Crocodiles may be forced to change ways due to climate change, researchers find
BRISBANE, Australia – The world's changing climate may be altering the behavior and health of crocodiles, leading to noticeable changes.
A recent study led by researchers at Australia's University of Queensland's School showed that warming temperatures are pushing crocodiles closer to their thermal limits, altering their behaviors.
Fifteen years of data collected from some 200 wild crocodiles revealed that the reptiles spend more time than ever around their critical body temperature range of 32-33°C, leading to changes in their cooling behavior.
"As ectotherms, crocodiles can't regulate their own temperature like birds and mammals, so as their environment is becoming warmer, the animals in our study are also getting hotter and needing to spend more time on cooling behaviours," Kaitlin Barham, a researcher at the University of Queensland, said in a statement. "But if their time and energy is dominated by the need to stay cool, activity necessary for hunting, keeping safe from predators, or reproducing is reduced."
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The warmer temperatures drive the reptile's ability to remain submerged for extended periods, which can alter behaviors such as hunting, swimming, and reproduction.
Higher temperatures can lead to heavier breathing in animals, as the ectotherms rely on external heat to regulate their body temperature.
Biologists warn that if temperatures rise above critical thermal limits, it could lead to increased stress and trigger more frequent episodes of breathing, which impacts their norms.
"Hotter crocodiles don't dive for as long, which is concerning because, as ambush hunters, they need to wait underwater holding their breath for a wallaby or feral pig to come past," Craig Franklin, a co-author of the study, stated.
Nearly a quarter of the animals examined in the study had body temperatures that climbed above 34 °C, but researchers did not mention if there were any deaths attributed to the warm weather.
"By monitoring [body temperature] and diving activity in 203 free-ranging estuarine crocodiles over 15 years, we show that the [body temperature] of crocodiles has increased alongside rising air temperatures since 2008, reflecting the climatic shifts caused by the ENSO cycle," the study said.
ENSO is the abbreviation for the El Niño-Southern Oscillation, which controls global weather patterns through extremes such as La Niña and El Niño over parts of the Pacific.
Since reliable technology started keeping track of world temperatures in the 1950s, the warmest year of any decade has been periods dominated by an El Niño event, which have led to the planet's warmest years.
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The study did not explore whether alligators face the same challenges as crocodiles.
Biologists note that while both are reptiles, there are significant differences between the two species.
Alligators have a broad, U-shaped snout, whereas crocodiles feature a narrow, V-shaped snout.
According to government estimates, there are more than 100,000 saltwater crocodiles living in the wild in Australia, while alligators are not native to the continent and are even considered to be an invasive species.Original article source: Crocodiles may be forced to change ways due to climate change, researchers find
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