Fig 1.
Distribution of the timberline wren in Costa Rica (dark orange area).
Sites include the Irazú Volcano in the Central Volcanic mountain range and the Talamanca Mountain Range above 2800 m a.s.l. The blue line indicates the position of the single barrier identified by Monmonier's algorithm for genetic and song divergence among populations. Black triangles indicate the location of the four study sites. IV = Irazú Volcano, CV = Cerro Vueltas, CBV = Cerro Buena Vista, CCH = Cerro Chirripó.
Fig 2.
Spectrograms showing a portion of timberline wren songs from three different locations.
Note how a sequence of song elements is followed by an identical sequence. CBV = Cerro Buena Vista, CV = Cerro Vueltas, CCH = Cerro Chirripó, IV = Irazú Volcano.
Table 1.
Song elements recorded in four mountainous sites in Costa Rica.
Fig 3.
Group assignment for each timberline wren based on song dissimilarity.
Males were assigned to one of the two groups based on the partitioning around medioids (PAM) function. CBV = Cerro Buena Vista, CV = Cerro Vueltas, CCH = Cerro Chirripó, IV = Irazú Volcano.
Fig 4.
Principal component analysis plot using the first two components of six T. browni song acoustic traits.
CBV = Cerro Buena Vista, CV = Cerro Vueltas, CCH = Cerro Chirripó, IV = Irazú Volcano.
Table 2.
Loading scores of the first two principal components from the T. browni songs’ acoustic traits.
Table 3.
Summary of mean (± sd) T. browni song traits for each study site.
Fig 5.
Bill length of timberline wrens from four populations in Costa Rica: CBV = Cerro Buena Vista, CV = Cerro Vueltas, CCH = Cerro Chirripó, IV = Irazú Volcano.
Table 4.
Mean (± sd) genetic diversity estimates for six microsatellite loci from the timberline wren in four populations in Costa Rica.
Fig 6.
Individual assignment of timberline wren genotypes to one of two clusters defined by STRUCTURE and the evanno method.
Bars represent individuals and colors depict percentage admixture from two different clusters. Populations: CBV = Cerro Buena Vista, CV = Cerro Vueltas, CCH = Cerro Chirripó, IV = Irazú Volcano.
Table 5.
Geographic and genetic distance matrix.
Fig 7.
Correlation between linear geographic distance and timberline wren’s genetic and song dissimilarities.
Each point represents a direct comparison between two populations. Yellow dots represent pairwise comparisons between populations separated only by distance, and blue dots represent pairwise comparisons between populations separated by a geographic barrier. Correlation between Fst and linear geographic distance in km (A), song dissimilarity and linear geographic distance in km (B), and between song dissimilarity and Fst (C). Fst estimates were transformed to Fst / (1 –Fst).