Read the following text carefully and answer the questions correctly. 
The text is for numbers 1 - 5. 

     Koala is one of the Australia's unique animals that have pockets (marsupials) like a kangaroo. The name of Koala comes from the aboriginal language which means "not drinking". It is because Koala rarely drinks water. They rely on water contained in eucalyptus leaves. They can be found along the eastern coast of Australia from Adelaide to Cape York Peninsula. They can also be found far inside the jungle. They live in areas which have enough rainfalls. 

      They have a distinctive body shape. They have thick and soft fur and wide ears. They also have large claws for climbing trees. The body weight is different from one another. For example, the males can reach 14 kg, while the females in the northern part weigh only 5 kg. 

     They spend all their time at the top of the tree. They are quiet animals and do not like a fuss. They spend 20 hours each day to sleep. However, during the mating season, they become more active. Even the males can emit a loud sound and can be heard up to a radius of 1 km. 

     In the wild, they only eat eucalyptus leaves. They contain low protein phenolic and terpene compounds. These compounds can be toxic to other animals. However, they can neutralize those toxins in their heart. They usually eat at night because during the day, they always fall asleep. They generally spend about 500 grams of eucalyptus leaves per day. They will chew it till smooth before swallowing it.

"Even the males can emit a loud sound and …" (paragraph 3). What does the underlined word mеаn?