Richprins wrote: ↑Fri Dec 04, 2020 7:19 pm
Blood through the ears?
The African elephant has large cooling ears, accounting for 20% of their overall surface area. They make useful fans, but also have other mechanisms that cool the elephant down in more subtle ways. Thin flaps dissipate heat fast and therefore the ears are immediately cooler than other parts of the body, but to accentuate this elephants control the volume of blood that flows through their ears via a network of blood vessels. The vessels can be dilated to increase the flow of blood to the ears and increase heat loss. It works in a similar way to a car radiator and when needed, they can pump up to 12 litres of blood through each ear every minute.
But it don't know if it is a record such as the densest network of blood vessels or the highest content of blood in an ear
It is sometimes claimed that elephants have the largest ears, but it is not true.
The long-eared jerboa has ears that are two-thirds as long as its body, the animal has the largest ears relative to size in the animal kingdom. It lives in the deserts of north-west China and southern Mongolia.
The highest volume of daily water loss ever recorded in a land animal
Elephants cannot use evaporation of sweat to cool down, but elephants' hides seem to be more permeable to water than other animal skins.
An elephant in subtropical South Africa would need to dedicate just 22 liters/day of water towards cooling, whereas an elephant in the semi-arid Namibian savannah would need almost five times that, incurring a water debt of at least 100 liters/day.
When the weather is warm, elephants can lose up to 10% of all the water in their bodies in a single day, according to a new study. That’s the equivalent of nearly two bathtubs full, the highest volume of daily water loss ever recorded in a land animal.
In cool temperatures (from 6°C to 14°C), males lost an average of 325 liters per day. But around 24°C, they lost an average of 427 liters, and sometimes up to 516 liters, the team reports this week in Royal Society Open Science.
That’s as much as 10% of their total body water—or up to 7.5% of their body mass. One elephant lost nearly 9% of his body mass in a single day, says study co-author Rebecca Rimbach, an ecophysiologist at Duke University. Because animals constantly replenish lost fluids through drinking, eating, and metabolic processes, though, the elephants’ net daily water loss would be lower. Overall, elephants must drink at least every 2 to 3 days to avoid “potentially dangerous levels of dehydration,” she says.
“This is surprising when you consider that these are animals that have adapted to living in the African savanna,” Kendall says.
Horses in a hot environment can lose 40 liters in a day—about 6% of their body mass—and humans typically expend about 3 to 5 liters—about 5% of our body mass, although that can nearly double when active people, like marathon runners or soldiers, are really sweating.
Re: Record Holders (with Quiz)
Posted: Sat Dec 05, 2020 6:27 pm
by Lisbeth
Something new once more! How do they measure the loss of water in a elephant
Re: Record Holders (with Quiz)
Posted: Sat Dec 05, 2020 6:36 pm
by Klipspringer
Read the link, this was a study in captive elephants.
