Vocal Signatures help Penguins identify their offspring

Sharon Begley writes a science column in the Wall Street Journal on fridays. It is often the column that I read first on fridays. Given that its a narrow column it tends to be short and it usually packs a fascinatng nugget of knowledge. Two weeks back, she wrote about Emperor Penguins and their problem of identifying their young ones when they return from their food  hunt after a few weeks. Their problem is compounded by the fact that all the young ones look nearly alike even to themselves and all of them are making a huge amount of noise making their own calls to their family. Apparently, they teach their young ones a specific vocal signature before they leave for their food hunt and use that to identify their young ones amidst the noise. Interestingly, on our trip to the Galapagos Islands, we quizzed our guide about how the Sea Lions identify their young ones in their colony when they return from their food hunt. Our guide, Luis Die, remarked that they use vocal signatures to identify their young ones. References:
1. Interesting study report on “how does a fur seal mother recognize the voice of her pup“. It makes for a heavy read. In plain english, fur seals (also related to Sea Lions) use vocal signatures. Notes:
1. Luis Die is one of the best guides I have come across. He possesses encyclopedic knowledge of the Galapagos Islands’ flora, fauna, history, geology, you name it. BTW, Mountain Travel Sobek, that organized our tour is one of the best as well.