Mandy Moore voices 'fierce' love for son Gus on his 1st birthday

Feb. 21 (UPI) -- Mandy Moore is celebrating her son's first birthday.

The 37-year-old singer and actress marked the occasion Sunday by posting a tribute to Gus, her son with her husband, musician Taylor Goldsmith, on Instagram.

Moore shared a video featuring a slideshow of photos from throughout her first year with her son.

"Gus- Being your mom is a gift beyond my comprehension, a love so fierce and mighty that I know I will never touch the depths of. Happy Birthday to our ever joyful and curious boy!!! You turned on all the lights, Goosey. #thisisus," she captioned the post.

Moore's This is Us co-star Chrissy Metz, singer and actress Ashley Tisdale, and model Tess Holliday also wished Gus a happy birthday in the comments.

"Happy Birthday, GUS!!!" Metz wrote.

"Happy birthday gus!!!!" Tisdale added.

"He is so perfect! Happy Birthday Gus!!" Holliday said.

Goldsmith posted a video on his own account of Gus vocalizing while sitting in a highchair during a meal.

"1ST BIRTHDAY!!!! THANKS FOR BEING THE COOLEST GUY I KNOW, GUS! I don't think I can put into words what this last year has meant to me and how much I love this little human...." Goldsmith wrote.

"Happy Birthday Goose. Sorry you don't know what that means yet. Can't wait to watch you faceplant a cake today," he said.

Moore later shared photos from Gus' birthday party. The family hosted an outdoor picnic for their friends and their kids.

"1st birthday party was a hit! Making memories and so full of love and cake. #thisisgus," Moore captioned the post.

Moore and Goldsmith married in November 2018 and welcomed Gus in February 2021. Moore returned to the This is Us set in March 2021 after giving birth.

Moore plays Rebecca Pearson on This is Us, which is in the midst of a sixth and final season on NBC. The series also stars Milo Ventimiglia, Sterling K. Brown and Justin Hartley.