Differential haemoparasite intensity between black sparrowhawk (Accipiter melanoleucus) morphs suggests an adaptive function for polymorphism

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dc.contributor.authorLei, Bonnieen_ZA
dc.contributor.authorAmar, Arjunen_ZA
dc.contributor.authorKoeslag, Annen_ZA
dc.contributor.authorGous, Tertius Aen_ZA
dc.contributor.authorTate, Gareth Jen_ZA
dc.date.accessioned2015-11-11T14:28:50Z
dc.date.available2015-11-11T14:28:50Z
dc.date.issued2013en_ZA
dc.description.abstractRecent research suggests that genes coding for melanin based colouration may have pleiotropic properties, in particular conveying raised immune function. Thus adaptive function of polymorphism may be associated with parasite resistance. The black sparrowhawk Accipiter melanoleucus is a polymorphic raptor with two morphs. Over most of its range the light morph is commonest, however within the recently colonised Western Cape of South Africa the dark morph predominates. The species breeds in winter throughout South Africa, however unlike in the rest of the species' South African range, the Western Cape experiences a winter rainfall regime, where arthropod vectors which transmit haematozoan parasites may be more abundant. We hypothesise that the higher frequency of dark morph birds in this region may be due to their improved parasite resistance, which enables them to cope with higher parasite pressure. If so, we predict that dark morph black sparrowhawks would have lower parasite burdens than light morph birds. Within our population the prevalence of the two most common haematozoan parasites was high, with 72% of adults infected with Haemoproteus nisi and 59% of adults infected with Leucocytozoon toddi . We found no difference in prevalence for either parasite between adult morphs, or between chicks of different parental morphs. However, within adults infected with H. nisi , infection intensity was significantly higher in light morphs than dark morphs. This suggests that dark morphs have lower parasite loads than light morphs due to resistance rather than morph-specific habitat exploitation. Greater resistance to Haemoproteus parasites may therefore be one of the mechanisms through which dark morph black sparrowhawks have a selective advantage in this region and may explain why they are most common in our study area. In other regions, the cost to benefit ratio may be in favour of the light morph, where parasites are less abundant or virulent.en_ZA
dc.identifier.apacitationLei, B., Amar, A., Koeslag, A., Gous, T. A., & Tate, G. J. (2013). Differential haemoparasite intensity between black sparrowhawk (Accipiter melanoleucus) morphs suggests an adaptive function for polymorphism. <i>PLoS One</i>, http://hdl.handle.net/11427/14930en_ZA
dc.identifier.chicagocitationLei, Bonnie, Arjun Amar, Ann Koeslag, Tertius A Gous, and Gareth J Tate "Differential haemoparasite intensity between black sparrowhawk (Accipiter melanoleucus) morphs suggests an adaptive function for polymorphism." <i>PLoS One</i> (2013) http://hdl.handle.net/11427/14930en_ZA
dc.identifier.citationLei, B., Amar, A., Koeslag, A., Gous, T. A., & Tate, G. J. (2012). Differential haemoparasite intensity between black sparrowhawk (Accipiter melanoleucus) morphs suggests an adaptive function for polymorphism. PloS one, 8(12), e81607-e81607. doi:10.1371/journal.pone.0081607en_ZA
dc.identifier.ris TY - Journal Article AU - Lei, Bonnie AU - Amar, Arjun AU - Koeslag, Ann AU - Gous, Tertius A AU - Tate, Gareth J AB - Recent research suggests that genes coding for melanin based colouration may have pleiotropic properties, in particular conveying raised immune function. Thus adaptive function of polymorphism may be associated with parasite resistance. The black sparrowhawk Accipiter melanoleucus is a polymorphic raptor with two morphs. Over most of its range the light morph is commonest, however within the recently colonised Western Cape of South Africa the dark morph predominates. The species breeds in winter throughout South Africa, however unlike in the rest of the species' South African range, the Western Cape experiences a winter rainfall regime, where arthropod vectors which transmit haematozoan parasites may be more abundant. We hypothesise that the higher frequency of dark morph birds in this region may be due to their improved parasite resistance, which enables them to cope with higher parasite pressure. If so, we predict that dark morph black sparrowhawks would have lower parasite burdens than light morph birds. Within our population the prevalence of the two most common haematozoan parasites was high, with 72% of adults infected with Haemoproteus nisi and 59% of adults infected with Leucocytozoon toddi . We found no difference in prevalence for either parasite between adult morphs, or between chicks of different parental morphs. However, within adults infected with H. nisi , infection intensity was significantly higher in light morphs than dark morphs. This suggests that dark morphs have lower parasite loads than light morphs due to resistance rather than morph-specific habitat exploitation. Greater resistance to Haemoproteus parasites may therefore be one of the mechanisms through which dark morph black sparrowhawks have a selective advantage in this region and may explain why they are most common in our study area. In other regions, the cost to benefit ratio may be in favour of the light morph, where parasites are less abundant or virulent. DA - 2013 DB - OpenUCT DO - 10.1371/journal.pone.0081607 DP - University of Cape Town J1 - PLoS One LK - https://open.uct.ac.za PB - University of Cape Town PY - 2013 T1 - Differential haemoparasite intensity between black sparrowhawk (Accipiter melanoleucus) morphs suggests an adaptive function for polymorphism TI - Differential haemoparasite intensity between black sparrowhawk (Accipiter melanoleucus) morphs suggests an adaptive function for polymorphism UR - http://hdl.handle.net/11427/14930 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/14930
dc.identifier.urihttp://dx.doi.org/10.1371/journal.pone.0081607
dc.identifier.vancouvercitationLei B, Amar A, Koeslag A, Gous TA, Tate GJ. Differential haemoparasite intensity between black sparrowhawk (Accipiter melanoleucus) morphs suggests an adaptive function for polymorphism. PLoS One. 2013; http://hdl.handle.net/11427/14930.en_ZA
dc.language.isoengen_ZA
dc.publisherPublic Library of Scienceen_ZA
dc.publisher.departmentPercy FitzPatrick Institute of African Ornithologyen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.rightsThis is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.en_ZA
dc.rights.holder© 2013 Lei et alen_ZA
dc.rights.urihttp://creativecommons.org/licenses/by/4.0en_ZA
dc.sourcePLoS Oneen_ZA
dc.source.urihttp://journals.plos.org/plosoneen_ZA
dc.subject.otherParasitic diseasesen_ZA
dc.subject.otherBirdsen_ZA
dc.subject.otherHaemoproteusen_ZA
dc.subject.otherBlooden_ZA
dc.subject.otherMelaninen_ZA
dc.subject.otherImmune responseen_ZA
dc.subject.otherImmune suppressionen_ZA
dc.subject.otherRaptorsen_ZA
dc.titleDifferential haemoparasite intensity between black sparrowhawk (Accipiter melanoleucus) morphs suggests an adaptive function for polymorphismen_ZA
dc.typeJournal Articleen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceArticleen_ZA
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