ABSTRACT. During flight, hummingbirds achieve the maximum aerobic metabolism rates within vertebrates. To meet such demands, these birds have to take in as much energy as possible, using strategies such as selecting the best food resources and adopting behaviors that allow the greatest energy gains. We tested whether hummingbirds choose sources that have higher sugar concentrations, and investigated their behaviors near and at food resources. The study was conducted at and T. glaucopis exhibited interspecific and intraspecific dominance; 2) the remaining species exhibited subordinance to the dominant hummingbirds, and 3) P. eurynome and Phaethornis spp. adopted a hide-and-wait strategy to the dominant hummingbird species. The frequency of aggressive behaviors was correlated with the time the hummingbird spent feeding, and bird size. Our results showed that hummingbirds can adopt different strategies to enhance food acquisition; that more aggressive species feeding more than less aggressive species; and that the birds, especially if they were dominant species, visited high quality food resources more often.
Total de espécies de aves do Brasil (1981Brasil ( -2013 CBRO | LISTAS DAS AVES DO BRASIL | 11ª. Ed.2 Além do acúmulo de novidades ao longo de três anos, a lista nova espelha em seus números a quantidade crescente de trabalhos taxonômicos e sistemáticos na ornitologia, fruto em parte da sempre destacada revolução por que passa a Zoologia (e a biologia) com o desenvolvimento de técnicas de análise moleculares (cada vez mais acessíveis), mas também na disponibilidade cada vez maior de dados como gravações sonoras e mesmo de estudantes e profissionais ligados a instituições acadêmicas no Brasil desenvolvendo tais pesquisas. Dessa forma, o total de 70 espécies novas na edição que ora vem a lume equivale a uma média de 20 novas espécies por ano reconhecidas para o Brasil nos últimos 3 anos, superando em muito a média de 7,8 novas espécies por ano no período de listas anuais (2005)(2006)(2007)(2008)(2009)(2010); ver gráfico acima). A continuar esse crescimento (e tudo indica que os próximos anos serão tão ou mais intensos do que os últimos), tentar privilegiar uma estabilidade na sistemática das Listas de Aves do Brasil do CBRO torna-se um objetivo cada vez mais difícil de alcançar.Se, por um lado, a instabilidade incomoda muitos usuários da nossa lista (ao menos num primeiro momento) e até dificulta a pesquisa de dados ornitológicos publicados há vários anos (sob outros nomes de espécies), essa inevitável instabilidade é fruto do desenvolvimento da ornitologia brasileira e neotropical, levando a um reconhecimento muito mais avançado da real diversidade e riqueza de aves do Brasil, com consequências até mesmo para a conservação da biodiversidade brasileira. De certa forma, essa instabilidade nada mais é do que um reflexo coletivo dos esforços individuais de diversos pesquisadores que se dedicam com afinco, no Brasil e no exterior, ao estudo de nossas aves. Conviver com essa instabilidade é reconhecer e valorizar a dedicação de todos esses pesquisadores.Em nome de todos os membros do Comitê Brasileiro de Registros ornitológicos, agradeço a todos aqueles que contribuem direta ou indiretamente para a construção e melhora de nossas listas de aves. É dada uma especial atenção à autoria e datação dos táxons, incluindo aquelas dos nomes dos táxons superiores. Os nomes em Português, um único para cada espécie, tem caráter meramente instrumental e não devem ser entendidos como uma tentativa de normatização. Para uma listagem abrangente dos nomes populares recomenda-se consultar o site do Centro de Estudos Ornitológicos (http://www.ib.usp.br/ceo/nomespop.htm).Além da lista primária (a lista principal) de aves brasileiras, há duas outras listas: secundária e terciária, que serão igualmente organizadas e permanentemente atualizadas pelo CBRO. Uma definição técnica de cada uma destas é dada a seguir.Lista Primária -Espécies com pelo menos um dos registros de ocorrência no Brasil provido de evidência documental. Neste contexto, são evidências documentais os itens disponíveis, para consulta independente, na forma exclusiva de espécim...
· Habitat loss and fragmentation is recognized as one of the main causes of global biodiversity declines. Birds of prey are considered good environmental bioindicators because they are sensitive to changes in the environment and can suffer local extinctions due to habitat fragmentation. In this study, we aimed to determine whether forest fragment area is correlated with the richness and abundance of owl species, and whether owl species recorded exhibit preferences for fragment edge or interior. The study was undertaken in six remnants of southeastern Atlantic Forest located in Minas Gerais State, Brazil. Six species of owls were recorded: Buff-fronted Owl (Aegolius harrisii), Tropical Screech-Owl (Megascops choliba), Tawny-browed Owl (Pulsatrix koeniswaldiana), Striped Owl (Asio clamator), Mottled Owl (Strix virgata), and Rusty-barred Owl (Strix hylophila). Megascops choliba was the most abundant species. The richness and abundance of species were higher at the edge when compared to the interior of the fragments. The owl species recorded did not seem to prefer the forest interior, while M. choliba had a preference for forest edges. This study adds new empirical knowledge on the effects of fragmentation on Neotropical owl communities.Resumen · Comunidades de lechuzas y búhos en fragmentos de bosque Atlántico en Brasil El proceso de pérdida y fragmentación del hábitat se identifica como una de las principales causas del declive de la biodiversidad mundial. Las aves de presa se consideran un buen bioindicador ambiental porque son sensibles a los cambios en el medio ambiente y pueden extinguirse localmente con la fragmentación del bosque. El objetivo del estudio fue responder a las siguientes preguntas: ¿La fragmentación de los bosques influyen en la riqueza y abundancia de las especies de búhos? ¿Las especies de búho tienen preferencia por el borde o el interior de los fragmentos del bosque? El estudio se llevó a cabo de octubre de 2011 a septiembre de 2012 en seis localidades de la Mata Atlántica suroriental, ubicadas en el estado de Minas Gerais, Brasil. Seis especies de búhos fueron registradas: Lechucita Acanelada (Aegolius harrisii), Currucutú Común (Megascops choliba), Lechuzón Mocho Chico (Pulsatrix koeniswaldiana), Búho Gritón (Asio clamator), Mocho Carijó (Strix virgata) y Rusty-barred Owl (Strix hylophila). M. choliba fue la especie más abundante. La riqueza y abundancia de especies fue mayor en el borde comparado con el interior de los fragmentos. La comunidad de búhos en nuestra área de estudio no parece tener preferencia por el interior del bosque, sin embargo, M. choliba es más abundante en los bordes del bosque. Este estudio aporta nuevos conocimientos sobre la riqueza y abundancia de los búhos Neotropicales y su respuesta a la fragmentación de la Mata Atlántica.
Interspecific competition can strongly influence community structure and shape niche breadth and overlap. One of the main factors that determine the hummingbird community structure is competition for food. Hummingbirds functional attributes, such as beak length and body mass, influence nectar acquisition in the flowers, shaping foraging niches according to hummingbird dominance and foraging strategy. This study evaluates how the hummingbirds' functional and behavioral attributes are related to plants assemblage in rocky outcrops' habitats. We tested the following hypothesis: H1) Functional traits (beak length and body mass) are related to the richness and frequency of pollen grain morphotypes carried by hummingbirds; H2) Dominant and territorial hummingbirds carry a lower richness and frequency of pollen types when compared to subordinate hummingbirds, and H3) Hummingbird species carry different types of pollen grains. 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 built based on trapdoors. We recorded their beak size and body masses, marked with commercial bird rings and ink on parts of the body, and then released. Behavioral responses to artificial feeders were collected regarding each visit's time and duration and the outcome of aggressive interactions. The pollen adhered to the body parts was collected and identified in the laboratory. Our results showed that neither body size nor aggressive behaviors influenced pollen richness and frequency in rocky outcrops. Beak length was the most important hummingbirds' attribute that influenced pollen richness, but not pollen frequency. Short-billed hummingbirds carried the greatest richness of pollen grains. Pollen grain richness and frequency were not related to hummingbird body mass or aggressive behavior. The hummingbird-pollen grain interaction network has shown to be generalized in the pollen grain transport. We conclude that hummingbirds' beak length is the central morphological variable to measure pollen grain transport. It has direct implications for the pollination of different plant species.
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 interactions. 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 central morphological variable related to pollen grain transport in rocky outcrops.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.