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Charles R Brown - One of the best experts on this subject based on the ideXlab platform.
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arbovirus infection is a major determinant of fitness in house sparrows passer domesticus that invade cliff swallow petrochelidon pyrrhonota colonies
The Auk, 2012Co-Authors: Charles R BrownAbstract:ABSTRACT. Wild birds play a key role in the amplification and transmission of many of the arthropod-borne viruses (arboviruses). Determining the extent to which birds are affected by these viruses is critical in predicting the pathogens' spread or maintenance in vertebrate host populations. Little is known about how arboviruses affect amplifying hosts' fitness, especially in cases where these viruses infect Nestling birds. Buggy Creek virus (BCRV; Togaviridae: Alphavirus) is an RNA arbovirus transmitted by the Swallow Bug (Oeciacus vicarius) to Cliff Swallows (Petrochelidon pyrrhonota) and House Sparrows (Passer domesticus) that have recently occupied Cliff Swallow nesting colonies. We examined fitness, as measured by fledging success, of House Sparrows occupying Cliff Swallow nesting colonies in western Nebraska. Most Nestlings naturally infected by BCRV at 4–6 days of age died, and even older Nestlings, when infected, showed fledging success of <40%. Whether ≥1 Nestling in a brood was infected with BCRV...
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group size and nest spacing affect buggy creek virus togaviridae alphavirus infection in Nestling house sparrows
PLOS ONE, 2011Co-Authors: Valerie A Obrien, Charles R BrownAbstract:The transmission of parasites and pathogens among vertebrates often depends on host population size, host species diversity, and the extent of crowding among potential hosts, but little is known about how these variables apply to most vector-borne pathogens such as the arboviruses (arthropod-borne viruses). Buggy Creek virus (BCRV; Togaviridae: Alphavirus) is an RNA arbovirus transmitted by the swallow bug (Oeciacus vicarius) to the cliff swallow (Petrochelidon pyrrhonota) and the introduced house sparrow (Passer domesticus) that has recently invaded swallow nesting colonies. The virus has little impact on cliff swallows, but house sparrows are seriously affected by BCRV. For house sparrows occupying swallow nesting colonies in western Nebraska, USA, the prevalence of BCRV in Nestling sparrows increased with sparrow colony size at a site but decreased with the number of cliff swallows present. If one Nestling in a nest was infected with the virus, there was a greater likelihood that one or more of its nest-mates would also be infected than Nestlings chosen at random. The closer a nest was to another nest containing infected Nestlings, the greater the likelihood that some of the Nestlings in the focal nest would be BCRV-positive. These results illustrate that BCRV represents a cost of coloniality for a vertebrate host (the house sparrow), perhaps the first such demonstration for an arbovirus, and that virus infection is spatially clustered within nests and within colonies. The decreased incidence of BCRV in sparrows as cliff swallows at a site increased reflects the “dilution effect,” in which virus transmission is reduced when a vector switches to feeding on a less competent vertebrate host.
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Group Size and Nest Spacing Affect Buggy Creek Virus (Togaviridae: Alphavirus) Infection in Nestling House Sparrows
2011Co-Authors: Valerie A. O’brien, Charles R BrownAbstract:The transmission of parasites and pathogens among vertebrates often depends on host population size, host species diversity, and the extent of crowding among potential hosts, but little is known about how these variables apply to most vector-borne pathogens such as the arboviruses (arthropod-borne viruses). Buggy Creek virus (BCRV; Togaviridae: Alphavirus) is an RNA arbovirus transmitted by the swallow bug (Oeciacus vicarius) to the cliff swallow (Petrochelidon pyrrhonota) and the introduced house sparrow (Passer domesticus) that has recently invaded swallow nesting colonies. The virus has little impact on cliff swallows, but house sparrows are seriously affected by BCRV. For house sparrows occupying swallow nesting colonies in western Nebraska, USA, the prevalence of BCRV in Nestling sparrows increased with sparrow colony size at a site but decreased with the number of cliff swallows present. If one Nestling in a nest was infected with the virus, there was a greater likelihood that one or more of its nest-mates would also be infected than Nestlings chosen at random. The closer a nest was to another nest containing infected Nestlings, the greater the likelihood that some of the Nestlings in the focal nest would be BCRV-positive. These results illustrate that BCRV represents a cost of coloniality for a vertebrate host (the house sparrow), perhaps the first such demonstration for an arbovirus, and that virus infection is spatially clustered within nests and within colonies. The decreased incidence of BCRV in sparrows as cliff swallows at a site increased reflects the ‘‘dilution effect,’ ’ in which virus transmission is reduced when a vector switches to feeding on a les
Marketa Zarybnicka - One of the best experts on this subject based on the ideXlab platform.
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factors affecting the duration of Nestling period and fledging order in tengmalm s owl aegolius funereus effect of wing length and hatching sequence
PLOS ONE, 2015Co-Authors: Marek Kouba, Luděk Bartos, Erkki Korpimaki, Marketa ZarybnickaAbstract:In altricial birds, the Nestling period is an important part of the breeding phase because the juveniles may spend quite a long time in the nest, with associated high energy costs for the parents. The length of the Nestling period can be variable and its duration may be influenced by both biotic and abiotic factors; however, studies of this have mostly been undertaken on passerine birds. We studied individual duration of Nestling period of 98 Tengmalm’s owl chicks (Aegolius funereus) at 27 nests during five breeding seasons using a camera and chip system and radio-telemetry. We found the Nestlings stayed in the nest box for 27 – 38 days from hatching (mean ± SD, 32.4 ± 2.2 days). The individual duration of Nestling period was negatively related to wing length, but no formally significant effect was found for body weight, sex, prey availability and/or weather conditions. The fledging sequence of individual Nestlings was primarily related to hatching order; no relationship with wing length and/or other factors was found in this case. We suggest the length of wing is the most important measure of body condition and individual quality in Tengmalm’s owl young determining the duration of the Nestling period. Other differences from passerines (e.g., the lack of effect of weather or prey availability on Nestling period) are considered likely to be due to different life-history traits, in particular different food habits and nesting sites and greater risk of nest predation among passerines.
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perching of tengmalm s owl aegolius funereus Nestlings at the nest box entrance effect of time of the day age wing length and body weight
PLOS ONE, 2014Co-Authors: Marek Kouba, Luděk Bartos, Marketa ZarybnickaAbstract:The behaviour of the Nestlings of nocturnal cavity-nesting species has relatively rarely been studied in detail because of problems connected with use of the technical devices required to provide long-term monitoring of individuals. However, long-term observation of Nestling behaviour is crucial in order to identify different types of behaviour which may be caused by sibling competition at the end of nesting period. We studied behaviour of 43 Tengmalm's owl (Aegolius funereus) Nestlings at 14 nests using a camera and a chip system. The Nestlings perched at the nest box entrance from an average age of 28 days from hatching (range 24-34 days) until fledging, spending around 2 hours per day here in total, in periods ranging from a few seconds to 147 min (7.6±10.9 min, mean ± SD). We found that individual duration of perching at the nest box entrance was significantly influenced by Nestlings' age and wing length and that the duration of perching at the nest box entrance significantly decreased with time of night. However, during daylight hours, time of day had no effect on either probability or duration of Nestlings' perching. We suggest daylight perching at the nest box entrance results from Nestlings' preparation for fledging, while individuals perching here during the night may gain an advantageous position for obtaining food from the parents; another possibility at all times of day is that Nestlings can reaffirm their social dominance status by monopolizing the nest box entrance.
Valerie A Obrien - One of the best experts on this subject based on the ideXlab platform.
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group size and nest spacing affect buggy creek virus togaviridae alphavirus infection in Nestling house sparrows
PLOS ONE, 2011Co-Authors: Valerie A Obrien, Charles R BrownAbstract:The transmission of parasites and pathogens among vertebrates often depends on host population size, host species diversity, and the extent of crowding among potential hosts, but little is known about how these variables apply to most vector-borne pathogens such as the arboviruses (arthropod-borne viruses). Buggy Creek virus (BCRV; Togaviridae: Alphavirus) is an RNA arbovirus transmitted by the swallow bug (Oeciacus vicarius) to the cliff swallow (Petrochelidon pyrrhonota) and the introduced house sparrow (Passer domesticus) that has recently invaded swallow nesting colonies. The virus has little impact on cliff swallows, but house sparrows are seriously affected by BCRV. For house sparrows occupying swallow nesting colonies in western Nebraska, USA, the prevalence of BCRV in Nestling sparrows increased with sparrow colony size at a site but decreased with the number of cliff swallows present. If one Nestling in a nest was infected with the virus, there was a greater likelihood that one or more of its nest-mates would also be infected than Nestlings chosen at random. The closer a nest was to another nest containing infected Nestlings, the greater the likelihood that some of the Nestlings in the focal nest would be BCRV-positive. These results illustrate that BCRV represents a cost of coloniality for a vertebrate host (the house sparrow), perhaps the first such demonstration for an arbovirus, and that virus infection is spatially clustered within nests and within colonies. The decreased incidence of BCRV in sparrows as cliff swallows at a site increased reflects the “dilution effect,” in which virus transmission is reduced when a vector switches to feeding on a less competent vertebrate host.
Marek Kouba - One of the best experts on this subject based on the ideXlab platform.
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factors affecting the duration of Nestling period and fledging order in tengmalm s owl aegolius funereus effect of wing length and hatching sequence
PLOS ONE, 2015Co-Authors: Marek Kouba, Luděk Bartos, Erkki Korpimaki, Marketa ZarybnickaAbstract:In altricial birds, the Nestling period is an important part of the breeding phase because the juveniles may spend quite a long time in the nest, with associated high energy costs for the parents. The length of the Nestling period can be variable and its duration may be influenced by both biotic and abiotic factors; however, studies of this have mostly been undertaken on passerine birds. We studied individual duration of Nestling period of 98 Tengmalm’s owl chicks (Aegolius funereus) at 27 nests during five breeding seasons using a camera and chip system and radio-telemetry. We found the Nestlings stayed in the nest box for 27 – 38 days from hatching (mean ± SD, 32.4 ± 2.2 days). The individual duration of Nestling period was negatively related to wing length, but no formally significant effect was found for body weight, sex, prey availability and/or weather conditions. The fledging sequence of individual Nestlings was primarily related to hatching order; no relationship with wing length and/or other factors was found in this case. We suggest the length of wing is the most important measure of body condition and individual quality in Tengmalm’s owl young determining the duration of the Nestling period. Other differences from passerines (e.g., the lack of effect of weather or prey availability on Nestling period) are considered likely to be due to different life-history traits, in particular different food habits and nesting sites and greater risk of nest predation among passerines.
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perching of tengmalm s owl aegolius funereus Nestlings at the nest box entrance effect of time of the day age wing length and body weight
PLOS ONE, 2014Co-Authors: Marek Kouba, Luděk Bartos, Marketa ZarybnickaAbstract:The behaviour of the Nestlings of nocturnal cavity-nesting species has relatively rarely been studied in detail because of problems connected with use of the technical devices required to provide long-term monitoring of individuals. However, long-term observation of Nestling behaviour is crucial in order to identify different types of behaviour which may be caused by sibling competition at the end of nesting period. We studied behaviour of 43 Tengmalm's owl (Aegolius funereus) Nestlings at 14 nests using a camera and a chip system. The Nestlings perched at the nest box entrance from an average age of 28 days from hatching (range 24-34 days) until fledging, spending around 2 hours per day here in total, in periods ranging from a few seconds to 147 min (7.6±10.9 min, mean ± SD). We found that individual duration of perching at the nest box entrance was significantly influenced by Nestlings' age and wing length and that the duration of perching at the nest box entrance significantly decreased with time of night. However, during daylight hours, time of day had no effect on either probability or duration of Nestlings' perching. We suggest daylight perching at the nest box entrance results from Nestlings' preparation for fledging, while individuals perching here during the night may gain an advantageous position for obtaining food from the parents; another possibility at all times of day is that Nestlings can reaffirm their social dominance status by monopolizing the nest box entrance.
Julie A Heath - One of the best experts on this subject based on the ideXlab platform.
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haematophagous ectoparasites lower survival of and have detrimental physiological effects on golden eagle Nestlings
Conservation Physiology, 2021Co-Authors: Benjamin M Dudek, Michael T Henderson, Stephanie Hudon, Eric J Hayden, Julie A HeathAbstract:Haematophagous ectoparasites can directly affect the health of young animals by depleting blood volume and reducing energetic resources available for growth and development. Less is known about the effects of ectoparasitism on stress physiology (i.e. glucocorticoid hormones) or animal behaviour. Mexican chicken bugs (Haematosiphon inodorus; Hemiptera: Cimicidae) are blood-sucking ectoparasites that live in nesting material or nest substrate and feed on Nestling birds. Over the past 50 years, the range of H. inodorus has expanded, suggesting that new hosts or populations may be vulnerable. We studied the physiological and behavioural effects of H. inodorus on golden eagle (Aquila chrysaetos) Nestlings in southwestern Idaho. We estimated the level of H. inodorus infestation at each nest and measured Nestling mass, haematocrit, corticosterone concentrations, telomere lengths and recorded early fledging and mortality events. At nests with the highest levels of infestation, Nestlings had significantly lower mass and haematocrit. In addition, highly parasitized Nestlings had corticosterone concentrations twice as high on average (42.9 ng/ml) than non-parasitized Nestlings (20.2 ng/ml). Telomeres of highly parasitized female Nestlings significantly shortened as eagles aged, but we found no effect of parasitism on the telomeres of male Nestlings. Finally, in nests with higher infestation levels, eagle Nestlings were 20 times more likely to die, often because they left the nest before they could fly. These results suggest that H. inodorus may limit local golden eagle populations by decreasing productivity. For eagles that survived infestation, chronically elevated glucocorticoids and shortened telomeres may adversely affect cognitive function or survival in this otherwise long-lived species. Emerging threats from ectoparasites should be an important management consideration for protected species, like golden eagles.
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effects of developmental conditions on Nestling american kestrel falco sparverius corticosterone concentrations
General and Comparative Endocrinology, 2011Co-Authors: Erin H Strasser, Julie A HeathAbstract:How n estling birds respond to stressful situations may constitute an important survival co mponent that has lasting developmental effects on the hypothalamic pituitary adrenal (HPA) axis. As birds are exposed to increasing amounts of potential anthropogenic stressors through land use change, understanding how these factors contribute to HPA development is important. We examined whether conditions experienced during the Nestling stage affected free-living American Kestrel (Falco sparverius) HPA activity prior to fledging. Kestrels experienced varying levels of human disturbance around their nest and we classified this environmental exposure as high or low environmental human disturbance based on traffic patterns and land use. We then exposed some broods from high and low disturbance areas to a standardized disturbance protocol. Prior to fledging we collected blood samples from 25day-old Nestlings immediately after capture and 15 min post-capture. Corticosterone (CORT) did not vary with environmental human disturbance levels, disturbance protocol treatment, or with an interaction between environmental human disturbance and disturbance protocol treatment suggesting that Nestling kestrels may not perceive external conditions related to human disturbance as stressful or kestrels may acclimate to disturbance. We also compared the relative effects of environmental human disturbance outside the nest cavity, conditions within the nest cavity (brood size), and individual condition (Nestling fat scores) on baseline and stress-induced CORT. Baseline CORT did not vary with human disturbance level, brood size or fat score. F at scores best explained stress-induced CORT with Nestlings in better condition displaying elevated CORT. These results suggest that individual variation is more likely to explain HPA development compared to nest conditions or the external environment. This study demonstrates the importance of considering the effects of developmental conditions on the stress response at several scales.
