China Sea. The Mekong River is the largest inland fishery in the world, providing a livelihood for millions of people and accounting for up to 25% of the global freshwater catch.
The region is home to iconic animals such as Asian elephants (Elephas maximus), tigers (Panthera tigris), Sunda pangolins (Manis javanica) and giant freshwater stingrays (Urogymnus polylepis). Since 1997, the total number of plants, fish, amphibians, reptiles, birds and mammals described in the Greater Mekong region has reached 3,389 species.
“While the Mekong region is a global biodiversity hotspot, it is also experiencing a vast array of threats,” Nilanga Jayasinghe, WWF-US Asian species manager, said in a statement. “We must continue to invest in the protection and conservation of nature, so these magnificent species don’t disappear before we know of their existence.”
In the Curare-Los Ingleses Indigenous Reserve, two communities are working to protect the black caiman (Melanosuchus niger), a species that has been hunted for decades for its commercially valuable skin.
After 14 years of fighting to protect the caiman’s habitat, in January 2022, the communities carried out the first-ever survey of the species, recording 123 specimens of various ages.
Local leaders say the community’s children will soon be able to learn about the caiman not only in a new book with illustrations and information from the conservationists’ work — but also in real life.
For the Indigenous peoples of Colombia’s lower Caquetá River, the lakes of Puerto Caimán form a huge maloca, a cultural and spiritual hub. This watery habitat is home to the black caiman (Melanosuchus niger), a sacred animal in their culture. According to local elders, “grandfather caiman” was once a man who came down to Earth from a planet of clouds and became the creature that today rules over the water and the fish.
“He has remained a being of important value; he is sacred,” says Moisés Yucuna, an elders from the Borikada community. “That’s why, wherever he is, in the depths of streams or lakes — where there is no river current and where they can be left in peace — there is an abundance of fish. He is the master of everything, governing the other animals. The fish always follow their grandfather caiman; they surround them, keeping close to their grandparents.”
In the non-municipalized area of La Pedrera in the northeast of the Amazonas department, located along the border with Brazil and on the lower Caquetá River, is the Curare-Los Ingleses Indigenous Reserve. For years, those in the territory have been working to preserve and protect this reptile that, for decades, was hunted for its coveted skins, which almost led to it disappearing from the area.
According to the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, since 2000 the black caiman has been categorized as “lower risk.” It is, however, “conservation dependent” to prevent it from becoming endangered again.
In 2008, the reserve’s two communities — Borikada and Curare — organized themselves into groups in order to monitor and care for the black caiman and the sacred sites it inhabits. But, back then, they were unaware of the reptile’s conservation status. In light of this, many years later they asked for support from Conservation International, an organization they had worked with previously. In January 2022, as part of the Amazonia Verde project, the first population survey of the species was carried out in Puerto Caimán, a system of three dark, highly acidic blackwater lakes.
The survey reported sightings of 123 individuals of different ages, including at least 18 adults, 26 subadults, 16 juveniles and 18 hatchlings. The largest caiman reached 5.7 meters (18.7 feet), while the smallest measured 23 centimeters (9 inches).
Such surveys would not be easy without the work of the elders, explains Yucuna. They are spiritually connected to the caimans and, through incantations, can ask them for permission so the team of monitoring staff and researchers can enter their territory safely. The humans promise not to disturb the caimans, and the caimans promise not to attack their visitors.
“The grandfathers always appear so they can do their job of monitoring and protecting the lake. They ensure that no harm is done to those they watch over, that nothing untoward happens to the other animals,” says Yucuna.
Community guardians saving the caiman
The black caiman is a large reptile that can reach 5-7 meters (16-23 feet) in length. It inhabits several countries in the Amazon Basin such as Bolivia, Brazil, Ecuador, Guyana, Peru and Colombia, where it has been reported in three departments — Amazonas, Putumayo and Vaupés. Caimans can be found inside lakes or in some black- and whitewater rivers, floodable forests or in shallow marginal ponds.
Caimans are generalist predators, meaning they eat any type of prey, ranging from very small animals to deer. This makes them a regulating species, contributing to the delicate balance of these ecosystems. Female caimans, depending on their age, lay between 20 and 40 eggs on the shores of lakes, where they take care of them for three months.
“Between the 1970s and early 1980s in that area of Colombia [near the reserve], there was a huge problem with caiman hunting. They have always been highly sought after for their skin and meat, not just by local people but also by outsiders, non-Indigenous people or for foreign trade,” says Jack Hernández, a biologist and consultant for Conservation International.
Hernández, who is also responsible for leading biological surveys and developing environmental management plans with Indigenous reserves and rural villages in the lower Caquetá River, says the Indigenous communities were worried. For more than 50 years it had been common to constantly see hundreds of hunted caimans being brought down from the lakes to the urban center for export and sale.
“At this time [in 2008], the reserve began to look for a solution to the indiscriminate hunting and overexploitation and asked for support from Conservation International. That is when the community conservation watch program was born,” Hernández explains.
In 2014, with funding from Conservation International, a cabin was built at the entrance to the lakes, where monitoring and surveillance tasks could be carried out. Since then, families living on the reserve take turns staying there once a month in order to keep an eye out for hunters and get paid for their work.
In January 2022, a knowledge exchange took place between Conservation International, the elders, the team of watchers and the co-researchers (the title given to collaborators who live in the Indigenous reserve) during a training session before carrying out the species survey.
“Our goal was to share knowledge, and they could tell us what they know about the caiman. They know a lot about the species, especially those who live in the reserve, because they have lived alongside them all their lives,” says Hernández.
In this first training meeting, the reserve’s team learned how caiman surveys are done from a scientific point of view and how sampling is carried out: how to count the number of caimans, how to measure them and why it was important to run surveys.
“But, in addition, we wanted to hear from them what they believed the aim of the survey to be because this project originated from the people living in the reserve.”
Albear Yucuna is one of the guardians at Puerto Caimán. His task, along with other colleagues, is to carry out protection, monitoring and surveillance patrols twice a day, in the morning and afternoon, to prevent outsiders from entering the area.
“We also conduct surveillance and protection work around the lakes of Puerto Caimán because there is a significant amount of aquatic fauna, especially umbrella species [those that require large habitats and ensure the ecosystem’s health and conservation]. This includes the silver arowana [Osteoglossum bicirrhosum], which years ago was being fished uncontrollably and was on the verge of extinction. This is a nursery site for the species,” the guardian says. “So far, our black caiman conservation work has yielded results and has been reflected in the abundance and growth of the population, which is why we continue with the same protection measures.”
Preparing for the survey
One of the highlights of the conservation strategy was the survey that ran Jan. 17-20, 2022. At night, aboard a small wooden paddle canoe, three researchers moved silently through the dark waters at just 5-10 kilometers (3-6 miles) per hour, steered by just one person at the back of the boat.
“In the center sits the person who is responsible for gathering the data and filling out the forms we designed to collect all the information on the caimans: who the observer is, the name of the river, the GPS coordinates, the date, the recorded species and the length of its head. In the bow of the boat is the observer, who basically illuminates the shores of the lake with a long-range flashlight. That’s where the caimans usually float at night,” explains Hernández.
This exposure causes an ocular reflection in the caimans’ eyes, an intense reddish flash caused by the effects of the tapetum lucidum, the reflective layer at the back of the eye.
“This a good approach because when you shine a light on a caiman, you can detect it even at 200 meters [650 feet] or so away,” says Hernández. “We use body morphometric measurements, that is, using the length of our hands [from the raft, at a distance of about 1 foot] we measure the length of the head, from the tip of the nose to the center of the eyes.” With that information, they use mathematical equations to estimate the actual size of the head and the entire animal.
“This methodology has been used in a number of studies, which show that if you calculate the length of the head using morphometric equations, you can get an estimate of the length of the body.”
Contrary to what many might imagine, Hernández says that the larger caimans were actually very calm and allowed the researchers to approach them, and the smaller ones were happy to be picked up and measured.
“Currently, the families that protect the caiman are also carrying out monitoring, surveillance and biological surveys on the trails they use periodically and are recording all the species of fauna that they see,” says Hernández.
As such, the project is intended to go beyond the black caiman. A little more than 2.5 kilometers (1.55 miles) from Puerto Caimán, the community guardians of Curare and Borikada are also working to protect several species, including the Arrau turtle (Podocnemis expansa) and the pirarucu fish (Arapaima gigas), both of which are native to the region.
“With the support of Conservation International, they are receiving training in participatory wildlife monitoring. This means that the entire community is trained, so that everyone has the necessary skills to conduct the monitoring,” explains Hernández.
Installing camera traps is one of the techniques used. These cameras help researchers understand the wildlife present in their territory and help them to better appreciate their conservation efforts. Their efforts are rewarded with a stable, well-populated fauna with rich diversity.
“They also receive financial recognition for the biological monitoring they do. They are carrying out work that benefits their territory,” says the biologist. “The cameras have not yet been placed near the Puerto Caimán area, but within the reserve. Since these animals have a very broad distribution, they are probably the same species found in the lake areas: large and medium-sized mammals and land birds. The cameras have recorded a diverse range of animals, such as jaguars, tapirs, bush pigs, anteaters, deer and a very rare species in the Amazon, the short-eared dog (Atelocynus microtis).”
However, the Río Puré Natural National Park, which is inhabited by Indigenous peoples in voluntary isolation, is also next to the reserve. As such, it is a protected area where cameras should not be placed in case they affect the residents’ way of life, says Hernández, explaining the importance of protecting this region.
Gonzalo Tanimuca is a co-researcher for the Curare community project and explains that, ultimately, the aim of the work is for new generations to learn about the black caiman and to raise awareness so they continue the conservation efforts.
The reserve hopes that soon, as research progresses, children will not only see the caiman in a book that is set to be distributed in schools — with illustrations by the reserve’s own people, alongside findings from the cultural research and survey — but will also have the opportunity to observe it in person. In fact, this is something local grandparents have asked for.
“In the ‘50s and ‘60s, according to our grandparents, the caiman was a sought-after animal for making shoes and bags. But our elders said this had to stop — our grandchildren have to get to know the animal and have to protect it. Our traditions led us to reduce this exploitation,” Tanimuca says. “Our traditions tell us, ‘Friends, this is our life, these are our beliefs, this is our future; we have to protect this animal.’ It is important because our children want to know the caiman. We now have a very important subject called environmental education, where we explain to them how it reproduced, how it was mistreated and how we are now protecting it.”