Systematics and cophylogenetics of toucans and their associated chewing lice

Historically, comparisons of host and parasite phylogenies have concentrated on cospeciation. However, many of these comparisons have demonstrated that the phylogenies of hosts and parasites are seldom completely congruent, suggesting that phenomena other than cospeciation play an important role in the evolution of host-parasite assemblages. Other coevolutionary phenomena, such as host switching, parasite duplication (speciation on the host), sorting (extinction), and failure to speciate can also influence host-parasite assemblages. In this dissertation I explore several aspects of the evolutionary history of Ramphastos toucans and their ectoparasitic chewing lice using molecular phylogenetic and cophylogenetic reconstructions. First, using mitochondrial DNA sequences, I reconstructed the phylogeny of the Ramphastos toucans. I used this phylogeny to assess whether the striking similarity in plumage and bare-part coloration of sympatric Ramphastos is due to convergence or shared ancestry. Ancestral character state reconstructions indicate that that at least half of the instances of similarity in plumage and bare-part coloration between sympatric Ramphastos are due to homoplasy. Second, using mitochondrial and nuclear protein-coding DNA sequences, I reconstructed the phylogeny of ectoparasitic toucan chewing lice in the Austrophilopterus cancellosus subspecies complex, and compared this phylogeny to the phylogeny of the hosts to reconstruct the history of coevolutionary events in this host-parasite assemblage. Three salient findings emerged. (1) reconstructions of host and louse phylogenies indicate that they do not branch in parallel and that their cophylogenetic history shows little or no significant cospeciation. (2) members of monophyletic Austrophilopterus toucan louse lineages are not necessarily restricted to monophyletic host lineages. Often, closely related lice are found on more distantly related, but sympatric, toucan hosts. (3) the geographic distribution of the hosts apparently plays a role in the speciation of these lice. These results suggest that for some louse lineages, biogeography may be more important than host associations in structuring louse populations and species. This is particularly true in cases where host life history (e.g. hole-nesting) or parasite life history (e.g. phoresis) might promote frequent host switching events between syntopic host species. These findings highlight the importance of integrating biogeographic information into cophylogenetic studies

Codistributed Lineages of Feather Lice Show Different Phylogenetic Patterns

Recent molecular phylogenies have suggested that hawks (Accipitridae) and falcons (Falconidae) form 2 distantly related groups within birds. Avian feather lice have often been used as a model for comparing host and parasite phylogenies, and in some cases there is significant congruence between them. Using 1 mitochondrial and 3 nuclear genes, I inferred a phylogeny for the feather louse genus Degeeriella (which are all obligate raptor ectoparasites) and related genera. This phylogeny indicated that Degeeriella is polyphyletic, with lice from falcons and hawks forming 2 distinct clades. Falcon lice were sister to lice from African woodpeckers, while Capraiella, a genus of lice from rollers lice, was embedded within Degeeriella from hawks. This phylogeny showed significant geographic structure, with host geography playing a larger role than host taxonomy in explaining louse phylogeny, particularly within clades of closely related lice. However, the louse phylogeny broadly reflects host phylogeny, for example Accipiter lice form a distinct clade. Unlike most bird species, individual kingfisher species (Aves: Alcidae) are typically parasitized by 1 of 3 genera of lice (Insecta: Phthiraptera). These lice partition hosts by subfamily: Alcedoecus and Emersoniella parasitize Daceloninae whereas Alcedoffula parasitizes both Alcedininae and Cerylinae. While Emersoniella is geographically restricted, Alcedoecus and Alcedoffula are widespread. I used 2 molecular markers, the nuclear gene EF-1α and mitochondrial gene COI to infer phylogenies for both widespread genera of kingfisher lice, Alcedoffula and Alcedoecus. Additinally, I combined published host records with new host records reported here and used ancestral state reconstruction to identify patterns of host parasitism. Lastly, I compared louse phylogenies to host phylogenies to reconstruct their cophylogenetic history. I determined there are 2 distinct clades within Alcedoffula, 1 infesting Alcedininae, and the other infesting Cerylinae. Ancestral state reconstruction of kingfisher lice across the kingfisher phylogeny showed Alcedoecus and Emersoniella parasitize distinct clades within the kingfisher subfamily Daceloninae, and a single host switch by Alcedoecus onto the portion of the Daceloninae clade, which typically hosts Emersoniella. Cophylogenetic analysis indicated that although Alcedoecus and the lineage of Alcedoffula occurring on Alcedininae did not show evidence of cospeciation, the lineage of Alcedoffula occurring on Cerylinae showed strong evidence of cospeciation. The chewing louse genus Colpocephalum parasitizes nearly a dozen distantly related orders of birds. Such a broad host range is uncommon among lice. However, the monophyly of the genus Colpocephalum with respect to a group of morphologically similar genera has never been tested. Using 1 nuclear and 1 mitochondrial gene, I inferred a phylogeny for 54 lice sampled from across the Colpocephalum-complex. The resulting phylogeny demonstrates several lineages were restricted to single host orders. These lineages corresponded to previously described genera. Maddison-Slatkin tests were performed on the resulting phylogeny and showed that host order, host family, and biogeographic region had significant phylogenetic signals when mapped onto the Colpocephalum-complex phylogeny. A PARAFIT analysis comparing the overall Colpocephalum-complex phylogeny to a host phylogeny revealed significant congruence between host and parasite trees. I also compared the cophylogenetic history of Colpocephalum and their hosts to that of a second distantly related feather louse genus, Degeeriella, which also infests diurnal birds of prey. Using PARAFIT to identify individual host-parasite links that contributed to overall congruence, I found no evidence of correlated cophylogenetic patterns between these 2 lice groups, which suggested that their distribution patterns were shaped by divergent evolutionary processes

Evaluation of Blood Gas Analytes and Ectoparasites from South Texas Birds

The handheld point of care analyzer is a quick and feasible option to obtain hematology data from individuals. The iSTAT-1 was used to evaluate select venous blood analytes obtained via jugular venipuncture from 238 passerine birds from South Texas. These data were used to assess the health of birds in the area while taking into consideration life history (migratory or sedentary), locale, seasonality, sex, and age. Migratory birds had increased concentrations of pO2, hematocrit, hemoglobin, and glucose as compared to sedentary birds. This can be attributed to the increased need of oxygen and carrying capacity involved with long duration flights. Increased glucose and lower ionized calcium concentrations were observed in migratory birds as a result of breakdown of fat deposits in the body to fuel the increased levels of muscular activity. During the hotter months of the year, birds’ response to handling environmental stress was exhibited with relative respiratory acidosis. When sedentary birds sampled from South Texas were compared to a previous study from Central Texas, venous blood analytes differed by locale but were within the ranges of healthy populations. This leads to the conclusion that sedentary avian communities can be used as bioindicators of a healthy ecosystem. Few assessments of louse-host associations in Texas involving multiple host families and genera have occurred. My assessment of 446 birds captured in South Texas revealed 64 host associations, of which 31 were previously unknown in the literature. In addition to these new host associations, I also was able to identify 25 unique genetic lineages. There are 17 unique genetic lineages that are associated with new host associations. This leads to the possibility of having at minimum 17 and as many as 25 potential new species from this study. Morphologically I was unable to identify any lice to species, but sequences from GenBank assisted with some specimen identification to species. Using louse-host associations and the unique genetic lineages found, I was able to identify specimens that could represent new sequences to GenBank or new species to science

Codistributed Lineages of Feather Lice Show Different Phylogenetic Patterns

Recent molecular phylogenies have suggested that hawks (Accipitridae) and falcons (Falconidae) form 2 distantly related groups within birds. Avian feather lice have often been used as a model for comparing host and parasite phylogenies, and in some cases there is significant congruence between them. Using 1 mitochondrial and 3 nuclear genes, I inferred a phylogeny for the feather louse genus Degeeriella (which are all obligate raptor ectoparasites) and related genera. This phylogeny indicated that Degeeriella is polyphyletic, with lice from falcons and hawks forming 2 distinct clades. Falcon lice were sister to lice from African woodpeckers, while Capraiella, a genus of lice from rollers lice, was embedded within Degeeriella from hawks. This phylogeny showed significant geographic structure, with host geography playing a larger role than host taxonomy in explaining louse phylogeny, particularly within clades of closely related lice. However, the louse phylogeny broadly reflects host phylogeny, for example Accipiter lice form a distinct clade. Unlike most bird species, individual kingfisher species (Aves: Alcidae) are typically parasitized by 1 of 3 genera of lice (Insecta: Phthiraptera). These lice partition hosts by subfamily: Alcedoecus and Emersoniella parasitize Daceloninae whereas Alcedoffula parasitizes both Alcedininae and Cerylinae. While Emersoniella is geographically restricted, Alcedoecus and Alcedoffula are widespread. I used 2 molecular markers, the nuclear gene EF-1α and mitochondrial gene COI to infer phylogenies for both widespread genera of kingfisher lice, Alcedoffula and Alcedoecus. Additinally, I combined published host records with new host records reported here and used ancestral state reconstruction to identify patterns of host parasitism. Lastly, I compared louse phylogenies to host phylogenies to reconstruct their cophylogenetic history. I determined there are 2 distinct clades within Alcedoffula, 1 infesting Alcedininae, and the other infesting Cerylinae. Ancestral state reconstruction of kingfisher lice across the kingfisher phylogeny showed Alcedoecus and Emersoniella parasitize distinct clades within the kingfisher subfamily Daceloninae, and a single host switch by Alcedoecus onto the portion of the Daceloninae clade, which typically hosts Emersoniella. Cophylogenetic analysis indicated that although Alcedoecus and the lineage of Alcedoffula occurring on Alcedininae did not show evidence of cospeciation, the lineage of Alcedoffula occurring on Cerylinae showed strong evidence of cospeciation. The chewing louse genus Colpocephalum parasitizes nearly a dozen distantly related orders of birds. Such a broad host range is uncommon among lice. However, the monophyly of the genus Colpocephalum with respect to a group of morphologically similar genera has never been tested. Using 1 nuclear and 1 mitochondrial gene, I inferred a phylogeny for 54 lice sampled from across the Colpocephalum-complex. The resulting phylogeny demonstrates several lineages were restricted to single host orders. These lineages corresponded to previously described genera. Maddison-Slatkin tests were performed on the resulting phylogeny and showed that host order, host family, and biogeographic region had significant phylogenetic signals when mapped onto the Colpocephalum-complex phylogeny. A PARAFIT analysis comparing the overall Colpocephalum-complex phylogeny to a host phylogeny revealed significant congruence between host and parasite trees. I also compared the cophylogenetic history of Colpocephalum and their hosts to that of a second distantly related feather louse genus, Degeeriella, which also infests diurnal birds of prey. Using PARAFIT to identify individual host-parasite links that contributed to overall congruence, I found no evidence of correlated cophylogenetic patterns between these 2 lice groups, which suggested that their distribution patterns were shaped by divergent evolutionary processes

Studies on the evolution and phylogeny of the Mallophaga (Insecta) with special reference to the relationships between the phylogeny of host and parasite

The Niallophaga, a suborder of the Pthiraptera, are a group of obligate ectoparasites living on birds and mammals which present interesting problems of evolution and phylogeny.+ The present distribution of the avian Niallophaga suggests that these insects became parasitic on the birds early in the evolution of the latter class and that they evolved with their hosts. In a group of related host species, each species may have allopatric species of a number of sympatric genera of Niallophaga common to the host group (VI: tables 1+, 5, 6), and in addition, sympatric species of one or more of these genera.In many cases, therefore, a single host species may have a considerable number of genera and species of Mallophaga (1 :279). The problem is to find an explanation of the presence of often closely related genera and species in what is the equivalent of a restricted and isolated geographical area. A study of the morphology of the Mallophaga and their present distribution both on a single host individual and throughout the class Aves makes it possible to deduce some of the factors which may have influenced speciation in this group of ectoparasites and to compare these factors with those influencing groups of free -living animals.Apart from the intrinsic interest of evolutionary problems in a group of ectoparasites, it is necessary when attempting to formulate a natural classification of the Mallophaga to have some understanding of the possible steps in the evolution of the group

Host Associations, Phylogenetics, and Biogeography of Parasitic Avian Chewing Lice (Insecta: Phthiraptera) from Sub-Saharan Africa

Parasitic chewing lice (Insecta: Phthiraptera) of birds are found everywhere their avian hosts are distributed, and their host relationships and taxonomy have been well studied in many regions. Lice have obligate parasitic relationships with their hosts (entire life cycle is carried out on the host body) and generally undergo vertical transmission across host generations. These biological traits of lice make them excellent model systems for exploring host-parasite co-evolution. Compared with Europe and the Americas, the ectoparasite fauna of Sub-Saharan African birds is poorly understood despite the avian fauna being relatively well-known. Recent field expeditions exploring the avian diversity in South Africa, Benin, and the Democratic Republic of the Congo allow an opportunity to obtain louse specimens from across Sub-Saharan Africa. The goal of this study was to investigate avian louse host associations and genetic diversity to increase our understanding of southern African parasite biodiversity, as well as to use molecular phylogenetic methods to examine potential broad biogeographic patterns in lice across Sub-Saharan Africa. From 1105 South African bird individuals and 170 species examined for lice, a total of 104 new louse-host associations were observed. Portions of the mitochondrial COI and nuclear EF-1α genes were amplified to observe phylogenetic relationships of southern African lice and investigate potential new species. The phylogenetic results gave strong support for multiple louse genera, and 26 genetically unique lineages were found, which may represent new louse species. Examining biogeographic patterns in parasitic lice across the entire region of Sub-Saharan Africa indicated that lice tend to follow host distributions rather than grouping by geographic region. Several promising louse taxa were identified as candidates for future phylogenetic and biogeographic studies investigating Sub-Saharan African chewing lice

Five New Species of Guimaraesiella (Phthiraptera: Ischnocera) from Broadbills (Aves: Passeriformes: Calyptomenidae: Eurylaimidae)

Under embargo until: 2020-11-15Five new species of Guimaraesiella Eichler, 1949 are described and illustrated from hosts in the Eurylaimidae and Calyptomenidae. They are Guimaraesiella corydoni n. sp. from Corydon sumatranus laoensisMeyer de Schauensee, 1929; Guimaraesiella latirostris n. sp. from Eurylaimus ochromalusRaffles, 1822; Guimaraesiella cyanophoba n. sp. from Cymbirhynchus macrorhynchus malaccensisSalvadori, 1874 and C. m. siamensisMeyer de Schauensee and Ripley, 1940; Guimaraesiella altunai n. sp. from Calyptomena viridis caudacutaSwainson, 1838; and Guimaraesiella forcipata n. sp. from Eurylaimus steerii steeriiSharpe, 1876. These represent the first species of Guimaraesiella described from the Calyptomenidae and Eurylaimidae, as well as the first species of this genus described from the Old World suboscines.acceptedVersio

Host Associations, Phylogenetics, and Biogeography of Parasitic Avian Chewing Lice (Insecta: Phthiraptera) from Sub-Saharan Africa

Parasitic chewing lice (Insecta: Phthiraptera) of birds are found everywhere their avian hosts are distributed, and their host relationships and taxonomy have been well studied in many regions. Lice have obligate parasitic relationships with their hosts (entire life cycle is carried out on the host body) and generally undergo vertical transmission across host generations. These biological traits of lice make them excellent model systems for exploring host-parasite co-evolution. Compared with Europe and the Americas, the ectoparasite fauna of Sub-Saharan African birds is poorly understood despite the avian fauna being relatively well-known. Recent field expeditions exploring the avian diversity in South Africa, Benin, and the Democratic Republic of the Congo allow an opportunity to obtain louse specimens from across Sub-Saharan Africa. The goal of this study was to investigate avian louse host associations and genetic diversity to increase our understanding of southern African parasite biodiversity, as well as to use molecular phylogenetic methods to examine potential broad biogeographic patterns in lice across Sub-Saharan Africa. From 1105 South African bird individuals and 170 species examined for lice, a total of 104 new louse-host associations were observed. Portions of the mitochondrial COI and nuclear EF-1α genes were amplified to observe phylogenetic relationships of southern African lice and investigate potential new species. The phylogenetic results gave strong support for multiple louse genera, and 26 genetically unique lineages were found, which may represent new louse species. Examining biogeographic patterns in parasitic lice across the entire region of Sub-Saharan Africa indicated that lice tend to follow host distributions rather than grouping by geographic region. Several promising louse taxa were identified as candidates for future phylogenetic and biogeographic studies investigating Sub-Saharan African chewing lice