Looks like Chipping Sparrow to me, perhaps two calls from the same bird - a clue is the 80+ ms duration, but also there is a faint initial downsweep that is structurally more in line with CHSP.
Bill From: Preston Lust Sent: Wednesday, April 24, 2019 4:39 PM To: Night Flight Call Discussions Subject: [nfc-l] Nocturnal Flight Calls – Prothonotary Warbler? Last night I recorded two calls in my yard that I believe may be prothonotary. I was wondering what anyone else thought, or what the criteria are for prothonotary warbler in the first place. I have attached a spectrogram of the call, as well as the recording. Thank you very much! Preston Lust, Westport, CT -- NFC-L List Info: Welcome and Basics Rules and Information Subscribe, Configuration and Leave Archives: The Mail Archive Surfbirds Birding.ABA.Org Please submit your observations to eBird! -- -- NFC-L List Info: Welcome and Basics � http://www.northeastbirding.com/NFC_WELCOME Rules and Information � http://www.northeastbirding.com/NFC_RULES Subscribe, Configuration and Leave � http://www.northeastbirding.com/NFC-L_SubscribeConfigurationLeave.htm Archives: The Mail Archive � http://firstname.lastname@example.org/maillist.html Surfbirds � http://www.surfbirds.com/birdingmail/Group/NFC-L Birding.ABA.Org � http://birding.aba.org/maillist/NFC Please submit your observations to eBird! ��http://ebird.org/content/ebird/ --