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%.

Humans may be the ultimate invasive species

Originating in East Africa, Homo sapiens migrated across the world beginning about 60,000 years ago and directly harmed countless species by consuming resources and modifying ecosystems to serve our needs. While meeting the definition of an invasive species, some ecologists argue the opposite, claiming that humans have helped preserve numerous species.

From 1970 to 2017, invasive species have caused $1.28T in damage globally

The costliest species were the Asian tiger and yellow fever mosquitoes ($149B), which arrived in the US from Asia and sub-Saharan Africa, respectively. The bulk of their damage came from their transmission of diseases such as Zika, chikungunya, and dengue. (Some readers may experience a paywall.)

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

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.

Window collisions and cats kill more birds than wind turbine farms

Researchers are developing solutions to reduce bird fatalities due to wind turbine farms, including radar systems integrating AI to detect birds and shut down systems. Painting blades with various patterns is also being tested, which may reduce bird strikes by 70%.

The Burmese pythons in the Florida Everglades and the spotted lanternfly—native to Asia and now found throughout the US—are among the invasive species accidentally introduced and spread by humans.

Invasive species may harm new ecosystems via the spread of disease

Besides damaging native species through direct interactions such as competition for resources and predation, invasive species may come from environments with greater biodiversity than the new environment. This makes them more likely to carry pathogens unfamiliar to native species, increasing the risk of biodiversity loss.

Increasing contact between humans and wild animals is driving zoonotic threats

Zoonotic diseases, which spread from animals to humans, present one of the most significant emerging threats worldwide. Scientists have identified around 200 viruses capable of infecting humans, and unfortunately, the number of such diseases are on the rise—at least 60% of all emerging infectious diseases are zoonotic in origin.

Invasive species can harm infrastructure and threaten human health

The wildfires in Hawaii in 2022 were made worse by flammable invasive grasses introduced from Africa as livestock pasture, and Zebra mussels native to the Caspian and Black Seas have spread across Europe and the US, where they can clog power plant pipes. Invasive mosquitoes can carry diseases, such as dengue and malaria.

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.

Nearly all species introduced into a new environment are not invasive

Introduced by zoologist Charles Elton in 1958, the term "invasive species" refers to organisms that are not native to an environment but cause harm after their introduction. Some ecologists argue that terminology such as "native" and "non-native" may only serve to assist in extinction when legislation is limited to protecting "native" organisms.

Cats began cozying up to humans around 10,000 years ago

The feline family is a hugely diverse group of lions, panthers, and kitties that have spread all over the world. The ancestors of the cats we love today helped solve rodent problems when humans first invented agriculture. They've been worshipped, loved, and scorned by humans since.

Cane toads are an example of an intentional species introduction turned invasive

In 1935, Australian scientists imported several hundred cane toads to hunt and eat beetles that were damaging sugar cane fields. However, the toads could not reach the bugs at the top of the plant or the grubs in the soil. Instead, they negatively affected native species populations as their numbers grew to over 2 billion.

Benign species can become invasive if introduced into predator-free habitats

Most ecosystems contain organisms that, over many generations, have evolved into a stable balance with one another and their surroundings. In a new environment, a species may no longer be restricted by the limiting factors it is used to, and the native organisms in the area may not adapt quickly enough to the invader to establish a new balance.

Mosquitoes top the ranking of the world's deadliest animals.

Are cats good for our health?

Being a cat lover can have a profound effect on your life. This article in The Conversation presents a fascinating collection of findings related to the benefits and consequences of cat ownership. Discover compelling research about the positive heart health and mental health outcomes cats can bring, along with potential risks.

Vector-borne diseases kill more than 700,000 people globally each year—and are growing

The diseases with the greatest potential to spread widely aren't the ones that quickly kill human hosts. Instead, the best hosts or reservoirs for vector-borne diseases would be chronically ill over the long term, increasing the likelihood that the pathogen could be transmitted to others.

Scientists are using CRISPR to genetically modify felines so they don't trigger allergies in humans.

Native, wild bees are at much greater risk of extinction than honey bees

It is estimated that there are more honey bees, which often compete with native bees for resources, on the planet than at any point in human history. Meanwhile, 40% of invertebrate pollinator species, including wild bees and butterflies, face extinction in the coming decades.

What if we killed every mosquito on Earth?

Mosquitoes aren't just annoying, they're deadly. they're also responsible for an estimated 725,000 deaths worldwide, every year. Would it be so bad if we found a way to wipe them out completely? Real scientists have gamed out this hypothetical scenario, concluding it actually wouldn't be that bad. This five-minute video breaks down one way this could happen.

Bird Flu is spreading—what does that mean for us and other species?

The rapid global spread of H5N1 bird flu—from remote Antarctic islands to US farms—shows how animal spillover, driven by human activity and ecological disruption, is accelerating pandemic risk across species long before sustained human transmission begins.

Butterfly populations have declined by 22% from 2000 to 2020

Research suggests that one in every five butterflies is lost due to pesticide use, habitat loss, and climate change. Playing a vital role in pollination, their declining populations threaten plant reproduction and the health of ecosystems.

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.

Scientists found that if cats ate infected rodents, they could get West Nile in lab experiments.

View some of the most invasive species in US waters

Introduced in the late 1600s from Eastern Asia, the goldfish is considered the first invasive fish in North America. The venomous lionfish is safe to consume, but catching it is complicated by its reluctance to respond to hook-and-line-style fishing attempts.

Black cats got their frightening reputation in the Middle Ages

Though many cultures in Africa, Asia, and Europe recognize black cats as symbols of good fortune, they're associated with bad luck and America's spookiest holiday. Their association with evil didn't gain traction until the 13th century, as religious figures and European folklore drew connections between cats, Satan worshippers, and witches.

London pet detectives set out to prove a spate of cat killings is the work of a serial killer

With dozens of felines turning up dead around London, a pair of pet detectives set out to prove it was the work of a serial killer.

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.

Noise pollution from humans and technology alters animal behavior

Animals may experience chronic stress and health issues due to noise pollution, which often interferes with their mating sounds. Due to traffic, nightingales sing louder on weekday mornings, and birds near airports start singing earlier to avoid upticks in takeoffs and landings.

Mosquitoes are the world's deadliest animal, but gene drives could kill them.

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.

Mapping migrations of hundreds of bird species

The birds we see throughout the year are long distance fliers, often traveling over thousands of miles to reach optimal nesting grounds, better feeding, and more. This thorough interactive map tracks over 450 types of bird on their annual migrations, depicting both their route as well as some of the conservation hurdles each species faces. Fly along with your favorite bird here.

The most effective method of managing invasive species is prevention education

Controlling a spread after a species has become established in an area is much more costly and time-consuming than early detection and rapid response. Control methods include the purposeful introduction of predators, the use of pesticides, herbicides, fungicides, and insecticides, and physical collection and removal.

About one-third of the world's food supply depends on pollinators like bees, butterflies, and bats to transfer pollen between flowers, which use bright colors, scents, and nectar to attract them.

Bats are uniquely suited to act as reservoirs of viruses.

Some of the deadliest diseases to jump from animals to humans originate in bat species. This rich visualization explores the diversity of bats and the factors that make them efficient vectors for harboring and transmitting disease, from their long lifespans to their migration patterns.

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

Biologists believe over 5,000 coyotes inhabit LA as of 2025

Panic and fear of coyotes spread in the 1980s after the first recorded instance of a human killed by the animal in American history, but LA and Chicago residents today are learning to live alongside the animal. Research shows that coyotes can even benefit urban ecosystems by helping to control populations of geese and deer, and by improving songbird survival through preying on cats.

View a breakdown of the identified species on Earth, led by about one million insect species, while mammals such as humans make up one of the smallest groups.