Elephants have a good memory and they can recall the smell of a relative even after a decade apart.
When Franziska Horner and her team1 planned reunions（团聚） between two mother-daughter pairs at zoos in Germany, they took advantage of the chance to test the elephants' 2 . One pair had been3 for two years,4 the other had spent 12 years apart.
Franziska5 faecal （排泄物的） samples from these African elephants and others at German zoos, carrying the smelly 10-to-15-kilogram faeces around in her tiny car. Her team6 these samples one at a time to the four elephants7 their reunions.
When they encountered faeces from8 elephants, either those in the same zoo or unfamiliar animals, they sniffed （闻） the faeces piles and walked away. But when presented with a 9 from the mother or daughter they were due to be reunited with, the female elephants10 sniffed the samples and showed a variety of11 , from making deep sounds to swinging their ears.
Such reactions may be linked to positive emotions, the researchers say. "That was amazing and intense," says Franziska, "We were sure they did12 , and they knew exactly what they were13 there. The sample size was small, but it would be14 to do similar tests on elephants that weren't being reunited. "
"I am not surprised that elephants have memories, especially in social contexts, that15 a long time," says another scientist.
