Christopher Pledger/Associated Press

Imagine the cultural reverberations that would have been set off if John Lennon, Paul McCartney and Ringo Starr had simultaneously informed George Harrison that he alone was left to run the Beatles; or if Agnetha, Benny and Björn turned to Anni-Frid and told her that ABBA was now her responsibility.

Now picture a similarly significant occurrence taking place in the Southern Hemisphere, within a pop act aimed at a somewhat younger audience, and you will understand the seismic waves and anguished cries emanating from Australia, where Jeff Fatt, Murray Cook and Greg Page — better known as the Purple, Red and Yellow Wiggles — have said they will depart the popular children’s music group the Wiggles at the end of their current tour.

This changing of the guard within the Wiggles, a band known for enduring songs like “Toot Toot, Chugga Chugga, Big Red Car,” will take place at the end of the year after the group completes its current tour, The Associated Press reported.

Mr. Page, who previously left the Wiggles in 2006 due to his declining health but made a surprise return to the band at the start of this year, said in a statement, “With Murray and Jeff’s decision to stop performing at the end of the year it’s a nice sense of closure to also end my time onstage during the final tour with all the original members of the group.”

This move will leave Anthony Field, the original Blue Wiggle, as the only founding member to remain with the group, though Mr. Cook, Mr. Fatt and Mr. Page will remain involved behind the scenes, they said. Emma Watkins, Lachlan Gillespie, and Simon Pryce will take over as the Yellow, Purple and Red Wiggles.

The membership of popular onstage supporting characters like Wags the Dog and Henry the Octopus is believed to be secure.