When Daniela Chushi, now at Indiana University in the United States, learned that many captive elephants were overweight and that their low birth rates suggested they might be facing a fertility crisis, she began to see parallels with the current obesity crisis. No one really measured how fat elephant elephants (Elephas maximus) in zoos are.
“I was wondering if the methods that are commonly used in human health research could help us learn more about elephants,” said Chushid, then at the University of Alabama in Birmingham, USA (UAB). He and his colleagues decided to find out about the relationship between the amount of fat animals eat and their health. They published their discovery that captive Asian elephants were less fat than Journal of Experimental Biology,
He says. “Obesity is not clearly defined in humans, especially elephants.” However, the Smithsonian Institution of Conservation Biology Chusid, Ine Anin Brown և Tim Nagin (UAB) doubted that they could get a reasonably accurate estimate by paradoxically measuring the body water of elephants, which could then be removed from the body mass of animals. to calculate the fat level. The best way to measure body water is to give the animal a dose of so-called heavy water, although it is easier said than done. can not be spilled.
“We thought of using bread soaked in heavy water to deliver it to the elephants,” he laughs, explaining that the animals are particularly partial to it. “I quickly became their best friend,” he smiles. Animal watchdogs also collected blood samples from elephants 20 days before drinking heavy water to track the amount of heavy water in their bodies.
Returning to UAB և Canadian-Canadian zoo specimens, Chusid analyzed them with the support of Catherine Humble և John von Speckman at the University of Aberdeen, UK. Calculating the water ջրի fat content of the animals, they found that, on average, males had slightly less fat (~ 8.5%) than females (-10%). Healthy people average 6-31% fat. Overall, women’s body fat ranged from 2% to% 25%, although men were taller and had more fat. But how did animal fat levels relate to their overall fitness ընդհանուր fertility?
Placing an elephant-sized fitness monitor on each animal, the team was pleased to see that the captured animals walked as far as free-ranging animals (0.03 to 2.8 km per hour) and the youngest elephants walked the farthest. In addition, when David Allison, Lillian Gozari-Arroyo, and Stephanie Dickinson at Indiana University compared female fertility, they were surprised to find that infertile women were low in fat, much less like poor female fertility cycles.
However, when the team compared the animal insulin levels, the fattest elephants tended to have the highest insulin levels.
“It is possible that elephants will be able to develop a state like diabetes,” said Chusid, adding that the jury is still deciding whether the captured Asian elephants are obese. But when it comes to the care of luxury mammals by zoos, Chusyd says: “They do a great job; they know their individual elephants best,” he said, adding that activity seems to be the key to keeping elephants in shape.
Reference. Chusyd, DE, Nagy, TR, Golzarri-Arroyo, L., Dickinson, SL, Speakman, JR, Hambly, C. “Asian zoo elephant (Elephas maximus)” obesity, reproductive անակ metabolic health և activity level. , Johnson, MS, Allison, DB and Brown, JL, January 26, 2021, Journal of Experimental Biology,
DOI: 10.1242 / jeb.219543: