Around the second day of playing Animal Crossing New Horizons, a bird named Gulliver will wash up on your shore near the airport. To wake Gulliver up, keep talking to him numerous times! Eventually, he will wake up. When he does, you’ll learn he fell off his ship and has no way of contacting his crew to come and pick him up. Gulliver will task you with finding 5 communicator parts, which are buried in the sand. To figure out where to dig, look for a small, dark dot appears in the sand that squirts a stream of water out (see image below). *NOTE: Other objects can also be dug up in these spots besides the communicator parts.
When you find all 5 communicator parts, return to Gulliver and hand them over. Gulliver with then be able to call his crew and promises to send you something in the mail tomorrow as a reward!