Synchrony and Periodicity of Eruptions by Boreal Birds

  title={Synchrony and Periodicity of Eruptions by Boreal Birds},
  author={Walter D. Koenig},
Abstract I examined 38 years of Christmas Bird Count data in order to resolve conflicting earlier findings as to whether eruptions of boreal seed-eating birds are synchronized and occur at regular intervals. A total of 15 species was analyzed, including several largely insectivorous boreal species. Interspecific synchrony was common, with 34 species pairs (32% of a possible 105) statistically synchronous across all or part of North America and clusters of up to five species exhibiting… 

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