The Role of Environmental Heterogeneity in Maintaining Reproductive Isolation between Hybridizing Passerina (Aves: Cardinalidae) Buntings

Table 1

Sampling localities, sample sizes, and the proportion of hybrid individuals for populations analyzed in this study.

Code	Locality	Latitude	Longitude	𝑁	Proportion of hybrids (80–20)	Proportion of hybrids (90–10)
1	WA	47.8	−118.9	29	—	—
2	ID	44.1	−116.2	3	—	—
3	MT: Custer National Forest no. 1	45.1	−108.5	4	0.00	0.00
4	WY: Bighorn National Forest no. 1	44.8	−107.3	8	0.00	0.00
5	WY: Bighorn National Forest no. 2	44.6	−107.7	2	0.00	0.00
6	CO: Roosevelt National Forest	40.7	−105.2	7	0.14	0.14
7	MT: Custer National Forest no. 2	45.7	−106	5	0.00	0.00
8	WY: Medicine Bow National Forest	42.4	−105.3	3	0.00	0.00
9	ND: Little Missouri National Grassland	46.8	−103.5	13	0.00	0.00
10	SD: Custer National Forest	45.3	−103.2	10	0.00	0.00
11	WY: Sand Creek*	44.5	−104.1	14	0.36	0.50
12	NE: White River*	42.6	−103.5	8	0.38	0.50
13	SD: Black Hills National Forest	43.7	−103.8	5	0.20	0.20
14	NE: Ponderosa State Wildlife Management Area	42.6	−103.3	7	0.57	1.00
15	SD: The Nature Conservancy Whitney Preserve	43.3	−103.6	3	0.00	0.00
16	NE: Nebraska National Forest	42.8	−102.9	8	0.25	1.00
17	SD: Ft. Meade National Recreation Area	44.4	−103.5	4	0.50	0.50
18	NE: Nenzel*	42.8	−101.1	4	0.25	0.25
19	NE: The Nature Conservancy	42.8	−100	18	0.00	0.00
	Niobrara Valley Preserve
20	SD: Carpenter Game Production Area	43.7	−99.5	13	0.08	0.08
21	ND: The Nature Conservancy	46.3	−97.3	4	0.00	0.00
	Pigeon Point Preserve
22	NE: Wiseman State Wildlife Area	42.8	−97.1	10	0.00	0.00
23	SD: Newton Hills Game Production Area	43.2	−96.6	13	0.00	0.08
24	MN	44.9	−93.7	10	—	—
25	IL	40.5	−88.9	10	—	—
26	MI	42.3	−83.7	7	—	—

*Access to these localities generously provided by private landowners.