DOI: 10.5061/dryad.t6j52
title: Data from: Species collapse via hybridization in Darwin's tree finches

description: Species hybridization can lead to fitness costs, species collapse, and
 novel evolutionary trajectories in changing environments. Hybridization is
 predicted to be more common when environmental conditions change rapidly.
 Here, we test patterns of hybridization in three sympatric tree finch
 species (small tree finch Camarhynchus parvulus, medium tree finch
 Camarhynchus pauper, and large tree finch: Camarhynchus psittacula) that
 are currently recognized on Floreana Island, Galápagos Archipelago.
 Genetic analysis of microsatellite data from contemporary samples showed
 two genetic populations and one hybrid cluster in both 2005 and 2010;
 hybrid individuals were derived from genetic population 1 (small morph)
 and genetic population 2 (large morph). Females of the large and rare
 species were more likely to pair with males of the small common species.
 Finch populations differed in morphology in 1852–1906 compared with
 2005/2010. An unsupervised clustering method showed (a) support for three
 morphological clusters in the historical tree finch sample (1852–1906),
 which is consistent with current species recognition; (b) support for two
 or three morphological clusters in 2005 with some (19%) hybridization; and
 (c) support for just two morphological clusters in 2010 with frequent
 (41%) hybridization. We discuss these findings in relation to species
 demarcations of Camarhynchus tree finches on Floreana Island.
description: Allele size data
 Floreana Tree Finches 2005 & 2010Allele size data for
 tree finches on Floreana Island, Galapagos. "Year" refers to
 whether an individual was sampled in 2005 or 2010. "FTA" is a
 unique number that was given to the blood sample of each sampled
 individual (this number was written next to blood samples stored on FTA
 paper). "Ring number" refers to the identifier inscribed on an
 aluminum band around a bird's tarsus. "Pop" refers to the
 species category given to each individual in the field: small tree
 finch=1, medium tree finch=2, large tree finch=3. Remaining information
 refers to allele size (maximum height at peak of allele) at each of 10
 microsatellite loci (Gf01, Gf03, Gf04, Gf05, Gf06, Gf07, Gf09, Gf11, Gf12,
 Gf13)Allele
 size data Floreana Tree Finches 2005 and 2010
 Dryad.xlsxGenetic Population and
 Morphology_Floreana Tree Finches 2005 and 2010_Am NatMorphological
 measurements of tree finches sampled on Floreana Island, Galapagos, 2005
 and 2010. Techniques for measuring morphological features are described in
 the associated manuscript. Genetic population refers to population
 assignment based on analyses of microsatellite loci (using the program
 STRUCTURE).Assortative Pairing and
 Genetic Population_Am NatAssortative pairing,
 genetic and morphological data for male and female tree finches sampled on
 Floreana Island, Galapagos, 2005 and 2010. Techniques for measuring
 morphological features are described in the associated manuscript. Genetic
 population refers to population assignment based on analyses of
 microsatellite loci (using the program STRUCTURE).Philornis Intensity and
 Genetic Population Floreana Tree Finches_Am NatTotal Philornis downsi
 larvae intensity per nest for tree finches breeding on Floreana Island in
 2005, 2010 and 2012. Genetic population refers to population assignment
 based on analyses of microsatellite loci (using the program STRUCTURE).
 Male colour and putative species assignment are also provided (STF=small
 tree finch, MTF=medium tree finch, LTF= large tree
 finch).Philornis Intensity and Genetic
 Population_Floreana Tree Finches_Am
 Nat.xlsx