It takes place in a world much like our own except that magic works and a large proportion of the population are witches who are able to control it. Lucy Parker was such a witch and also a birder. Every Yule Day, Sunset Grove, California the small town she lived in, had a friendly competition with its neighbor of Fernwood to see whose residents could spot the most types of birds that day. Friendly, but with witches involved, intense.
Witch Way to the Mall is part of the "supernatural suburbanites" trilogy, along with Strip Mauled (2009, werewolves) and Fangs for the Mammaries (2010, vampires). Witch is the only volume with a Turtledove story.