Data from pairwise sequential Markovian coalescent (PSMC) analyses reflecting effective population sizes (Ne) through history at depths > 50 Kyr and the five variables derived and analyzed from that output. Taxa shaded in gray are Neotropical residents.

Partial historic effective population size curves from all lineages in this study, based on pairwise sequential Markovian coalescent (PSMC) analyses. Each peak of initial growth is set to zero years to set a common framework in which to visualize the periods and magnitudes of initial growth among migrant (red) and resident (blue) lineages. See specific lineages with their bootstrapped results in Fig. S2.

Historic effective population size curves from all lineages, based on pairwise sequential Markovian coalescent (PSMC) analyses. Migrant lineages are in red and resident lineages in blue. See specific lineages with their bootstrapped results in Fig. S2.

Specimen data and NCBI-SRA numbers. Vouchered specimens are housed in the following institutions: UAM (University of Alaska Museum), MSB (Museum of Southwestern Biology, University of New Mexico), LSUMNS (Louisiana State University Museum of Natural Science), and FMNH (Field Museum of Natural History).

Results of phylogenetic generalized least squares (PGLS) regressions using corPagel and associated lambda values (see Revell 2012).

Distribution maps of the thrush taxa in this study. Among seasonal migrants, green indicates breeding range and yellow is wintering range. Among sedentary lineages (those shaded in gray), purple indicates year-round range. Data are from BirdLife International and the Handbook of the Birds of the World (2021), Bird species distribution maps of the world. Version 2021.1. Available at http://datazone.birdlife.org/species/requestdis.

Graphic presentation of the Catharus minimus PSMC dataset, showing effective population size (Ne) from 50 kyr back in time to the lineages’ origins as estimated from genomic data. The variables in our analyses are the mean and SD of the effective population size (Ne) values, deltaT of initial growth (timetrough – timepeak), the degree of that growth (1 – [Ntrough/Npeak]), and the rate of that growth (degree/deltaT).

The phylogenetic tree of Catharus and outgroup Hylocichla with the population growth metric deltaT mapped onto it. Resident taxa are highlighted in gray. Positive centered and scaled deltaT values are in black and negative values are in white, and their size is proportional to the absolute value. This trait has significant phylogenetic signal (see Jombart et al. 2012) and therefore comprises attributes both of migratory/sedentary lineages and of their deeper evolutionary history.

Montage of the historic effective population size curves of all lineages analyzed in this study, with each lineage in a separate panel (based on pairwise sequential Markovian coalescent, or PSMC, analyses). Sedentary lineages are highlighted in gray. Note that scales on both axes vary among panels, and that the X axis is on a log scale. Bold red lines are the main curves from the original data, and pink lines reflect 100 replicates from bootstrapped sequences. Bold red curves are all overlaid on common axes in the single panel of Fig. 1.