Why do dogs howl at fire engine sirens? Michael, Lake Forest, Calif.
For those who have never seen this, here is a classic example of the behavior you are talking about:
This brings up another good question - Why do dogs howl at all? By observing wolves, researchers know that howling is something wolves do when they are lonely, or when they are trying to call back other pack members. According to this article:
“Because howling is long and sustained, its carrying distance is further than a bark, which is short and brief,” says Lisa Peterson, communications director for the American Kennel Club. “It's like a ‘long distance' doggie telephone call, since the long, drawn-out sound can travel for distances of several miles."
So this makes sense. Dogs have created a long-distance communication system. Since dogs are social pack animals, communication like this would be handy.
We also know that if you have one dog howling, others will howl. Which also makes sense. If you are howling to communicate, then multiple howlers will increase the volume and therefore the distance.
The problem for some pet owners is that there are many things in our civilized world that sound a lot like howling. Fire engine sirens are one of them. When some dogs hear this sound, these dogs mimic the sound and start howling, just like their wolf cousins would do in the wild.