Hayman states that Paleartic Kentish Plover flight call is a soft "pit". Do Snowy Plovers also make this call? Nathan Pieplow, in his Field Guide to Bird Sounds of North America, describes this call for Snowy Plover as "cheep" and portrays the principal harmonic as falling between 4 and 5 kHz, giving the Snowy Plover a lower-pitched call note. I was able to record a sonogram of the mystery plover's flight call note, a high-pitched "chit" reminiscent of a sparrow or finch (the recording is available from ebird.org at this link: https://ebird.org/checklist/S118469384 ). The sonogram indicates the principal harmonic falling above 5 khz, hence a higher pitch than expected for Snowy Plover. I searched the sound files of flight calls for Snowy and Kentish Plovers in eBird and found very few similar calls. The three I was able to find were all from China and Taiwan, presumably from the Asian population of Kentish Plover. Photos of those three sonograms from eBird are presented in this gallery, with the similar calls highlighted with yellow. UPDATE 9/25/2022: I’ve added images of six Snowy Plover sonagrams demonstrating the lower pitch of the equivalent flight call. Click on these images for the live link to the eBird checklists where you can listen to each sound file.