In this wiki answer it is stated that:. Sounded ok, but in this website, frogmatters , it 1 says the opposite, thus confirming the picture:. Although that link does not work, this archived link does work. In Chacha. From Is Sleep Essential? It has been argued that the assumption that sleep is universal is based on poor evidence 7.
The bullfrog is often promoted as an example of an animal that does not sleep. There is, however, only one study on this topic, published in This report concluded that bullfrogs do not sleep because even during the resting phase they never failed to show a change in respiratory responses after painful stimuli cutaneous shock. The same report acknowledged that arousal thresholds could not be measured during the cyclic phases with the lowest respiratory activity, nor could they be tested with other physiological stimuli, such as light or sound.
Also, the underlying assumption in that study was that shocks delivered late at night presumably in the middle of sleep should elicit less respiratory response than those given early in the night when sleep had just started ; however, the opposite was found In fact, we now know that in rodents and humans the deepest sleep occurs early after sleep onset. At the very least, it seems that more experiments are needed before concluding that bullfrogs do not sleep.
Scientists are looking at a variety of explanations. Maybe sleep is just a nice pastime — like playing baseball or watching television — that is useful for keeping us out of trouble but not necessarily for good health. With multiple ideas about why animals sleep, first scientists had to decide what counts as sleep.
The scientists defined sleep as being still and having little to no reaction to attempts to awaken. The scientists looked at three different ways that animals sleep to see if it is true that some animals really don't need sleep. They examined:. However, there were some problems with how the bullfrogs were tested. The dolphin was also considered a special case because dolphins have the ability to put only half their brains to sleep at a time.
The half-asleep brain made it difficult to measure response time and made scientists start to question their initial definition of sleep. Remember, part of being asleep means being still, and since dolphins still swam around it seemed that they did not fit into that category. They found a few animals like bees that seemed to not need extra sleep. Yet, the scientists decided the experiments done were flawed because only the length of sleep was tested, not the quality of sleep. Here is a table from the original article that lists all the animals the scientists thought were examples of not sleeping or not using rebound sleep.
The first column looks at animals that meet the definition of sleep, the second column looks at whether the animals make up their sleep and the third column talks about why the animals were considered special cases. Finally, scientists looked at whether not sleeping has serious consequences. In studies where people went without sleep, they found that people became half-awake, kind of like zombies walking around mindlessly. The scientists also found that sleep-deprived people got so tired they fell asleep no matter what they were doing.
As for resting during non-hibernation months? Can we call that sleep? It depends on who you ask. A study concluded that bullfrogs showed the same response time whether fully awake or resting.
But since that time, other scientists have raised concerns about how the bullfrogs were tested. Until this research gets conducted, the final word on bullfrog beauty sleep remains up in the air. But we can say with certainty that, like college students after finals, binge sleeping bullfrogs know how to make up for lost time come hibernation. Newsletter Subscription Blog Sign up for our Newsletter and get weird news and exclusive offers to Ripley's, delivered straight to your inbox!
Frankensteins Colton Kruse , October 29, But, some do not sleep or sleep very little or at the very least sleep in ways that are barely recognizable to us as sleep. Here are some animals who survive just fine without their eight hours. In captivity, giraffes sleep just for four or five hours, mostly at night, but in the wild giraffes will only sleep for short bursts at a time.
You might see them sleeping while laying down or, oddly, standing up, which is especially common among older giraffes. Giraffes can also enter into an irregular deep sleep phase, where they bend their neck and rest their head on the thigh or hip. Experts call this position paradoxical sleep: a state where they are resting but with rapid eye movement and reduced muscle activity.
Dolphins accomplish something called unihemispheric sleep: only half their brain sleeps, while the other half ensures the dolphin is close to the surface to breathe and stays on guard for predators. They alternate between the two hemispheres to get sufficient sleep for their whole brain.
These mammals do not sleep in the first month of their lives can you imagine!
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