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Projeto de investigação
Ectoparasitas de aves recém-colonizadoras: dinâmica parasitária de populações continentais e insulares de Passeriformes - Parasites of wild birds and environmental changes: impacts and ecological implications
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Publicações
Louse flies in Azorean and mainland populations of four Passeriformes species_a new perspective to parasite Island syndromes
Publication . Tomás, André; Pereira da Fonseca, Isabel; Valkenburg, Thijs; Rebelo, Maria Teresa
Hippoboscid flies, also known as louse flies, are obligate blood-feeders ectoparasites of birds and mammals. By studying louse fly parasites of four Passeriformes species, Eurasian blackbird (Turdus merula), Eurasian blackcap (Sylvia atricapilla), common chaffinch (Fringilla coelebs) and European robin (Erithacus rubecula), with dissimilar time of colonization of Azores islands, we tested whether: (i) island host populations have lower parasite richness than the mainland one; (ii) island host populations undergo higher parasite prevalence, mean intensities and mean abundance than the mainland one; (iii) island parasite diversity are composed exclusively by specific parasites and (iv) parasite richness is positively correlated with the island area and proximity to the continent.
For these purposes, 775 birds were sampled for presence of louse flies, by modified fumigation chamber method, from Azores Islands (S˜ao Miguel, Terceira and Flores) and Portugal mainland. Insular and mainland parasite assemblages were statistically compared. We record for the first time to Azores, Ornithomya fringillina and Icosta minor from Portugal mainland. Louse flies had highest prevalence and abundance from Azores Islands compared to those observed in mainland birds, especially blackbirds. The insular parasite diversity of Azores blackbirds, blackcaps and chaffinches was richer than the one observed in mainland population. None of the hippoboscid flies observed on the islands and mainland were host-specific. Thus, our findings provide an upgrade of parasite island syndromes knowledge, in the context of the ectoparasites, namely to the ippoboscid flies case.
Passeriformes colonization and related ectoparasites in insular and mainland populations
Publication . Tomás, André Filipe Ventura; Rebelo, Maria Teresa Ferreira Ramos Nabais de Oliveira; Sampaio, Isabel Maria Soares Pereira da Fonseca de
The isolation process of Island parasite populations has revealed a remarkable set of changes in their characteristics, termed parasite island syndromes. Improving knowledge of the effect of insularity on parasite communities from hosts with different time scales of isolation, is essential for understanding the processes involved in the evolution of parasitism and how the period of host isolation, manifests itself on parasite island syndromes.
This thesis addresses the ectoparasite communities of Turdus merula, Sylvia atricapilla, Fringilla coelebs and Erithacus rubecula, from mainland Portugal and three Islands of the Azores Archipelago, specifically São Miguel, Terceira and Flores. The Azores Archipelago, geographically positioned as the Northernmost Archipelago of Macaronesia and composed of nine Oceanic Islands recognized as biodiversity hotspots, make it an important area to study the patterns of insular evolution. Live birds were captured with mist nets and sampled for presence of ectoparasites using the modified fumigation chamber method. Traditional methods were used for microscopic identification of hippoboscid flies, fleas and chewing lice. Insular ectoparasite communities of host species were compared with continental communities based on parasite island syndromes (species richness, prevalence and host specificity). Additionally, insular species richness was compared between the area of the Islands and their distance from the mainland.
The present study showed that ectoparasites do not failed to establish to the Azores Islands, and furthermore, the diversity of the ectoparasites communities, especially to chewing lice, was clearly enriched on the Azores Islands, with more 3 species than mainland birds. The results also revealed a high insular prevalence of ectoparasites. In regards to host specificity, insular ectoparasites have retained the characteristic specificity of the mainland. Even though island syndromes were not correlated with Island area and distance from the mainland, the overall findings indicate that characteristics associated with the Islands, specifically ambient humidity, the parasites, mainly ability to tolerate ambient humidity, and the hosts, particularly population densities, body size, and nest sanitation, influence the structuring of insular ectoparasite assemblages. Parasite island syndromes were especially notable in T. merula, a bird with two colonization events on the Azores Islands, which suggest that the host isolation on Islands may influence the evolution of insular parasite communities.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
FARH
Número da atribuição
PD/BD/127919/2016