To tame a Hesperornis, you must kill a fish, and drag the fish's corpse to the Hesperornis to feed it. The fish's size plays a major factor in how many fish will be required (a 1.0x fish appears to fill up the taming bar twice as much as a 0.5x fish). Level of fish does not appear to impact taming. The Sabertooth Salmon is by far the most effective fish, equivalent of about 4 Coels of the same size, while the Piranha is equivalent to about 2.4 Coels.
Figured out a very streamlined way to get golden goose eggs!
First, tame yourself a female goose friend. You do this by dragging fish to feed, so I'd recommend taking an icthyornis (seagull) before attempting to tame even a minimum level, since their golden fish buff is absolutely needed.
Once she's tamed, find a pond with a lot of fish in it; try to make sure it's safe for your goose! Throw her into the water and set her to wander and aggressive. Then stand back and let her do her work.
Once your hesperornis starts to appear passive, even in the presence of coel, she's ready! Pick her up on your shoulder and throw her on shore, and she'll lay an egg and return to the water on her own. This is usually a regular egg, but don't worry, since these can be refined into oil in your cooking pot!
Once you do get a golden egg, make sure you're ready to use it (have Laz Chowder premade, if you're making kibble!) cause these things spoil and they spoil FAST.
Tame to this kill fish and drag there body to it and once tamed if you feed them more dead fish corpses it will build up and lay a golden egg which is used as a buff to certain dinos or oil or a player buff
The most frustrating thing about taming these guys is not only do they take a lot of fish but the same button to feed them is the same button to drop the fish(i don’t know if it’s different in pc or ps4)and it’s constantly swinging around your face making it annoying because you’re constantly dropping it. Either make it so the controls to feed them are different then dropping it or make ur so it’s not constantly in ur face.