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Piotr Tryjanowski - One of the best experts on this subject based on the ideXlab platform.
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The wintering distribution of Great Grey Shrike Lanius excubitor in Poland: predictions from a large-scale historical survey
Acta Ornithologica, 2009Co-Authors: Lechosław Kuczyński, M. Rzepala, Artur Goławski, Piotr TryjanowskiAbstract:Kuczynski L., Rzepala M., Golawski A., Tryjanowski P. 2009. The wintering distribution of Great Grey Shrike Lanius excubitor in Poland: predictions from a large-scale historical survey. Acta Ornithologica 44: 159-166. DOI 10.3161/000164509X482731 Abstract. The wintering Great Grey Shrike Lanius excubitor was censused in Poland more than two decades ago (during the winters of 1988/89 and 1989/90). Single censuses were made during each winter on sample plots varying from 4.1 to 35.1 km 2 (mean: 16.4 km 2 ). Altogether, data from 404 plots, covering in total more than 6.6 thousands km 2 were used for the analysis. Based on this data and environmental information gathered in GIS databases (Corine land cover "CLC1990" database, digital elevation model "GTOPO30" dataset) we modelled habitat- and spatial-related variation in shrike distribution. Birds were recorded on 45% of study plots. The mean density was 4.8 individuals/100 km2. In both seasons density in meadows was roughly two times higher than in arable fields. We modelled spatial distribution of wintering birds using combination of GLM and three-dimensional local regression. Models were cross-validated to check their temporal consistency. Repeatable spatial pattern of population distribution allowed to make predictive dis- tribution maps. As a general rule, wintering shrikes avoid regions with severe, continental climate and prefer lowlands dominated by agriculture. On the basis of our models, population of the Great Grey Shrike wintering in Poland during late 1980s can be roughly estimated at about 7.7 thousands of individuals.
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Size variation in chewing lice Docophorulus coarctatus: how host size and louse population density vary together
Evolutionary Ecology, 2007Co-Authors: Piotr Tryjanowski, Anetta Szczykutowicz, Zbigniew AdamskiAbstract:Chewing lice of the species Docophorulus coarctatus were extracted from museum specimens of their host, the great grey shrike Lanius excubitor , by combing feathers from 36 freshly shot birds (shot between 1962 and 1974), and samples of ten individual lice (five female, five male) were randomly collected for measurements from each bird. Female lice were bigger than males for all studied measurements ( P
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Sex differences in fluctuating asymmetry of body traits in chewing lice Docophorulus coarctatus (Phthiraptera: Ischnocera)
Parasitology Research, 2007Co-Authors: Piotr Tryjanowski, Zbigniew AdamskiAbstract:Fluctuating asymmetry (FA) that reflects randomly directed deviations from bilateral symmetry has been shown to increase in organisms exposed to environmental and/or genetic stress. We studied fluctuating asymmetry in head and prothorax of chewing lice Docophorulus coarctatus , a parasite of the great grey shrike Lanius excubitor , to investigate associations between parasite body size and fluctuating asymmetry. Samples of ten individual lice (five females, five males) were randomly collected for measurements from 32 shrikes. Relative FA (scaled to trait size) was estimated for head and prothorax. Sex and trait differences in FA were very distinct (all differences significant at P
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Patterns in the distribution of avian lice (Phthiraptera: Amblycera, Ischnocera) living on the great grey shrike Lanius excubitor
Parasitology Research, 2006Co-Authors: Anetta Szczykutowicz, Zbigniew Adamski, M Artin Hromada, Piotr TryjanowskiAbstract:The lice parasite community of great grey shrike Lanius excubitor collected in NE Slovakia during 1962–1974 was quantitatively studied. Lice fauna comprised of three species: Docophorulus coarctatus , Bruelia cruciata (Ischnocera) and Lanicanthus camelinus (Amblycera). All these species were previously indicated as characteristic for that host. The prevalence of lice was high—lice were recovered from 96.3% ( n =108) host specimens. Distributions of lice on the great grey shrike, a strictly territorial bird, were aggregated, indicating substantial variation in the abundance of lice. Sex ratios of lice were biased towards females and not correlated with the subpopulation size of lice on individual hosts.
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Frogs and toads in the food of the Great Grey Shrike (Lanius excubitor): larders and skinning as two ways to consume dangerous prey
Animal Biology, 2005Co-Authors: Marcin Antczak, M Artin Hromada, Piotr TryjanowskiAbstract:Department of Behavioural Ecology, Adam Mickiewicz University, Umultowska 89, 61-614,Pozna´ n, PolandAbstract In this note we present several previously unpublished cases of Great Grey Shrike,Lanius excubitor , predation in western Poland on adult amphibians, including poisonous toads, anda novel special behaviour skinning toads. We briey discuss the potential implications of theseobservations for understanding shrike foraging behaviour and gaps in our current knowledge on bird-toad interactions.Keywords : food; foraging; Lanius excubitor ; novel prey; predator-prey relationship.
Zbigniew Adamski - One of the best experts on this subject based on the ideXlab platform.
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Size variation in chewing lice Docophorulus coarctatus: how host size and louse population density vary together
Evolutionary Ecology, 2007Co-Authors: Piotr Tryjanowski, Anetta Szczykutowicz, Zbigniew AdamskiAbstract:Chewing lice of the species Docophorulus coarctatus were extracted from museum specimens of their host, the great grey shrike Lanius excubitor , by combing feathers from 36 freshly shot birds (shot between 1962 and 1974), and samples of ten individual lice (five female, five male) were randomly collected for measurements from each bird. Female lice were bigger than males for all studied measurements ( P
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Sex differences in fluctuating asymmetry of body traits in chewing lice Docophorulus coarctatus (Phthiraptera: Ischnocera)
Parasitology Research, 2007Co-Authors: Piotr Tryjanowski, Zbigniew AdamskiAbstract:Fluctuating asymmetry (FA) that reflects randomly directed deviations from bilateral symmetry has been shown to increase in organisms exposed to environmental and/or genetic stress. We studied fluctuating asymmetry in head and prothorax of chewing lice Docophorulus coarctatus , a parasite of the great grey shrike Lanius excubitor , to investigate associations between parasite body size and fluctuating asymmetry. Samples of ten individual lice (five females, five males) were randomly collected for measurements from 32 shrikes. Relative FA (scaled to trait size) was estimated for head and prothorax. Sex and trait differences in FA were very distinct (all differences significant at P
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Patterns in the distribution of avian lice (Phthiraptera: Amblycera, Ischnocera) living on the great grey shrike Lanius excubitor
Parasitology Research, 2006Co-Authors: Anetta Szczykutowicz, Zbigniew Adamski, M Artin Hromada, Piotr TryjanowskiAbstract:The lice parasite community of great grey shrike Lanius excubitor collected in NE Slovakia during 1962–1974 was quantitatively studied. Lice fauna comprised of three species: Docophorulus coarctatus , Bruelia cruciata (Ischnocera) and Lanicanthus camelinus (Amblycera). All these species were previously indicated as characteristic for that host. The prevalence of lice was high—lice were recovered from 96.3% ( n =108) host specimens. Distributions of lice on the great grey shrike, a strictly territorial bird, were aggregated, indicating substantial variation in the abundance of lice. Sex ratios of lice were biased towards females and not correlated with the subpopulation size of lice on individual hosts.
Reuven Yosef - One of the best experts on this subject based on the ideXlab platform.
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Contrasting reactions of loggerhead shrikes to two types of chemically defended insect prey
Journal of Chemical Ecology, 1996Co-Authors: Reuven Yosef, James E. Carrel, Thomas EisnerAbstract:Feeding tests with loggerhead shrikes ( Lanius ludovicianus ) showed this bird to accept Utetheisa ornatrix , a moth (Arctiidae) protected by pyrrolizidine alkaloids, but to avoid Lytta polita , a beetle (Meloidae) containing cantharidin.
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From nest building to fledging of young in Great Grey Shrikes (Lanius excubitor) at Sede Boqer, Israel
Journal of Ornithology, 1992Co-Authors: Reuven YosefAbstract:During 1987, 1988, and 1989 the reproductive biology of 21 pairs of Great Grey Shrikes,Lanius excubitor, was observed in Israel. Eggs were laid at 24 h intervals, 69 % of the clutches comprised 6 eggs, and average clutch size was 5.8 eggs. Incubation period averaged 16.8 days, and month of nesting and ambient temperature influenced length of incubation. Earlier nestings had longer incubation periods, greather hatching success, and less egg mass loss than later ones. An average of 4.7 eggs per nest hatched, and overall nesting success was 63 %. Infertility, predation and adverse weather were the major cause of nesting failure.
Stephen C. Lougheed - One of the best experts on this subject based on the ideXlab platform.
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Migratory connectivity in the Loggerhead Shrike (Lanius ludovicianus).
Ecology and evolution, 2018Co-Authors: Amy A. Chabot, Keith A. Hobson, Steven L. Van Wilgenburg, Guillermo E. Pérez, Stephen C. LougheedAbstract:Aim We combine genetic and stable isotope data to quantify migration patterns in Loggerhead Shrike (Lanius ludovicianus), a species of conservation concern in North America, to assess how connectivity differs and impacts population evolution, ecology, and conservation. Location We sampled shrikes across the majority of their nonbreeding range, from the Atlantic Coast to the western United States east of the Rocky Mountains and throughout Mexico. Methods Our study used a Bayesian framework using δ2Hf from a breeding season origin feather and nuclear genetic microsatellite markers to distinguish between co-occurring migratory and nonmigratory individuals on the wintering grounds and, for migrants, to assign individuals to a breeding ground origin and genetic group. Results Migratory shrikes were present throughout the nonbreeding range but the proportion differed among sample areas. Four main wintering areas were identified. Connectivity ranged from weakly negative in birds wintering on the Atlantic Coast to strongly positive between wintering grounds in the southwestern United States and Mexico and northwestern breeding populations. Connectivity was weakest in L. l. migrans, and strongest in L. l. mexicanus and L. l. excubitorides. Although believed to be nonmigratory, long-distance movements of individuals were observed in L. ludovicianus and L. l. mexicanus. Our data support a pattern of chain migration, again most notable in the western half of the species nonbreeding range, and differential migration based on age. Main conclusions Our study provides of one such of the first quantitative measures of migratory connectivity and is among the first studies of a short-distance migratory passerine in North America. The higher migratory connectivity among western, versus eastern populations, and less severe population declines attributable to habitat loss or reproductive success, may result in more localized and/or less severe limiting factors for western populations and more severe on the Atlantic coast and Mississippi Alluvial Valley wintering grounds.
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Characterization of 17 microsatellite loci for use in population genetic and mating system studies of the endangered North American passerine, loggerhead shrike (Lanius ludovicianus)
Conservation Genetics Resources, 2011Co-Authors: Angela Coxon, Amy A. Chabot, Stephen C. Lougheed, José A. Dávila, Bradley N. WhiteAbstract:Seventeen polymorphic microsatellite DNA markers were isolated from the loggerhead shrike (Lanius ludovicianus) using individuals from two geographically distinct populations (Ontario and mainland California). The number of alleles per locus ranged from 6 to 20 and expected heterozygosity varied from 0.639 to 0.902. All loci were heterozygous and private alleles were found for most. Combined non-exclusion probability of identity ranged from 0.047 to 0.122 in the Ontario population and 0.011–0.060 in the California population. Our results indicate that these markers will be useful for studies of genetic population structure, parentage and pedigree analysis.
Anetta Szczykutowicz - One of the best experts on this subject based on the ideXlab platform.
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Size variation in chewing lice Docophorulus coarctatus: how host size and louse population density vary together
Evolutionary Ecology, 2007Co-Authors: Piotr Tryjanowski, Anetta Szczykutowicz, Zbigniew AdamskiAbstract:Chewing lice of the species Docophorulus coarctatus were extracted from museum specimens of their host, the great grey shrike Lanius excubitor , by combing feathers from 36 freshly shot birds (shot between 1962 and 1974), and samples of ten individual lice (five female, five male) were randomly collected for measurements from each bird. Female lice were bigger than males for all studied measurements ( P
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Patterns in the distribution of avian lice (Phthiraptera: Amblycera, Ischnocera) living on the great grey shrike Lanius excubitor
Parasitology Research, 2006Co-Authors: Anetta Szczykutowicz, Zbigniew Adamski, M Artin Hromada, Piotr TryjanowskiAbstract:The lice parasite community of great grey shrike Lanius excubitor collected in NE Slovakia during 1962–1974 was quantitatively studied. Lice fauna comprised of three species: Docophorulus coarctatus , Bruelia cruciata (Ischnocera) and Lanicanthus camelinus (Amblycera). All these species were previously indicated as characteristic for that host. The prevalence of lice was high—lice were recovered from 96.3% ( n =108) host specimens. Distributions of lice on the great grey shrike, a strictly territorial bird, were aggregated, indicating substantial variation in the abundance of lice. Sex ratios of lice were biased towards females and not correlated with the subpopulation size of lice on individual hosts.
