On my recent trip to Australia, I saw many of the country’s wonderfully weird animals. Unfortunately, albeit not for lack of trying, I did not manage to see the species I was most curious about: the platypus. Now, it seems it may soon be even harder to spot one of these interesting animals.
New research shows that, as with many other species, the platypus habitat is being impacted by climate change, specifically the animals are suffering from the warming of the Australian continent.
The platypus is truly remarkable: it is one of the few species of mammals that lay eggs.
It is also peculiar in that there is no other animal with similar looks.
In fact, the first European scientist to describe the platypus, the British naturalist George Shaw in 1799, initially thought the specimen he was examining to be an elaborate hoax. According to the Australian Platypus Conservancy website, “he even took a pair of scissors to the pelt, expecting to find stitches attaching the bill to the skin.” He thought someone had sewn a duck’s beak onto the body of a creature similar to a beaver.
Platypuses are semi-aquatic animals with mammalian fur and broad, flat tails like those of beavers, but they have duck’s beaks and lay eggs. Their reptilian gait, the ability to sense electric fields through electroreceptors in their bills, and the fact that the males are capable of delivering venom (a rarity among mammals), only add to the bizarreness of the species.
Who wouldn’t want to catch a glimpse of such an animal? Unfortunately, even if you travel to their native habitat in eastern Australia and Tasmania, you’ll have a hard time finding one in the wild.
The easiest places to spot a platypus are large rivers and small streams as the animals spend much of their time in the water foraging for food, and hide in burrows when outside. However, they are typically visible only when they resurface for 10 to 20 seconds in-between dives and are hard to identify in a fast-flowing stream. They are also alarmed by noise and sudden movements so keep their distance from the less-quiet observer.
According to a new study, lead by Professor Jenny Davis (Monash University, Australia) and published in the journal Global Change Biology, the love of water of this species is precisely why it is vulnerable to climate change.
The reason for this is the animal’s fur. On one hand, this fur coat keeps the platypus insulated for up to 10 hours a day in water with temperatures that can go down to zero degrees Centigrade. But in warmer waters it will make it harder for the animal to cool down. (Thermal infrared images show that the platypus only loses body-heat from its eyes, which are closed under water.)
“The highly insulating fur is an asset for surviving in cooler climates but becomes a liability in warmer conditions,” Prof. Davis told the BBC.
One of the platypus cooling strategies is remaining in its burrow. However, the animal needs to eat about 20% of its body weight each day, meaning that it spends many hours looking for food. And the water is where the shrimps, crayfish and insects that make up its diet are. The platypus can’t stay in its burrow for too long or it will starve.
To find out exactly how vulnerable the species is to the warming of the Australian continent, the team started by examining the known distribution of the platypus. They found out that both temperature and rainfall are factors that determine where the species is present.
They then set out to determined what factor was more important. This was done by analyzing historical records of the distribution of platypus over the past two centuries.
Surprisingly, researchers found that rainfall was the determining factor until about the 1960’s. But since then, the temperature has been having a bigger influence on the distribution of platypus on the Australian continent.
As explained in the article, “this correlates directly with the change in the annual maximum temperature anomaly from cooler to warmer conditions in southeastern Australia.” In other words, the warmer temperatures drove the platypus out of regions in south Australia that the species previously inhabited.
As the climate continues its warming tendency, both higher water temperatures and drying water streams will have an effect on the platypus way of life. The new research suggests that “there is real cause for concern over the future status of this species,” the authors write.
At present, the animal is not in danger of extinction. Moreover, if current average temperatures continue to rise, the species will probably adapt, as it did in the past, by moving to cooler parts of Australia such as Tasmania and other islands.
However, because they are so hard to spot, there are very few accurate estimates of platypus numbers. This means that it could take a while before someone notices they are disappearing from places where they were once abundant.
It seems one more species may fall prey to climate change. And as BBC’s Matt Walker writes, “not just any easy-to-ignore species, but an evolutionary icon, and an animal symbolic of the wildlife on an entire continent.”