In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.
Q: Recordings Reveal That Baby Humpback Whales 'Whisper' To Their Mothers 
  
 Enlarge this image toggle caption Fredrik Christiansen/Functional Ecology Fredrik Christiansen/Functional Ecology 
  
 Baby humpback whales seem to whisper to their mothers, according to scientists who have captured the infant whales' quiet grunts and squeaks. 
  
 The recordings, described in the journal Functional Ecology, are the first ever made with devices attached directly to the calves. 
  
 Listen to a calf whisper 0:21 
  
 "When they're born, these whales are around 5 meters long," says Simone Videsen at Aarhus University in Denmark, who notes that this is "pretty big considering it's a baby." 
  
 Calves must travel with their mothers for thousands of miles during an annual migration to the food-rich waters of the Antarctic. Exactly what happens during that period is a mystery. 
  
 "These early life stages of wild whales are so elusive because they're an aquatic animal," Videsen explains. "We can't follow them around all the time to see what they're doing." 
  
 However, she and some colleagues recently were able to track eight baby whales, using special sound and movement recorders. These recorders had suction cups that let the researchers just stick them onto the babies' skin. "It can stay there for about a day and then it falls off," Videsen says. 
  
 The researchers weren't sure exactly what they'd hear when they retrieved the devices and played the audio. It turns out that the babbling of baby whales is very different than the haunting, eerie songs sung by adult male humpbacks. 
  
 "It's like a squeaky sound, and some of them are really like grunting sounds," Videsen says. 
  
 What's more, the sounds are very quiet — like the baby humpback is whispering so that it won't get overheard by something dangerous lurking nearby. 
  
 "There are lots of killer whales in the area which are predating on these calves," says Videsen, "and they can use these sounds between mother and calf as like homing cues." 
  
 So why do the calves say anything at all? The researchers found that baby whales mostly whisper when they're swimming, rather than when they're resting or nursing, so it may be that these intimate sounds help mothers keep track of their young in murky waters. ||||| Humpback calves ‘whisper’ to avoid being heard by killer whales. Listen here 
  
 Humpback whales are known for their operatic songs that carry across the seas. Their calves, however, whisper, uttering soft squeaks and grunts to their mothers (which you can hear above). Now, a new study suggests that loud calf voices can also attract some unwanted visitors: male humpbacks, who might separate the pair by trying to mate with the mother, and killer whales, who dine on young humpbacks. To record their sounds, scientists placed temporary tagging devices on eight humpback whale mothers and calves in the Exmouth Gulf off Western Australia, where the young whales spend months suckling to gain enough weight for their annual migrations to the Antarctic or Arctic. After listening to the recordings, scientists say the calves’ careful whispers are not cries for food, as previously thought. Instead, they may help them stay in close contact with their mothers when swimming. And, say researchers, writing today in Functional Ecology , the low decibel sounds help keep would-be predators away from the “nursery.” |||||
A: 
Baby humpback whales "whisper" to their mothers, according to a paper published Tuesday in Functional Ecology. And that could speak volumes about the intelligence of these aquatic giants. NPR reports scientists—for the first time ever—attached recording devices directly to humpback calves. "It's like a squeaky sound, and some of them are really like grunting sounds," researcher Simone Videsen describes the results. The sounds are a lot different—and a lot quieter—than the songs sung by adult humpbacks. Scientists originally thought calves made noise when they wanted food, but that appears to not be the case, according to Science. Researchers now theorize baby humpbacks whisper to help their moms keep track of them while the family is on the move. Mother humpback whales will occasionally whisper back to their calves despite being capable of making much louder noises, Seeker reports. It's possible the calves themselves are also physically capable of making louder noises. This suggests to researchers the whales are whispering to avoid being detected by predators—such as killer whales, which Videsen says "can use these sounds ... like homing cues"—or by male humpback whales that would break up the family. If that's the case, it could be evidence of high intelligence in humpbacks. “It can only make you happy to hear these sounds," Videsen says. NPR has a recording of the whispers. (Meanwhile, a new habit of humpback whales is puzzling researchers.)