Evolutionary Ecology

, Volume 28, Issue 2, pp 299–322

Ecology, song similarity and phylogeny predict natural hybridization in an avian family

  • Pamela M. Willis
  • Rebecca E. Symula
  • Irby J. Lovette
Original Paper

DOI: 10.1007/s10682-013-9677-4

Cite this article as:
Willis, P.M., Symula, R.E. & Lovette, I.J. Evol Ecol (2014) 28: 299. doi:10.1007/s10682-013-9677-4


Hybridization is important in the evolution of many animal groups; however, broad scale patterns of natural hybridization are still poorly understood. Using phylogenetic comparative analyses, we tested for relationships between demographic, ecological, phenotypic and phylogenetic variables and the incidence of natural hybridization among 45 species of North American wood warbler. Since 1980, hybrids have been documented in 24 species (53 %). We detected negative relationships between the incidence of hybridization and both breeding range size and phylogenetic distance, and positive relationships between the incidence of hybridization and (1) song similarity, (2) the extent of breeding sympatry of species pairs and (3) the number of additional heterospecific warbler species that co-occur during breeding. Neither population size nor breeding habitat quality (as measured by threats to survival or reproduction in breeding areas) explained variation in the incidence of hybridization. Our results suggest a potential role of limited breeding habitat in wood warbler hybridization events and a net positive effect of breeding sympatry. They also support the hypothesis that mating signal similarity facilitates hybridization events and are consistent with an increase in reproductive isolation with increasing genetic divergence. Our results also suggest the presence of phylogenetic signal in wood warbler hybridization. By investigating natural hybridization at the taxonomic level of family, we have identified several previously undocumented patterns of natural hybridization. This study demonstrates the utility of examining the combined effects of ecology, demography, phenotype and phylogeny when studying variation in the expression of natural hybridization among taxa.


Hybridization Mate choice Breeding habitat Warblers Song Phylogenetic signal 

Supplementary material

10682_2013_9677_MOESM1_ESM.pdf (3.1 mb)
Supplementary material 1 (PDF 3225 kb)

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Pamela M. Willis
    • 1
    • 4
  • Rebecca E. Symula
    • 1
    • 3
  • Irby J. Lovette
    • 2
  1. 1.Section of Integrative BiologyUniversity of Texas at AustinAustinUSA
  2. 2.Fuller Evolutionary Biology Program, Cornell Lab of OrnithologyCornell UniversityIthacaUSA
  3. 3.Department of BiologyUniversity of MississippiOxfordUSA
  4. 4.Department of BiologyUniversity of VictoriaVictoriaCanada