The threats facing endangered species
A species rarely disappears for a single reason. Usually, several threats pile up until the population can no longer replace itself. Here are the main drivers of decline, illustrated by the ten species on this site, along with the solutions that have proven themselves.
Each example below links to a species page, where you will find detailed figures and their sources.
Habitat loss
The problem. Every species needs somewhere to feed, shelter and breed. When a forest is cut down, a wetland drained or a grassland turned into pasture, animals lose their home. What is left is often broken into small, isolated patches where individuals struggle to find each other.
Examples. The last Sumatran rhinos live in forest fragments so scattered that they struggle to find a mate. In Mexico City, urban sprawl is eating into the canals of Xochimilco, the axolotl’s only refuge. In Brazil, the blue-eyed ground dove is losing ground to farming, tree plantations and fire.
Solutions. Protect the last habitats with parks and reserves, restore what has been damaged and reconnect fragments with wildlife corridors. For the Hainan gibbon, a national park was created in 2020, and fruit trees are being planted to expand its territory.
Overexploitation: poaching and trafficking
The problem. Some animals are killed or captured to be sold: for their horn, their meat, a body part, or as pets. As a species becomes rarer, its black-market price rises, attracting even more poachers.
Examples. Poachers confessed to killing 26 Javan rhinos for their horns between 2019 and 2023. The ploughshare tortoise, with its golden shell, is targeted by collectors willing to pay huge sums.
Solutions. Anti-poaching patrols on the ground, investigations to dismantle trafficking networks, border controls and lower demand. International trade in endangered species is regulated by the CITES convention.
Bycatch and accidental deaths
The problem. An animal can die without being targeted: caught in a net, tangled in ropes or struck by a ship. For a species that is already rare, every accidental death counts.
Examples. The vaquita drowns in gillnets, especially those set illegally for another protected fish, the totoaba. The North Atlantic right whale dies mainly from entanglement in fishing gear and collisions with vessels.
Solutions. Ban the most dangerous gear where endangered species live, develop safer fishing gear, slow ships down and temporarily close areas when animals are present. In Canada, these measures have been applied every year in the Gulf of St. Lawrence since 2017.
Invasive species
The problem. Animals or plants introduced by people into places where they never existed can wreak havoc. Native species, which have never faced these newcomers, often have no defence.
Examples. In New Zealand, introduced rats, cats, ferrets and stoats devastated the kākāpō, a flightless parrot. In Ujung Kulon National Park, an invasive palm is smothering the plants the Javan rhino feeds on.
Solutions. Remove introduced predators, especially on islands, and keep them from coming back. Today, kākāpō live on three islands entirely cleared of predators.
Disease
The problem. An epidemic can hit an entire population at once. The risk is higher when wild animals live close to livestock or domestic animals, which can pass diseases on to them.
An example. Livestock from villages near Ujung Kulon can transmit diseases to Javan rhinos through biting flies.
Solutions. Monitor the health of wild animals, limit contact between livestock and wildlife, and establish a second population elsewhere so that a single outbreak cannot wipe out everything. That is the long-term goal for the Javan rhino.
Pollution
The problem. Pesticides, polluted water, waste: pollution degrades habitats, especially rivers and wetlands, and weakens the animals living there.
An example. In Xochimilco, canal pollution, made worse by heavy pesticide use, is contributing to the axolotl’s decline. The last axolotls survive only in canals where the water is still clean.
Solutions. Cut pollution at the source, filter water and support farming that relies less on pesticides. In Xochimilco, farmers are turning their chinampas, farm islets dating back to Aztec times, into “chinampa refuges” where water is filtered and axolotls are protected.
Climate change
The problem. Warming changes temperatures, currents and where prey can be found. It also makes fires, droughts and storms harder to predict. For a species already weakened, it is one more pressure.
Examples. Climate change adds to the other threats facing the North Atlantic right whale and the blue-eyed ground dove, whose habitat is exposed to fire.
Solutions. Cut greenhouse gas emissions, and make species less vulnerable by reducing other threats and protecting habitats that are large and varied enough for them to adapt.
The small-population trap
The problem. When only a few dozen individuals remain, new dangers appear. Animals are often related, and inbreeding lowers fertility. A single event, such as a storm, an earthquake or a poor breeding season, can be enough to tip the species over the edge.
Examples. In 2024 and 2025, two distant earthquakes sent waves through the cave of the Devils Hole pupfish, washing away its eggs and food. The Hainan gibbon and the kākāpō both suffer from very low genetic diversity.
Solutions. Establish several separate populations so as not to put all the eggs in one basket, run carefully planned breeding programmes and, where possible, reintroduce animals to their former range.
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