I think some people here are confused, so let's clarify something. Those are not onomatopeias, those are the verbs for the animal sounds. That, plus the fact they're conjugated in the third person in OP's post, is the reason for the silent letters.

If I take the list and use the onomatopoeias instead, it goes like this. There's a lot less because I'm only indicating once the sounds that are used for multiple animals, and a lot of animals either don't have a fixed onomatopoeia, or I don't know it.

1. Chat and other felines 🐈 : miaou (miauler) / ronron (ronronner)
2. Chien and other canines 🐕 : ouaf (aboyer) / aouh (hurler)
3. Vache and other bovines 🐄 : meuh (mugir)
4. Cheval 🐎 : hii (hennir)
5. Mouton 🐑 : bêê (bêler)
6. Cochon 🐖 : grouin/grouik (grogner)
7. Poule 🐔 : cot cot cot (caqueter)
8. Coq 🐓 : cocorico
9. Canard 🦆 : coin coin (cancaner)
10. Grenouille 🐸 : coa coa (coasser)
11. Serpent 🐍 : ssssss (siffler)
12. Abeille and most buzzing bugs 🐝 : bzzz (bourdonner)
13. Singe 🐒 : ouh ouh
14. Pigeon 🕊️ : rou rou (roucouler)
15. Corbeau 🐦‍⬛ : croa (croasser)
16. Chouette/hibou 🦉 : hou hou (hululer)
17. Dindon 🦃 : glouglou (glouglouter)
18. Paon 🦚 : I don't know how common it is, but everytime someone imitates one, they say "Léon, Léon!"
19. Most small birds 🐦 : cui cui / piou piou (piailler, pépier)
20. Cigale : cr cr cr (cymbaliser, not striduler, that's the criquet)
21. Âne 🫏 : hi han (braire)

1. Homme 🤷‍♂️: damn f&$k

Waouh, très bonne idée! Faites de même pour les autres choses!

I have been repeatedly asking my husband (fr) to tell me animals sounds so I can teach our kids one day and he doesn’t remember/know. Merci beaucoup, saving this asap!!!

soldat 😡🛡️🗡️ : mugit (dans nos campagnes)

All the cries that end in T—isn't that silent? Why end with a silent letter for an onomatopoeia?