Global warming poses a major problem for animals that are warm-blooded, that must keep the body’s temperature at a constant level. Anyone who has experienced heatstroke can attest that our bodies get extremely stressed when we are overheated.
Animals deal to global warming in different ways. Certain species migrate towards cooler zones like close to poles, or to higher elevations. Certain alter the time of life’s major activities like migration and breeding, so that they occur in cooler seasons. Some also alter in their bodies’ size to reduce their temperature faster.
Our new study explored a different method by which animals cope to climate change: altering how big their tails, ears beaks, and other appendages. We analyzed the literature and discovered examples of animals enlarging their appendages along with changes in climate and the corresponding temperature rises.
As a result, we discovered a variety of animal species which are likely “shape-shifters” – including species that are found in Australia. The pattern is widely distributed, and suggests that climate warming could cause fundamental changes in the animal’s form.
Following Allen’s rules
It is well-known that animals utilize their appendages to regulate internal temperature. African elephants for instance pump warm blood into their ears which can then be fanned out to distribute heat. They also have bird’s beaks also serve a similar purpose as blood flow is directed to the bill when the bird is extremely hot. The function of dispersing heat is illustrated on the image below of the thermal of the king parrot below which shows that the beak is warmer than the rest the body.
It is clear that there are advantages to larger appendages in warmer climates. In fact, as long as the 1870s, American Zoologist Joel Allen noted in colder regions, warm-blooded mammals – also known as endotherms were more likely to possess smaller appendages, whereas those with warmer climates have larger appendages.
Studies of birds and mammals have confirmed Allen’s rule.
The patterns in the biological world like Allen’s rules can aid in making predictions regarding the evolution of animals as the temperature rises. Our study aimed to discover evidence of the evolution of animal shapes in the last century, in line with the climatic temperature rise and Allen’s law.
What animal species are changing?
The most well-documented instances of shape-shifting in birds, specifically, the increase in the size of their beaks.
This covers a variety of species from Australian birds, including parrots. Studies have shown that the beak size of gang-gang cockatoos as well as the red-rumped parrot has increased by between 4 and 10% over the course of 1871.
Mammal appendages are also growing in dimensions. For instance for the masked the shrew the tail and leg length have significantly increased from 1950. As for the huge roundleaf bat wings, the size of the wing has is up 1.64 percent over the same time period.
The wide variety of instances suggests the phenomenon of shape shifting is occurring in many types of appendages as well as in many species of species of animals, across a variety of the globe. However, further research is required to discover which types of animals are the most affected.
Other applications of appendages
Appendages of animals aren’t just for regulating body temperature. This is why scientists have looked at other causes which could explain the changes in the shape of animals’ bodies.
For instance, studies have revealed that the beak size for the Galapagos small ground finch varied over time according to the size of the seeds and is dependent on rainfall. Our study examined earlier collected data to determine whether temperatures also affected changes in the size of beaks of the finches.
These results show that the fact that rainfall (and as a result the size of seeds) is a factor in the size of the beak. In summers that were dry, the survival of birds with small beaks was diminished.
We found clear evidence that birds with smaller beaks are less likely to endure warmer summers. The effect on survival was greater than that seen with rain. This indicates that the impact of temperature might be just more important than other applications of appendages like feeding to drive the size of appendages to change.
Our study also suggests that we could draw some conclusions about the species most likely to alter the size of their appendages in response to temperature increases – specifically, those that follow Allen’s rule.
They include (with certain caveats) singing sparrows, starlings and a variety of small mammals and seabirds including South American gracile opossums.
Why is shape-shifting important?
The research we conduct contributes to the scientific knowledge of the ways that wildlife react to the effects of climate changes. Alongside enhancing our ability to anticipate the effects from climate change it will help us determine which species are at greatest risk and need to be protected.
The previous month’s report of the Intergovernmental Panel on Climate Change found that we are in a very short time to prevent the catastrophic global warming.
While our research has shown that certain species have adapted to the climate changes however, the majority of animals will not. For instance, certain birds could have to eat certain diets, which means they can’t alter their beaks. Some animals might cannot develop over time.
While forecasting how wildlife will react to the effects of climate change are vital but the most effective way to ensure the survival of species in the next century is to significantly cut greenhouse gases and stop the most global warming feasible.
