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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A POMBA-DE-BANDO (ZENAIDA AURICULATA - AVES, COLUMBIDAE) NAS PAISAGENS AGRÍCOLAS DO SUDOESTE DO BRASIL: DISTRIBUIÇÃO, ABUNDÂNCIA E INTERAÇÕES COM A AGRICULTURA / Eared dove (Zenaida auriculata - Aves, Columbidae) in agricultural landscape in southwestern of Brazil: Distribution, abundance and interactions with agriculture

Silva, Giliandro Gonçalves 26 February 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Agriculture expansion and intensification reassemble bird communities, including the loss of species, reduced diversity and the population increase of some species able to use the novel resources available. In some circumstances these species may be perceived as overabundant and conflict with human activities. This dissertation examines 1) the influence of the land use in agricultural landscapes in the abundance of eared dove and 2) the recognition of eared dove's populations as overabundant in the Southwestern of Brazil. The study was conducted in grain-producing regions comprising the part of the States of Rio Grande do Sul, Santa Catarina, Paraná and São Paulo. We counted birds along 50 routes, each comprising 12 counting stations, placed on secondary roads and relate occurrence and abundance with land uses. We applied questionnaires to farmers record their perception about damages by eared doves in agriculture. Our data demonstrated that the eared dove was the most abundant species, representing 48% of total individuals counted and also one of the most common, being found in 93% of samples. At the landscape scale, the abundance of eared doves was associated positively with routes crossing landscapes dominated by plantations in winter and negatively associated with routes with large tracts of forests and mixed farming in summer. At the local scale the abundance of doves in winter was greater in routes with higher frequency of maize plantations and in summer in routes with higher frequency of sugar cane and soybean plantations. Thus, the type of land use influenced the abundance of doves. Of the farmers interviewed, 41% claimed some kind of damage to their crops. Among these, 70% reported damages of less than 10% of the planted area. The highest percentage of positive responses about damages occurred in Paraná, with 54% of complaints. Sixty seven percent of the reported damages were located up to 100 km from nesting colonies. The probability of reporting damages decreases 1% every 10 km away from a colony. We consider that eared doves can be classified as overabundant in parts of the States of Paraná and São Paulo, where the agricultural landscape favor high abundance of this species all over the year and risk of conflicts with agriculture is higher. / A expansão da agricultura e a intensificação dos processos agrícolas levam a um rearranjo nas comunidades de aves, incluindo a perda de diversidade e o aumento populacional de espécies capazes de aproveitar os novos recursos disponíveis. Em algumas circunstâncias espécies podem apresentar um marcado aumento populacional passando a ser percebidas como superabundantes e conflitantes para atividades humanas. Esta dissertação analisa 1) a influência do uso do solo na abundância da pomba-de-bando e 2) a aplicação de conceitos de superabundância para esta espécie no Sudoeste do Brasil. A área de estudo abrangeu regiões produtoras de grãos dos Estados do Rio Grande do Sul, Santa Catarina, Paraná e São Paulo. Contamos aves em 50 rotas, cada uma com 12 estações de contagem, alocadas em estradas vicinais em meio a matrizes agrícolas e relacionamos ocorrência e abundância com a paisagem. Aplicamos questionários aos agricultores com a intenção de obter dados da percepção dos mesmos frente a danos causados pela pomba na agricultura. A pomba-de-bando foi a espécie mais abundante, representando 48% do total de indivíduos contados, e também uma das mais frequentes, sendo encontrada em 93% das amostras. Na escala da paisagem, mais ampla, a abundância esteve positivamente associada às áreas destinadas à agricultura e agropecuária no inverno e negativamente associada às áreas com grandes extensões de agropecuária e remanescente florestais no verão. Na escala local, mais fina, a abundância de pombas no inverno foi maior em rotas de contagem em que houve maior frequência de plantações de milho. Já no verão a abundância foi positivamente relacionada com a maior frequência de plantações de cana-de-açúcar e soja. Assim, o tipo de uso do solo na paisagem agrícola influenciou a abundância de pombas nas duas escalas. Dos respondentes aos questionários, 41% alegaram dano às suas plantações, sendo que 70% relataram danos inferiores a 10% da área plantada. O maior percentual de respostas positivas se deu no Paraná, com 54% de reclamações. Sessenta e sete por cento responderam sim a ocorrência de danos quando o local de aplicação do questionário estava a menos de 100 km de uma colônia de pombas. A probabilidade de reclamações decaiu 1% a cada 10 km de afastamento da colônia mais próxima. Consideramos que a pomba-de-bando pode ser classificada como superabundante somente em partes do Paraná e de São Paulo, onde a paisagem agrícola favorece uma alta abundância de pombas durante todo o ano e o risco de conflitos com a agricultura é maior.
2

Bird Abundance at Bird Feeders in Response to Temperature, Wind Speed and Precipitation During the Winter Season

Kahal, Siddhant 01 June 2018 (has links) (PDF)
The goal of this project is to explore how 23 different bird species respond to 3 climatic attributes. These attributes are lower than average temperatures, wind speed and precipitation level. Information about the bird species and all of the data associated with them is provided by Project FeederWatch (PFW). This is a citizen based survey study that provides key information about bird species abundance through the use of backyard and community feeders. The study volunteers from across the United States and Canada monitor these bird feeders and note important information about the species such as the number of individuals seen. Other standard information is also included such as location data and date. An original data collection pipeline was developed for this study to append climate data from Weather Underground (WU) to the PFW bird feeder data. The final dataset helped to explore how exactly the birds are reacting to winter temperatures, wind speeds and rain levels. Our results indicate that birds species in general visit the bird feeders more often as temperatures dip below average. We found that the body mass of the bird plays no role in the number of visits. Birds don't seem to be significantly affected by precipitation or wind speed as our results indicate no relationship between these climatic factors and abundance at the feeders.

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