More than 700 mammals and birds currently threatened with extinction already appear to have been adversely affected by climate change, according to a major review of scientific studies.
Primates and marsupials are believed to have the most individual species suffering as a result of global warming, according to a paper in the journal Nature Climate Change.
Only two groups of mammals, rodents and insect-eaters, are thought to have benefited. This is partly because they have fast breeding rates, tend not to be specialists suited to a particular habitat, and often live in burrows which provide insulation against changes in the weather.
The figures are much higher than previously thought, making up 47 per cent of land mammals and 23 per cent of the birds on the International Union for Conservation of Nature’s Red List of species threatened with extinction.
According to the list itself, just seven per cent of the mammals and four per cent of the birds are described as being threatened by “climate change and severe weather”.
The researchers developed a model to compare the animals’ weight and other characteristics with changes in the climate, such as the temperature.
“Using this model, we estimated that 47 per cent of terrestrial [non-flying] threatened mammals (out of 873 species) and 23.4 per cent of threatened birds (out of 1,272 species) may have already been negatively impacted by climate change in at least part of their distribution,” the article in Nature Climate Change said.
“Our results suggest that populations of large numbers of threatened species are likely to be already affected by climate change, and that conservation managers, planners and policy makers must take this into account in efforts to safeguard the future of biodiversity.”
Primates and marsupials are more at risk than other animals partly because they have lived mostly in tropical parts of the world which have had a stable climate for thousands of years.
“Many of these [animals] have evolved to live within restricted environmental tolerances and are likely to be most affected by rapid changes and extreme events,” the paper added.
“In addition, primates and elephants are characterised by very slow reproductive rates that reduce their ability to adapt to rapid changes in environmental conditions.”
One reason why climate change is causing a problem for animals is changes in the distribution of plants.
“In areas with reduced precipitation and/or temperature seasonality, it is likely that plant species may have narrower climatic tolerances, and therefore that these areas may have already experienced vegetation changes with consequential loss of habitat for animals living there,” the paper said.
Animals in decline
Animals in decline
1/8 Harbour seal (Phoca vitulina)
Where: Orkney Islands. What: Between 2001-2006, numbers in Orkney declined by 40 per cent. Why: epidemics of the phocine distemper virus are thought to have caused major declines, but the killing of seals in the Moray Firth to protect salmon farms may have an impact.
2/8 African lion (Panthera leo)
Where: Ghana. What: In Ghana’s Mole National Park, lion numbers have declined by more than 90 per cent in 40 years. Why: local conflicts are thought to have contributed to the slaughter of lions and are a worrying example of the status of the animal in Western and Central Africa.
3/8 Leatherback turtle (Dermochelys coriacea)
Where: Indonesia, Malaysia, Mexico, Costa Rica. What: Numbers are down in both the Atlantic and Pacific. It declined by 95 per cent between 1989-2002 in Costa Rica. Why: mainly due to them being caught as bycatch, but they’ve also been affected by local developments.
4/8 Wandering albatross (Diomedea exulans)
Where: South Atlantic. What: A rapid decline. One population, from Bird Island, South Georgia, declined by 50 per cent between 1972-2010, according to the British Antarctic Survey. Why: being caught in various commercial longline fisheries.
5/8 Saiga Antelope (Saiga tatarica)
Where: Kazakhstan, Mongolia, Russia, Turkmenistan, Uzbekistan. What: fall in populations has been dramatic. In the early 1990s numbers were over a million, but are now estimated to be around 50,000. Why: the break up of the former USSR led to uncontrolled hunting. Increased rural poverty means the species is hunted for its meat
6/8 Swordfish (Xiphias gladius)
Where: found worldwide in tropical, subtropical and temperate seas. Why: at risk from overfishing and as a target in recreational fishing. A significant number of swordfish are also caught by illegal driftnet fisheries in the Mediterranean
7/8 Argali Sheep (Ovis mammon)
Where: Central and Southern Asian mountains,usually at 3,000-5,000 metres altitude. Why: domesticated herds of sheep competing for grazing grounds. Over-hunting and poaching.
8/8 Humphead Wrasse (Cheilinus undulatus)
Where: the Indo-Pacific, from the Red Sea to South Africa and to the Tuamoto Islands (Polynesia), north to the Ryukyu Islands (south-west Japan), and south to New Caledonia. Why: Illegal, Unregulated and Unreported (IUU) fishing and trading of the species
“A more specialised diet was also associated with greater probability of negative responses in mammals.
“Our findings are in agreement with previous studies on the predictors of general extinction risk, in which species with narrower diet breadths were associated with lower ability to exploit resources and adapt to new environmental conditions and selective pressures.”
Birds living in the world’s cold mountain regions appear to be particularly at risk.
“Populations of species living at high altitudes and in colder places have fewer opportunities to move towards cooler areas or upslope to avoid increasing temperatures, and hence may have increased extinction risk,” the paper said.
Another problem is that higher temperatures are inducing birds to lay eggs earlier.
“For animals living in these environments the effects of temperature changes may have been exacerbated, potentially leading to disruption in synchronisation between the timing of chick-feeding and peak food availability,” the paper said.