Shifting microbiomes complement life stage transitions and diet of the bird parasite Philornis downsi from the Galapagos Islands

AbstractThe Avian Vampire Fly, Philornis downsi, has invaded the Galapagos Islands, where it causes high mortality of endemic and native landbird species, including most species of Darwin’s finches. Control methods are under development, but key information is missing about the reproductive biology of P. downsi and the behavior of flies in and near nests of their hosts. We used external and internal nest cameras to record the behavior of P. downsi adults within and outside nests of the Galapagos Flycatcher, Myiarchus magnirostris, throughout all stages of the nesting cycle. These recordings showed that P. downsi visited flycatcher nests throughout the day with higher fly activity during the nestling phase during vespertine hours. The observations also revealed that multiple P. downsi individuals can visit nests concurrently, and that there are some interactions among these flies within the nest. Fly visitation to nests occurred significantly more often while parent birds were away from the nest than in the nest, and this timing appears to be a strategy to avoid predation by parent birds. We report fly mating behavior outside the nest but not in the nest cavity. We discuss the relevance of these findings for the adaptive forces shaping P. downsi life history strategies as well as rearing and control measures.

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Distribution of the introduced parasitic fly Philornis downsi (Diptera, Muscidae) in the Galapagos Islands

Pacific Conservation Biology ◽

10.1071/pc070014 ◽

2007 ◽

Vol 13 (1) ◽

pp. 14 ◽

Cited By ~ 30

Author(s):

David A. Wiedenfeld ◽

Gustavo A. Jiménez U. ◽

Birgit Fessl ◽

Sonia Kleindorfer ◽

Juan Carlos Valarezo

Keyword(s):

Infection Intensity ◽

Galapagos Islands ◽

Parasite Infection ◽

Control Methods ◽

Galápagos Islands ◽

Mortality And Morbidity ◽

Philornis Downsi ◽

Nestling Survival ◽

Survival And Growth ◽

Altricial Birds

The avifauna of the Galapagos islands is characterized by a small number of endemic species, including the 13 species of Darwin's finches. The introduced fly parasite Philornis downsi reduces nestling survival and growth rate of altricial birds, and can cause mortality and morbidity of the nestlings. We examined the occurrence of Philornis downsi among islands and at different elevations. The parasite was found in nests from 11 of 13 islands sampled. The two islands on which P. downsi was not found were Espa�ola and Genovesa, both arid islands with no humid highlands and distant from the centre of the archipelago. Parasite infection intensity was greater in nests at higher elevations, and on islands that have moist highlands, which may serve as a reservoir for the files. A full understanding of the fly's ecology may permit the development of eradication or control methods, or at least mitigation of its effects on the birds.

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Trypanosomatids Detected in the Invasive Avian Parasite Philornis downsi (Diptera: Muscidae) in the Galapagos Islands

Insects ◽

10.3390/insects11070422 ◽

2020 ◽

Vol 11 (7) ◽

pp. 422

Author(s):

Courtney L. Pike ◽

María Piedad Lincango ◽

Charlotte E. Causton ◽

Patricia G. Parker

Keyword(s):

First Record ◽

Galapagos Islands ◽

Molecular Methods ◽

Insect Species ◽

Galápagos Islands ◽

Suitable Host ◽

Direct Damage ◽

Endemic Birds ◽

Philornis Downsi ◽

Alien Insect

Alien insect species may present a multifaceted threat to ecosystems into which they are introduced. In addition to the direct damage they may cause, they may also bring novel diseases and parasites and/or have the capacity to vector microorganisms that are already established in the ecosystem and are causing harm. Damage caused by ectoparasitic larvae of the invasive fly, Philornis downsi (Dodge and Aitken) to nestlings of endemic birds in the Galapagos Islands is well documented, but nothing is known about whether this fly is itself associated with parasites or pathogens. In this study, diagnostic molecular methods indicated the presence of insect trypanosomatids in P. downsi; to our knowledge, this is the first record of insect trypanosomatids associated with Philornis species. Phylogenetic estimates and evolutionary distances indicate these species are most closely related to the Crithidia and Blastocrithidia genera, which are not currently reported in the Galapagos Islands. The prevalence of trypanosomatids indicates either P. downsi arrived with its own parasites or that it is a highly suitable host for trypanosomatids already found in the Galapagos Islands, or both. We recommend further studies to determine the origin of the trypanosomatid infections to better evaluate threats to endemic fauna of the Galapagos Islands.

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Philornis downsi (Diptera: Muscidae), an Avian Nest Parasite Invasive to the Galapagos Islands, in Mainland Ecuador

Annals of the Entomological Society of America ◽

10.1093/aesa/sav026 ◽

2015 ◽

Vol 108 (3) ◽

pp. 242-250 ◽

Cited By ~ 21

Author(s):

M. Bulgarella ◽

M. A. Quiroga ◽

G. A. Brito vera ◽

J. S. Dregni ◽

F. Cunninghame ◽

...

Keyword(s):

Galapagos Islands ◽

Galápagos Islands ◽

Philornis Downsi ◽

Avian Nest ◽

Nest Parasite

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Invasion of an Avian Nest Parasite, Philornis downsi, to the Galapagos Islands: Colonization History, Adaptations to Novel Ecosystems, and Conservation Challenges

Disease Ecology - Social and Ecological Interactions in the Galapagos Islands ◽

10.1007/978-3-319-65909-1_9 ◽

2017 ◽

pp. 213-266 ◽

Cited By ~ 13

Author(s):

Birgit Fessl ◽

George E. Heimpel ◽

Charlotte E. Causton

Keyword(s):

Galapagos Islands ◽

Novel Ecosystems ◽

Galápagos Islands ◽

Colonization History ◽

Philornis Downsi ◽

Avian Nest ◽

Nest Parasite

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Oceanic islands and climate: using a multi-criteria model of drivers of change to select key conservation areas in Galapagos

Regional Environmental Change ◽

10.1007/s10113-021-01768-0 ◽

2021 ◽

Vol 21 (2) ◽

Author(s):

Daniel Escobar-Camacho ◽

Paulina Rosero ◽

Mauricio Castrejón ◽

Carlos F. Mena ◽

Francisco Cuesta

Keyword(s):

Ecosystem Services ◽

Environmental Change ◽

Southern Oscillation ◽

Marine Reserve ◽

Galapagos Islands ◽

Tourism Industry ◽

Assessment Model ◽

Human Populations ◽

Galápagos Islands ◽

Drivers Of Change

AbstractThe unique marine and terrestrial ecosystems of the Galapagos Islands are highly vulnerable to human-based drivers of change, including the introduction of invasive species, unsustainable tourism, illegal fishing, overexploitation of ecosystem services, and climate change. These drivers can interact with climate-based drivers such as El Niño-Southern Oscillation (ENSO) at multiple temporal and spatial scales, exacerbating their negative impacts on already fragile ecosystems and the socioeconomic system of the Archipelago. In this review, we performed a literature review based on published literature from 1945 to 2020 and local and global climate databases to analyze drivers of change in the Galapagos. We developed and applied a spatial impact assessment model to identify high-ecological value areas with high sensitivity and exposure scores to environmental change drivers. We identified 13 priority HEVA that encompass ca. 23% (14,715 km2) of the Galapagos Archipelago, distributed in nearly 3% of the Galapagos Marine Reserve and 20% Galapagos National Park. Current and future impacts are likely to concentrate on the inhabited islands’ highlands, whereas marine impacts concentrate along most of the Galapagos Islands’ shorelines. These results are important for guiding the design and implementation of adaptation measures aimed at increasing ecosystem resilience and human adaptive capacity in the face of global environmental change. Overall, these results will be valuable in their application for preserving Galapagos biota, securing the provision of vital ecosystem services for resident human populations, and sustaining the nature-based tourism industry.

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