Global warming is forcing wildlife to adapt in unexpected ways; however, this adaptation is not sufficient for the fragile and interconnected ecosystems on our planet.
The rising temperatures on Earth not only affect human life but also impact many animal species around the globe. The intense heatwave that enveloped Mexico last May killed over 50 howler monkeys.
The zebra seahorse has evolved to survive in warmer waters. (Photo: Getty Images).
While humans can employ various cooling measures to survive, animal species must rely on the adaptations they have inherited over millions of years of evolution to endure.
For example, dogs pant and breathe heavily to shed heat; kangaroos lick their front feet and rub them on their bodies to cool down; elephants flap their large ears to reduce body temperature.
However, some animal species are forced to change much more to continue surviving in a warming world. Giovanni Strona, an ecologist with the European Commission, notes that this phenomenon is described as “winners and losers in climate change.”
Strona led a 2022 study published in the journal Science Advances, which found that under a medium emissions scenario, we could lose nearly 20% of vertebrate biodiversity by the end of this century. In a worst-case warming scenario, that loss could rise to nearly 30%.
So which animals are the “winners”, and how will they truly adapt as temperatures rise, droughts increase, and habitats are lost?
Changes in Form
Ecogeographic rules describe the trend of physical traits in animals changing geographically, providing clues about how species will adapt to harsher climates.
According to Allen’s Rule, individuals in warmer climates have larger appendages, such as wings and beaks, which help facilitate heat regulation, while body size tends to decrease to retain less heat.
Red-tailed parrots change beak size and wingspan as temperatures rise. (Source: Wikimedia Commons)
In the United States, a recent study of 70,716 migratory birds representing 52 species shows that they have been getting smaller over the past four decades, but their wingspans have been increasing.
This change in bird species may alter their migration patterns, causing ripple effects throughout the ecosystems they inhabit.
Adaptive Evolution
How well wildlife can withstand extreme temperatures depends on their metabolic processes and the types of environments they inhabit.
Particularly resilient species will adapt in various ways. The California sea lion is one such example. They not only adjust their geographic range but also alter their physiology to improve neck flexibility and biting force, allowing them to consume a wider variety of prey.
California sea lion. (Source: Los Angeles Times).
Some species are nesting earlier; for instance, coastal birds in North America have responded to rising temperatures by nesting up to 12 days earlier than they did nearly a century ago.
A study by Associate Professor of Biology Michael P. Moore (University of Colorado Denver) and Associate Professor of Ecology and Evolution James T. Stroud (Georgia Institute of Technology, USA) shows that darker-colored dragonflies are becoming lighter to reduce the amount of heat they absorb from the sun, while lizards are becoming more tolerant to colder temperatures to cope with harsher climate conditions.
The Losers
While there may be some “short-term winners” as the Earth warms, scientists believe that the number of “losers” far outweighs them, as climate change affects entire food chains, leaving many species unable to evolve quickly enough.
Research by ecologist Giovanni Strona indicates that organisms positioned lower on the food chain, such as insects and rodents, may adapt better to survive as the Earth warms.
Larger animals, like elephants, will struggle as the climate changes. (Source: Shutterstock).
In contrast, larger animals and those higher up in the food chain are among the most vulnerable to the impacts of climate change.
The Earth is currently approximately 1.1 degrees Celsius warmer than it was in the 1800s. Based on current predictions, global temperatures are projected to rise by 2.7 degrees Celsius by the end of this century.
This temperature increase could lead to the collapse of fragile ecosystems and massive extinction events.
According to a report by the World Wildlife Fund (WWF), approximately 1 million species are currently facing the risk of extinction as the Earth continues to warm. Our planet may be entering its sixth mass extinction event.
Researchers say the only way to limit future extinctions is to quickly cease burning fossil fuels, reduce emissions, and conserve habitats for species.
