National Geographic

128 NATIONAL GEOGRAPHIC • FEBRUARY 2018Showing Empathy6FLHQWLVWVVD\WKDWFKLFNHQVOLNHWKHVHRQ0DWW6LJHOÅ V:\RPLQJIDUPDUHFRJQLWLYHO\DGYDQFHG7KH\OLYHLQKLHUDUFKLFDOVRFLHWLHVWUDFNQXPEHUVDQGGREDVLFPDWKDQGDUHOLNHO\WRH[SHULHQFHHPRWLRQVIURPERUHGRPDQGIUXVWUDWLRQWRKDSSLQHVV$QGWKH\VKRZVLJQVRIHPSDWK\,IDLULVEORZQRQFKLFNVÅ IHDWKHUVZKLFKWKHELUGVGRQÅ WOLNHWKHLUZDWFKLQJPRWKHUÅ VKHDUWUDWHJRHVXSSTILL, LARGE BRAINS are a kind of handicap forbirds. So why do they have them?Many researchers think that, as with primates,complicated societies are the real spur behindcomplex cognition. To test this in ravens, ThomasBugnyar, a cognitive biologist at the University ofVienna, travels to the Austrian Alps each month tothe Konrad Lorenz Research Center for studyinganimal behavior and cognition. Here, he and hiscolleagues have examined the social dynamics ofa flock of a few hundred wild common ravens—large birds with black, iridescent feathers that aredistributed across the world. Common ravens areclosely related to American crows, the birds thatGabi Mann befriended.Birds’ societies differ from those of mammalsin a fundamental way, Bugnyar stresses. “Themost basic social bond in mammals is betweenmother and infant, but in birds it’s the pair-bond.It’s a bond that develops through learning.”Ravens begin trying to develop such socialbonds when they’re merely six months old, andbefore they’re sexually mature. Most adult pairsare heterosexual, and the two adults work togeth-er to defend a territory for breeding and raisinga family. Adults also form alliances with birdsother than their mates to build social supportnetworks. Ravens learn about each other—whatother birds like or dislike, their personalities,who’s brave and who’s a coward—by watchingthem stash and give and steal from one anoth-er. “They can make an object in their stash morevaluable just by showing it to another bird,”Bugnyar explains.Other ravens keep tabs on any budding rela-tionships, and break them up if possible. Of ap-proximately 180 “affiliative interactions” among90 ravens that Bugnyar or his colleagues wit-nessed, “one quarter were broken up by a thirdparty.” That’s because “alliances are powerful.Birds rise in the dominance hierarchy as soon asthey form a social bond. The other birds want toprevent them from gaining that power.” Ravenswith numerous allies get first dibs on limited re-sources, such as food and nesting sites.Further complicating matters, the ravens—like humans, chimpanzees, elephants, anddolphins— live in a “fission-fusion society,”meaning that the larger flock splits apart in theday as individuals fly to other valleys in search offood, new territories, or companions. There areonly seven to 10 mated pairs in Bugnyar’s Alpinestudy group. The hundreds of other birds roosttogether in small groups at night, where theygroom each other, play, squabble, and exchangeinformation. “Usually they go only a short dis-tance to check for food and, we think, socialopportunities,” Bugnyar says.In contrast, the breeding pairs rarely leave thearea. All keep track of other birds’ relationshipsas they try to figure out when it’s most advan-tageous to aid or intervene with others. “Theravens must learn how to form social bonds andhow to use these like tools if they are to success-fully reproduce,” Bugnyar explains. “That’s a lotof pressure, and I think it’s led them to evolvetheir large brains and cognitive skills—at least, Ithink that’s what my data will ultimately show.”