Half the giants are in trouble

Take every land mammal big enough to notice — anything from a 10-kilogram dog upward: the tigers, elephants, bears, wolves, gorillas, big cats, antelope, the large animals we put on flags and in children’s books. Nearly half of them — 47% — are now sliding toward extinction¹, classed by the IUCN as vulnerable, endangered, or critically endangered. Add the “near-threatened” tier and the share reaches 59%: closer to two in three than one in two.

If the worsening of recent decades keeps pace, that 47% climbs toward 70% by 2080 — a projection we’ve extrapolated from the trend, not an IUCN forecast, and flagged as such⁶.

Why size is a death sentence

Body size turns out to be one of the strongest predictors of extinction risk, because everything that makes an animal large also makes it fragile. Big mammals breed slowly — long pregnancies, few offspring, late maturity — so populations recover sluggishly from any loss. They need room: home ranges measured in square kilometres, exactly the kind of continuous habitat that roads and farms carve up first. They collide with people more often, hunted for meat and trophies and traditional medicine, shot in retaliation for taking livestock, killed on highways. And they matter ecologically out of all proportion to their numbers — an apex predator or a multi-tonne grazer shapes an entire ecosystem in ways no small species can replace.

The 10kg threshold is somewhat arbitrary, but it captures the animals most people picture when they hear the word “wildlife”: tigers, elephants, bears, wolves, deer, kangaroos, primates, big cats, large antelope, sea lions, dolphins.

This started 50,000 years ago

The 47% figure is the modern snapshot. The longer trajectory is even starker.

Roughly 50,000 years ago, as anatomically modern humans began expanding out of Africa, the planet’s large land animals started disappearing — the episode palaeontologists call the Late Quaternary megafauna extinctions². At least 161 large mammal species were lost, and the total biomass of big terrestrial vertebrates fell by roughly an order of magnitude. The very largest suffered most: of the 57 species of megaherbivore over a tonne that walked the Earth 50,000 years ago, just 11 survive today. The woolly mammoths, mastodons, giant ground sloths, glyptodonts, and woolly rhinos are all gone.

For most of the 20th century, the conventional explanation was climate change — the end of the last ice age. Recent research, including 2024 analyses from Aarhus University, has shifted the consensus³:

Models including human factors outperformed all purely climatic models.

In other words: humans drove the first wave of large-mammal extinction, beginning roughly when anatomically modern humans arrived in each region. The pattern is consistent across Australia (50,000 years ago, coincident with human arrival), the Americas (15,000 years ago, coincident with human arrival), Madagascar (2,000 years ago), New Zealand (700 years ago).

The current wave — which the counter on this page is measuring — is the same process, accelerated.

What “Empty Forest Syndrome” looks like

The 2014 Dirzo et al. Science paper introduced a concept that has shaped the field since: defaunation⁴.

Defaunation is biodiversity loss that happens before habitat loss. A forest can look structurally intact from a satellite — same canopy, same area — while having lost all its large vertebrates to hunting, road mortality, and snares. The ecological function collapses; the trees remain.

The paper coined “Empty Forest Syndrome” to describe this. Across much of the tropics — Central Africa, Southeast Asia, parts of Amazonia — the forests are still there, but the large animals that disperse seeds, prune saplings, and recycle nutrients are gone or going. The forests are, ecologically, hollow.

This matters for any “% of forests remaining” statistic: those numbers can stay stable while the wildlife inside is being stripped out. The Living Planet Index picks this up; satellite forest maps don’t.

What’s killing them now

For the 47% of large mammals now at risk, the IUCN’s ranking of causes is depressingly familiar. Agricultural expansion tops it — the conversion of habitat to cropland and pasture, especially across the tropics. Then hunting and poaching, for meat, trade, medicine, and in retaliation for livestock losses. Then the slow strangulation of habitat fragmentation, as roads, dams, and cities sever the continuous range these animals need. Climate change pushes habitat zones faster than species can follow and thins out their prey, while invasive species and disease deliver the final blow, most devastatingly on islands.

What makes it hard to reverse is that these pressures rarely arrive alone. The majority of threatened large mammals face several at once — which means saving them takes more than fixing any single thing.

Where this ends up

The line heads toward ~70% of large mammals threatened by 2080. That number is a linear extrapolation of the rate at which species have been added to threatened categories in successive Red List updates — roughly half a percentage point per year added to the threatened share over recent decades.

The IUCN itself doesn’t publish forward forecasts; Red List status is a current-state assessment, not a projection. We’re translating “the rate of recent worsening” into “where the line points in 2080” so the counter has something credible to tick toward. The actual outcome depends on:

• Whether the 30×30 global protected-area goal materially expands large-mammal habitat
• Whether tropical deforestation slows, stays, or accelerates
• Whether climate change pushes the curve steeper (very plausible)
• Whether specific high-impact interventions (anti-poaching, corridor protection, prey-base restoration) scale up

Two ways to measure the same loss

If the Living Planet Index measures the population dimension of vertebrate decline, this counter measures the species-extinction-risk dimension. They’re complementary: populations can decline catastrophically without species going extinct, and species can be near-extinction even with a few stable populations remaining.

The 47% figure is also the most direct measure of where conservation triage will be focused in the next 25 years. Large mammals require habitat at scale; they’re expensive and politically complex to protect. The trajectory from here depends on choices made now about where to draw the lines on land use.