scholarly journals Behavior of the Avian Parasite Philornis downsi (Diptera: Muscidae) in and Near Host Nests in the Galapagos Islands

2021 ◽  
Author(s):  
Courtney L. Pike ◽  
Ismael E. Ramirez ◽  
David J. Anchundia ◽  
Birgit Fessl ◽  
George E. Heimpel ◽  
...  
Keyword(s):  
Life History ◽  
Mating Behavior ◽  
Galapagos Islands ◽  
Control Measures ◽  
Life History Strategies ◽  
Control Methods ◽  
Galápagos Islands ◽  
Nest Cavity ◽  
Philornis Downsi ◽  
And Control

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.

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

2007 ◽  
Vol 13 (1) ◽  
pp. 14 ◽  
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.

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

2021 ◽  
Author(s):  
Polpass Arul Jose ◽  
Michael Ben‐Yosef ◽  
Paola Lahuatte ◽  
Charlotte E. Causton ◽  
George E. Heimpel ◽  
...  
Keyword(s):  
Life Stage ◽  
Galapagos Islands ◽  
Galápagos Islands ◽  
Philornis Downsi ◽  
Bird Parasite

Sexual size dimorphism and life history traits in an island-mainland system: an overview of the lizard genus Microlophus

2021 ◽  
pp. 1-7
Author(s):  
Ken S. Toyama ◽  
Christopher K. Boccia
Keyword(s):  
Life History ◽  
South America ◽  
Life History Theory ◽  
Life History Traits ◽  
Sexual Size Dimorphism ◽  
Life History Strategies ◽  
Galápagos Islands ◽  
Size Dimorphism ◽  
Rensch's Rule ◽  
Comprehensive Compilation

Abstract Opposing life history strategies are a common result of the different ecological settings experienced by insular and continental species. Here we present a comprehensive compilation of data on sexual size dimorphism (SSD) and life history traits of Microlophus, a genus of lizards distributed in western South America and the Galápagos Islands, and test for differences between insular and continental species under life history theory expectations. Contrary to our predictions, we found no differences in SSD between localities or evidence that Microlophus follows Rensch’s rule. However, as expected, head dimensions and maturity sizes were significantly larger in insular species while continental species had larger clutches. Our results show that Microlophus exhibits some of the patterns expected from an island-mainland system, but unexplained patterns will only be resolved through future ecological, morphological and behavioural studies integrating both faunas.

Principles and control methods

2015 ◽  
Author(s):  
Karen E Goldstone
Keyword(s):  
Radiation Protection ◽  
Control Measures ◽  
Risk Assessments ◽  
Control Methods ◽  
Alara Principle ◽  
Radiation Sources ◽  
Dose Limits ◽  
Dose Constraints ◽  
And Control ◽  
Dose Levels

Justification, optimization, and limitation are the three underlying principles of good radiation protection. This chapter considers how these principles apply in a variety of exposure situations. Risk-based application of the principles results in control methods comprising control over areas, control over people, and control over radiation sources. These are implemented through judgements based on the use of dose limits, dose constraints, and application of the ALARA principle. Potential dose levels and possible control measures appropriate to each situation are reviewed and evaluated in risk assessments prior to work being undertaken.

The life-history and control of Hapatesus hirtus Candeze (Coleoptera: Elateridae) in Victoria

1991 ◽  
Vol 42 (5) ◽  
pp. 827 ◽  
Author(s):  
PA Horne ◽  
JA Horne
Keyword(s):  
Life History ◽  
Field Trials ◽  
Soil Samples ◽  
Control Measures ◽  
Potato Tubers ◽  
Larval Stages ◽  
Complete Development ◽  
History Of ◽  
And Control ◽  
Potato Crops

The incidence and life-history of potato wireworm, Hapatesus hirtus Candeze, in Victorian potato crops were studied, and insecticidal control measures assessed. Larval stages were present and active throughout the year. Ten larval instars were identified, probably requiring several years to complete development. Egg development occurred in October-November and the most likely timing of oviposition was December. The relative numbers of larval H. hirtus detected in soil samples, pre-planting baits and harvested tubers are presented. Baiting with halves of potatoes provided an efficient means of detecting areas likely to suffer wireworm damage. One formulation of chlorpyrifos ('Lorsban') was effective in reducing damage to, and larval numbers in, potatoes in field trials. The granular formulation of tefluthrin and the controlled release chlorpyrifos were not effective in protecting potato tubers.

The Non-Progress of Non-Progression: Two Responses to Lyell's Doctrine

1976 ◽  
Vol 9 (2) ◽  
pp. 166-174 ◽  
Author(s):  
Michael Bartholomew
Keyword(s):  
Life History ◽  
Environmental Conditions ◽  
Galapagos Islands ◽  
Ecological Niches ◽  
Galápagos Islands ◽  
Essential Point ◽  
The Real ◽  
History Of

‘Non-Progression’, the interpretation of life-history launched by Lyell in 1830 and defended by him for over twenty years, can be summarized as follows. Palaeontologists, Lyell contended, should assume that at every period of the earth's recoverable past, each class of plants and animals has been represented somewhere on earth. Species have been created solely as responses to perpetually shifting environmental conditions, and not as temporally conditioned stages in the unique unrolling of a grand plan. If certain environments are especially suited to reptiles, then the Creator tailors collections of beautifully adapted terrestrial, aquatic, and even aerial reptiles for them—as He did, for example, for the environments recorded in the British Jurassic; as He did, much more recently, for the Galapagos Islands; and as He will do again, if conditions somewhere on earth ever force mammals into extinction, leaving ecological niches which can more suitably be filled by reptiles. If, for example, changes in the topography and climate of the Sussex Weald eventually lead to the re-establishment of an environment that particularly suits iguanodons, then iguanodons will assuredly appear there again. The essential point about Lyell's interpretation is that time does nothing to determine a particular flora and fauna. When designing a new animal, the Creator, according to Lyell's view, has to take into account only the creature's or plant's destined environment: He has to consult no timetable, or lineage, governing the production of new forms. In notes for a speech given in 1852 Lyell reduced his interpretation to the epitome, ‘Adaptation to geographical circumst5 not progressive develop the real history of past changes’.

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

Insects ◽  
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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