Screech
mid 16th century: alteration of archaic scritch, of imitative origin.
wiktionary
1602; altered with expressive vowel lengthening from earlier skrech (1577), variant of obsolete scritch, from Middle English skriken, shrichen, schrichen (1250), from Old English (attested as scriccettan) and Old Norse skríkja, both from Proto-Germanic *skrīkijaną (compare Icelandic skríkja, Old Saxon scricōn, Danish skrige, Swedish skrika), derivative of *skrīhaną (compare Middle Dutch schriën, German schreien, Low German dial. schrien, schriegen), ultimately of imitative origin.
etymonline
screech (v.)
1570s, alteration of scritch (mid-13c., schrichen), possibly of imitative origin (compare shriek). Related: Screeched; screeching. Screech-owl is attested from 1590s (scritch-owl is from 1520s).
screech (n.)
1550s, from screech (v.). Earlier scritch (1510s).