RESUMO

Members of the genus Lueheia Travassos, 1919, are endoparasites of birds, particularly passerines, throughout the Americas. Adults of Lueheia sp., (Plagiorhynchidae Golvan, 1960; Porrorchinae Golvan, 1956) were recovered from the intestine of the American robin (Turdus migratorius phillipsi Bangs) in Mexico City, and two other species of acanthocephalans identified as Porrorchis nickoli, (Plagiorhynchidae: Porrorchinae) Salgado-Maldonado and Cruz-Reyes, 2002 and Centrorhynchus microcephalus (Bravo-Hollis, 1947) Golvan, 1956 (Centrorhynchidae Van Cleave, 1916), were recovered from the Virginia opossum (Didelphis virginiana Allen) and groove-billed ani (Crotophaga sulcirostris Swainson), respectively in southeastern Mexico. Specimens of three species were sequenced at two molecular markers, the small subunit (SSU) and large subunit (LSU) of the nuclear rDNA and compared with other sequences available in GenBank. Maximum likelihood and Bayesian inference analyses of the combined (LSU + SSU) dataset and each individual dataset revealed that the specimens of Lueheia sp. formed an independent lineage, which is recognized herein as a new species, Lueheia aztecae n. sp., representing the fifth species of the genus in the Americas, and the second in the Nearctic region. The new species can be morphologically distinguished from the other five species in the genus by having a cylindrical proboscis, armed with 24-26 longitudinal rows with 9-10 hooks each. Phylogenetic inference performed with the combined dataset consisting of two genes (LSU + SSU) revealed that Lueheia aztecae n. sp. and P. nickoli belonging to subfamily Porrorchinae, formed two independent lineages, indicating that the subfamily is paraphyletic. Porrorchis nickoli and C. microcephalus formed a clade with other species of the genus Centrorhynchus, suggesting that P. nickoli should be transferred to genus Centrorhynchus, to form C. nickoli n. comb. In addition, we briefly discuss the ecological associations between the members of the families Plagiorhynchidae and Centrorhynchidae.

Assuntos

RESUMO

A total of thirty Austral thrushes Turdus falcklandii Quoy & Gaimard, 1824 (Turdidae) carcasses were brought to the Departamento de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad de Concepción, to be examined for ecto- and endoparasites. Ectoparasites were found on 20% (6/30) of the thrushes and belonged to species Brueelia magellanica Cichino, 1986 (Phthiraptera), Menacanthus eurysternus Burmeister, 1838 (Phthiraptera) and Tyrannidectes falcklandicus Mironov & González-Acuña, 2011 (Acari). Endoparasites were isolated from 26.6% (8/30) of the birds and identified as Lueheia inscripta Westrumb, 1821 (Acanthocephala), Plagiorhynchus cylindraceus Goeze, 1782 (Acanthocephala), Wardium sp. sensu Mayhew, 1925 (Cestoda), Dilepis undula (Cestoda) Schrank, 1788, and Zonorchis sp. (sensu Travassos, 1944) (Trematoda). To our knowledge, all endoparasites collected in this study are new records in T. falcklandii and expand their distributional range to Chile.

Assuntos

RESUMO

Abstract A total of thirty Austral thrushes Turdus falcklandii Quoy & Gaimard, 1824 (Turdidae) carcasses were brought to the Departamento de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad de Concepción, to be examined for ecto- and endoparasites. Ectoparasites were found on 20% (6/30) of the thrushes and belonged to species Brueelia magellanica Cichino, 1986 (Phthiraptera), Menacanthus eurysternus Burmeister, 1838 (Phthiraptera) and Tyrannidectes falcklandicus Mironov & González-Acuña, 2011 (Acari). Endoparasites were isolated from 26.6% (8/30) of the birds and identified as Lueheia inscripta Westrumb, 1821 (Acanthocephala), Plagiorhynchus cylindraceus Goeze, 1782 (Acanthocephala), Wardium sp. sensu Mayhew, 1925 (Cestoda), Dilepis undula (Cestoda) Schrank, 1788, and Zonorchis sp. (sensu Travassos, 1944) (Trematoda). To our knowledge, all endoparasites collected in this study are new records in T. falcklandii and expand their distributional range to Chile.

Resumo Um total de trinta carcaças do tordo-austral Turdus falcklandii Quoy & Gaimard, 1824 (Turdidae) foi encaminhado ao Departamento de Ciência Animal, Facultad de Ciencias Veterinarias, Universidad de Concepción, para ser examinado quanto a presença de parasitas externos e internos. Parasitas externos foram encontrados em 20% (6/30) dos tordos inspecionados e identificados como Brueelia magellanica Cichino, 1986 (Phthiraptera), Menacanthus eurysternus Burmeister, 1838 (Phthiraptera), e Tyrannidectes falcklandicus Mironov & González-Acuña, 2011 (Acari). Parasitas internos foram identificados em 26,6% (8/30) dos espécimes examinados como Lueheia inscripta Westrumb, 1821 (Acanthocephala), Plagiorhynchus cylindraceus Goeze, 1782 (Acanthocephala), Wardium sp. sensu Mayhew, 1925 (Cestoda), Dilepis undula sensu Schrank, 1788 (Cestoda) e Zonorchis sp. (sensu Travassos, 1944) (Trematoda). Tanto quanto é do nosso conhecimento, todos os parasitas internos coletados neste estudo pertencem a novos registros em T. falcklandii e com expansão de sua distribuição para o Chile.

Assuntos

RESUMO

BACKGROUND: Haemoproteus and Plasmodium species are widespread avian blood parasites. Several Plasmodium species are known for their high virulence and have caused significant declines in naïve bird populations. The impact of closely related Haemoproteus parasites is largely unknown. Recently we reported a lethal disease in two parrot aviaries caused by Haemoproteus parasites. RESULTS: Here we show that the causative pathogen Haemoproteus minutus is responsible for further 17 lethal outbreaks in parrot aviaries in Denmark, Germany and Great Britain. All affected parrots are endemic to Australasia and South America. We sequenced the cytochrome b gene from megalomeront-infected muscle tissue of 21 parrots and identified the two lineages TUPHI01 and TURDUS2 as causative agents, commonly naturally infecting the common blackbird (Turdus merula) and the song thrush (Turdus philomelos), respectively, in the Palaearctic. No intraerythrocytic parasite stages were found in any of the parrots. We failed to detect H. minutus in invasive Indian ring-necked parakeets (Psittacula krameri) in Germany. Together this suggests that abortive infections with two virulent lineages of H. minutus are lethal for naïve parrot species from Australasia and South America. We asked whether we could detect H. minutus in New Zealand, where its Turdus hosts were introduced in the 1800s. We therefore tested invasive blackbirds and song thrushes, and the co-existing endemic red-fronted parakeet (Cyanoramphus novaezelandiae) population on three New Zealand islands. No Haemoproteus spp. DNA was detected in all blood samples, indicating absence of transmission. CONCLUSIONS: The results of this study show that captive parrots in Europe are threatened by two lineages of an otherwise benign parasite of Turdus spp. Aviary collections of parrots should be protected from Culicoides spp. vectors in Europe. Animal trade and climate changes extending the current vector and parasite distribution have to be considered as potential risk factors for the introduction of the disease in naïve parrot populations.

Assuntos

RESUMO

We document chigger mite (Acari: Trombiculidae) ectoparasitic infestation (prevalence and intensity) on a population of Catharus ustulatus (Turdidae) wintering at a site (PAD A) in southeastern Peru undergoing development for natural gas exploration. We compare prevalence (i.e., the proportion of individuals infested by chigger mites) and intensity (i.e., the average number of larvae and larvae clusters in infested individuals) at forest edge (<100 m) and interior (>100 m) from PAD A because variations in biotic (e.g., vegetation cover) and abiotic (e.g., relative humidity and temperature) factors are expected to influence chigger mite abundance. Chigger mite prevalence was 100%; all C. ustulatus captured were infested regardless of distance. The range of variation in larvae (2-72 larvae/individual) and cluster intensity (1-4 clusters/individual) did not differ between edge and interior ( P > 0.05), despite differences in herbaceous vegetation cover (UM-W = 180, n = 30, 31; P < 0.01). Ectoparasitic prevalence and intensity in long-distance migratory birds might add risks to an already hazardous journey; because ectoparasitic variation and other selective pressures experienced by individuals at each locality not only may be a cause of within-site mortality, but, by affecting the physical condition of birds, may be carried over to subsequent sites and affect reproductive success and survival. Documenting ectoparasitism at any phase of the life cycle of migrants could improve understanding of population declines of migratory birds.

Assuntos

RESUMO

Plasmodium spp. are haemosporidian protozoans that alternate their live cycles between bloodsucking Culicidae dipterans and vertebrate hosts (mammals, reptiles, and birds). In birds, these parasites are the causative agents of the so-called avian malaria, a disease associated with considerable declines and extinctions in the avifauna in different geographical regions. In this work, we applied a multidisciplinary approach, light microscopy and cytochrome oxidase b (cyt b) gene sequence analysis, for characterization of Plasmodium spp. found in association with wild birds of the genus Turdus, collected in Atlantic forest fragments of southeastern Brazil. From the total 90 analyzed birds, 58 (47 Turdus rufiventris, 9 Turdus leucomelas, 1 Turdus albicollis, and 1 Turdus flavipes) were positively infected with Plasmodium unalis, a haemosporidian that was previously detected in Turdus fuscater in Colombia and in penguins in Brazil, but has never been found in association with these Turdus species of this present work. Moreover, all 7 new sequences of P. unalis cyt b gene clustered into a monophyletic clade with previously characterized P. unalis sequences with a mean genetic divergence of 1.6% and with a maximum divergence of 3.1%, indicating for a high degree of intraspecific polymorphism within this parasitic species. Together, our data highlight the existence a high degree of intraspecific variation within P. unalis and highlight the importance of integrative taxonomy to an accurate identification and characterization of avian haemosporidian parasites.

Assuntos

RESUMO

Populations of green-winged saltators, Saltator similis, are decreasing especially because of illegal trade and infectious diseases. We describe natural cases of an extraintestinal isosporoid coccidian in caged S. similis, and suggest the need of preventive measures in handling these birds. Nonspecific clinical signs were seen in all of them, however, intracytoplasmic Atoxoplasma sp. was found in peripheral blood, reinforcing the idea of systemic isosporosis. Leukocytosis with high number of heterophils and monocytes suggested that atoxoplasmosis in green-winged saltators can progress as an acute disease. The birds showed clinical improvement after treatment. Handling recommendations were proposed to upgrade hygienic conditions of the facilities. We concluded that nonspecific symptoms and an acute inflammatory process can be associated with atoxoplasmosis in young S. similis. We emphasize the importance of blood smear to detect merozoites.(AU)

As populações de trinca-ferro, Saltator similis, estão declinando especialmente em função do comércio illegal e das doenças infecciosas. Descrevem-se casos naturais de coccidiose extraintestinal em S. similis de cativeiro, sugerindo a necessidade de medidas preventivas no manejo desses animais. Sinais clínicos inespecíficos foram observados em todos os animais, contudo, formas intracitoplasmáticas de Atoxoplasma sp. foram vistas no sangue periférico, reforçando a ideia de isosporose sistêmica. Leucocitose com aumento de heterófilos e monócitos sugeriram que a atoxoplasmose em trinca-ferro pode progredir como uma doença aguda. As aves apresentaram melhora clínica após tratamento. Recomendações de manejo foram propostas a fim de melhorar as condições higiênicas das instalações das aves. Concluiu-se que sinais inespecíficos e processo inflamatório agudo podem ser associados com a atoxoplasmose em S. similis jovens. Enfatizamos a importância da avaliação do esfregaço sanguíneo para detector os merozoítos.(AU)

Assuntos

RESUMO

Populations of green-winged saltators, Saltator similis, are decreasing especially because of illegal trade and infectious diseases. We describe natural cases of an extraintestinal isosporoid coccidian in caged S. similis, and suggest the need of preventive measures in handling these birds. Nonspecific clinical signs were seen in all of them, however, intracytoplasmic Atoxoplasma sp. was found in peripheral blood, reinforcing the idea of systemic isosporosis. Leukocytosis with high number of heterophils and monocytes suggested that atoxoplasmosis in green-winged saltators can progress as an acute disease. The birds showed clinical improvement after treatment. Handling recommendations were proposed to upgrade hygienic conditions of the facilities. We concluded that nonspecific symptoms and an acute inflammatory process can be associated with atoxoplasmosis in young S. similis. We emphasize the importance of blood smear to detect merozoites.(AU)

As populações de trinca-ferro, Saltator similis, estão declinando especialmente em função do comércio illegal e das doenças infecciosas. Descrevem-se casos naturais de coccidiose extraintestinal em S. similis de cativeiro, sugerindo a necessidade de medidas preventivas no manejo desses animais. Sinais clínicos inespecíficos foram observados em todos os animais, contudo, formas intracitoplasmáticas de Atoxoplasma sp. foram vistas no sangue periférico, reforçando a ideia de isosporose sistêmica. Leucocitose com aumento de heterófilos e monócitos sugeriram que a atoxoplasmose em trinca-ferro pode progredir como uma doença aguda. As aves apresentaram melhora clínica após tratamento. Recomendações de manejo foram propostas a fim de melhorar as condições higiênicas das instalações das aves. Concluiu-se que sinais inespecíficos e processo inflamatório agudo podem ser associados com a atoxoplasmose em S. similis jovens. Enfatizamos a importância da avaliação do esfregaço sanguíneo para detector os merozoítos.(AU)

Assuntos

RESUMO

Abstract The aim of the present study was to report and describe Isospora albicollis Lainson and Shaw, 1989 parasitizing a white-necked thrush Turdus albicollis Vieillot, 1818 and a pale-breasted thrush Turdus leucomelas Vieillot, 1818 in two different localities: the Itatiaia National Park and Cacaria, in southeastern Brazil. The oocysts identified were ovoidal, 24.4 × 19.7 μm, with a smooth, bilayered wall, around 1.4 μm thick. Oocyst residuum was absent, but a micropyle and a polar granule were present. The sporocysts were ellipsoidal, 15.4 × 10.1 μm. The Stieda body was knob-like to rounded and the sub-Stieda body was prominent and wide. Sporocyst residuum was present, usually as a cluster of granules that appear to be membrane-bounded. The sporozoites were vermiform with one posterior refractile body and a centrally located nucleus. Besides recording the new host T. leucomelas, the identification of I. albicollis in the Itatiaia National Park and Cacaria, in southeastern Brazil, provide records of new localities for its parasitism, and reveals the wide distribution and dispersion of this coccidium in Brazil.

Resumo O objetivo do presente estudo foi relatar e descrever Isospora albicollis Lainson e Shaw, 1989, parasitando um sabiá-coleira Turdus albicollis Vieillot, 1818 e um sabiá-barranco Turdus leucomelas Vieillot 1818, em duas localidades diferentes: Parque Nacional do Itatiaia e Cacaria, no Sudeste do Brasil. Os oocistos identificados foram ovóides, 24,4 × 19,7 μm, com uma parede lisa e dupla, com cerca de 1,4 μm de espessura. Resíduo do oocisto foi ausente, mas uma micrópila e um grânulo polar foram presentes. Esporocistos elipsoidais, 15,4 × 10,1 μm, corpo de Stieda em forma de botão a arredondado e corpo de sub-Stieda proeminente e largo. Resíduo do esporocisto presente, usualmente como um aglomerado de grânulos que parecem estar envolvidos por uma membrana. Esporozoítos vermiformes com um corpo refráctil posterior e um núcleo centralizado. Além de registrar o novo hospedeiro T. leucomelas, a identificação de I. albicollis no Parque Nacional de Itatiaia e Cacaria, no Sudeste do Brasil, fornece registros de novas localidades para seu parasitismo e revela a ampla distribuição e dispersão desse coccídio no Brasil.

Assuntos

RESUMO

The aim of the present study was to report and describe Isospora albicollis Lainson and Shaw, 1989 parasitizing a white-necked thrush Turdus albicollis Vieillot, 1818 and a pale-breasted thrush Turdus leucomelas Vieillot, 1818 in two different localities: the Itatiaia National Park and Cacaria, in southeastern Brazil. The oocysts identified were ovoidal, 24.4 × 19.7 µm, with a smooth, bilayered wall, around 1.4 µm thick. Oocyst residuum was absent, but a micropyle and a polar granule were present. The sporocysts were ellipsoidal, 15.4 × 10.1 µm. The Stieda body was knob-like to rounded and the sub-Stieda body was prominent and wide. Sporocyst residuum was present, usually as a cluster of granules that appear to be membrane-bounded. The sporozoites were vermiform with one posterior refractile body and a centrally located nucleus. Besides recording the new host T. leucomelas, the identification of I. albicollis in the Itatiaia National Park and Cacaria, in southeastern Brazil, provide records of new localities for its parasitism, and reveals the wide distribution and dispersion of this coccidium in Brazil.

Assuntos

RESUMO

A new coccidian species (Protozoa: Apicomplexa: Isospora) is described parasitizing white-necked thrushes Turdus albicollis Vieillot, 1818; rufous-bellied thrushes Turdus rufiventris Vieillot, 1818; pale-breasted thrushes Turdus leucomelas Vieillot, 1818; and yellow-legged thrushes Turdus flavipes Vieillot, 1818 from 3 different localities in Brazil. Isospora sabiai n. sp. has oocysts that are subspherical to ellipsoidal, 20.9 × 18.6 µm, with smooth, delicate, bilayered wall, ∼1.1 µm thick. Micropyle inconspicuous or imperceptible. Oocyst residuum absent, but small polar granules rounded or comma-shaped are present. Sporocysts are elongate ellipsoidal to reniform, 16.5 × 9.2 µm. The Stieda body is knob-like. Sub-Stieda body rounded to conical, sometimes homogeneous with the Stieda body. Sporocyst residuum is present, usually as a cluster of numerous granules. Sporozoites are vermiform with 2 refractile bodies. The oocysts and sporocysts of I. sabiai n. sp. are uniform in the proportionality of width on length, but exhibited different patterns of size associated with each host species; therefore, an ecological discussion is introduced aimed at associating these morphometrical patterns of the oocysts with the habits of the different species of thrushes. This is the seventh isosporoid coccidian reported from New World turdids.

Assuntos

RESUMO

A new coccidian species (Protozoa: Apicomplexa: Eimeriidae) collected from the red warbler Cardellina rubra (Swainson) is reported from the Nevado de Toluca National Park, Mexico. Isospora cardellinae n. sp. has subspherical oöcysts, measuring on average 26.6 × 25.4 µm, with smooth, bi-layered wall, c.1.3 µm thick. Micropyle, oöcyst residuum, and polar granule are absent. Sporocysts are ovoidal, measuring on average 19.0 × 12.0 µm, with a knob-like Stieda body, a trapezoidal sub-Stieda body and sporocyst residuum composed of scattered spherules of different sizes. Sporozoites are vermiform with one refractile body and a nucleus. This is the fourth description of an isosporoid coccidian infecting a New World warbler.

Assuntos

RESUMO

A new isosporoid coccidian species (Protozoa: Apicomplexa: Eimeriidae) is reported from the southern house wren Troglodytes musculus, a very well distributed species in South and Central America. Isospora corruirae sp. nov. oocysts are subspherical to ovoidal, 24.1 × 21.4 µm, with smooth, bilayered wall. Micropyle and oocyst residuum are absent, but small spherules and splinter-like granules are frequently present. Sporocysts are ovoidal to piriform, 14.0 × 9.5 µm. Stieda body is prominent knob-like and substieda body is delicate. Sporocyst residuum is composed of scattered fragments of different sizes. Sporozoites are vermiform with posterior refractile bodies, anterior striations and a nucleus. This is the second description of an isosporoid coccidium infecting a New World wren.

Assuntos

RESUMO

A new feather mite species, Pteronyssoides turdinus n. sp. (Acariformes: Pteronyssidae), is described from two species of thrushes, Turdus amaurochalinus Cabanis (type-host) and T. leucomelas Vieillot (Passeriformes: Turdidae) in Minas Gerais, Brazil. The new species belongs to the parinus species group and most clearly differs from previously known species of this group by the following features: in both sexes of P. turdinus, setae c2 are anterior to the level of the sejugal furrow; in males, the anterior margin of the hysteronotal shield has a deep trapezoidal concavity, setae d1 are situated on the striated tegument, the adanal shield is represented by a narrow longitudinal sclerite, and tarsus and tibia of legs IV are subequal in length; in females, the opisthosomal sclerites are split into proper opisthosomal sclerites and pygidial fragments encompassing the bases of setae h2 and h3. This is the first description of a feather mite of the genus Pteronyssoides Hull, 1931 from birds of the family Turdidae.

Assuntos

RESUMO

A new coccidian species (Protozoa: Apicomplexa: Eimeriidae) is described from a specimen of the Eurasian blackbird Turdus merula Linnaeus held for rehabilitation and reintroduction into the wild in a centre for research and recovery of wild animals in Quinta de Marim, Olhão, Portugal. Isospora lusitanensis n. sp. has subspherical to ovoidal oöcysts, measuring on average 26.4 × 23.4 µm, with smooth, bi-layered wall c.1.1 µm thick. Micropyle and oöcyst residuum are absent, but a polar granule is present. Sporocysts are ellipsoidal, measuring on average 16.0 × 10.9 µm. Stieda body is knob-like and sub-Stieda body is prominent and rounded. Sporocyst residuum is composed of scattered spherules. Sporozoites are vermiform, with one refractile body and a nucleus. The morphological and morphometric data for the new species were compared with those for species parasitising birds of the Muscicapidae, Turdidae, Timaliidae, Troglodytidae and Cinclidae, which are considered phylogenetically close. The original histograms of Isospora turdi Schwalbach, 1959 were redrawn for comparison with I. lusitanensis n. sp. and a linear regression of width against length of the oöcysts is presented for characterisation. This is the first isosporoid coccidian described from T. merula in mainland Portugal.

Assuntos

RESUMO

We examined Swainson's warblers (Limnothlypis swainsonii (Audubon, 1834), Aves: Parulidae) for lice fauna during 2 yr at three study sites in Arkansas, USA. A total of 66 individuals were examined; eight birds (10.6%) were parasitized with 16 lice of two new species belonging to two genera Myrsidea Waterson, 1915 (Amblycera: Menoponidae) and Brueelia Kéler, 1936 (Ischnocera: Philopteridae). Parasitological parameter data are given on the prevalence of lice on Swainson's warblers. Species descriptions and illustrations are provided for Myrsidea bensoni sp. nov. and Brueelia limnothlypiae sp. nov.; including a key for females of the genus Myrsidea that parasitize Parulidae (Passeriformes).

Assuntos

RESUMO

A new coccidian species (Protista: Apicomplexa: Eimeriidae) is described from the orange-crowned warbler Oreothlypis celata (Say) collected in the Nevado de Toluca National Park, Mexico at 3,000 metres above sea level. Isospora celata n. sp. has subspheroidal oöcysts, measuring 28.4 × 26.4 µm, with smooth, bi-layered wall c.1.2 µm thick. Micropyle and polar granule are absent, but oöcyst residuum is present as a compact mass. Sporocysts are ovoidal, 18.2 × 12.8 µm. Stieda body knob-like and sub-Stieda body irregular and barely discernible. Sporocyst residuum is composed of granules of different sizes. Sporozoites are vermiform with one refractile body and a nucleus. This is the third description of an isosporoid coccidian infecting a New World warbler.

Assuntos

RESUMO

Urbanization drastically alters natural ecosystems and the structure of their plant and animal communities. Whereas some species cope successfully with these environmental changes, others may go extinct. In the case of parasite communities, the expansion of urban areas has a critical effect by changing the availability of suitable substrates for the eggs or free-larval stages of those species with direct life cycles or for the range of hosts of those species with complex cycles. In this study we investigated the influence of the degree of urbanization and environmental heterogeneity on helminth richness, abundance and community structure of rufous-bellied thrushes (Turdus rufiventris) along a rural-urban gradient in the metropolitan region of Porto Alegre, State of Rio Grande do Sul, Brazil. This common native bird species of southern Brazil hosts 15 endoparasite species at the study region. A total of 144 thrushes were collected with mist nets at 11 sites. The degree of urbanization and environmental heterogeneity were estimated by quantifying five landscape elements: buildings, woodlands, fields, bare lands, and water. Landscape analyses were performed at two spatial scales (10 and 100 ha) taking into account home range size and the potential dispersal distance of thrushes and their prey (intermediate hosts). Mean parasite richness showed an inverse relationship with the degree of urbanization, but a positive relationship with environmental heterogeneity. Changes in the structure of component communities along the rural-urban gradient resulted from responses to the availability of particular landscape elements that are compatible with the parasites' life cycles. We found that the replacement of natural environments with buildings breaks up host-parasite interactions, whereas a higher environmental (substrate) diversity allows the survival of a wider range of intermediate hosts and vectors and their associated parasites.

Assuntos

RESUMO

A new coccidian species (Protozoa: Apicomplexa: Eimeriidae) are reported from the white-necked thrush Turdus albicollis Vieillot, 1818, a very common species in South America. Isospora massardi sp. nov. oocysts are subspherical, 18.6 × 17.7 µm, with smooth, bilayered wall, ~0.9 µm. Micropyle, oocyst residuum are absent, but two polar granules are frequently present. Sporocysts are ovoidal, 14.8 × 9.3 µm. Stieda body is knob-like to rounded and substieda body is rounded. Sporocyst residuum is composed of scattered spherules of different sizes. Sporozoites are vermiform with posterior and anterior refractile bodies and a nucleus. This is the sixth description of an isosporoid coccidium infecting a New World turdid bird.

Assuntos

RESUMO

BACKGROUND: Urbanization can strongly impact the physiology, behavior, and fitness of animals. Conditions in cities may also promote the transmission and success of animal parasites and pathogens. However, to date, no studies have examined variation in the prevalence or severity of several distinct pathogens/parasites along a gradient of urbanization in animals or if these infections increase physiological stress in urban populations. METHODOLOGY/PRINCIPAL FINDINGS: Here, we measured the prevalence and severity of infection with intestinal coccidians (Isospora sp.) and the canarypox virus (Avipoxvirus) along an urban-to-rural gradient in wild male house finches (Haemorhous mexicanus). In addition, we quantified an important stress indicator in animals (oxidative stress) and several axes of urbanization, including human population density and land-use patterns within a 1 km radius of each trapping site. Prevalence of poxvirus infection and severity of coccidial infection were significantly associated with the degree of urbanization, with an increase of infection in more urban areas. The degrees of infection by the two parasites were not correlated along the urban-rural gradient. Finally, levels of oxidative damage in plasma were not associated with infection or with urbanization metrics. CONCLUSION/SIGNIFICANCE: These results indicate that the physical presence of humans in cities and the associated altered urban landscape characteristics are associated with increased infections with both a virus and a gastrointestinal parasite in this common songbird resident of North American cities. Though we failed to find elevations in urban- or parasite/pathogen-mediated oxidative stress, humans may facilitate infections in these birds via bird feeders (i.e. horizontal disease transmission due to unsanitary surfaces and/or elevations in host population densities) and/or via elevations in other forms of physiological stress (e.g. corticosterone, nutritional).

Assuntos