Stability of chewing louse (Phthiraptera: Amblycera and Ischnocera) populations infesting great horned owls (Aves: Strigidae)

2019 ◽  
Vol 152 (1) ◽  
pp. 60-69 ◽  
Author(s):  
Robert J. Lamb ◽  
Terry D. Galloway
Keyword(s):  
Temporal Variation ◽  
Temporal Variability ◽  
Sampling Error ◽  
Small Sample ◽  
Chewing Louse ◽  
Female Ratio ◽  
Mean Intensity ◽  
Chewing Lice ◽  
Louse Species ◽  
Small Sample Sizes

AbstractThe annual abundance of chewing lice (Phthiraptera) was recorded on great horned owls (Bubo virginianus (Gmelin), Aves: Strigidae) from 1994 to 2015 in Manitoba, Canada. Kurodaia magna Emerson (Amblycera: Menoponidae) had a mean annual abundance about half that for Strigiphilus oculatus (Rudow) (Ischnocera: Philopteridae). Mean intensity, rather than prevalence, explained the variation in annual abundance. Temporal variation (measured as population variability) in abundance and mean intensity were high and similar (0.62–0.67), but lower for nymph to female ratio (0.36–0.38). Temporal variation of prevalence and sex ratio were higher for K. magna (0.34–0.35) than for S. oculatus (0.21–0.22), and typical for other louse species. The high temporal variability for abundance and mean intensity suggest lower year-to-year stability than exhibited by other chewing lice, but over 80% of this variability was due to sampling error resulting from small sample sizes in some years and extreme intensities in the aggregated distributions of intensity. The remaining variation, < 20%, revealed no significant differences in annual abundance or mean intensity among years, and therefore stable populations over 22 years. Populations of 12 species of chewing lice show lower temporal variability and therefore greater stability than three other insect taxa.

scholarly journals RFU derived LRs for activity level assignments using Bayesian Networks

2021 ◽  
Author(s):  
Peter Gill ◽  
Øyvind Bleka ◽  
Ane Elida Fonneløp
Keyword(s):  
Bayesian Networks ◽  
Sampling Error ◽  
Small Sample ◽  
Activity Level ◽  
Likelihood Ratios ◽  
Dna Profile ◽  
Transfer Data ◽  
Secondary Transfer ◽  
Logistic Regressions ◽  
Small Sample Sizes

A comparative study has been carried out, comparing two different methods to calculate activity level likelihood ratios (LRa) using Bayesian Networks. The first method uses the sub-source likelihood ratio (log10LRφ) as a 'quality indicator'. However, this has been criticised as introducing potential bias from population differences in allelic proportions. An alternative method has been introduced that is based upon the total RFU of a DNA profile that is adjusted, by multiplication, of the mixture proportion (Mx) which is calculated from quantitative probabilistic genotyping software (EuroForMix). Bayesian logistic regressions of direct transfer data showed that the two methods were comparable. Differences were attributed to sampling error, and small sample sizes of secondary transfer data. The Bayesian approach facilitates comparative studies by taking account of sampling error; it can easily be extended to compare different methods.

scholarly journals Chewing lice (Phthiraptera: Amblycera, Ischnocera) from chukars (Alectoris chukar) from a pheasant farm in Jinacovice (CzechRepublic)

2012 ◽  
Vol 50 (No. 5) ◽  
pp. 213-218 ◽  
Author(s):  
O. Sychra
Keyword(s):  
Czech Republic ◽  
Species Diversity ◽  
The Other ◽  
Mean Intensity ◽  
Chewing Lice ◽  
Alectoris Chukar ◽  
Louse Species ◽  
First Time

One hundred and twenty captive chukars (Alectoris chukar) and other hosts from a pheasant farm in Jinacovice (Czech Republic) were searched for chewing lice from July 2003 to April 2004. Seven species of chewing lice were found on chukars: Amyrsidea perdicis, Menacanthus pallidulus, Menopon gallinae (Amblycera); Goniodes colchici, Lipeurus maculosus, Goniocotes microthorax and Cuclotogaster heterographus (Ischnocera). Except for the last two mentioned species, the other five louse species are recorded for the first time on chukars. The prevalence, mean intensity of infestation and mean abundance of the lice from chukars were recorded. The species diversity and distribution of chewing lice from another eight species of gallinaceous birds kept in the pheasant farm were also recorded.

Abundance and stability of populations of chewing lice (Phthiraptera: Amblycera and Ischnocera) infesting two species of woodpeckers (Aves: Piciformes: Picidae)

2018 ◽  
Vol 150 (2) ◽  
pp. 180-189 ◽  
Author(s):  
Robert J. Lamb ◽  
Terry D. Galloway
Keyword(s):  
Population Dynamics ◽  
Sex Ratio ◽  
Population Variability ◽  
The Other ◽  
Population Stability ◽  
Mean Intensity ◽  
Chewing Lice ◽  
The Mean ◽  
Louse Species ◽  
Colaptes Auratus

AbstractThe annual abundance of chewing lice (Phthiraptera) was recorded from 1996 to 2015 in Manitoba, Canada, on two species of woodpeckers (Piciformes: Picidae). Yellow-bellied sapsuckers (Sphyrapicus varius (Linnaeus)) were infested with Menacanthus pici (Denny) (Amblycera: Menoponidae) and Penenirmus auritus (Scopoli) (Ischnocera: Philopteridae); northern flickers (Colaptes auratus (Linnaeus)) were also infested with M. pici, as well as two other Ischnocera, Penenirmus jungens (Kellogg) and Picicola porisma Dalgleish. The mean annual abundance varied from nine to 51 lice per bird for the four species, with prevalence, mean intensity, sex ratio, and nymphs per female also varying among louse species. Menacanthus pici populations on both hosts were unstable: abundance rose over two decades because of increasing prevalence, whereas the abundance of the other three louse species fluctuated around a mean. Population variability was similar for the lice on both hosts, with the metric, PV, ranging from 0.41 to 0.51 on a 0–1 scale, once the effect of the trend in abundance for M. pici had been removed. Although the population dynamics for species of lice on these two woodpeckers were distinct, inter-specific differences in population stability were less pronounced than observed in the few other species of bird lice studied in this way.

Chewing lice (Phthiraptera: Amblycera and Ischnocera) infesting woodpeckers and sapsuckers (Aves: Piciformes: Picidae) in Manitoba, Canada

2016 ◽  
Vol 148 (5) ◽  
pp. 520-531 ◽  
Author(s):  
Terry D. Galloway ◽  
Robert J. Lamb
Keyword(s):  
Louse Infestation ◽  
Mean Intensity ◽  
Chewing Lice ◽  
Northern Flicker ◽  
Picoides Pubescens ◽  
Louse Species ◽  
Colaptes Auratus ◽  
Pileated Woodpeckers ◽  
Picoides Villosus

AbstractFive species of woodpeckers (Piciformes: Picidae) in Manitoba, Canada were examined for chewing lice (Phthiraptera: Amblycera and Ischnocera): downy woodpecker (DOWO) (Picoides pubescens (Linnaeus), n=56), hairy woodpecker (HAWO) (Picoides villosus (Linnaeus), n=32), pileated woodpecker (PIWO) (Dryocopus pileatus (Linnaeus), n=12), northern flicker (NOFL) (Colaptes auratus (Linnaeus), n=223), and yellow-bellied sapsucker (YBSA) (Sphyrapicus varius (Linnaeus), n=192). Seven species of lice were collected (total number=40 613): Menacanthus pici (Denny) from all species of woodpeckers, Brueelia straminea (Denny) from both species of Picoides Lacépède, Penenirmus jungens (Kellogg) from northern flicker, Penenirmus auritus (Scopoli) from all species of woodpeckers examined except northern flickers, Picicola porisma Dalgleish from northern flickers, Picicola snodgrassi (Kellogg) from both species of Picoides, and Picicola marginatulus (Harrison) from pileated woodpeckers. Prevalence for total louse infestation ranged from 32.3% to 85.7% (NOFL>YBSA>PIWO>DOWO>HAWO). Mean intensity for total lice ranged from 29.2 to 232.4 (PIWO>NOFL>HAWO>YBSA>DOWO). Infestation parameters for each louse/host combination are provided. Distribution of louse infestations was highly aggregated. In all louse/host combinations, either females were more prevalent than males or there was no significant deviation from 50:50. There was a tendency for louse species to co-occur on the same host specimen.

Host body size and the abundance of chewing lice (Phthiraptera: Amblycera, Ischnocera) infesting eight owl species (Aves: Strigiformes) in Manitoba, Canada

2019 ◽  
Vol 151 (5) ◽  
pp. 621-628 ◽  
Author(s):  
Robert J. Lamb ◽  
Terry D. Galloway
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Louse Infestation ◽  
Mean Intensity ◽  
Chewing Lice ◽  
Host Body ◽  
Abundant Genus ◽  
Louse Species ◽  
The Relationship ◽  
Host Body Mass

AbstractSpecimens (n = 508) of eight species of owl (Aves: Strigiformes) collected from 1994 to 2017 in Manitoba, Canada, were weighed and examined for chewing lice (Phthiraptera: Amblycera, Ischnocera). The relationship between host body mass and infestation by 12 species of lice was examined. Host body mass explained 52% (P = 0.03) of the variation in mean intensity of louse infestation among hosts, due primarily to a high abundance of lice on the heaviest owl species. The relationship was due to the mean intensity of lice, and neither species richness nor the prevalence of lice was related to host body mass. For individual louse species, the relationship was due primarily to Kurodaia acadicae Price and Beer, Kurodaia magna Emerson, and an undetermined species of Kurodaia Uchida (Phthiraptera: Menoponidae) (R2 = 0.997), but not the nine Strigiphilus Mjöberg (Phthiraptera: Philopteridae) species (R2 = 0.27). Louse intensity did not increase with body size for individual birds of any of the owl species. Mean intensity is expected to increase in proportion with the size, specifically the surface area, of the host. Why that relationship holds only for one louse genus, and not for the most abundant genus of lice on owls, and weakly compared with other families of birds, has yet to be determined.

scholarly journals Changing the logic of replication: A case from infant studies

2019 ◽  
Author(s):  
Francesco Margoni ◽  
Martin Shepperd
Keyword(s):  
Statistical Power ◽  
Sampling Error ◽  
Meta Analysis ◽  
Statistical Significance ◽  
Small Sample ◽  
Infant Research ◽  
Replication Studies ◽  
Wide Range ◽  
Small Sample Sizes ◽  
Meta Analyses

Infant research is making considerable progresses. However, among infant researchers there is growing concern regarding the widespread habit of undertaking studies that have small sample sizes and employ tests with low statistical power (to detect a wide range of possible effects). For many researchers, issues of confidence may be partially resolved by relying on replications. Here, we bring further evidence that the classical logic of confirmation, according to which the result of a replication study confirms the original finding when it reaches statistical significance, could be usefully abandoned. With real examples taken from the infant literature and Monte Carlo simulations, we show that a very wide range of possible replication results would in a formal statistical sense constitute confirmation as they can be explained simply due to sampling error. Thus, often no useful conclusion can be derived from a single or small number of replication studies. We suggest that, in order to accumulate and generate new knowledge, the dichotomous view of replication as confirmatory/disconfirmatory can be replaced by an approach that emphasizes the estimation of effect sizes via meta-analysis. Moreover, we discuss possible solutions for reducing problems affecting the validity of conclusions drawn from meta-analyses in infant research.

scholarly journals Ectoparásitos asociados a polluelos del Búho Cornudo (Aves: Strigidae) en un paisaje fragmentado de la península de Baja California, México

2018 ◽  
Vol 34 (1) ◽  
pp. 1-15
Author(s):  
Raquel Bolaños-García ◽  
Ricardo Rodríguez-Estrella ◽  
Carmen Guzmán-Cornejo
Keyword(s):  
Baja California ◽  
Health Condition ◽  
Host Population ◽  
Avian Host ◽  
New Host ◽  
Chewing Louse ◽  
Fragmented Habitat ◽  
Mean Intensity ◽  
Chewing Lice ◽  
Feather Mite

Ectoparasites are important in avian host population because they can affect health condition, regulate population dynamics and alter interspecific competition. Studies of ectoparasites in wild raptors are scarce and even few have been made in owls. This is the first study of the prevalence and intensity of ectoparasites in Great Horned Owl (Bubo virginianus) fledglings. We studied ectoparasites on fledglings from nests in a fragmented arid landscape at Baja California peninsula, during the breeding seasons of 2015 and 2017. The fledglings of 40 days of age were handled and taken from their nests for the collection of ectoparasites. A total of 81 epizoic species were collected from 36 nestlings from 15 nests, distributed in five orders: Diptera (Icosta americana); Hemiptera (Cimicidae gen. sp.); Phthiraptera (Neohaematopinus sciurinus, Colpocephalum pectinatum); Siphonaptera (Orchopea sp.) and Mesostigmata (Ornihtonysus sylviarum). Likewise, one species of chewing lice (n=5) (Geomydoecus telli) and one species of feather mite (n=7) were also recorded associated with the Great Horned Owl. Five species were hematophagous parasites. Louse fly I. americana and chewing louse C. pectinatum showed the highest levels of prevalence (26.5% and 20.6% respectively), while the hematophagous feather mite Ornihtonysus silviarum presented the higher mean intensity in only one nest (15.5). The flea Orchopea sp. and the chewing louse G. telli and sucking louse N. sciurinus exhibited the lowest values of prevalence and mean intensity; these species have been recorded in association mainly with rodents, so probably they could have been transmitted to the owls when they were captured as preys and taken into their nest. Additionally a bug (Cimicidae gen. sp.) was found in one host. Colpocephalum pectinatum is the first recorded from Great Horned owl, such as new host. The abundance of ectoparasites in one owl nest was independent of their abundance in neighbor nests (Moran´s I = 0.010; z = 0.16, P > 0.05). We discuss the implications of ectoparasitism for a Great Horned owl population in fragmented habitat of the Baja California arid desert.

Infestation parameters for chewing lice (Phthiraptera: Amblycera, Ischnocera) infesting owls (Aves: Strigidae, Tytonidae) in Manitoba, Canada

2019 ◽  
Vol 151 (5) ◽  
pp. 608-620 ◽  
Author(s):  
Terry D. Galloway ◽  
Robert J. Lamb
Keyword(s):  
Barn Owl ◽  
Tyto Alba ◽  
Bubo Virginianus ◽  
Mean Intensity ◽  
Aegolius Funereus ◽  
Chewing Lice ◽  
Strix Varia ◽  
Asio Flammeus ◽  
Louse Species ◽  
Boreal Owl

AbstractEleven of the 12 species of owls (Aves: Strigidae, Tytonidae) known to occur in Manitoba, Canada, were examined for chewing lice (Phthiraptera: Amblycera, Ischnocera) from 1976 to 2015: barn owl (Tyto alba (Scopoli); Aves: Tytonidae) (n = 2), snowy owl (Bubo scandiacus (Linnaeus); Aves: Strigidae) (n = 77), great horned owl (Bubo virginianus (Gmelin); Aves: Strigidae) (n = 262), great grey owl (Strix nebulosa Förster; Aves: Strigidae) (n = 142), barred owl (Strix varia Barton; Aves: Strigidae) (n = 10), northern hawk owl (Surnia ulula (Linnaeus); Aves: Strigidae) (n = 18), short-eared owl (Asio flammeus (Pontoppidan); Aves: Strigidae) (n = 74), long-eared owl (Asio otus (Linnaeus); Aves: Strigidae) (n = 67), eastern screech owl (Megascops aslo (Linnaeus); Aves: Strigidae) (n = 59), boreal owl (Aegolius funereus (Linnaeus); Aves: Strigidae) (n = 47), and northern saw-whet owl (Aegolius acadicus (Gmelin); Aves: Strigidae) (n = 44), a total of 802 owls. No lice were found infesting barn owl (Tyto alba (Scopoli); Aves: Tytonidae) or eastern screech owl (Megascops asio (Linnaeus); Aves: Strigidae). We collected a total of 113 810 lice of 12 species: Kurodaia Uchida (Phthiraptera: Menoponidae) – three species; and Strigiphilus Mjöberg (Phthiraptera: Philopteridae) – nine species. Overall prevalence of infestation ranged from 10.0% to 88.9%. Mean intensity for total lice ranged from 22.4 to 506.5. Infestation parameters for each louse–host combination are provided; prevalence and mean intensity were not related for louse–host species combinations. Distribution of louse infestations was highly aggregated. In all louse–host combinations but one, either females were more prevalent than males or there was no significant deviation from 50:50. Male Strigiphilus ceblebrachys Denny significantly outnumbered females in snowy owls. There was a tendency for louse species to co-occur on the same host specimen. Where sample sizes for owls were large enough, no seasonal patterns in abundance of lice were detected.

A penguin-chewing louse (Insecta : Phthiraptera) phylogeny derived from morphology

2004 ◽  
Vol 18 (1) ◽  
pp. 89 ◽  
Author(s):  
Jonathan C. Banks ◽  
Adrian M. Paterson
Keyword(s):  
Phylogenetic Relationships ◽  
Morphological Characters ◽  
Monophyletic Group ◽  
Host Switching ◽  
Chewing Louse ◽  
Chewing Lice ◽  
Switching Event ◽  
Full Analysis ◽  
Louse Species

Penguins are parasitised by 15 species of lice in the genera Austrogoniodes and Nesiotinus and present an opportunity to analyse phylogenetic relationships of two complete genera of chewing lice parasitising a monophyletic group of hosts. Taxonomy of penguin lice has been revised several times, including the erection of the genus Cesareus to contain some of the penguin-chewing louse species. Additionally, other groups of species within Austrogoniodes have been proposed. We constructed a phylogeny for all the chewing lice parasitising penguins from 46 parsimony-informative morphological characters and found support for two groups within Austrogoniodes, but little support for the Cesareus genus. Austrogoniodes metoecus, the only Austrogoniodes species parasitising a bird other than a penguin, was basal in the phylogeny, which suggests that if A. metoecus did originate from a louse species parasitising penguins, the host-switching event was unlikely to have been recent. A�superficial comparison of louse and penguin phylogenies identified some potential instances of co-speciation. However, a full analysis of co-phylogenetic relationships between penguins and their lice awaits the publication of a better-resolved penguin phylogeny.

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