Table 1

Estimates of mtDNA percent sequence divergence and estimated ages for pairs of North American songbird species (13) that have been postulated to have differentiated during most recent Pleistocene glacial advances (4, 5). Standard errors are shown when available. ND2, NADH subunit 2; ND6, NADH subunit 6.

Taxon pairSequence divergence (%)Estimated age (2% divergence/My)Data typeSource [see (18)]
Parus bicolor versus P. inornatus (Tufted and Plain titmice)7.43,700,000RFLP, 19 endonucleases, 134 restriction sitesh
Parus b. bicolor versus P. b. atricristatus (Tufted and Black-crested titmice)0.4200,000RFLP, 19 endonucleases, 83 restriction sitesa
Quiscalus major versus Q. mexicanus (Boat-tailed and Great-tailed grackles)1.6800,000RFLP, 19 endonucleases, 80 restriction sitesa
Parus atricapillus versusP. carolinensis (Black-capped and Carolina chickadees)4.62,300,000RFLP, 15 endonucleases, 48 restriction sitesb
Sturnella magna versus S. neglecta (Eastern and Western meadowlarks)5.32,650,000RFLP, 9 endonucleases, 171 restriction sitesc
Polioptila melanura versusP. nigriceps (Black-tailed and Black-capped gnatcatchers)4.82,400,000Sequence, cytochrome (cyt) b, ND2, ND6, 922 nucleotidesd
Polioptila melanura versusP. california (Blacktailed and California gnatcatchers)4.02,000,000Sequence, cyt b, ND2, ND6, 922 nucleotidesd
Pipilo erythrophthalmus versus P. Maculatus (Rufous-sided and Spotted towhees)0.8400,000RFLP, 16 endonucleasesf
Dendroica c. coronata versus D. c. auduboni (Myrtle and Audubon's warblers)0.6300,000RFLP, 14 endonucleases, 49 restriction sitesg
Dendroica townsendi versusD. occidentalis (Townsend's and Hermit warblers)0.7350,000RFLP, 14 endonucleases, 49 restriction sitesg
Dendroica townsendi versusD. virens (Townsend's and Black-throated Green warblers)2.51,250,000RFLP, 14 endonucleases, 49 restriction sitesg
Ammodramus caudacutus versusA. nelsoni (Saltmarsh and Nelson's Sharp-tailed sparrows)1.3650,000RFLP, 17 endonucleases, 82 restriction sitesi
Ammodramus maritimusssp. (Gulf and Atlantic coastal forms)1.0500,000RFLP, 18 endonucleases, 89 restriction sitesj
Piranga olivacea versus P. ludoviciana (Scarlet and Western tanagers)6.4 (±0.75)3,200,000Sequence, cyt b, 1050 nucleotidesk
Passerina cyanea versus P. amoena (Indigo and Lazuli buntings)6.6 (±0.78)3,300,000Sequence, cyt b, 1050 nucleotidesk
Passerina cyanea versus P. versicolor (Indigo and Varied buntings)6.4 (±0.77)3,200,000Sequence, cyt b, 1050 nucleotidesk
Sialia sialias versus S. mexicana (Eastern and Western bluebirds)5.0 (±0.67)2,500,000Sequence, cyt b, 1050 nucleotidesk
Cardinalis cardinalis versus C. sinuatus (Northern Cardinal and Pyrrhuloxia)8.7 (±0.87)4,350,000Sequence, cyt b, 1050 nucleotidesk
Calcarius lapponicus versus C. mccownii (Lapland and McCown's longspurs)8.7 (±0.87)4,350,000Sequence, cyt b, 1050 nucleotidesk
Calcarius lapponicus versus C. ornatus (Lapland and Chestnut-collared longspurs)9.2 (±0.89)4,600,000Sequence, cyt b, 1050 nucleotidesk
Oporornis philadelphia versus O. tolmiei (Mourning and McGillivray's warblers)2.1 (±0.44)1,050,000Sequence, cyt b, 1050 nucleotidesk
Oporornis philadelphia versus O. agilis (Mourning and Connecticut warblers)7.3 (±0.80)3,650,000Sequence, cyt b, 1050 nucleotidesk
Spizella pallida versus S. breweri (Clay-colored and Brewer's sparrows)6.1 (±0.74)3,050,000Sequence, cyt b, 1050 nucleotidesk
Pheucticus ludovicianus versus P. melanocephalus (Rose-breasted and Black-headed grosbeaks)4.4 (±0.63)2,200,000Sequence, cyt b, 1050 nucleotidesk
Cyanocitta cristata versus C. stelleri (Blue and Steller's jays)10.75,350,000Sequence, cyt b, 1032 nucleotidesk
Amphispiza belli versus A. bilineata (Sage and Black-throated sparrows)10.95,450,000Sequence, cyt b, 288 nucleotidese
Pipilo aberti versus P. crissalis (Abert's and California towhees)2.11,050,000Sequence, cyt b, ND2, 744 nucleotidesl
Pipilo aberti versus P. fuscus (Abert's and Canyon towhees)5.72,850,000Sequence, cyt b, ND2, 744 nucleotidesl
Toxostoma rufum versus T. longirostre (Brown and Long-billed thrashers)6.33,150,000Sequence, cyt b, ND2, ND6, 944 nucleotidesl
Toxostoma lecontei versus T. redivivum (Leconte's and California thrashers)8.14,025,000Sequence, cyt b, ND2, ND6, 944 nucleotidesl
Toxostoma lecontei versus T. crissale (Leconte's and Crissal thrashers)8.34,125,000Sequence, cyt b, ND2, ND6, 944 nucleotidesl
Toxostoma redivivum versus T. crissale (California and Crissal thrashers)7.13,550,000Sequence, cyt b, ND2, ND6, 944 nucleotidesl
Toxostoma bendirei versus T. cinereum (Bendire's and Gray thrashers)1.7825,000Sequence, cyt b, ND2, ND6, 944 nucleotidesl
Icterus galbula versus I. bullockii (Baltimore and Bullock's orioles)4.72,350,000Sequence, cyt b, 530 nucleotidesm
Agelaius phoeniceus versus A. tricolor (Red-winged and Tricolored blackbirds)6.73,350,000Sequence, cyt b, 890 nucleotidesm
Mean values (n =35)5.1 (±3.0)2,550,000