A new study has found that elephant seals have to work very hard to stay corpulent. Scientists paid special attention to females of the species during difficult two-month trips, or migrations, in the northeastern Pacific Ocean.
The seals were found to spend up to 20 hours every day and sometimes full 24 hours a continuous deep-diving to feed on fish. They fed 1,000 to 2,000 times daily to gain the body weight necessary for reproduction and warmth in the cold waters. Researchers studied 48 female elephant seals from Ano Nuevo State Park in California as they traveled large ocean distances. Their entire trip was around 6. 000 kilometers.
Scientists based their findings on data collected in 2011 and 2018. They used three small movable devices. The first device, attached under the jaw, counted the number of times the seals fed and measured their depth. The second satellite-linked device on the head, followed the seals' ocean movements and sensed their food. The third device was a "smart" video camera with an infra-red LED light and another depth sensor. It was also placed on their heads.
Elephant seals get their name from the large noses. These noses look like an elephant's trunk. There are two species—the northern elephant seal and the slightly larger southern elephant seal. The two are the world's biggest seals and the largest ocean mammals other than whales.
The northern male elephant seals can grow up to 4 meters long and weigh up to 2,000 kilograms. The northern females are smaller, getting up to about 3 meters in length and 590 kilograms. The males feed only in coastal waters.
Some large ocean mammals depend on deep dives to get enough food to support their large bodies. Sperm whales(抹香鲸), for example, hunt for large prey like giant squid, Female elephant seals, which are large, but not as big as sperm whales, have a different solution. They eat huge amounts of small fish. But it is hard for them to catch enough small fish to meet the energy needs of their large bodies.
8. What does the underlined word "corpulent" in paragraph 1 mean?
A.Fat. | B.Distant. | C.Deep | D.Cautious. |
9. What is the common feature of the three devices in paragraph 3?
A.'They sensed the seals' food. | B.They were linked to the satellite. |
C.They followed the seals' movements. | D.They were attached to the seals' body |
10. Where does elephant seals' name come from?
A.Their behavior. | B.Their appearance. | C.Their weight. | D.Their length. |
11. What does the author mainly try to do in the last paragraph?
A.Introduce the similarities of mammals. |
B.Show the size of male and female elephant seals. |
C.Advocate the conservation of sperm whales' ocean food. |
D.Compare sperm whales' hunts and female elephant seals' hunts. |