Australian estuarine crocodiles are struggling due to global warming. As their body temperatures rise, they spend less time diving and more time cooling down. A new study found that over a 15-year period, the average body temperature of these crocodiles increased by a small but significant amount.
Crocodiles, being ectothermic reptiles, regulate their body temperatures with external sources like sunlight or shade. However, as global warming increases their temperatures, they appear to be changing their behavior. The researchers tracked 203 estuarine crocodiles at the Steve Irwin Wildlife Reserve in Queensland and found that they spent more days at their critical thermal limit.
A hotter crocodile has a higher metabolism, leading to reduced swimming and diving performance. This changes their behavior as they spend more time attempting to cool themselves and reduce activity. The study also recorded nearly 6.5 million temperature readings from the crocodiles, showing an increase in body temperatures linked to El Niño periods.
The researchers are concerned about how these alterations to the crocodiles’ behavior may affect their survival. As stealth predators, they rely on ambush prey while submerged, but increased hot weather may reduce their ability to hunt and eventually impact their health.
Source: https://www.livescience.com/animals/alligators-crocodiles/crocodiles-are-overheating-due-to-climate-change-and-its-changing-their-behavior