Mary River turtle
© Daniela Parra CC BY-NC 2.0
Written by Olivia Nater | Published: August 29, 2025
Panic over declining birthrates is widespread, with headlines warning of “population collapse” and even human extinction. This is absurd, considering that our global population is still growing and on track to exceed 10 billion in the second half of this century. Nevertheless, pro-growth pundits seem obsessed with raising alarm over the trend towards smaller family sizes.
At Population Connection, we argue that lower fertility is a very positive development because it is driven by choice and charts a path to a more sustainable population size, which will take pressure off our already heavily overburdened planet. The fact is that our 8.2-billion-strong and counting human enterprise is rapidly wiping out the many wonderful species that also inhabit this planet.
The sixth mass extinction crisis is still accelerating due to our relentlessly increasing population and demand for resources, which are causing habitat destruction, overexploitation of species, climate change, and pollution. WWF estimates that vertebrate wildlife populations fell by a staggering 73 percent between 1970 and 2020. In that time, human numbers more than doubled.
Charismatic megafauna like tigers, elephants, and polar bears are the poster children of biodiversity loss, but there are thousands of less-known species that are just as fascinating and important to ecosystems and are also in danger of being lost forever. To date, around 170,000 species of plants, animals, and fungi have been assessed for the International Union for Conservation of Nature (IUCN) Red List, the global authority on species’ conservation status. More than 47,000 of these assessed species are threatened (meaning they have been classified as either Vulnerable, Endangered, Critically Endangered, or Extinct in the Wild). Let’s take a look at some of them.
Amphibians are one of the most imperiled groups, with 41 percent of the more than 8,000 described species threatened with extinction. Among them is the Malagasy rainbow frog (Scaphiophryne gottlebei), a colorful little creature that lives in the humid canyons of Madagascar’s Isalo Massif. Special adhesive discs on its feet allow it to climb vertical canyon walls to escape flash floods.
The Malagasy rainbow frog is classified as Endangered on the IUCN Red List. Its habitat is threatened by fire, wood extraction, livestock overgrazing, and mining activities. It also suffers from over-collection for the exotic pet trade and, like all amphibians, is vulnerable to climate change.
Around 90 percent of Madagascar’s wildlife species are endemic, meaning they are found nowhere else on Earth. This combined with Madagascar’s rapid human population growth creates a very high extinction risk for many Malagasy species.
An estimated 27 percent of all mammals are threatened with extinction. A relative of the civet, the binturong or ‘bearcat’ (Arctictis binturong) is a shaggy dog-sized mammal native to the tropical forests of Southeast Asia.
Despite its large size, relatively little is known about the ecology of this secretive species. Binturongs are primarily arboreal (tree-dwelling) and are thought to be mainly frugivorous (fruit-eating). They are said to smell distinctly of popcorn – their urine contains the same compound (aldehydes) that forms from chemical reactions during the popping of popcorn.
The binturong is classified as Vulnerable on the IUCN Red List. Its habitat is rapidly dwindling due to widespread deforestation for logging and land conversion. Binturongs are also hunted for meat and traditional medicine throughout their range. This species is believed to be close to national extinction in some of its range countries, including Vietnam and China.
Sharks and rays are struggling to survive, with 37 percent of all species classified as threatened. The angelshark (Squatina squatina) is a temperate bottom-dwelling shark of the continental shelves of Europe and the Mediterranean basin.
Angelsharks have flattish bodies with broad pectoral fins and eyes on top of their heads. They hang out in sandy seabeds, where they bury themselves with just their eyes protruding while waiting for prey. This shark used to be common across the Northeast Atlantic and Mediterranean until the early 20th century, but overfishing has caused steep population declines. The species is now only observed regularly in the Canary Islands, with occasional records from the Northeast Atlantic. The angelshark has been classified as Critically Endangered on the IUCN Red List.
While they are not specifically targeted, angelsharks are very vulnerable to bycatch from industrial fishing operations, which have rapidly intensified over the past century. Coastal development also poses a threat to angelshark habitat, especially key nursery areas in shallow inshore waters.
Tree species don’t receive a lot of conservation attention, yet they face the same threats as wildlife. An estimated 34 percent of conifers are threatened with extinction. The Patagonian cypress (Fitzroya cupressoides) is endemic to southern Chile and Argentina. It is an impressively long-lived, slow growing tree – there are records of it living to more than 3,600 years old. The Patagonian cypress is also thought to be the largest tree species in South America – nicknamed the ‘redwood of the south,’ it can grow up to 70 meters (around 230 ft) in height and up to 5 meters (16 ft) in trunk diameter.
This tree reproduces slowly, undergoing long periods of low to no seed production. The Patagonian cypress is the only extant species of the Fitzroya genus, which can be traced back to the Cretaceous period.
This ancient conifer is classified as Endangered on the IUCN Red List due to deforestation. The Patagonian cypress has been heavily over-exploited for three centuries due to its highly prized wood, while human-set fires and conversion of forest to pasture land are also decimating both the trees and their habitat. In Argentina, an estimated 60 percent of subpopulations show signs of anthropogenic disturbances linked with cattle ranching and browsing.
According to the IUCN Red List, 12 percent of bird species are at risk of extinction. The imperial woodpecker (Campephilus imperialis) is (was?) a very large, striking black-and-white woodpecker that used to be distributed throughout the pine forests of the Sierra Madre Occidental in Mexico, but unfortunately there have been no confirmed sightings since 1956. It is classified as Critically Endangered (Possibly Extinct). The Red List notes the imperial woodpecker was “hunted for fun, food, and supposed medicinal purposes over a long period of time,” while the expansion of lumber operations dealt a further blow, resulting in the widespread removal of the pine trees it depends on.
Insects are the most diverse group of animals, representing around 40 percent of all known living species. Countless insects have not even been described yet – scientists estimate that there may be between 10 and 30 million species. Sadly, creatures with more than four legs tend to receive little love, despite playing key roles in the healthy functioning of ecosystems.
The American burying beetle (Nicrophorus americanus) is a large, attractive black and orange beetle native to temperate eastern North America and originally found in at least 35 states. The species is now believed to be extirpated from Canada as well as all but nine US states. Burying beetles have a fascinating and unique life cycle, burying and processing small animal carcasses before laying their eggs next to them. Once the larvae hatch, they are fed by the parents with regurgitated, predigested carrion.
The American burying beetle is classified as Critically Endangered on the IUCN Red List and is primarily threatened by habitat loss and fragmentation, as well as a reduction in the number of small mammals and birds which they depend on for food and reproduction.
Among reptiles, 21 percent are classified as threatened with extinction. The Mary River turtle (Elusor macrurus) is endemic to the Mary River in south-eastern Queensland, Australia. This odd freshwater turtle can breathe underwater using special glands in its reproductive organs, which allow it to remain submerged for as long as 72 hours. It is the only species in the Elusor genus, having diverged from all other living species around 40 million years ago. Individuals don’t become sexually mature until they reach 25 years old, meaning they are very slow to reproduce.
The Mary River turtle is classified as Endangered on the IUCN Red List, having declined precipitously since 1970 due to the building of dams and collection of eggs for the pet trade.
This is just a small selection of the amazing and unique species teetering on the brink of extinction due to human activities. Our planet is truly incredible in the diversity of life it holds, yet we seem set on wiping it out. Changing our relationship with the natural world and reining in our destructiveness are essential to preserving biodiversity and preventing these and countless other species from disappearing forever.
