Golden oyster mushrooms, known for their bright yellow caps and earthy flavors, are native to Asia. However, these prized edible mushrooms have gained popularity throughout North America, where they’re spreading across forests and displacing native fungal species, a recent study has found.

Aishwarya Veerabahu, lead author and a doctoral student at the University of Wisconsin-Madison, U.S., told Mongabay by email that the study was prompted by a growing number of wild golden oyster observations in North America across citizen science biodiversity databases.

“[T]he public, mushroom enthusiasts, and community scientists were logging their observations of this non-native mushroom on online biodiversity databases like iNaturalist and MushroomObserver,” Veerabahu said. “Local mycologists (Drs. Anne Pringle and Todd Osmundson) were also increasingly noticing this mushroom that they knew to be introduced to the region and were alarmed at how rapidly it was multiplying and spreading.”

By Dec. 31, 2023, observations of the mushroom had been reported from 23 states in the U.S. and Ontario, Canada.

To find out how the golden oyster’s spread could be affecting native fungal species, Veerabahu and her colleagues examined 78 samples of wood from 26 dead elm trees near Madison. Half of the trees had golden oysters growing on them.

The team then used DNA analysis to identify the different fungi that grew on each sample. They found that trees with golden oysters hosted about half as many native fungal species as those that didn’t have them.

“Though we have yet to study downstream impacts, we suspect changes to native fungal diversity in dead trees could potentially affect wood decay processes, rates of carbon emissions from dead wood, and changes to deadwood habitat for birds, mammals, and tree seedlings,” Veerabahu said.

She added that fungal biodiversity in general is poorly documented, so as golden oysters outcompete native fungi, “we may lose species we don’t even know about yet along with their unique chemistry — we may lose undiscovered medicinal compounds that these fungi produce.”

Matthew P. Nelsen, a mycologist at the Field Museum of Natural History in Chicago, who wasn’t involved in the study, told The New York Times that golden oyster mushrooms have been “popping up like crazy all over the place” in the past five years. He added the study “paints a troubling picture of what this means for the diversity of wood-rotting fungi and all the other organisms that rely on these fungi.”

The mushrooms, which were first imported into North America in the early 2000s, are now sold in popular mushroom-growing kits.

“The take home message for people who grow and cultivate mushrooms is that non-native mushrooms are often cultivated in North America but can become invasive, causing devastating effects on native fungal biodiversity,” Veerabahu said. She added that all stakeholders, from mushroom cultivators and sellers to researchers, must come together and jointly develop a management plan for golden oysters.

Banner image: Golden oyster mushrooms. Image by Jordan Cook via Flickr (CC BY-NC 2.0).

The tiger, once wide-ranging across Asia, has disappeared from much of its historic range. But thanks to concerted conservation efforts and communities willing to coexist with them, the majestic predator is making a comeback in some parts of the continent despite threats including habitat loss and poaching.

South Asia continues to be a stronghold for tigers (Panthera tigris), but some other regions are also showing promise. On International Tiger Day, July 29, Mongabay presents three stories from the past year that offer hope for the big cat.

Thailand’s tiger recovery

Tiger numbers are rising in western Thailand’s Huai Kha Khaeng and Thung Yai (HKK-TY) wildlife reserves, which make up a UNESCO World Heritage Site. Since camera-trap surveys began there in 2007, the tiger population has more than doubled, Mongabay’s Carolyn Cowan reported in July 2024. There could now be up to 140 Indochinese tigers in HKK-TY.

Thailand is now the last stronghold of the Indochinese tiger (P. t. corbetti). Researchers attribute the increase in tiger numbers in HKK-TY to long-term conservation actions like strengthening ranger patrols to control poaching and efforts to boost prey populations.

“Tiger recoveries in Southeast Asia are few, and examples such as these highlight that recoveries can be supported outside of South Asia, where most of the good news [about tigers] appears to come from,” Abishek Harihar, tiger program director for the NGO Panthera, told Mongabay.

Sumatran tigers surviving in unprotected forests

In Indonesia’s Aceh province, researchers installed camera traps across the massive unprotected forests of the Ulu Masen Ecosystem, where they photographed 11 Sumatran tigers (P. t. sumatrae). This is a small but promising population of the rare subspecies, Cowan reported in November 2024.

The survey also recorded several tiger prey species, including sambar deer (Rusa unicolor), serow antelope (Capricornis sumatraensis) and wild boar (Sus scrofa).

However, habitat loss, poaching and illegal mining remain significant threats in Ulu Masen. Scientists have called for better protection of Ulu Masen to support tiger conservation and recovery, saying they hope the new evidence about Ulu Masen’s tiger population will bring in more investment from conservation funders.

Rare Amur tigers reintroduced in Kazakhstan

In September 2024, two Siberian tigers (P. t. tigris) named Bodhana and Kuma were moved from a sanctuary in the Netherlands to a seminatural enclosure in Kazakhstan’s Ile-Balkhash Nature Reserve. Tigers in the region were hunted to extinction some 70 years ago, and the pair is part of an ambitious reintroduction project.

Kazakhstan has reportedly spent six years reforesting part of Ile-Balkhash with native trees, and reintroduced prey species like the Bukhara deer (Cervus hanglu bactrianus) and the Asiatic wild ass (Equus hemionus), WWF said in a blogpost.

Experts say they hope that Bodhana and Kuma will breed, and their cubs will become the first wild-born tigers in Kazakhstan, spurring a new population in the region.

Banner image of a Sumatran tiger by Rhett A. Butler/Mongabay.

Environmental activist Hipólito Quispe Huamán was shot and killed Saturday night in the Madre de Dios region of southeastern Peru, in what authorities suspect was a targeted attack linked to his work defending the Amazon rainforest, AFP reports.

Quispe Huamán was driving along the Interoceanic Highway when he was gunned down, according to local prosecutors.

Karen Torres, a regional prosecutor, told reporters that investigators are considering his environmental advocacy as the likely motive.

“This is a murder with a firearm of yet another defender of the Madre de Dios region,” she was quoted as saying by AFP.

Quispe Huamán had served as an active member of the Tambopata National Reserve Management Committee and was a vocal opponent of deforestation and illegal land use in the Peruvian Amazon. His killing has sparked outrage from human rights and environmental organizations, which say the attack reflects a growing pattern of violence against Indigenous leaders and environmental defenders in the region.

“We condemn the murder of environmental defender Hipólito Quispe Huamán in Madre de Dios, another victim of the growing violence against those who protect our territories and ecosystems,” said the National Coordinator for Human Rights (CNDDHH) in a statement posted on social media. “Not one more death!”

Quispe Huamán’s brother, Ángel, called for accountability. “I demand justice for my brother’s death. This kind of thing cannot happen,” he told local media.

The Ministry of Justice has pledged to support the legal defense of Quispe Huamán’s family and ensure the perpetrators are brought to justice. However, critics say the government’s response mechanisms remain under-resourced. The Intersectoral Mechanism for the Protection of Human Rights Defenders, led by the Ministry of Justice, has faced ongoing criticism for lacking the budget and personnel needed to respond effectively to threats.

Attacks against environmental defenders have increased across Peru’s Amazonian regions, where extractive industries, drug trafficking, and illegal land grabs often operate with impunity. In July 2024, the Interethnic Association for the Development of the Peruvian Rainforest (AIDESEP) declared a state of emergency after an Indigenous leader was tortured and killed in central Peru, citing escalating threats from coca growers and criminal networks.

According to Global Witness, at least 54 land and environmental defenders have been murdered in Peru since 2012—more than half of them Indigenous. Many of these killings remain unsolved.

Quispe Huamán’s death has reignited calls for stronger protections for those who safeguard the rainforest and Indigenous territories. As investigations continue, activists and family members are demanding not only justice—but a systemic response to end the violence.

When BP’s Deepwater Horizon oil rig exploded in the Gulf of Mexico in 2011, it led to the largest oil spill in U.S. history, severely damaging marine ecosystems. Part of the settlement money that BP agreed to pay has since been used for a deep-sea restoration project that has achieved significant milestones in spawning corals through new innovative methods, Mongabay’s Liz Kimbrough reported in May.

The eight-year, deep-sea Mesophotic and Deep Benthic Communities (MDBC) restoration projects, led by the U.S. National Oceanic and Atmospheric Administration (NOAA) and partner institutions, involve propagating coral, as well as mapping, assessing, protecting and managing deep ocean habitats across the Gulf of Mexico.

The teams first use autonomous underwater vehicles (AUVs) and remotely operated vehicles (ROVs) to map and scan the seafloor. Their camera footage helps researchers identify locations with the most damaged coral species, allowing them to focus on areas where they can make the greatest impact.

“We are mapping the Gulf to a level that is practically unprecedented,” Andrew Davies, a professor of marine biology from the University of Rhode Island, told Kimbrough. Since 2022, they’ve mapped 19,400 square kilometers (7,500 square miles) of the seafloor, nearly the size of the country of Wales.

Once the maps are ready, the researchers use the ROVs’ mechanical arms to carefully collect small cuttings of healthy corals, avoiding damage the rest. Researchers then further cut these clippings into smaller pieces and mount them on a concrete rack. After just a few days, or sometimes hours, the racks are carried back down, where the ROVs spread them around the seafloor.

In May 2023, the first month of such planting, the team placed 200 coral fragments of three species at a depth of 230 feet (70 meters). They planted another 140 fragments in 2024. Depending on the coral species, survival rates can range from 60-90%, Kimbrough reported.

Highly trained U.S. Navy divers, capable of going beyond the recreational scuba limit of 40 m (130 ft), have also helped experiment with planting corals. During the 20 minutes they’re allowed to spend at depths down to 100 m (330 ft), they fragment the corals by hand and glue them to racks placed directly on the seafloor. At the time of the story’s publishing, researchers weren’t sure about those corals’ conditions.

In a parallel effort, scientists are growing deep-sea corals in three federal laboratories in conditions that precisely mimic deep-sea habitats. At NOAA’s lab in Galveston, Texas, one coral species started reproducing in 2023, producing 1,000 baby corals. Under the carefully managed lab conditions, the corals seem to be growing faster than expected, Chris Gardner, a U.S. government fisheries biologist, told Kimbrough.

The first lab-to-ocean coral transplantation is planned for later this year.

Read the full story by Liz Kimbrough here.

Banner image of Swiftia exserta, or red polyp octocoral, being fed in the lab. Image courtesy of NOAA.

NEW YORK (AP) — This year’s United Nations climate conference in November is in Belem, Brazil, a city facing high poverty and infrastructure challenges. It’s a location chosen in part to highlight the urgent need for climate action. COP30 President-designate André Corrêa do Lago said in an interview with The Associated Press that it’s important to address inequalities and sustainability in these talks and that Brazil wants negotiators to see the uncomfortable consequences. It’s already potentially uncomfortable because Brazil is working to accommodate a large number of attendees, with high lodging prices a concern. This year, countries must update their climate plans to align with goals set by the Paris agreement to limit atmospheric warming.

By Seth Borenstein, Associated Press

Founder’s Briefs: An occasional series where Mongabay founder Rhett Ayers Butler shares analysis, perspectives and story summaries.

In the mid-1990s, the kākāpō seemed destined for extinction. Only 51 individuals of the flightless, nocturnal parrot remained, all of them descended from a shrinking gene pool and spread across remote corners of New Zealand. A victim of its own evolutionary success, the kākāpō had once flourished in a predator-free island ecosystem. But its defenses—freezing when threatened, nesting on the ground, and producing a strong scent—proved fatal once humans introduced cats, rats, and stoats.

Against these odds, the kākāpō recovery has become one of conservation’s most carefully managed comebacks. The entire population is now named, monitored, and fitted with smart transmitters. Breeding, which occurs only during occasional mast years when native trees fruit heavily, is bolstered by artificial insemination and precision feeding. Drones ferry sperm across island sanctuaries in minutes, shortening a journey that once took hours on foot. Data loggers track every movement, weight change, and mating.

The results are cautiously encouraging. As of 2024, the known population stands at 244 individuals. All reside on predator-free islands, with a few reintroduced to the New Zealand mainland under close surveillance. Scientists have even sequenced the genome of every adult kākāpō, using genetic data to manage breeding pairs and reduce the risks of inbreeding.

Success remains fragile. The species is still critically endangered, and low genetic diversity continues to affect fertility. Yet the recovery offers valuable lessons for other conservation efforts. The kākāpō’s survival is a testament to long-term planning, technological innovation, and sheer persistence. What began as a desperate salvage mission has become a case study in high-stakes species management.

Lessons from the kākāpō recovery:

• Technology scales conservation: Smart transmitters, automated feeders, and drones allow for real-time, individualized care across remote terrain.
• Genetics matter: Sequencing every bird helps mitigate inbreeding risks and improves mate selection in small populations.
• Predator control is essential: Removing invasive mammals remains the foundation of any island-based recovery program.
• Breeding requires precision: Artificial insemination and targeted nutrition can enhance reproductive outcomes, even in reluctant breeders.
• Persistence pays off: The kākāpō’s recovery has taken decades, demanding patience, trial and error, and sustained funding.

Few species have fallen so far and clawed back so much. The kākāpō still cannot fly—but extinction is no longer its only trajectory.

Header image: An adult female kākāpō. Image by Andrew Digby/New Zealand Department of Conservation.