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Background: Biodiversity, crucial for understanding ecosystems, encompasses species richness, composition, and distribution. Ecological and environmental factors, such as habitat type, resource availability, and climate conditions, play pivotal roles in shaping species diversity within and among communities, categorized into alpha (within habitat), beta (between habitats), and gamma (total regional) diversity. Hummingbird communities are influenced by habitat, elevation, and seasonality, making them an ideal system for studying these diversities, shedding light on mutualistic community dynamics and conservation strategies. Methods: Over a year-long period, monthly surveys were conducted to record hummingbird species and their visited flowering plants across four habitat types (oak forest, juniper forest, pine forest, and xerophytic shrubland) in Tlaxcala, Mexico. Three locations per habitat type were selected based on conservation status and distance from urban areas. True diversity measures were used to assess alpha, beta, and gamma diversity of hummingbirds and their floral resources. Environmental factors such as altitude and bioclimatic variables were explored for their influence on beta diversity. Results: For flowering plants, gamma diversity encompassed 34 species, with oak forests exhibiting the highest richness, while xerophytic shrublands had the highest alpha diversity. In contrast, for hummingbirds, 11 species comprised the gamma diversity, with xerophytic shrublands having the highest richness and alpha diversity. Our data reveal high heterogeneity in species abundance among habitats. Notably, certain floral resources like Loeselia mexicana and Bouvardia ternifolia emerge as key species in multiple habitats, while hummingbirds such as Basilinna leucotis, Selasphorus platycercus, and Calothorax lucifer exhibit varying levels of abundance and habitat preferences. Beta diversity analyses unveil habitat-specific patterns, with species turnover predominantly driving dissimilarity in composition. Moreover, our study explores the relationships between these diversity components and environmental factors such as altitude and climate variables. Climate variables, in particular, emerge as significant contributors to dissimilarity in floral resource and hummingbird communities, highlighting the influence of environmental conditions on species distribution. Conclusions: Our results shed light on the complex dynamics of hummingbird-flower mutualistic communities within diverse habitats and underscore the importance of understanding how habitat-driven shifts impact alpha, beta, and gamma diversity. Such insights are crucial for conservation strategies aimed at preserving the delicate ecological relationships that underpin biodiversity in these communities.

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The diversity of plant-pollinator interactions is grounded in floral resources, with nectar considered one of the main floral rewards plants produce for pollinators. However, a global evaluation of the number of animal-pollinated nectar-producing angiosperms and their distribution world-wide remains elusive. We compiled a thorough database encompassing 7621 plant species from 322 families to estimate the number and proportion of nectar-producing angiosperms reliant on animal pollination. Through extensive sampling of plant communities, we also explored the interplay between nectar production, floral resource diversity, latitudinal and elevational gradients, contemporary climate, and environmental characteristics. Roughly 223 308 animal-pollinated angiosperms are nectar-producing, accounting for 74.4% of biotic-pollinated species. Global distribution patterns of nectar-producing plants reveal a distinct trend along latitudinal and altitudinal gradients, with increased proportions of plants producing nectar in high latitudes and altitudes. Conversely, tropical communities in warm and moist climates exhibit greater floral resource diversity and a lower proportion of nectar-producing plants. These findings suggest that ecological trends driven by climate have fostered the diversification of floral resources in warmer and less seasonal climates, reducing the proportion of solely nectar-producing plants. Our study provides a baseline for understanding plant-pollinator relationships, plant diversification, and the distribution of plant traits.

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The decline of honey bee populations significantly impacts the human food supply due to poor pollination and yield decreases of essential crop species. Given the reduction of pollinators, research into critical landscape components, such as floral resource availability and land use change, might provide valuable information about the nutritional status and health of honey bee colonies. To address this issue, we examine the effects of landscape factors like agricultural area, urban area, and climatic factors, including maximum temperature, minimum temperature, relative humidity, and precipitation, on honey bee hive populations and nutritional health of 326 honey bee colonies across varying landscapes in Mexico. DNA metabarcoding facilitated the precise identification of pollen from 267 plant species, encompassing 243 genera and 80 families, revealing a primary herb-based diet. Areas characterized by high landscape diversity exhibited greater pollen diversity within the colony. Conversely, colonies situated in regions with higher proportions of agricultural and urban landscapes demonstrated lower bee density. The maximum ambient temperature outside hives positively correlated with pollen diversity, aligning with a simultaneous decrease in bee density. Conversely, higher relative humidity positively influenced both the bee density of the colony and the diversity of foraged pollen. Our national-level study investigated pollen dietary availability and colony size in different habitat types, latitudes, climatic conditions, and varied levels and types of disturbances. This effort was taken to gain a better insight into the mechanisms driving declines in honey bee populations. This study illustrates the need for more biodiverse agricultural landscapes, the preservation of diverse habitats, and the conservation of natural and semi-natural spaces. These measures can help to improve the habitat quality of other bee species, as well as restore essential ecosystem processes, such as pollination and pest control.

RESUMO

Rising temperatures and increasing drought in Mediterranean-type climate areas are expected to affect plant-pollinator interactions, especially in plant species with specialised pollination. Central Chile experienced a mega drought between 2010 and 2020 which reached an extreme in the austral summer of 2019-2020. Based on intensive pollinator sampling and floral studies we show that the subalpine form of Mutisia subulata (Asteraceae) is a specialised hummingbird-pollinated species. In a two-year study which included the severest drought year, we quantified visitation frequency, flower-head density, flower-head visitation rates, two measures of floral longevity, nectar characteristics and seed set and monitored climatic variables to detect direct and indirect climate-related effects on pollinator visitation. Flower-head density, nectar standing crop and seed set were significantly reduced in the severest drought year while nectar concentration increased. The best model to explain visitation frequency included flower-head density, relative humidity, temperature, and nectar standing crop with highly significant effects of the first three variables. Results for flower-head density suggest hummingbirds were able to associate visual signals with reduced resource availability and/or were less abundant. The negative effect of lower relative humidity suggests the birds were able to perceive differences in nectar concentration. Reduced seed set per flower-head together with the availability of far fewer ovules in the 2019-2020 austral summer would have resulted in a major reduction in seed set. Longer and more intense droughts in this century could threaten local population persistence in M. subulata.

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Samples of corbicular and stored pollen gathered by Tetragonisca angustula (Latreille, 1811) in an Amazon-Chiquitano transitional forest during the dry season were analyzed. The pollen spectrum was established as well as the dynamics of the relationship between the stingless bee and the surrounding flora. Pollen samples obtained from three rational hives were subjected to acetolysis and 55 pollen types were identified, the most frequent being from Anadenanthera (Fabaceae), Chenopodiaceae, and Dydimopanax (Araliaceae). Significant differences in pollen families used between hives along the months of collection were found in stored pollen and non-significant differences in corbicular pollen. Mean values of alpha diversity (H') showed T. angustula as a generalist while beta diversity qualitatively showed that pollen composition was similar between two hives both of which differed from the third hive. Pollen types in corbicular and stored pollen were in general related with richness of flowering plants in the foraging area; the pollen offer was less diverse than the pollen collected, and a trend to prefer the collection of pollen from the most abundant flowering species could be discerned. T. angustula showed polylectic feeding habits and a capacity to adapt to food availability.

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ABSTRACT Varronia curassavica, a subshrubby medicinal species associated with restinga in the Atlantic Forest, has been exploited by local people and the pharmaceutical industry. Indeed, restingas have experienced a continuous process of degradation, and thus, with species and ecosystem both at risk, efforts to support conservation actions are required. The present study aimed to evaluate aspects of V. curassavica reproductive biology. To accomplish this, morphological characterization was performed by monitoring flowering events. The availability of nectar and pollen, as well as the frequency and behavior of floral visitors and dispersers, was also evaluated. This species exhibits both heterostyly and protogyny. Anthesis is diurnal, and flowers last less than a day. The high number of flower and fruit abortions suggests that mechanisms, such as self-incompatibility intra-morphs and easily detached flowers, contribute to reduced fruit production. The high diversity of floral visitors indicate a generalist pollination syndrome. Diptera, Hymenoptera and Lepidoptera were the main pollinators, and nectar was the main resource sought by these insects. Fruits were dispersed by birds and ants. It can be concluded that the interaction of V. curassavica with several species is a key factor in its own survival and for maintaining the biological diversity of restinga.

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Na Chapada Diamantina, porção norte da Cadeia do Espinhaço, ainda é escasso o conhecimento sobre as comunidades de beija-flores e das plantas que visitam, sendo que os registros disponíveis são de áreas de campo rupestre e caatinga. Este estudo objetivou identificar a troquilofauna de uma área de cerrado ralo da Chapada Diamantina, Bahia, reportando sua sazonalidade e interações agonísticas, além das espécies de plantas que exploram, considerando seus atributos florais e sua fenologia de floração. Os dados foram coletados no município de Mucugê, de outubro de 2005 a agosto de 2006, durante expedições bimestrais em área de cerrado ralo, denominado localmente como "Gerais de Mucugê" (13º 07'15,7"S; 41º 34'53,6"W). Foram registradas quais as espécies de beija-flores ocorrem, sua sazonalidade, suas interações agonísticas inter e intraespecíficas, quais as espécies de plantas visitam, seus atributos florais (morfometria floral, tipo e coloração da flor, concentração de néctar) e seu período de floração. Oito espécies de beija-flores foram registradas: Phaethornis pretrei, Chlorostilbon lucidus, Heliactin bilophus, Eupetomena macroura, Colibri serrirostris, Calliphlox amethystina, Chrysolampis mosquitus e Anopetia gounellei - as três primeiras, residentes na área. Apenas 21 interações agonísticas foram observadas, nas quais Heliactin bilophus esteve envolvido em 12 delas. Esta espécie de beijaflor forrageou o maior número de espécies de plantas (nove espécies), das quais cinco espécies são ornitófilas, e foi considerada a espécie organizadora desta guilda de polinizadores nesta área. Onze espécies de plantas foram utilizadas por beija-flores, das quais sete ornitófilas. O padrão fenológico de floração estimado foi sequencial e contínuo, garantindo recursos aos beija-flores residentes durante todo o ano.

In the northern portion of the Espinhaço Range, records of hummingbird communities and their plants are restricted to rocky fields ("campo rupestre") and dry lands ("caatinga") habitats. This study aimed to identify the flower resources used by hummingbirds in a savannah area at Chapada Diamantina. With this purpose we described hummingbirds' seasonality and agonistic interactions, and floral attributes and flowering phenology of their plant resources. The surveys were carried out at "Gerais de Mucugê" (13º 07'15,7"S; 41º 34'53,6"W) in Chapada Diamantina, municipality of Mucugê, state of Bahia, Brazil. Twelve expeditions were undertaken on a bi-monthly basis between October, 2005 and August, 2007 at an open savannah area. Field activities included observations of hummingbird species, their behavior, and the frequency of their visits; as well as the plant species they visited, their floral attributes, size of corollas, and the flowering period. Eight species of hummingbirds were recorded: Phaethornis pretrei, Chlorostilbon lucidus, Heliactin bilophus, Eupetomena macroura, Colibri serrirostris, Calliphlox amethystina, Chrysolampis mosquitus and Anopetia gounellei - the first three species were residents. We observed 21 agonistic interactions, in which Heliactin bilophus was involved in 12 of them. This species of hummingbird visited the largest number of plant species (nine species), most of which were considered ornithophilous (five species), and it was considered the organizer of the pollinator's guild of the study area. Eleven species of plants were used by hummingbirds, of which seven were considered ornithophilous. The plant community presented a continuous flowering, providing year-round resource for resident hummingbirds.

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To describe plant phenological patterns and correlate functioning for the quantity and quality of resources available for the pollinator, it is crucial to understand the temporal dynamics of biological communities. In this way, the pollination syndromes of 46 species with different growth habits (trees, shrubs, herbs, and vines) were examined in an area of Caatinga vegetation, northeastern Brazil (7° 28′ 45″ S and 36° 54′ 18″ W), during two years. Flowering was monitored monthly in all the species, over two years (from January 2003 to December 2004). Pollination syndromes were characterised based on floral traits such as size, colour, morphology, symmetry, floral resources, as well as on direct visual observation of floral visitors on focal plants and published information. We observed differences among the plant growth habits with respect to floral traits, types of resources offered, and floral syndromes. The flowering periods of the species varied among floral syndrome groups. The majority of the melittophilous species flowered during the rainy season in the two study years, while the species of the other pollination syndroms flowered at the end of the dry season. An asynchrony of flowering was noted among the chiropterophilous species, while the phalenophilous group concentrated during the rainy season. The overall availability of floral resources was different during the rainy and the dry seasons, and also it varied among plants with different growth habits. The availability of oil-flowers coincided with the period of low nectar availability. We observed a relationship between the temporal distribution of the pollination syndromes and the availability of floral resources among each growth habits in this tropical ecosystem. Resource allocation in seasonal environments, such as the Caatinga, can function as a strategy for maintaining pollinators, facilitating therefore the reproductive success of plant species. The availability of floral resources during all the year, specially in seasonal environments such as the Caatinga, may function as a strategy to maintain pollinator populations ensuring the reproductive success of the plants.(AU)

Descrever o padrão fenológico das plantas e correlacionar com a quantidade e qualidade dos recursos disponíveis para os polinizadores é fundamental para entender a dinâmica temporal das comunidades biológicas. Neste sentido, foram estudadas as síndromes de polinização de 46 espécies com diferentes hábitos (árvores, arbustos, ervas, trepadeiras) em uma área de caatinga, no Cariri Paraibano no Nordeste do Brasil (7° 28′ 45″ S e 36° 54′ 18″ W) durante dois anos. Para as diferentes espécies foi acompanhado o período de floração, sendo destacada a fase de início e o pico. As síndromes de polinização foram caracterizadas com base nos atributos florais, como tamanho, cor, morfologia, simetria, tipo de recurso, bem como a partir de observações visuais diretas dos visitantes florais em plantas focais e informações de literatura. Foram encontradas diferenças entre os hábitos, relacionadas aos distintos atributos florais, tipo de recurso e síndrome floral. O período de floração das espécies mostrou-se distinto entre os diferentes tipos de síndromes. A maioria das espécies melitófilas floresceu na estação úmida, enquanto as demais no final da estação seca, nos dois anos de estudo. Foi observada assincronia na floração das espécies quiropterófilas e concentração entre as esfingófilas na estação úmida. A disponibilidade de recursos florais apresentou diferenças entre as estações seca e chuvosa, diferindo também entre os hábitos. A oferta de flores de óleo coincidiu com o período de menor disponibilidade de néctar. Foi observada relação entre a distribuição temporal das diferentes síndromes de polinização, juntamente com a disponibilidade dos recursos florais, nos diferentes hábitos para este ecossistema tropical. A alocação de recursos em ambientes sazonais, como a Caatinga estudada, pode funcionar como uma estratégia para manutenção de polinizadores, facilitando, portanto o sucesso reprodutivo das espécies vegetais.(AU)

Assuntos

RESUMO

To describe plant phenological patterns and correlate functioning for the quantity and quality of resources available for the pollinator, it is crucial to understand the temporal dynamics of biological communities. In this way, the pollination syndromes of 46 species with different growth habits (trees, shrubs, herbs, and vines) were examined in an area of Caatinga vegetation, northeastern Brazil (7° 28′ 45″ S and 36° 54′ 18″ W), during two years. Flowering was monitored monthly in all the species, over two years (from January 2003 to December 2004). Pollination syndromes were characterised based on floral traits such as size, colour, morphology, symmetry, floral resources, as well as on direct visual observation of floral visitors on focal plants and published information. We observed differences among the plant growth habits with respect to floral traits, types of resources offered, and floral syndromes. The flowering periods of the species varied among floral syndrome groups. The majority of the melittophilous species flowered during the rainy season in the two study years, while the species of the other pollination syndroms flowered at the end of the dry season. An asynchrony of flowering was noted among the chiropterophilous species, while the phalenophilous group concentrated during the rainy season. The overall availability of floral resources was different during the rainy and the dry seasons, and also it varied among plants with different growth habits. The availability of oil-flowers coincided with the period of low nectar availability. We observed a relationship between the temporal distribution of the pollination syndromes and the availability of floral resources among each growth habits in this tropical ecosystem. Resource allocation in seasonal environments, such as the Caatinga, can function as a strategy for maintaining pollinators, facilitating therefore the reproductive success of plant species. The availability of floral resources during all the year, specially in seasonal environments such as the Caatinga, may function as a strategy to maintain pollinator populations ensuring the reproductive success of the plants.

Descrever o padrão fenológico das plantas e correlacionar com a quantidade e qualidade dos recursos disponíveis para os polinizadores é fundamental para entender a dinâmica temporal das comunidades biológicas. Neste sentido, foram estudadas as síndromes de polinização de 46 espécies com diferentes hábitos (árvores, arbustos, ervas, trepadeiras) em uma área de caatinga, no Cariri Paraibano no Nordeste do Brasil (7° 28′ 45″ S e 36° 54′ 18″ W) durante dois anos. Para as diferentes espécies foi acompanhado o período de floração, sendo destacada a fase de início e o pico. As síndromes de polinização foram caracterizadas com base nos atributos florais, como tamanho, cor, morfologia, simetria, tipo de recurso, bem como a partir de observações visuais diretas dos visitantes florais em plantas focais e informações de literatura. Foram encontradas diferenças entre os hábitos, relacionadas aos distintos atributos florais, tipo de recurso e síndrome floral. O período de floração das espécies mostrou-se distinto entre os diferentes tipos de síndromes. A maioria das espécies melitófilas floresceu na estação úmida, enquanto as demais no final da estação seca, nos dois anos de estudo. Foi observada assincronia na floração das espécies quiropterófilas e concentração entre as esfingófilas na estação úmida. A disponibilidade de recursos florais apresentou diferenças entre as estações seca e chuvosa, diferindo também entre os hábitos. A oferta de flores de óleo coincidiu com o período de menor disponibilidade de néctar. Foi observada relação entre a distribuição temporal das diferentes síndromes de polinização, juntamente com a disponibilidade dos recursos florais, nos diferentes hábitos para este ecossistema tropical. A alocação de recursos em ambientes sazonais, como a Caatinga estudada, pode funcionar como uma estratégia para manutenção de polinizadores, facilitando, portanto o sucesso reprodutivo das espécies vegetais.

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RESUMO

The foraging activity of Geotrigona mombuca Smith, 1863 was studied under natural conditions aiming to verify the influence of seasonal changes on daily flight activity and annual cycle of the colony. Daily flight activity was monitored for a year based on the observation and counting of foragers leaving and entering the hive, as well as the kind of material transported and meteorological factors such as day time, temperature and relative humidity. The influence of seasonal changes was evidenced by alterations on daily rhythm of flight activity and by differences on transportation of food resources, building material and garbage. These data indicate that forager behavior is related to daily microclimate conditions and it is synchronized with the requirements of colony annual cycle, which determines an intense pollen collection in the summer. Thus, the recomposition of the intranidal population in spring and summer can be ensured, which is characterized both for a higher intensity of flight activity and increase in garbage and resin transport, as well as the swarming process in the spring. In this way, an action targeting the preservation or management of the species in a natural environment should consider that survival and reproduction of the colony depends greatly on the amount of available pollen in late winter.

A atividade de forrageamento de Geotrigona mombuca Smith, 1863 foi estudada em condições naturais com o objetivo de verificar a influência das mudanças sazonais na atividade diária e no ciclo anual da colônia. A atividade diária de voo foi monitorada, durante um ano, através de contagens de campeiras observadas saindo e entrando na colmeia e o tipo de material transportado, juntamente com os fatores meteorológicos hora do dia, temperatura e umidade relativa do ar. A influência das mudanças sazonais foi constatada pela alteração do ritmo diário da atividade de voo e pelas diferenças no transporte de recursos alimentares, material de construção e de resíduos. Esses dados evidenciam que o comportamento das campeiras está relacionado às condições microclimáticas diárias e sincronizadas com as exigências do ciclo anual da colônia, o qual determina uma intensa coleta de pólen no verão, garantindo a recomposição da população intranidal na primavera e verão, caracterizada tanto pela maior intensidade de atividadede de voo como pelo aumento do transporte de resina e lixo, e enxameagem na primavera. Desse modo, ações direcionadas para a preservação da espécie em ambiente natural ou para o manejo devem considerar que a sobrevivência e reprodução da colônia depende muito da quantidade de pólen disponível no final do inverno.

Assuntos

RESUMO

The foraging activity of Geotrigona mombuca Smith, 1863 was studied under natural conditions aiming to verify the influence of seasonal changes on daily flight activity and annual cycle of the colony. Daily flight activity was monitored for a year based on the observation and counting of foragers leaving and entering the hive, as well as the kind of material transported and meteorological factors such as day time, temperature and relative humidity. The influence of seasonal changes was evidenced by alterations on daily rhythm of flight activity and by differences on transportation of food resources, building material and garbage. These data indicate that forager behavior is related to daily microclimate conditions and it is synchronized with the requirements of colony annual cycle, which determines an intense pollen collection in the summer. Thus, the recomposition of the intranidal population in spring and summer can be ensured, which is characterized both for a higher intensity of flight activity and increase in garbage and resin transport, as well as the swarming process in the spring. In this way, an action targeting the preservation or management of the species in a natural environment should consider that survival and reproduction of the colony depends greatly on the amount of available pollen in late winter.(AU)

A atividade de forrageamento de Geotrigona mombuca Smith, 1863 foi estudada em condições naturais com o objetivo de verificar a influência das mudanças sazonais na atividade diária e no ciclo anual da colônia. A atividade diária de voo foi monitorada, durante um ano, através de contagens de campeiras observadas saindo e entrando na colmeia e o tipo de material transportado, juntamente com os fatores meteorológicos hora do dia, temperatura e umidade relativa do ar. A influência das mudanças sazonais foi constatada pela alteração do ritmo diário da atividade de voo e pelas diferenças no transporte de recursos alimentares, material de construção e de resíduos. Esses dados evidenciam que o comportamento das campeiras está relacionado às condições microclimáticas diárias e sincronizadas com as exigências do ciclo anual da colônia, o qual determina uma intensa coleta de pólen no verão, garantindo a recomposição da população intranidal na primavera e verão, caracterizada tanto pela maior intensidade de atividadede de voo como pelo aumento do transporte de resina e lixo, e enxameagem na primavera. Desse modo, ações direcionadas para a preservação da espécie em ambiente natural ou para o manejo devem considerar que a sobrevivência e reprodução da colônia depende muito da quantidade de pólen disponível no final do inverno.(AU)

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RESUMO

We studied hummingbirds and their food plants in an area of caatinga vegetation. We specifically examined their seasonal use of this habitat, migratory and non-migratory status, their foraging strategies and community roles The study was conducted in an area of arboreal-shrub caatinga, located in the Serra do Pará, municipality of Santa Cruz do Capibaribe, state of Pernambuco in northeastern Brazil. Field work was undertaken during 12 expeditions on a monthly basis between June, 2007 and May, 2008. Five species of hummingbirds were recorded visiting flowers in the community studied. Three were considered residents: Chlorostilbon lucidus (Shaw, 1812), Eupetomena macroura (Gmelin, 1788), and Heliomaster squamosus (Temminck, 1823). Hummingbirds visited 31 species of plants, of which only five presented attributes related to ornithophily. C. lucidus visited 29 plant species, including all ornithophilous species, and it was the most aggressive, defending territories. Among hummingbirds, C. lucidus may be considered the principal pollinator. Hummingbirds may also be acting as pollen vectors for some of the plant species not identified as ornithophilous. The hummingbird guilds varied among the plant species used as floral resources, as well as in their frequency of visits. Differences in plant species abundance, hummingbird preference, competitive exclusion or flowering seasonality are factors likely to influence those variations.

Propôs-se estudar os beija-flores e as espécies de plantas utilizadas como recurso alimentar em uma área de caatinga, estudando especificamente a sazonalidade das espécies de beija-flores nesse habitat, os status migratório e não migratório, as suas estratégias de forrageamento e os papéis comunitários. O estudo foi conduzido em uma área de caatinga arbóreo-arbustiva, localizada na Serra do Pará, município de Santa Cruz do Capibaribe, Estado de Pernambuco, no nordeste do Brasil. Os trabalhos de campo foram realizados durante 12 expedições mensais entre junho de 2007 e maio de 2008. Cinco espécies de beija-flores foram registradas visitando flores na comunidade estudada. Três espécies foram consideradas residentes: Chlorostilbon lucidus (Shaw, 1812), Eupetomena macroura (Gmelin, 1788) e Heliomaster squamosus (Temminck, 1823). Os beija-flores visitaram 31 espécies de plantas, das quais apenas cinco apresentaram atributos relacionados à ornitofilia. C. lucidus visitou 29 espécies de plantas, incluindo todas as ornitófilas, assim como também foi a espécie mais agressiva, defendendo territórios. Entre os beija-flores, C. lucidus pode ser considerado como o principal polinizador. Os beija-flores podem estar atuando como vetores de pólen para algumas espécies de plantas não identificadas como ornitófilas. As guildas de beija-flores variaram entre as espécies de plantas utilizadas como recurso floral, assim como nas suas frequências de visitas. Diferenças na abundância das espécies de plantas, na preferência por parte dos beija-flores, na exclusão competitiva ou na sazonalidade de floração são fatores que podem ter influência sobre essas variações.

Assuntos

RESUMO

We studied hummingbirds and their food plants in an area of caatinga vegetation. We specifically examined their seasonal use of this habitat, migratory and non-migratory status, their foraging strategies and community roles The study was conducted in an area of arboreal-shrub caatinga, located in the Serra do Pará, municipality of Santa Cruz do Capibaribe, state of Pernambuco in northeastern Brazil. Field work was undertaken during 12 expeditions on a monthly basis between June, 2007 and May, 2008. Five species of hummingbirds were recorded visiting flowers in the community studied. Three were considered residents: Chlorostilbon lucidus (Shaw, 1812), Eupetomena macroura (Gmelin, 1788), and Heliomaster squamosus (Temminck, 1823). Hummingbirds visited 31 species of plants, of which only five presented attributes related to ornithophily. C. lucidus visited 29 plant species, including all ornithophilous species, and it was the most aggressive, defending territories. Among hummingbirds, C. lucidus may be considered the principal pollinator. Hummingbirds may also be acting as pollen vectors for some of the plant species not identified as ornithophilous. The hummingbird guilds varied among the plant species used as floral resources, as well as in their frequency of visits. Differences in plant species abundance, hummingbird preference, competitive exclusion or flowering seasonality are factors likely to influence those variations.

Propôs-se estudar os beija-flores e as espécies de plantas utilizadas como recurso alimentar em uma área de caatinga, estudando especificamente a sazonalidade das espécies de beija-flores nesse habitat, os status migratório e não migratório, as suas estratégias de forrageamento e os papéis comunitários. O estudo foi conduzido em uma área de caatinga arbóreo-arbustiva, localizada na Serra do Pará, município de Santa Cruz do Capibaribe, Estado de Pernambuco, no nordeste do Brasil. Os trabalhos de campo foram realizados durante 12 expedições mensais entre junho de 2007 e maio de 2008. Cinco espécies de beija-flores foram registradas visitando flores na comunidade estudada. Três espécies foram consideradas residentes: Chlorostilbon lucidus (Shaw, 1812), Eupetomena macroura (Gmelin, 1788) e Heliomaster squamosus (Temminck, 1823). Os beija-flores visitaram 31 espécies de plantas, das quais apenas cinco apresentaram atributos relacionados à ornitofilia. C. lucidus visitou 29 espécies de plantas, incluindo todas as ornitófilas, assim como também foi a espécie mais agressiva, defendendo territórios. Entre os beija-flores, C. lucidus pode ser considerado como o principal polinizador. Os beija-flores podem estar atuando como vetores de pólen para algumas espécies de plantas não identificadas como ornitófilas. As guildas de beija-flores variaram entre as espécies de plantas utilizadas como recurso floral, assim como nas suas frequências de visitas. Diferenças na abundância das espécies de plantas, na preferência por parte dos beija-flores, na exclusão competitiva ou na sazonalidade de floração são fatores que podem ter influência sobre essas variações.

RESUMO

Sunflower (Helianthus annuus L.) is an allogamic plant, which needs insects on flowering, especially the honeybees for seed production. Collecting nectar and pollen by honeybees in agricultural crops is essential to apiculture, as well as a better understanding of plant biology. The foraging behavior of Africanized Apis mellifera L. (Hymenoptera, Apidae) and its efficiency of pollination on seed yield of sunflower genotypes (open pollination and restricted pollination) were evaluated. There were peaks of visits by A. mellifera for nectar collection on the 2nd and 3rd flowering days between 7h00 and 8h30. The average density of A. mellifera during increased visitation ranged from 2.27 to 2.94 bees per capitulum. Nectar collecting bees were more frequent (2.28 bees per capitulum) than pollen collecting (0.40 bees per capitulum). On the 3rd flowering day, Helio 360 and Aguará hybrids had higher (p 0.05) number of bee visits per flower head than the other genotypes. Seed yield was 43 % higher (p 0.05) from sunflower plants that were visited by pollinator-insects compared with plants restricted to pollinators.

RESUMO

Sunflower (Helianthus annuus L.) is an allogamic plant, which needs insects on flowering, especially the honeybees for seed production. Collecting nectar and pollen by honeybees in agricultural crops is essential to apiculture, as well as a better understanding of plant biology. The foraging behavior of Africanized Apis mellifera L. (Hymenoptera, Apidae) and its efficiency of pollination on seed yield of sunflower genotypes (open pollination and restricted pollination) were evaluated. There were peaks of visits by A. mellifera for nectar collection on the 2nd and 3rd flowering days between 7h00 and 8h30. The average density of A. mellifera during increased visitation ranged from 2.27 to 2.94 bees per capitulum. Nectar collecting bees were more frequent (2.28 bees per capitulum) than pollen collecting (0.40 bees per capitulum). On the 3rd flowering day, Helio 360 and Aguará hybrids had higher (p 0.05) number of bee visits per flower head than the other genotypes. Seed yield was 43 % higher (p 0.05) from sunflower plants that were visited by pollinator-insects compared with plants restricted to pollinators.

RESUMO

The aim of this study is to describe interactions between hummingbirds and ornithophilous species at Serra da Bodoquena in midwest Brazil, with focus on flowering phenology and pollination of these plant species. In two habitats, gallery forest and semi-deciduous forest, data on flowering phenology of ornithophilous species were collected monthly over 14 months. In addition, data on morphology and floral biology, as well as visitor frequency and hummingbird behavior, were recorded. The studied community contained eight ornithophilous plant species and six hummingbird species. The ornithophilous species flowered throughout the year, and the greatest abundance of flowers was at the end of the rainy season and the beginning of the dry one. The herit huingbird Phaethornis pretrei and feales of Thalurania furcata, were the most similar in floral resource use. Acanthaceae is the most representative family of ornithophilous plant species in Serra da Bodoquena and, thus, represents the main food source for hummingbirds. Ruellia angustiflora is especially important because it flowers continuously throughout the year and is a significant food resource for P. pretrei, which is the main visitor for this plant guild.

O objetivo deste estudo é descrever as interações entre beijaflores e espécies ornitófilas na Serra da Bodoquena na região Centro-Oeste do Brasil, com foco na fenologia de floração e polinização destas espécies vegetais. Em dois habitats, mata ciliar e floresta semi-decídua, dados de fenologia de floração de espécies ornitófilas foram coletados mensalmente ao longo de 14 meses. Além disso, dados de morfologia e biologia floral bem como a frequência dos visitantes e o comportamento dos beija-flores foram registrados. A comunidade estudada contém oito espécies de plantas ornitófilas e seis espécies de beija-flores. As espécies ornitófilas floresceram todo o ano, e a maior abundância de flores foi no final da estação chuvosa e início da seca. O beija-flor eremita Phaethornis pretrei e a fêmea de Thalurania furcata foram os mais similares no uso dos recursos florais. Acanthaceae é a família mais representativa das espécies vegetais ornitófilas na Serra da Bodoquena e representa a principal fonte de recurso para os beija-flores. Ruellia angustiflora é especialmente importante porque floresce continuamente ao longo do ano e é uma importante fonte de recurso para P. pretrei, que é o principal visitante floral para esta guilda de plantas.

Assuntos

RESUMO

Observations on nectar production, flowering and visiting bees were conducted from October 1999 to October 2000 in a wild population of Eriope blanchetii (Benth) Harley (Lamiaceae) located at Abaeté sand dunes (12º56'S, 38º21'W), in Salvador, Bahia. Fifteen bee species were collected with those varying from medium to large-sized being predominant. The effective pollinators were Xylocopa cearensis Ducke, 1910 and Colletes petropolitanus Dalla Torre, 1896, considering their body size, behaviour and frequency on flowers. Flowering is continuous in E. blanchetii and the degree of synchrony, duration and intensity of flowering in individual plants enforces the interplant movement and gene flow provided by pollinators with different energetic demands and generalist behavior. The pollen deposition is ventral at the same site where anthers and stigma touch bee body, but only C. petropolitanus carried pure E. blanchetii pollen loads. Pollen grain removal generally occurs during male phase and pollen deposition on receptive stigmas during female phase. Nectar was sampled from May to October 2000. Its concentration was 22% (n=10 flowers) and total amount produced ranged from 0.01 to 0.98 ml. The highest amount of nectar was found during male phase (U=2972.5; P 0.05), but there was no significant difference in nectar volume between bagged and unbagged flowers (U=3632; P>0.05) nor in relation to flower position on the inflorescence (ANOVA=4.478; P>0.05). Daily pattern of flowering, nectar production and accessibility are important attractants for potential pollinators.

As observações sobre a floração, produção de néctar e abelhas visitantes foram realizadas entre outubro de 1999 e outubro de 2000, em uma população natural de Eriope blanchetii (Benth) Harley (Lamiaceae) distribuída em dunas litorâneas, Salvador (12º56'S, 38º21'W), Bahia. Entre as 15 espécies de abelhas registradas, predominaram aquelas de porte corporal médio e grande. Os polinizadores efetivos são Xylocopa cearensis Ducke, 1910 e Colletes petropolitanus Dalla Torre, 1896, considerando seu tamanho, comportamento e freqüência nas flores. A floração contínua da população de E. blanchetii e o grau de sincronia, duração e intensidade da floração entre os indivíduos estimula o movimento interplanta e o transporte de pólen pelos polinizadores com diferentes demandas energéticas e comportamento generalista. A deposição de pólen ocorre na região ventral do corpo do polinizador na região que contata as anteras e o estigma durante o forrageio, mas apenas C. petropolitanus transportou exclusivamente pólen de E. blanchetii. O pólen, removido principalmente durante a fase masculina é, posteriormente, depositado em flores com estigmas receptivos durante a fase feminina. Entre maio e outubro de 2000, o volume de néctar variou de 0,01 a 0,98 ml sendo maior na fase masculina (U=2972,5; P 0,05); a concentração registrada foi de 22% (n=10 flores). A diferença entre o volume de néctar em flores em relação à sua posição na inflorescência (ANOVA=4.478; P>0.05) e entre aquelas ensacadas e não ensacadas (U=3632; P>0.05) não foi significativa. O padrão de floração, a produção e acessibilidade do néctar tornam as flores de E. blanchetii atrativas aos seus polinizadores potenciais.

RESUMO

Observations on nectar production, flowering and visiting bees were conducted from October 1999 to October 2000 in a wild population of Eriope blanchetii (Benth) Harley (Lamiaceae) located at Abaeté sand dunes (12º56'S, 38º21'W), in Salvador, Bahia. Fifteen bee species were collected with those varying from medium to large-sized being predominant. The effective pollinators were Xylocopa cearensis Ducke, 1910 and Colletes petropolitanus Dalla Torre, 1896, considering their body size, behaviour and frequency on flowers. Flowering is continuous in E. blanchetii and the degree of synchrony, duration and intensity of flowering in individual plants enforces the interplant movement and gene flow provided by pollinators with different energetic demands and generalist behavior. The pollen deposition is ventral at the same site where anthers and stigma touch bee body, but only C. petropolitanus carried pure E. blanchetii pollen loads. Pollen grain removal generally occurs during male phase and pollen deposition on receptive stigmas during female phase. Nectar was sampled from May to October 2000. Its concentration was 22% (n=10 flowers) and total amount produced ranged from 0.01 to 0.98 ml. The highest amount of nectar was found during male phase (U=2972.5; P 0.05), but there was no significant difference in nectar volume between bagged and unbagged flowers (U=3632; P>0.05) nor in relation to flower position on the inflorescence (ANOVA=4.478; P>0.05). Daily pattern of flowering, nectar production and accessibility are important attractants for potential pollinators.

As observações sobre a floração, produção de néctar e abelhas visitantes foram realizadas entre outubro de 1999 e outubro de 2000, em uma população natural de Eriope blanchetii (Benth) Harley (Lamiaceae) distribuída em dunas litorâneas, Salvador (12º56'S, 38º21'W), Bahia. Entre as 15 espécies de abelhas registradas, predominaram aquelas de porte corporal médio e grande. Os polinizadores efetivos são Xylocopa cearensis Ducke, 1910 e Colletes petropolitanus Dalla Torre, 1896, considerando seu tamanho, comportamento e freqüência nas flores. A floração contínua da população de E. blanchetii e o grau de sincronia, duração e intensidade da floração entre os indivíduos estimula o movimento interplanta e o transporte de pólen pelos polinizadores com diferentes demandas energéticas e comportamento generalista. A deposição de pólen ocorre na região ventral do corpo do polinizador na região que contata as anteras e o estigma durante o forrageio, mas apenas C. petropolitanus transportou exclusivamente pólen de E. blanchetii. O pólen, removido principalmente durante a fase masculina é, posteriormente, depositado em flores com estigmas receptivos durante a fase feminina. Entre maio e outubro de 2000, o volume de néctar variou de 0,01 a 0,98 ml sendo maior na fase masculina (U=2972,5; P 0,05); a concentração registrada foi de 22% (n=10 flores). A diferença entre o volume de néctar em flores em relação à sua posição na inflorescência (ANOVA=4.478; P>0.05) e entre aquelas ensacadas e não ensacadas (U=3632; P>0.05) não foi significativa. O padrão de floração, a produção e acessibilidade do néctar tornam as flores de E. blanchetii atrativas aos seus polinizadores potenciais.

RESUMO

A goiaba-serrana (Acca sellowiana, Myrtaceae) é uma das poucas espécies vegetais cujas pétalas são habitualmente usadas como alimento por aves nos Neotrópicos. Registramos aqui o consumo de pétalas desta mirtácea por nove espécies de aves Passeriformes, numa arvoreta isolada em área urbana de Gramado, Rio Grande do Sul. A maior freqüência de visitas foi registrada para espécies de Thraupidae, aves predominantemente frugívoras. As aves tomavam as pétalas entre as mandíbulas e arrancavam ou cortavam porções, deixando sinais característicos nas flores. Thraupis sayaca e Tangara preciosa foram registrados recolhendo porções de pétalas e levando-as entre as mandíbulas, a primeira espécie tendo sido duas vezes observada fornecendo pétalas a ninhegos. Devido ao seu porte médio e à beleza das suas flores, bem como à atração de diversas espécies de pássaros mesmo em área urbanizada, reiteramos aqui o uso de A. sellowiana em arborização urbana no Sul e Sudeste do Brasil.

The feijoa (Acca sellowiana, Myrtaceae) is one of the few plant species whose petals are habitually eaten by birds in the Neotropics. We record here the use of petals of this myrtaceous plant by nine species of passerine birds of an isolated plant in the urban area of Gramado, Rio Grande do Sul, southern Brazil. Highest visiting frequency was recorded for tanagers (Thraupidae), a predominantly frugivorous bird group. The birds took the petals within their mandibles and tore or cut pieces off. Thraupis sayaca and Tangara preciosa were recorded collecting several petal pieces with their mandibles, the first species being observed twice feeding petals to nestlings. Due to its medium size and the showy flowers, as well as to its attractiveness to several bird species even in an urbane area, we reiterate here the recommendation to use A. sellowiana in parks and gardens in southern and southeastern Brazil.

Assuntos

RESUMO

The study was carried out in a 8.2 ha area in an environmental protection area of tropical sea coastal sand dune with "restinga" vegetation in Salvador, Bahia, northeastern Brazil. A total of 1760 bees of Xylocopa (Neoxylocopa) cearensis Ducke, 1910 were netted during the whole year on flowers of 43 plant species belonging to 26 botanic families. The majority of the individuals (79%) concentrated their foraging activity in five plant species. Individuals foraged all day long being the greatest activity between 8 h and 14 h. Similar proportions of young and old bees were sampled over the year. The density of substrates used for nesting was 4.56/ha. In total, 94% of the nests were found in branches of Agaristha revoluta (Spr.) DC. (Ericaceae). The great occurrence (68.7%) of old perforations indicates that the nests were used twice or more times by bees.