From RPGSite: “Tales of Arise is chock full of collectibles. From cooking recipes and Astral Flowers to artifacts and rare fish, the latest game in the series has plenty of fun diversions. One of the earliest examples you’ll encounter is a Sub-Quest titled “The Owl Forest.” The prompt for this extensive quest cannot be missed; it will trigger upon the party’s arrival in Nevira’s White Silver Plains. The gist is equally simple: there are 38 owls scattered across the world of Dahna and it’s up to you to find them all.
True to franchise form, locating collectibles is worth your while. As you work on “The Owl Forest,” you’ll periodically be rewarded with new costumes, accessories, and other fun bits. Some owls are tougher to find than others, so we’ll guide your discoveries across all five Dahnan realms on a bird-by-bird basis.”
Source: N4G PC Tales of Arise Owl Locations: where to find them and your rewards for doing so