Haunting howl of the Wolf

Argggh! I was hoping to get a description typed here before anyone looked at this photo and commented!!!! Sorry, Machel, Patricia and Rebecca - I wish I could say I was lucky enough to see this magnificent creature in the wild, but she is one of three female Timber Wolves at the Calgary Zoo. I would LOVE to see a Wolf in the wild some day! All three were howling to echo a distant siren (ambulance?), just as wild Coyotes do here in the city.