Insect ectoparasites from wild passerine birds in the Azores Islands

Multivariate study of lice (Insecta: Psocodea: Phthiraptera) assemblages hosted by hummingbirds (Aves: Trochilidae)

Lice were collected from 579 hummingbirds, representing 49 species, in 19 locations in Brazil, Costa Rica, Honduras, Paraguay and Peru, at elevations 0–3000 m above sea level. The following variables were included in an ecological analysis (1) host species' mean body mass, sexual size dimorphism, sexual dichromatism, migratory behaviour and dominance behaviour; (2) mean elevation, mean and predictability of temperature, mean and predictability of precipitation of the host species' geographic area; (3) prevalence and mean abundance of species of lice as measures of infestation. Ordination methods were applied to evaluate data structure. Since the traits are expressed at different scales (nominal, interval and ratio), a principal component analysis based on d-correlations for the traits and a principal coordinates analysis based on the Gower index for species were applied. Lice or louse eggs were found on 80 (13.8%) birds of 22 species. A total of 267 lice of 4 genera, Trochiloecetes, Trochiliphagus, Myrsidea and Leremenopon, were collected, with a total mean intensity of 4.6. There were positive interactions between migration behaviour and infestation indices, with elevational migrants having a higher prevalence and abundance of lice than resident birds. Further, we found weak negative correlations between host body mass and infestation indices and positive correlations between mean elevation and prevalence and abundance of Trochiliphagus. Thus, formerly unknown differences in the ecological characteristics and infestation measures of Trochiliphagus and Trochiloecetes lice were revealed, which allows a better understanding of these associations and their potential impacts on hummingbirds.

Chewing lice of passerine birds in reed beds in Slovakia, with a special focus on Panurus biarmicus

A total of 1185 passerine birds representing five species were examined for chewing lice in reed beds in southwestern Slovakia in spring (April) 2008, 2009 and 2016. Additional collecting focused only on chewing lice from Panurus biarmicus (Linnaeus, 1758) (Passeriformes: Panuridae) was carried out in spring (April), summer (July) and autumn (October) 2019. A total of 283 (24%) birds were parasitized by 10 species of chewing lice of four genera: Penenirmus, Menacanthus, Philopterus, and Brueelia. Most birds showed only very light (1-10 lice/host; 74%) to light infestations (11-20 lice/host; 16%). The authors found significantly higher prevalences and mean abundances of chewing lice on residents/short-distance migrants, that is, P. biarmicus, Acrocephalus melanopogon (Temminck, 1823) (Passeriformes: Acrocephalidae), than on long-distance migratory birds, that is, Acrocephalus scirpaceus (Hermann, 1804), Acrocephalus schoenobaenus (Linnaeus, 1758) (Passeriformes: Acrocephalidae), Locustella luscinioides (Savi, 1824) (Passeriformes: Locustellidae). No significant difference was found in the total mean intensity of chewing lice between these two groups of birds. Ischnoceran lice were more prevalent and abundant than amblyceran lice on residents and short-distance migrants, whereas the opposite was found on bird species that migrate long distances. A total of 146 (58%, n = 251) P. biarmicus were parasitized by 1490 chewing lice. Males of P. biarmicus showed higher prevalence and mean abundance than females with gradually descending values of prevalence, mean abundance and mean intensity from spring to autumn. The knowledge of the occurrence and population dynamics of lice on wild passerine birds can be useful in endangered species conservation programs and can also be applied to captive passerine birds, which may be analogous to resident birds in this sense.

Louse flies in Azorean and mainland populations of four Passeriformes species: A new perspective to parasite Island syndromes

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 (São 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 hippoboscid flies case.

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We investigate the louse flies of four Passeriformes species from Macaronesia.

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Louse flies of Azores blackbirds had highest prevalence than in mainland birds.

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Insular parasite diversity was richer than the one observed in mainland population.

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Hippoboscid flies observed on the islands and mainland were not host-specific.

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Ornithomya fringillina recorded for the first time to Azores.