Local host specialization, host-switching, and dispersal shape the regional distributions of avian haemosporidian parasites

Research output: Contribution to journalArticle


The drivers of regional parasite distributions are poorly understood, especially in comparison with those of free-living species. For vector-transmitted parasites, in particular, distributions might be influenced by host-switching and by parasite dispersal with primary hosts and vectors. We surveyed haemosporidian blood parasites (Plasmodium and Haemoproteus) of small land birds in eastern North America to characterize a regional parasite community. Distributions of parasite populations generally reflected distributions of their hosts across the region. However, when the interdependence between hosts and parasites was controlled statistically, local host assemblages were related to regional climatic gradients, but parasite assemblages were not. Moreover, because parasite assemblage similarity does not decrease with distance when controlling for host assemblages and climate, parasites evidently disperse readily within the distributions of their hosts. The degree of specialization on hosts varied in some parasite lineages over short periods and small geographic distances independently of the diversity of available hosts and potentially competing parasite lineages. Nonrandom spatial turnover was apparent in parasite lineages infecting one host species that was well-sampled within a single year across its range, plausibly reflecting localized adaptations of hosts and parasites. Overall, populations of avian hosts generally determine the geographic distributions of haemosporidian parasites. However, parasites are not dispersal-limited within their host distributions, and they may switch hosts readily.


  • Vincenzo A. Ellis
  • Michael D. Collins
  • Matthew C.I. Medeiros
  • Eloisa H R Sari
  • Elyse D. Coffey
  • Rebecca C. Dickerson
  • Camile Lugarini
  • Jeffrey A. Stratford
  • Donata R. Henry
  • Loren Merrill
  • Alix E. Matthews
  • Alison A. Hanson
  • Jackson R. Roberts
  • Michael Joyce
  • Melanie R. Kunkel
  • Robert E Ricklefs
External organisations
  • University of Missouri-St. Louis
  • Federal University of Minas Gerais
  • University of Missouri-Columbia
  • Centro Nacional de Pesquisa e Conservação de Aves Silvestres
  • Tulane University
  • University of Illinois at Urbana-Champaign
  • Arkansas State University
  • Texas A and M University
  • Auburn University
  • Rhodes College
  • Wilkes University
  • Rhodes University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Zoology
  • Ecology


  • Avian malaria, Community assembly, Emerging infectious disease, Haemosporida, Parasite communities
Original languageEnglish
Pages (from-to)11294-11299
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number36
Publication statusPublished - 2015 Sep 8
Publication categoryResearch
Externally publishedYes