It’s the end of another era at Discovery Networks in Canada, with veteran exec Ken MacDonald announcing his retirement.

MacDonald has led the network as GM and VP since 2015, the latest chapter in a 15-year career at the factual network.

Prior to becoming GM, MacDonald was VP of programming, a position he held since 2005 and which saw him usher in some of Discovery Canada’s biggest hits, including Highway to Hell, Canada’s Worst Driver and Heavy Rescue 401. He also led key Discovery initiatives of recent years, including the launch of Discovery GO and its first scripted drama, Frontier. MacDonald was a longtime colleague of former Discovery president and GM Paul Lewis, who exited the company in 2015 amidst restructuring. Both had come from journalism backgrounds before joining the channel.

Discovery Networks is a Bell Media property, operating distinctly from its stateside brand sister, Discovery. That enterprise is also in the midst of an evolution, having acquired lifestyle broadcaster Scripps Networks Interactive in a blockbuster $14 billion deal that closed this January.

During MacDonald’s tenure, the media landscape has changed dramatically, but Discovery has continued to occupy a unique and interesting space in Canada’s TV business, and in Bell Media itself. The channel has long had its own leadership and dedicated exec staff – longtime programmer Edwina Follows remains at the net – within the Bell Media channel portfolio, and has its own in-house prodco, EPI, which produces and exports content globally. And while Discovery in Canada shares in key global Discovery programming events, like Shark Week, it has also cultivated a distinct Canadian brand via original commissions and evolving programming strategies. But as disruption has relentlessly pushed forward, more drastic changes have been made, including the recent end to Discovery’s 23-year-old flagship news show, Daily Planet.

According to an internal memo, Bell Media will announce a succession plan for MacDonald shortly.