No description available.

I estimated the non-trophic effects of arctic fox (Vulpes lagopus) denning activities on soil nutrient dynamics, vegetation production and quality, snow cover thickness, and their primary terrestrial prey, collared lemmings (Dicrostonyx richardsoni), near Churchill, Manitoba in April, June and August 2014. Arctic foxes increased soil inorganic nitrogen and extractable phosphorous concentration on their dens. This increase in soil nutrient levels resulted in greater vegetation quantity (measured as biomass and cover) and quality (measured as nitrogen content) on dens. Increased vegetation cover, specifically Salix sp. and Leymus mollis cover, positively affected snow cover thickness on dens by trapping blowing snow. Increased snow cover thickness made dens attractive nesting sites to collared lemmings (measured as lemming nest counts). In addition, dens with lemming nests had greater snow cover thickness compared to dens without lemming nests. Greater vegetation quantity and quality on dens could also attract lemmings to dens for winter nesting. / February 2016

O gavião-de-pescoço-branco Leptodon forbesi Swann, 1922, endêmico da Mata Atlântica do Centro Pernambuco, é uma espécie cujo status taxonômico ainda é controverso. Autores como Swann (1922 e 1945), Teixeira et al. (1987) e del Hoyo (1994) consideram a espécie como válida, enquanto que outros, como Grossman e Hamlet (1964), Brown e Amadon (1968), Blake (1977) e Sick (1994) optam por considerá-la como uma variante morfológica do gavião-de-cabeça-cinza L. cayanensis. As diagnoses tradicionais de L. forbesisão as coberteiras inferiores das asas, brancas ao invés de negro; píleo cinza; lados do pescoço brancos; ápice das escapulares, manto e rêmiges esbranquiçados; e a cauda com uma larga faixa branca (Swann 1945; Hellmayr e Conover 1949; Pinto 1964). O presente trabalho teve como objetivos estudar e descrever a variação morfológica e morfométrica de L. cayanensis, e testar a validade dos táxons componentes deste complexo, com especial atenção para o táxon L. forbesie sua distribuição geográfica. Foram analisados 128 espécimes do gênero Leptodon, provenientes do México até o estado do Rio Grande do Sul, Brasil. Dados morfométricos foram obtidos e analisados para se avaliar diferenças entre os sexos, o polimorfismo de coloração nas plumagens dos juvenis, e as subespécies propostas por Swann (1922) para L. cayanensis. Além disso, caracteres de plumagem também foram analisados para se testar a validade de L. forbesi. Concluiu-se que há dimorfismo sexual em L. cayanensis, sendo as fêmeas de maior porte (I); que ocorrem duas, e não três, fases de coloração nas plumagens juvenis de L. cayanensis (II); que as subespécies propostas por Swann (1922) para L. cayanensis não são válidas, sendo a variação geográfica do porte mais bem explicada por um gradiente em resposta ao módulo da latitude, como previsto pela Lei de Bergmann (III); e que a espécie L. forbesié um táxon válido, com base nos caracteres da coloração das penas coberteiras inferiores e da borda de ataque das asas, brancas em L. forbesie pretas em L. cayanensis, do contraste entre a coloração ventral das rêmiges, sendo as primárias escuras e as secundárias mais claras em L. forbesi, e da coloração das penas da região do pescoço, brancas em L. forbesie cinzas em L. cayanensis (IV). Desta forma, L. forbesi constitui mais uma espécie endêmica do Centro Pernambuco de Endemismo. / The White-collared (or Forbes) Kite Leptodon forbesi Swann, 1922 is an endemic raptor of the Centro Pernambuco, the northernmost portion of the Atlantic Forest, in Northeastern Brazil, and its taxonomic status is still a case of controversy. It is considered a valid species by Swann (1922, 1954), Teixeira et al. (1987) and del Hoyo (1994), whereas Grossman and Hamlet (1964), Brown and Amadon (1968), Blake (1977) and Sick (1994) opt to consider it a morphological variant of the widespread Grey-headed Kite L. cayanensis. The traditional diagnoses of L. forbesiare the underwing coverts, white instead of black; grey pileum; white collar; white tip of quills, mantle and scapular feathers; and a wide white band on both sides of the tail (Swann 1945; Hellmayr and Conover 1949; Pinto 1964). The present study aims to analyse and describe the morphological and morphometrical variation in L. cayanensis, and to test the validity of taxa within the complex, with a special interest in L. forbesiand its geographical distribution. 128 specimes of the genus Leptodon, from Mexico to Southern Brazil, were studied. Morphometrical data was obtained and analysed to evaluate differences between sexes, colour polymorphism in the juvenile plumage, and the subspecies described by Swann (1922) for L. cayanensis. Plumage characters were also studied to test the validity of L. forbesi. We conclude that L. cayanensis shows sexual dimorphism, the females being larger (I); that there are two, not three, coloration morphs in the juvenile plumages of L. cayanensis (II); that the subspecies described by Swann (1922) for L. cayanensis are invalid, the geographical variation in size better explained as a response to latitude module, as predicted by Bergmanns Rule (III); and that the species L. forbesi is a valid taxon, based on the coloration of underwing and leading edge coverts, white in L. forbesi and black in L. cayanensis; on the coloration of the ventral side of the rêmiges, with a contrast between dark primaries and lighter secondaries in L. forbesi; and on the collar coloration, white in L. forbesiand grey in L. cayanensis (IV). Therefore, L. forbesi constitutes another endemic and endangered species of the Centro Pernambuco, in the Brazilian Atlantic Forest.

Historically, the collared peccary (Tayassu tajacu) occurred throughout much of Texas including the northern portion of the Texas Hill Country. Remaining peccary populations were extirpated in much of their former range due to over harvest and habitat loss. In 2004, efforts to restore peccary populations to the Texas Hill Country began when Texas Parks and Wildlife Department biologists translocated 29 collared peccaries into the 2,157 ha, Mason Mountain Wildlife Management Area (MMWMA). I evaluated the success of peccary translocations for mixed and intact family groups by comparing survival, ranges, and dispersal of translocated, radio-tagged peccaries. In addition, I evaluated two release methods (soft versus hard) to determine differences in population demographics. I found that peccary ranges and dispersal patterns did not differ (P > 0.05) between intact and mixed groups or release method (soft versus hard). However, I did find that peccary fidelity to release sites was greater for soft releases of family groups. Individuals from the soft release group dispersed the shortest distance and stayed on MMWMA. Only 2 individuals from the hard releases stayed on MMWMA while the rest (19 individuals) dispersed 4-8 km. Future peccary translocations should emphasize the release method employed and family structure of individuals released to improve translocation effectiveness in establishing populations in target areas.

Thesis (M. Sc.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on Jan. 22, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Ecology, Department of Biological Sciences, University of Alberta. Includes bibliographical references.

No description available.

In order to get full understanding of how evolution proceeds in natural settings it is necessary to reveal the genetic basis of the phenotypic traits that play a role for individual fitness in different environments. There are a few possible approaches, most of which stem from traditional mapping efforts in domestic animals and other model species. Here we set the stage for gene mapping in natural populations of birds by producing a large number of anchor markers of broad utility for avian genetical research and use these markers to generate a genetic map of the collared flycatcher (Ficedula albicollis). The map reveals a very high degree of synteny and gene order conservation between bird species separated by as much as 100 million years. This is encouraging for later stages of mapping procedures in natural populations since this means that there is a possibility to use the information from already characterized avian genomes to track candidate genes for detailed analysis in non-model species. One interesting aspect of the low degree of rearrangements occurring in the avian genomes is that this could play a role in the low rate of hybridization barriers formed in birds compared to for instance mammals. An analysis of Z-linked gene markers reveals relatively long-range linkage disequilibrium (LD) in collared flycatchers compared to other outbred species but still, LD seems to decay within < 50 kb indicating that > 20.000 markers would be needed to cover the genome in an association scan. A detailed scan of 74 Z-linked genes evenly distributed along the chromosome in both the collared flycatcher and the pied flycatcher (Ficedula hypoleuca) indicates that there are regions that evolve under directional selection, regions that might harbor loci of importance for adaptive divergence and/or hybrid inviability.

No description available.

Neotyphodium are fungal endosymbionts of grasses that reproduce asexually by infecting the hosts seed. This relationship has traditionally been considered mutualistic, with the fungus improving host fitness by alleviating important stresses. To determine the importance of biotic and abiotic stresses in mediating the endophyte-grass interaction, I investigated the relationship between grazing pressure by collared pikas and Neotyphodium sp. infection frequency in the grass Festuca altaica in an alpine meadow. I conducted a factorial design experiment combining endophyte infection, grazing history, fungicide and fertilizer. Leaf demography and herbivory damage were monitored every two weeks. In areas with chronic grazing history, infected plants were significantly less productive than uninfected tussocks, but there was no difference at low grazing history. There was no effect of infection on the likelihood of herbivory. Contrary to predictions of the mutualism theory, the Neotyphodium sp. / F. altaica symbiotum varied from parasitic to neutral across our gradient of interest. / Ecology

O gavião-de-pescoço-branco Leptodon forbesi Swann, 1922, endêmico da Mata Atlântica do Centro Pernambuco, é uma espécie cujo status taxonômico ainda é controverso. Autores como Swann (1922 e 1945), Teixeira et al. (1987) e del Hoyo (1994) consideram a espécie como válida, enquanto que outros, como Grossman e Hamlet (1964), Brown e Amadon (1968), Blake (1977) e Sick (1994) optam por considerá-la como uma variante morfológica do gavião-de-cabeça-cinza L. cayanensis. As diagnoses tradicionais de L. forbesisão as coberteiras inferiores das asas, brancas ao invés de negro; píleo cinza; lados do pescoço brancos; ápice das escapulares, manto e rêmiges esbranquiçados; e a cauda com uma larga faixa branca (Swann 1945; Hellmayr e Conover 1949; Pinto 1964). O presente trabalho teve como objetivos estudar e descrever a variação morfológica e morfométrica de L. cayanensis, e testar a validade dos táxons componentes deste complexo, com especial atenção para o táxon L. forbesie sua distribuição geográfica. Foram analisados 128 espécimes do gênero Leptodon, provenientes do México até o estado do Rio Grande do Sul, Brasil. Dados morfométricos foram obtidos e analisados para se avaliar diferenças entre os sexos, o polimorfismo de coloração nas plumagens dos juvenis, e as subespécies propostas por Swann (1922) para L. cayanensis. Além disso, caracteres de plumagem também foram analisados para se testar a validade de L. forbesi. Concluiu-se que há dimorfismo sexual em L. cayanensis, sendo as fêmeas de maior porte (I); que ocorrem duas, e não três, fases de coloração nas plumagens juvenis de L. cayanensis (II); que as subespécies propostas por Swann (1922) para L. cayanensis não são válidas, sendo a variação geográfica do porte mais bem explicada por um gradiente em resposta ao módulo da latitude, como previsto pela Lei de Bergmann (III); e que a espécie L. forbesié um táxon válido, com base nos caracteres da coloração das penas coberteiras inferiores e da borda de ataque das asas, brancas em L. forbesie pretas em L. cayanensis, do contraste entre a coloração ventral das rêmiges, sendo as primárias escuras e as secundárias mais claras em L. forbesi, e da coloração das penas da região do pescoço, brancas em L. forbesie cinzas em L. cayanensis (IV). Desta forma, L. forbesi constitui mais uma espécie endêmica do Centro Pernambuco de Endemismo. / The White-collared (or Forbes) Kite Leptodon forbesi Swann, 1922 is an endemic raptor of the Centro Pernambuco, the northernmost portion of the Atlantic Forest, in Northeastern Brazil, and its taxonomic status is still a case of controversy. It is considered a valid species by Swann (1922, 1954), Teixeira et al. (1987) and del Hoyo (1994), whereas Grossman and Hamlet (1964), Brown and Amadon (1968), Blake (1977) and Sick (1994) opt to consider it a morphological variant of the widespread Grey-headed Kite L. cayanensis. The traditional diagnoses of L. forbesiare the underwing coverts, white instead of black; grey pileum; white collar; white tip of quills, mantle and scapular feathers; and a wide white band on both sides of the tail (Swann 1945; Hellmayr and Conover 1949; Pinto 1964). The present study aims to analyse and describe the morphological and morphometrical variation in L. cayanensis, and to test the validity of taxa within the complex, with a special interest in L. forbesiand its geographical distribution. 128 specimes of the genus Leptodon, from Mexico to Southern Brazil, were studied. Morphometrical data was obtained and analysed to evaluate differences between sexes, colour polymorphism in the juvenile plumage, and the subspecies described by Swann (1922) for L. cayanensis. Plumage characters were also studied to test the validity of L. forbesi. We conclude that L. cayanensis shows sexual dimorphism, the females being larger (I); that there are two, not three, coloration morphs in the juvenile plumages of L. cayanensis (II); that the subspecies described by Swann (1922) for L. cayanensis are invalid, the geographical variation in size better explained as a response to latitude module, as predicted by Bergmanns Rule (III); and that the species L. forbesi is a valid taxon, based on the coloration of underwing and leading edge coverts, white in L. forbesi and black in L. cayanensis; on the coloration of the ventral side of the rêmiges, with a contrast between dark primaries and lighter secondaries in L. forbesi; and on the collar coloration, white in L. forbesiand grey in L. cayanensis (IV). Therefore, L. forbesi constitutes another endemic and endangered species of the Centro Pernambuco, in the Brazilian Atlantic Forest.