Time to listen up: What animals are telling us about climate change

Humans have turned to the natural world for signs and portents for millennia. So, it’s unsurprising that scientists are now increasingly looking to animals to better understand climate change and its wide-ranging effects – for them and us.

Investigations typically follow three distinct routes: studying changes in animal behaviour, whether this is mating patterns or animal sounds; identifying the physical changes – often to appendages like beaks and flippers – that animals are undergoing as they try to adapt to a changing climate; and employing animals to help boost environmental data collection.

Through these investigations, scientists are reaping numerous insights – increasingly aided by new technology like artificial intelligence (AI), which can be used to collect and analyse vast quantities of data. The resulting insights reveal the extent of change and our intertwined relationship with nature. They also suggest looming challenges.

The hope is that with the help of animals, humans can use the insights gathered to find their own means to adapt, as well as some possible solutions to counter the worst of the effects of climate change.

Animals have always had to adapt. Those that don’t – the dodo, infamously – have simply died out. The rate of species loss is growing, estimated to be between 1,000 and 10,000 times higher than the natural extinction rate. To put this into perspective, the World Wide Fund for Nature revealed a 73% decline in the average size of the wildlife populations monitored between 1970 and 2020. Currently, around a third of amphibian species are at risk of extinction, while 550 mammals are classed as endangered worldwide – 235 critically.

Mass extinction events can also cause animals to evolve as the territories they inhabit change so quickly – animals and plants must adapt to succeed in new environments where former wildlife has been eliminated. Research shows that evolution "exploded" after dinosaurs became extinct, for example. Our ancestors evolved three times faster in the 10 million years following the dinosaurs' extinction compared to the previous 80 million years.

Animals that can adapt well have a far greater chance of survival. And so, many animals are changing their physiology in the face of climate change. The most typical changes are to appendages. Many animals use hairless parts of their body to help regulate their body temperature. In the case of wood mice, their tails are becoming longer, while birds, which regulate their body temperature through their beaks, are growing larger beaks. Similarly, the wing spans of mammals like bats, as well as the ears of elephants, are growing.

This belies simple physics: Animals can cool off more quickly through larger surface areas. At the same time, animals are also becoming smaller (albeit with larger appendages), which again helps them to lose heat more quickly because of the greater surface areas to volume. These smaller sizes may also indicate stunted growth due to changes in food availability. Animals are also becoming lighter in colour, which, again, helps them to stay cooler and also to camouflage themselves more easily in sunny places.

Surely, it’s a good thing that animals are adapting? Well, yes and no. Adaptation to meet one challenge can create new challenges. Birds with larger beaks, for example, may find it more difficult to feed. And realistically, just how far can an animal adapt? The current situation has scientists concerned about the rate at which this "shapeshifting" is happening.

Scientists would admit that there are a lot of historic gaps in their data. Some can be filled with satellites, weather stations and ocean buoys, others require a different approach. Increasingly, scientists are fitting animals with sensors to chart migratory routes and how they are changing, as well as to collect data on local environmental conditions. This is particularly useful in remote parts of the world, where data is patchy at best.

Sensors can also provide an indication of the health and wellbeing of the carrier, with scientists employing technology to monitor how animals are dealing with environmental stresses. This ability to map more specific data in real time is creating a modern-day canary in the coalmine situation in which animals are becoming integral to alerting humans to impending crises. They are more accurately revealing the challenges the animal kingdom – and by extension, humans – are facing when it comes to climate change.

Securing this better data is vital. This, and a more robust observation of animals, their shifting patterns of behaviour and the changes their habitats are undergoing, provides us with a far more nuanced understanding of cause and effect.

Until recently, animal behaviour hadn’t really been integrated into conservation activities. A better understanding of why animals are, for example, socializing or hunting at different times of the day or seeking different habitats, and the new challenges they may confront (competitors, predators or even pathogens), helps create more effective conservation initiatives.

Similarly, gathering more data and altering conservation techniques in response, helps improve our understanding of ecosystem functions. This, in turn, provides us with answers.

The rapid decline since the 1990s in monarch butterfly numbers looks to have been halted thanks to a more holistic understanding of what these butterflies need to breed and survive. US-based environmental organization Adventure Scientists, also recently used motion-activated wildlife cameras to confirm habitat changes of the coastal Pacific Marten in Washington state's Olympic National Forest. Sightings had fallen but the camera's confirmed the martens were still there in greater numbers, just in higher, more isolated places.

Animals may also provide lessons for human adaptation. Biomimicry involves learning from nature to inform new products, architecture and even ecosystem design. This practice is growing, and there’s no reason why humans themselves can’t borrow from animal behaviour and adaptation strategies too.

Amid all this, it’s easy to forget that, as mammals, we’re part of this changing world. It’s also largely our activities that have spurred such swift degradation of the planet. Our job now is to work harder to listen to what animals and their ecosystems are telling us with the aim of reversing the worst of these effects. Where this isn’t possible, we need to find ways to support animals’ adaptation and ultimate survival.