All animals need energy to live. They use it to breathe, circulate blood, digest food, and move. Young animals use energy to grow and late in lifePlay.

Increasing body temperature increases the rate at which an animal uses energy. Because cold-blooded animals rely on thermal conditions in their surroundings to regulate their body temperatures, they are expected to require more energy as the planet warms.

However, our new research, published today in NatureClimate Change, suggests that temperature is not the only environmental factor that affects the future energy needs of cold-blooded animals. How they interact with other species will also play a role.

Our findings suggest that cold-blooded animals will need even more energy than previously thought in a warmer world. This may increase their risk of extinction.

what we already know

The amount of energy that animals use in a given period of time is called their metabolic rate.

Metabolic rate is influenced by a variety of factors, including body size and activity levels. Larger animals have higher metabolic rates than smaller animals, and active animals have higher metabolic rates than inactive animals.

The metabolic rate also depends on the body temperature. This is because temperature affects the speed at which the biochemical reactions involved in energy metabolism take place. Generally, if an animal’s body temperature increases, its metabolic rate accelerate exponentially.

Most animals alive today are cold-blooded, or “ectotherms.” Insects, worms, fish, crustaceans, amphibians and reptiles, basically all creatures except mammals and birds, they are ectotherms.

As human-induced climate change increases global temperatures, the body temperatures of cold-blooded animals are also expected to rise.

The researchers say The metabolic rate of some terrestrial ectotherms may already have increased by 3.5-12% due to climate warming that has already occurred. But this prediction does not take into account the animals’ ability to physiologically “acclimate” to warmer temperatures.

Acclimatization refers to an animal’s ability to reshape its physiology to cope with a change in its environment.

But rarely, acclimatization can completely nullify the effect of temperature on metabolic processes. For this reason, by the end of the century, terrestrial ectotherms are still predicted to have metabolic rates of about 20% to 30% higher than they are now.

Having a higher metabolic rate means that the animals will need more food. This means they could starve if no more food is available, leaving them with less energy to find a mate and reproduce.

our research

Previous research attempts to understand the energetic costs of climate warming for ectotherms have been limited in one important respect. They predominantly used animals studied in relatively simple laboratory settings where the only challenge they faced was a change in temperature.

However, animals face many other challenges in the wild. This includes interaction with other species, such as competition for food and predator-prey relationships.

Although species interact all the time in nature, I rarely study how this affects metabolic rates.

We wanted to examine how species interactions might alter predictions about the energetic costs of climate warming for cold-blooded animals. To do this, we turn to the fruit fly (of the genus Drosophila).

Fruit fly species they lay their eggs on decaying plant material. The larvae that hatch from these eggs interact and compete for food.

Our study involved rearing fruit fly species alone or together at different temperatures. We found that when two species of fruit fly larvae compete for food at warmer temperatures, they were more active as adults than adults not competing with other species as larvae. This means that they also used more energy.

From this, we use models to deduce that species interactions at warmer global temperatures increase future energy needs of fruit flies by 3-16%.

These findings suggest that previous studies have underestimated the energetic cost of climate warming for ectotherms. That means that purely physiological approaches to understanding the consequences of climate change for cold-blooded animals are likely to be insufficient.

let’s be realistic

Understanding the energy needs of animals is important to understanding how they will survive, reproduce, and evolve in challenging environments.

In a warmer world, the hotter ectotherms will need more energy to survive and reproduce. If there is not enough food to meet the energy demands of their bodies, their risk of extinction can increase.

Clearly, we need to more accurately predict how global warming will threaten biodiversity. This means studying the responses of animals to temperature change under more realistic conditions.

This article is republished from The conversation under a Creative Commons license. Read the Original article.