The jaguar is the largest feline in the Americas and serves as a keystone species by acting as an apex predator with a diverse diet across multiple environments, thereby regulating the populations of dozens of species.

Fig trees are considered keystone species because they provide year-round habitat and fruit, which are eaten by an estimated 1,300 species of birds and mammals worldwide.

Feral and free-ranging cats rank among the most harmful invasive species

Transported across the planet by humans, cats can now be found in many environments and are estimated to kill about 2 billion birds each year in the US. Studies suggest cats have contributed to the extinction of at least 63 species worldwide.

Although ecologists have struggled to identify a species as a keystone—one of outsized importance to its ecosystem—an analysis of 50 years of data and 157 studies identified 230 such species.

Tigers emerged much earlier as a species than lions

Both lions and tigers are iconic big cats known for their size and power, but they remain distinct species. Beyond just looking different, they can exhibit very different behaviors. For example, tigers are significantly less social than lions, who live in social matriarchal groups. Tigers and lions are unlikely to ever interact in the wild, but humans have artificially bred them in captivity, creating a "liger."

By targeting a diverse range of sick and injured marine life, sharks—a type of predatory keystone species—help keep ocean gene pools healthy and promote biodiversity by keeping prey species in check.

In Yellowstone National Park, grey wolves act as keystone predators by controlling elk and deer populations, which had previously overgrazed and disrupted river systems that supported many more mammal, fish, and avian species.

Possessing trunks that contain about 40,000 individual muscles, African elephants act as keystone species by trampling and clearing trees, making pathways in forests, digging water holes, and spreading seeds.

During a tropic cascade, the disappearance of a keystone species, which plays an indispensable role in ecosystems, triggers a domino effect within food webs that disrupts the populations of many more species.

A collection of fascinating facts about the planet and its creatures

You may have already heard that cheetahs are the fastest animals on land, but did you know that Savannah elephants are the strongest? This page on the World Wildlife Fund's UK website features a diverse range of articles on mammals, underwater creatures, birds, reptiles, insects, and landscapes. Discover captivating information about Earth and the creatures you share it with.

Indigenous people of the Amazon rainforest

Indigenous people have unrivalled knowledge of plants and animals and play a crucial role in conserving biodiversity. Protecting their rights preserves this unique knowledge.

These animals are only found in the Amazon rainforest.

The mighty Amazon River and its surrounding rainforest is home to millions of different species of animals, with new ones being discovered regularly.

Sea otters act as keystone predators by eating up to 15 pounds of seafood a day, including urchins, which feed on kelp forests that support over 800 species by providing them with habitats and food.

The concept of keystone species—organisms that have disproportionately large impacts on their ecosystems—was discovered through studies of purple starfish in Pacific tidepools.

Ten magnificent photos of lions

A new book of essays and images reveals the history of the big cats, elaborating on how they’ve become a vulnerable species today (and efforts to preserve them).

Amazon rainforest facts, species, and threats

The World Wildlife Federation presents a brief overview of the Amazon rainforest, covering key facts like location, size, and importance. An overview of threats includes unsustainable resource extraction, climate change, and poorly planned construction projects.

Over 1 million fish, marine mammals, and invertebrate species depend on coral reefs for habitats, camouflage, and food.

Desert wildlife: diverse, threatened, and misunderstood

This article sheds light on the surprisingly diverse wildlife that thrive in deserts, while also highlighting the gaps in human understanding of these ecosystems. Deserts are home to one-quarter of terrestrial vertebrate species—three percent of...

According to the International Union for Conservation of Nature, as of 2025, there are over 18,000 endangered animal species worldwide, with the share of fish, insects, mollusks, and reptiles increasing since 2007.

Infographic illustrates the diverse and fragile Amazon ecosystems

This infographic helps readers better understand the vast rivers, forests, plants, and animals that call the Amazon rainforest home. Home to the largest collection of plant and animal species in the world, the Amazon rainforest has 16 thousand known...

As environmental engineers—a main type of keystone species—prairie dogs support over 150 other species through their grazing habits and burrowing of underground tunnels, which serve as habitats for owls, snakes, ferrets, insects, and other organisms.

Finance sector has power to help the Amazon rainforest

Read this article to uncover the potential role of the financial industry in addressing deforestation, climate change, and biodiversity loss in the Amazon rainforest. The finance sector can significantly contribute to conservation efforts by...

Invasive species are the third biggest threat to Earth's biodiversity

According to the World Wildlife Fund's Living Planet Report 2020, changes in land and sea use account for about half of all recorded threats to the diversity of the planet's species. Species overexploitation is the second-largest proportional threat at 24%, while invasive species make up 13%.

Some mosquitoes are key pollinators—and eat disease-carrying mosquitoes.

See the world's first-known photo of a wild white Iberian lynx

Described by the photographer as the "white ghost of the Mediterranean forest," the lynx is a vulnerable species. Catching the genetic anomaly on camera is a testament to conservation efforts that began in 2011.

Contributing to one in every three bites of food consumed by humans, bees are a keystone species because of their essential role as pollinators of about 80% of all flowering plants worldwide.

While invasive species typically harm ecosystems by outcompeting native organisms for resources, some provide unexpected benefits, including new shelters, nesting habitats, and reduced environmental heat stress.

Large animals like giraffes and elephants have evolved unique cancer defenses.

The deep-sea fangtooth has the largest teeth of any marine species relative to body size

From transparent fish to the heaviest worms on the planet, these seven creepy creatures lurk in the deep sea. Learn all about them and the unique traits that help them survive and hunt.

Explore Amazon rainforest species in this interactive

Explore plant and animal species from different parts of the rainforest, including the canopy, forest floor, and river basin while learning some general facts specific to the Amazon rainforest.

The best national parks in America for wildlife spotting

Park-goers hoping to catch a glimpse of local wildlife can turn to this breakdown of animal-related data from the National Park Service. Birdwatchers should visit Carlsbad Caverns in New Mexico, which has the highest density of bird types at 194 species per 100km². Interested in marine life? Head to Biscayne National Park in Florida to find nearly 700 species of colorful fish in crystal-clear waters.

Zoo animals have developed allergies, too

Although scientists do not know if allergies manifest among wild animals—and if animals can survive with them—in a zoo setting, veterinarians have observed zoo animals with common allergy symptoms, including itchiness, crusty skin, and runny eyes. Veterinarians have identified Asian elephants with pollen allergies and at least one jaguar with an allergy to fleas.

Based on a species' population size, distribution, and habitat, it may be designated as a threatened species—vulnerable, endangered, or critically endangered—if it is at high risk of extinction.

How the California wildfires are impacting wildlife

The deadly 2025 Eaton and Palisades Fires in California have devastated neighborhoods, forested canyons and chaparral—a type of shrubland. In addition to taking dozens of human lives and displacing thousands, the fires destroyed countless habitats and displaced many species. See the unfortunate effects of the flames on wildlife populations, including birds, snakes, wildcats, and fish.

Even in nature reserves, climate change is driving rapid ecological collapse

Studies show a dramatic decline in insect populations, resulting in cascading global biodiversity losses across non-insect species. The balances in tropical ecosystems are the most affected by climate change.

Learn about the plant and animal species in every US county that are federally protected under the US Endangered Species Act with this interactive map.

Supertoxic rat poisons are wreaking havoc on unintended targets, including predator birds, mammals, amphibians, crustaceans, and insects.