The puppies were born in May to first-time mom, Zana, 3, and first-time dad, Flint, 5.
One of the puppies was named Nestor in memory of a wolf who used to reside at Brookfield Zoo. However, three of the puppies, two males and a female, are still in need of names.
Voting begins Thursday at www.CZS.org/WolfNames.
As of noon, the top names were Magdalena, Inigo (which means fiery in Spanish) and Aldo (a nod to conservationist Aldo Leopold).
Zoo staffers narrowed down three possible names for each pup. Other names picked for the male puppies include Coronado (the name given to a pack of wolves released to the wild) and Fausto (which means lucky in Spanish).
For the past several years, the U.S. Fish and Wildlife Service has been introducing zoo-born Gray Mexican Wolves back into the wild. Puppies like these have to be raised with as little human contact as possible. Once the pups are bigger, they could stay at Brookfield Zoo or be introduced into wild.