Fans of an Assiniboine Park Zoo tradition are voicing their displeasure on social media after word of the demise of Boo at the Zoo surfaced on Facebook.

A post on the zoo’s Facebook page said Boo at the Zoo is being cancelled due to rising costs and declining attendance at the event, usually held in the lead up to Halloween.

The zoo said it wants concentrate its efforts on the Journey to Churchill exhibit, slated to open in 2014, along with research, education and animal preservation.

For people who bought zoo memberships expecting to attend Boo at the Zoo, a letter is expected to be sent out with additional zoo passes as compensation.