Robert Irwin marks 21st birthday with loving tribute to late dad Steve: See the photo
"I carry his memory and passion with me in this new chapter of life."
Robert Irwin celebrated his latest milestone with a sweet nod to his late father Steve Irwin.
In a recent Instagram post, the wildlife photographer, conservationist and zookeeper, who runs Australia Zoo with his family, marked his 21st birthday by sharing two throwback photos of the beloved "Crocodile Hunter" star -- who died in 2006 at the age of 44 -- celebrating his own 21st birthday.
"Today I turn 21," Robert Irwin wrote in the post, dated Nov. 30. "I was looking through the archives a few days ago and I found these pictures of my dad on his 21st."
"It can be hard to celebrate the milestones when there's someone missing, but I carry his memory and passion with me in this new chapter of life," he continued. "I am one lucky guy to be surrounded by my amazing family today. Time to celebrate!"
The photos show Steve Irwin sitting at a dining table, cutting into a birthday cake covered with candles.
Robert Irwin's family also shared tributes for him on his special day.
His mom Terri Irwin wrote in an Instagram post, "Remembering all our fun family moments, and knowing your dad would be so proud of you. I love you, and I can't wait for the adventures to come."
Robert Irwin's sister Bindi Irwin, meanwhile, called him the "best brother, best uncle, best friend" in a sweet Instagram post of her own.
"Here's to every incredible adventure on the horizon," she continued. "Love you so much and beyond proud of you."
Robert Irwin's brother-in-law Chandler Powell, who is married to Bindi Irwin, also shared a birthday tribute to the 21-year-old on Instagram.
"Happy birthday, @robertirwinphotography 🎉 Between surfing, working with crocs, and occasionally modelling hats, I think this year is going to be fantastic," Powell wrote alongside a photo of the two wearing Australia Zoo baseball caps. "Can't wait to celebrate today! Thanks for being an awesome brother."