They’re like the fat cousins of an ordinary tree squirrel – and they’re getting even fatter as the mercury rises. Longer, warmer summers and shorter winters have been allowing marmots in the Colorado Rocky Mountains to grow larger and breed earlier in the season. Since 2000, their reproductive success has led to a marmot explosion, with numbers growing by a frisky 18% per year.
2. Cane Toads
It’s poisonous, invasive, full of warts and it eats just about anything it can swallow. Say hello to the cane toad. It takes a hardy sort of critter to mount an Aussie invasion, but that's exactly what the toads did when they were introduced there in 1935. And they’re not letting anything halt their march of ecological devastation, not even global warming. Their resilient cardiovascular systems actually benefit from warmer temperatures, making the toads more efficient.
It seems rather unfair that climate change is springboarding the tick to unprecedented success. It’s not like the species needs any help. These blood-guzzling parasites are highly specialized, difficult to remove and pretty hard to kill – and fossil records show they’ve been happily proliferating on various mammalian hosts for millions of years. And now warmer temperatures are allowing the parasites to expand their range. So while polar bears cling desperately to the world’s remaining pack ice, ticks are knocking back blood spritzers and spreading Lyme disease in previously uncharted territories. Salut!
Their venomous little nematocysts are poised for ocean domination. As our seas become heated by global warming, many of the world’s jellyfish species are expanding their ranges and increasing in numbers. According to some of the more gloomy predictions, overfishing and climate change will soon turn our oceans into a gelatinous Soupe à La Cnidaria.
5. Soay sheep
After the unsightly charms of the tick and the cane toad, it’s heartening to see that our next climate-change winner is of the cute-and-cuddly variety. Thanks to global warming, survival has become easier for wild Soay sheep on the Scottish island of Hirta. Even the smallest lambs (normally wiped out during harsh winters) are now reaching adulthood due to milder temperatures. In fact, these scrawny survivors are bringing down the average size of the wild flocks – a strange case of “shrinking sheep”.
6. Sea stars
If there’s one animal with the potential to challenge the jellyfish for control of the oceans, it just might be the sea star. While many marine life forms are being crippled by the two-pronged threat of rising ocean temperatures and CO2 concentrations, one particular species of sea star seems unaffected. In fact, higher temperatures and acidity seem to boost its growth rate.
Global warming is opening up exciting new territories for one of the world’s worst biting bugs: the mosquito. Thanks to warmer temperatures and seasonal shifts, the Asian tiger mosquito is one species that’s becoming a worldly traveller. Armed with a miscellany of deadly and largely unpronounceable diseases, this bloodsucker is leaving its former tropical abodes to thrive in places like Italy and the US.