Table 1.

Source, recording date, location, duration, and number of songs for each sample

Sample	Source	Date	Location	Length, s	No. of songs	No. of song types
1	Krause	Unknown	Southeast Alaska	120	30	6
2	Borror	07/11/1970	Upper Peninsula, MI	72	12	6
3	Borror	07/19/1955	Muscongus, ME	107	18	9
4	Borror	05/26/1988	Upper Peninsula, MI	249	65	9
5	Borror	07/15/1956	Muscongus, ME	98	23	9
6	Borror	07/19/1956	Muscongus, ME	119	22	10
7	Borror	06/10/1997	Homer, AK	332	66	7
8	Borror	07/01/1958	Nobleboro, ME	108	18	8
9	Borror	07/28/1953	Millinocket, ME	95	18	6
10	Borror	07/07/1965	Lewisburg, OR	104	26	7
11	Borror	07/09/1967	North Rim, AZ	114	18	9
12	Colver	06/28/1996	Kamas, UT	73	13	10
13	Colver	06/28/1996	Kamas, UT	212	40	9
14	Colver	2007	Homer, AK	171; 258	38; 58	9

Borror, Borror Laboratory of Bioacoustics; Colver, Dr. Kevin J. Colver; Krause, Dr. Bernie Krause.