As climate change causes global temperatures to soar, it is also making the weather less consistent. This means that animals don't have the same seasons, food sources or water supplies that their predecessors were dependent upon. For some animals, this scarcity of food isn't as much of a problem. Snakes, such as the Children's python (Antaresia childreni), don't eat that often, but when they do, they feast. But, snakes don't get water from their food, so, what happens when the weather is hot and they can't find enough to drink? Jill Azzolini, Travis Roderick and Dale DeNardo of Arizona State University think that the thirsty snakes might want to find a cooler spot to digest their meal than their hydrated brethren.
The researchers allowed the pythons to move between 25 and 45°C and measured their body temperature to see which they preferred and then gave them some food. The team then made half of the snakes thirsty over the course of several days before giving every python some food. For the first 4 days, all of the pythons wanted to stay in warmer areas, but afterwards, the thirsty pythons moved to cooler spots than well-hydrated snakes. After the snakes finished digesting their meal, they were allowed to slake their thirst and the groups were switched. This time, the formerly thirsty snakes were now full of water. When the snakes ate again, Azzolini and colleagues noticed that they also stayed in warmer areas than they did when they were thirsty.
The trio knew from previous studies that snakes are very efficient when digesting their food over a wide range of temperatures, so it didn't seem likely that they were looking to get more from their meal. They also knew that moving to a lower temperature would make the pythons take even longer to digest their meal – and this could have disastrous consequences. ‘Digestion is a vulnerable state for many animals, so if this process is slightly longer, wild animals could be more at risk of predation’, states Azzolini. So why might the thirsty snakes be choosing to stay in cooler temperatures if the results could be so life threatening? It turns out that pythons and other snakes lose more water when the temperatures rise; the thirsty snakes are trying to keep the water they have by risking it all and moving to a cooler climate.
Interestingly, it wasn't just the dehydrated snakes that were trying to keep cool. Male pythons were staying in warmer areas than females. The trio suggests that this might be due to differences in how males and females absorb nutrients from their food. However, Azzolini and the team are quick to point out that this would need to be tested. So, as climate change raises temperatures ever higher, making it harder to find reliable sources of water to drink, these pythons will be hit doubly hard. What these snakes will do if the temperature is high and they can't find any water is still a mystery. Will they eat less food? Will they eventually become so hungry that they stay in hotter areas even though they can't get a drink? For now, no one knows, but one thing is certain – if these pythons can't find a place to cool down, the thirsty ones will be in serious trouble.
