While they have multiple use as defenders and attackers and even use them to kamikaze to your target, you can also use them to hold your stuff. like food, narcotics, GPS, Bullets, tools, etc... That way a Pegomastax will never steel it from you. And if you carry a high level one (Recomended) they will shred noobs if they ever knock you silly. Just remember to always have them on follow before you put them on your shoulder (pick up) so that way they can't bait them. Also breeding them will make you have an army of flying birds that can even take down Rexs. Hit up-vote so people will know!
These little creatures are amazing for clearing caves just get about 20 of them drag them into a cave and watch them work you need to pay attention to there hp though there strength is in numbers so individuals can die
Best tame for the time and narcotics. I have about 20 of these above lvl 200 defend my base.. They shred people along with my turrets. I also raid with 10+ of them. They make shooting at me impossible as they swarm people not their mounts. Use the spyglass to scope dinos or people and whistle attack target. It is an invaluable sniper tool.
P.S. Keep them close to your fabricator and smithy to level faster.