Barry Lawrence, of the Department of Conservation, said the bright colours, bright jackets, the bustle of people and activity had attracted the native birds back to the area.
"A combination of curiosity, intelligence and lack of anything else to do has brought them to Coronet Peak for a bit of excitement.
It is a winter playground for them.
"My best guess is that these are juvenile birds. They get into groups and then behave like gangs of teenagers, and, like all teenagers, they find anything to save them from boredom."
Kea usually "hang around" in groups of 10 to 20 and Mr Lawrence liked to think their return to Coronet Peak was a reflection of a rising kea population in the Wakatipu area.
"Through the cessation of burning alpine shrublands, and control over goats and deer, the food supply has gone up enormously, so the future looks strong for kea.
"They are attracted to ski areas because it is a good place to have some fun, and get a snack on the side."
However, he warned skiers not feed kea.
"We want people to keep enjoying the kea and their antics, and not get into the situation where kea start causing maintenance problems."