The link for this challenge is: https://dailypost.wordpress.com/photo-challenges/trio/
I found many photos in my archives and in some recent shots that would meet this challenge.
Three Red Fox cubs playing in our backyard in May of this year.
Trio of Gold Finches in their non-breeding plumage.
Three European Starlings on their favorite perch: electrical wire.
Cormorant threesome taking off.
Snow Geese flying over Edwin B Forsythe Wildlife Refuge.