Browsing by Author "Martins, Cristiane"

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Fauna de abelhas de campos rupestres ferruginosos no Quadrilátero Ferrífero, Minas Gerais.
    (2012) Martins, Cristiane; Silveira, Rodrigo Assunção da; Nascimento, Nathália de Oliveira; Antonini, Yasmine
    Os campos rupestres ferruginosos são ricos em plantas polinizadas por abelhas, portanto, sua preservação está diretamente relacionada e dependente da preservação das populações destas. Nesse trabalho compilamos informações sobre a apifauna do Parque Estadual da Serra do Rola Moça e Ouro Preto a partir de dados primários e secundários. Os resultados encontrados apontam uma riqueza de 107 espécies sendo 101 na Serra do Rola Moça, 46 em Ouro Preto (área urbana) e 49 na Serra da Brígida, cada área apresentando cerca de 69, 4 e 13 espécies exclusivas, respectivamente. A maioria das espécies pode ser considerada rara pela baixa abundância. A grande riqueza de espécies raras e ou restritas aos ambientes de campos ferruginosos aumentam a importância desses ecossistemas para a conservação da fauna de abelhas.
  • No Thumbnail Available
    Item
    Is bigger always better? : neither body size nor aggressive behavior predicts specialization of hummingbirds in a rocky outcrop.
    (2022) Claudino, Ricardo Marcelino; Itabaiana, Yasmine Antonini; Martins, Cristiane; Beirão, Marina do Vale; Braga, Érika Martins; Azevedo, Cristiano Schetini de
    Interspecific competition can strongly influence community structure and shape niche breadth and overlap. One of the main factors that determines hummingbird community structure is competition for food. Hummingbirds’ functional attributes, such as beak length and body mass, influence nectar acquisition in flowers. This study evaluates how functional and behavioral attributes of hummingbirds influence their specialization, as measured by pollen transportation. We tested the following hypothesis: H1) smaller and short-billed hummingbirds will carry higher pollen richness and relatively more pollen grains than long-billed hummingbirds; H2) dominant and territorial hummingbirds carry a lower richness of pollen types and fewer pollen grains when compared to subordinate hummingbirds, and H3) the similarity in the composition of pollen morphotypes, between the hummingbirds species, will be low because we expect to find high specialization in the use of plant species. We conducted the study between September 2018 and March 2019 in a Campo Rupestre (rocky outcrops) in Southeastern Brazil. Hummingbirds were captured with a trap. The pollen adhered to the body parts was collected, counted, and identified in the laboratory. We recorded hummingbirds’ beak sizes and body masses. Behavioral responses of hummingbirds to artificial feeders were collected regarding the time and duration of each visit and the outcome of aggressive inter- actions. An interaction network was built based on the pollen grains found on each hummingbird. Our results showed that neither body size nor aggressive behaviors influenced pollen richness on hummingbirds’ bodies. Beak length was the most important hummingbird attribute that influenced pollen richness, but not pollen relative abundance. Short-billed hummingbirds carried the greatest richness of pollen grains. The hummingbird pollen-grain interaction network was generalized in the pollen grains transported. We conclude that hummingbirds’ beak length is the cen- tral morphological variable related to pollen grain transport in rocky outcrops.
  • No Thumbnail Available
    Item
    Reproductive biology of Cipocereus minensis (Cactaceae) — a columnarcactus endemic to rupestrian fields of a Neotropical savannah.
    (2016) Martins, Cristiane; Oliveira, Reisla Silva de; Mendonça Filho, Carlos Victor; Lopes, Liliane Teixeira; Silveira, Rodrigo Assunção da; Silva, Juliana Aparecida Pereira da; Aguiar, Ludmilla Moura de Souza; Antonini, Yasmine
    We studied the reproductive biology of Cipocereus minensis, an endemic columnar cactus of the Espinhac¸ oMountain Range, Southeastern Brazil, focusing on floral biology, breeding system, and pollination. Wedescribed floral morphology and evaluated the role of nocturnal and diurnal pollinators on the repro-ductive success in two populations. C. minensis has large, horizontal, cream-colored, chiropterophilousflowers with rigid petals that open at dusk and close on the following morning. Flowers produced ahuge amount of pollen grains and nectar production was nocturnal. Controlled pollination experimentsrevealed that the cactus is an obligate xenogamous species. Visitor-exclusion experiments revealed thatthe nocturnal visitors (bats) are the prominent pollinators whereas hummingbirds and social bees, whichvisited the flowers early in the morning, contributed little to fruit set. We conclude that the reproductivesuccess of this endemic columnar cactus is threatened in the absence of the effective pollinating bats.