Wolves’ howls have distinct identities, voice recognition study shows
arstechnica.com
arstechnica.com
Also, the advancement of science being reported is not that wolf howls are thought to be distinct, it's that somebody wrote the code that finally proves that they are. Granted, you might've thought that it was trivial code and it had already been done, but the fact is it hadn't been done until now, probably more because of funding issues than tech issues.
Hopefully, this tech (materials and code) will become more commonplace among zoologists, so that the cost of animal vocalization analysis comes down and gets funded quickly across all species. It seems like a promising new tool in the field.
And am I the only one that is thinking of the animated movie "Alpha and Omega" (http://en.wikipedia.org/wiki/Alpha_and_Omega_%28film%29)? One key part of the movie is that some wolves howl better than others, but they can also learn to improve.