RESUMO

Delayed flowering due to later snowmelt and colder temperatures at higher elevations in the alpine are expected to lead to flowering phenological adjustment to prevent decoupling of peak flowering from the warmest time of the year, thereby favoring pollination. However, even if flowering is brought forward in the season at higher elevations, an elevational temperature gap is likely to remain between the high- and low-elevation populations of a species at the time these reach peak flowering on account of the atmospheric reduction in temperature with increasing elevation. The negative effect of this temperature gap on pollination could be compensated by plastically-prolonged flower life spans at higher elevations, increasing the probability of pollination. In a tightly temperature-controlled study, the flowering phenology adjustment and flower longevity compensation hypotheses were investigated in an alpine species in the Andes of central Chile. The snow free period varied from 7 to 8.2 months over 810 m elevation. Temperatures were suitable for growth on 82-98% of the snow free days. Flowering onset was temporally displaced at the rate of 4.6 d per 100 m increase in elevation and flowering was more synchronous at higher elevations. Flowering phenology was adjusted over elevation. The latter was manifest in thermal sums tending to decrease with elevation for population flowering onset, 50% flowering, and peak flowering when the lower thermal limit for growth (TBASE) was held constant over elevation. For TBASE graded over elevation so as to reflect the growing season temperature decline, thermal sums did not vary with elevation, opening the door to a possible elevational decline in the thermal temperature threshold for growth. Potential flower longevity was reduced by passive warming and was more prolonged in natural populations when temperatures were lower, indicating a plastic trait. Pollination rates, as evaluated with the Relative Pollination Rate index (RPR), when weighted for differences in floral abundance over the flowering season, declined with elevation as did fruit set. Contrary to expectation, the life-spans of flowers at higher elevations were not more prolonged and failed to compensate for the elevational decrease in pollination rates. Although strong evidence for phenological adjustment was forthcoming, flower longevity compensation did not occur over Oxalis squamata´s elevational range. Thus, flower longevity compensation is not applicable in all alpine species. Comparison with work conducted several decades ago on the same species in the same area provides valuable clues regarding the effects of climate change on flowering phenology and fitness in the central Chilean alpine where temperatures have been increasing and winter snow accumulation has been declining.

RESUMO

BACKGROUNDS AND AIMS: Tropical plant species are already suffering the effects of climate change and projections warn of even greater changes in the following decades. Of particular concern are alterations in flowering phenology, given that it is considered a fitness trait, part of plant species ecological niche, with potential cascade effects in plant-pollinator interactions. The aim of the study was to assess the potential impacts of climate change on the geographical distribution and flowering phenology of hummingbird-pollinated plants. METHODS: We implemented ecological niche modelling (ENM) to investigate the potential impacts of different climate change scenarios on the geographical distribution and flowering phenology of 62 hummingbird-pollinated plant species in the Brazilian Atlantic Forest. KEY RESULTS: Distribution models indicate future changes in the climatic suitability of their current habitats, suggesting a tendency towards discontinuity, reduction and spatial displacement. Flowering models indicate that climate can influence species phenology in different ways: some species may experience increased flowering suitability whereas others may suffer decreased suitability. CONCLUSIONS: Our results suggest that hummingbird-pollinated species are prone to changes in their geographical distribution and flowering under different climate scenarios. Such variation may impact the community structure of ecological networks and reproductive success of tropical plants in the near future.

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BACKGROUND: Many species of birds are morphologically and physiologically adapted for migration. Migratory movements of birds can range from thousands of kilometers, such as when birds migrate from wintering to breeding sites in summer, to several kilometers, such as when birds migrate among habitats in a single mountain system. The main factor that influences bird migration is the seasonal fluctuation of food resources; climate, predation, competition for resources and endogenous programming are also important factors. Hummingbirds are highly dependent on nectar, so their migration is likely correlated with the blooming of plant species. The ecological implications of altitudinal migration in the mountains of North America as well as the latitudinal migration of Selasphorus rufus through Mexico are still poorly understood. To explore these issues, over three non-consecutive years, we evaluated interannual variation in the phenologies of a latitudinal migrant (S. rufus) and an altitudinal migrant (Amazilia beryllina) and their visited plants. METHODS: We assessed the relationship between two migratory hummingbirds and flower abundance in 20 fixed-radius plots (25 m radius). All available flowers were counted along transects (40 × 5 m) inside each fixed-radius plot. Sampling was performed every 10 days from November 12 through February 20 of 2010-2011, 2013-2014 and 2015-2016, resulting in a total of 11 samples of each plot per period. Phenological variation and the relationships among hummingbird abundance, flower abundance and vegetation type were evaluated using a generalized additive mixed model. RESULTS: S. rufus abundance was related to sampling time in the first and third periods; this relationship was not significant in the second period. A. beryllina abundance was related with the sampling time over all three periods. The abundance of S. rufus hummingbirds was significantly related to the number of Salvia iodantha flowers. The abundance of A. beryllina hummingbirds was related to the number of S. iodantha and Cestrum thyrsoideum flowers and the total number of flowers. We found a non-significant correlation between S. rufus and A. beryllina abundance and vegetation types. CONCLUSION: Contrary to expectations, the long-distance migration of S. rufus was not consistent over the sampling periods. The migration of S. rufus through the study region may be altered by changes in climate, as has occurred with other species of migratory birds. In the present study, the migration of S. rufus was correlated with the blooming of S. iodantha. In comparison, the altitudinal migrant A. beryllina responded to the availability of floral resources but was not associated with a particular plant. The migration of this latter species in the area probably depends on multiple factors, including climatic and demographic factors, but is particularly dependent on the supply of floral resources and competition for these resources.

RESUMO

Floral mechanisms that ensure seed production via autogamy are more likely to occur in species growing in environments where pollination is scarce. Amasonia obovata was studied in the State of Mato Grosso-Brazil, from 2009 to 2012, to analyze the morphological and reproductive characteristics, aside from investigating the association of the reproductive success with the pollinator frequency and identity. The flowering and fruiting of A. obovata was concentrated in a period of five months during the rainy season. The dichogamy in flowers of A. obovata is not clearly defined, since the sexual functions were overlapped in the male and female phases. The species is self-compatible and not apomictic. The fruiting percentage obtained by hand self-pollination did not differ from cross-breeding (F = 0.74, P =0.39). In the observations from 2010 to 2012, a hummingbird (Thalurania furcata) legitimate visited 20-100% of the flowers in the male and female phases on different A. obovata plants. Due to the high frequency, this hummingbird was considered the single potential pollinator of the species. These findings show that a limited availability of pollinators may select for floral traits and plant mating strategies that lead to a system of self-fertilization.

Mecanismos florais que garantem produção de sementes via autogamia, são mais prováveis de ocorrer em espécies que crescem em habitats onde a polinização é escassa. Amasonia obovata foi estudada na região sudoeste do estado de Mato Grosso, durante os anos de 2009 a 2012, e o estudo teve por objetivo analisar as características morfológicas, morfométricas e reprodutivas, além de associar o sucesso reprodutivo à frequência de polinizadores. A. obovata concentrou a floração e frutificação em um período de cinco meses, durante a estação chuvosa. A dicogamia em flores de A. obovata não está claramente demarcada, já que as funções sexuais se sobrepõem nas fases masculina e feminina. A espécie é autocompatível e não apomítica. Os valores percentuais de frutificação obtidos na autopolinização manual não diferiram dos valores obtidos na polinização cruzada (F= 0,74; P=0,39). Em observações realizadas nos anos de 2010 a 2012, o beija-flor (Thalurania furcata) realizou de 20 a 100% de visitas legítimas às flores nas fases masculina e feminina, de diferentes indivíduos de A. obovata e, devido à sua frequência, foi considerado o potencial polinizador da espécie. Os resultados mostram que a limitada disponibilidade de polinizadores pode selecionar plantas de características florais e estratégias de reprodução que levam a um sistema reprodutivo autogâmico.

RESUMO

Floral mechanisms that ensure seed production via autogamy are more likely to occur in species growing in environments where pollination is scarce. Amasonia obovata was studied in the State of Mato Grosso-Brazil, from 2009 to 2012, to analyze the morphological and reproductive characteristics, aside from investigating the association of the reproductive success with the pollinator frequency and identity. The flowering and fruiting of A. obovata was concentrated in a period of five months during the rainy season. The dichogamy in flowers of A. obovata is not clearly defined, since the sexual functions were overlapped in the male and female phases. The species is self-compatible and not apomictic. The fruiting percentage obtained by hand self-pollination did not differ from cross-breeding (F = 0.74, P =0.39). In the observations from 2010 to 2012, a hummingbird (Thalurania furcata) legitimate visited 20-100% of the flowers in the male and female phases on different A. obovata plants. Due to the high frequency, this hummingbird was considered the single potential pollinator of the species. These findings show that a limited availability of pollinators may select for floral traits and plant mating strategies that lead to a system of self-fertilization.(AU)

Mecanismos florais que garantem produção de sementes via autogamia, são mais prováveis de ocorrer em espécies que crescem em habitats onde a polinização é escassa. Amasonia obovata foi estudada na região sudoeste do estado de Mato Grosso, durante os anos de 2009 a 2012, e o estudo teve por objetivo analisar as características morfológicas, morfométricas e reprodutivas, além de associar o sucesso reprodutivo à frequência de polinizadores. A. obovata concentrou a floração e frutificação em um período de cinco meses, durante a estação chuvosa. A dicogamia em flores de A. obovata não está claramente demarcada, já que as funções sexuais se sobrepõem nas fases masculina e feminina. A espécie é autocompatível e não apomítica. Os valores percentuais de frutificação obtidos na autopolinização manual não diferiram dos valores obtidos na polinização cruzada (F= 0,74; P=0,39). Em observações realizadas nos anos de 2010 a 2012, o beija-flor (Thalurania furcata) realizou de 20 a 100% de visitas legítimas às flores nas fases masculina e feminina, de diferentes indivíduos de A. obovata e, devido à sua frequência, foi considerado o potencial polinizador da espécie. Os resultados mostram que a limitada disponibilidade de polinizadores pode selecionar plantas de características florais e estratégias de reprodução que levam a um sistema reprodutivo autogâmico.(AU)

RESUMO

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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The hummingbird-visited plant community located on the open-habitat mountaintop of the Espinhaço Range was studied for two years (from August 2007 to July 2009) in Serra do Cipó National Park, Southeastern Brazil (19° 15′ S and 43° 31′ W). The floral characteristics and flowering period of the hummingbird-visited plants was monthly recorded along trails located in three vegetation types: (1) typical campos rupestres (TCR), (2) open fields (OPF), and (3) capões de mata (CAM). Hummingbird visitation was observed in 51 plant species, 22 ornithophilous and 29 non-ornithophilous species. The TCR showed the greatest number of species visited (N = 38), followed by the OPF (N = 18) and CAM (N = 17). Six species of hummingbirds were recorded visiting flowers: Augastes scutatus, Campylopterus largipennis, Colibri serrirostris, Chlorostilbon lucidus, Eupetomena macroura and Phaethornis pretrei. This study demonstrates that the species richness and the number of ornithophilous species visited by the hummingbirds at the study site are more similar to hummingbird-plant communities of the Atlantic Forest than to those of the Cerrado communities and other Brazilian highland open-habitat communities. The plant families most visited by hummingbirds were Bromeliaceae and Asteraceae. Although the Asteraceae family is rarely used as a food resource for hummingbirds in other high and lowland communities, in the study site this family is used mainly by the endemic hummingbird Augastes scutatus. We found a large overlap of flowering throughout the year among the species visited by the hummingbirds. Thus, the nectar availability supports these resident hummingbirds. The present study also showed that the studied hummingbird-plant community is composed of many species endemic to the campos rupestres of the Espinhaço Range, some of which are considered to be in danger of extinction, thus constituting a unique and threatened community. Thus, understanding hummingbird-plant pollination dynamics becomes fundamental to the conservation of the campos rupestres.

A comunidade de flores visitadas por beija-flores em habitats abertos de montanhas da Serra do Espinhaço, sudeste do Brasil foi estudada por dois anos (de agosto de 2007 a julho de 2009) no Parque Nacional da Serra do Cipó (19° 15′ S e 43° 31′ W). As características florais e o período de floração das plantas visitadas foram registradas mensalmente ao longo de trilhas localizadas em três tipos vegetacionais: (1) campos rupestres típicos (TCR), (2) campos abertos (OPF), e (3) capões de mata (CAM). Foram observadas visitas de beija-flores a 51 espécies de plantas: 22 ornitófilas e 29 não-ornitófilas. O TCR apresentou o maior número de espécies visitadas (N = 38), seguido pelo OPF (N = 18) e CAM (N = 17). Seis espécies de beija-flores foram observadas visitando as flores: Augastes scutatus, Campylopterus largipennis, Colibri serrirostris, Chlorostilbon lucidus, Eupetomena macroura e Phaethornis pretrei. A riqueza de espécies e o número de espécies ornitófilas visitadas pelos beija-flores, neste estudo, foi mais similar à comunidades de plantas visitadas por beija-flores na Floresta Atlântica, que as comunidades do Cerrado, bem como de outras comunidades de ambientes abertos do Brasil. As famílias com maior número de plantas visitadas pelos beija-flores foram Bromeliaceae e Asteraceae. Apesar da família Asteraceae, raramente ser utilizada como fonte alimentar pelos beija-flores em outras comunidades, nas áreas amostradas neste estudo esta família foi utilizada, principalmente, pelo beija-flor endêmico A. scutatus. Nós registramos grande sobreposição de floração ao longo do ano entre as espécies visitadas pelos beija-flores. Portanto, a disponibilidade de néctar mantem os beija-flores residentes. Este estudo, demonstrou também, que a comunidade de plantas visitadas pelos beija-flores nesta área é composta por muitas espécies endêmicas dos campos rupestres da Serra do Espinhaço, algumas das quais consideradas em perigo de extinção, constituindo assim uma comunidade única e ameaçada. Portanto, o entendimento da dinâmica de polinização desta comunidade é fundamental para a conservação dos campos rupestres.

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The hummingbird-visited plant community located on the open-habitat mountaintop of the Espinhaço Range was studied for two years (from August 2007 to July 2009) in Serra do Cipó National Park, Southeastern Brazil (19° 15′ S and 43° 31′ W). The floral characteristics and flowering period of the hummingbird-visited plants was monthly recorded along trails located in three vegetation types: (1) typical campos rupestres (TCR), (2) open fields (OPF), and (3) capões de mata (CAM). Hummingbird visitation was observed in 51 plant species, 22 ornithophilous and 29 non-ornithophilous species. The TCR showed the greatest number of species visited (N = 38), followed by the OPF (N = 18) and CAM (N = 17). Six species of hummingbirds were recorded visiting flowers: Augastes scutatus, Campylopterus largipennis, Colibri serrirostris, Chlorostilbon lucidus, Eupetomena macroura and Phaethornis pretrei. This study demonstrates that the species richness and the number of ornithophilous species visited by the hummingbirds at the study site are more similar to hummingbird-plant communities of the Atlantic Forest than to those of the Cerrado communities and other Brazilian highland open-habitat communities. The plant families most visited by hummingbirds were Bromeliaceae and Asteraceae. Although the Asteraceae family is rarely used as a food resource for hummingbirds in other high and lowland communities, in the study site this family is used mainly by the endemic hummingbird Augastes scutatus. We found a large overlap of flowering throughout the year among the species visited by the hummingbirds. Thus, the nectar availability supports these resident hummingbirds. The present study also showed that the studied hummingbird-plant community is composed of many species endemic to the campos rupestres of the Espinhaço Range, some of which are considered to be in danger of extinction, thus constituting a unique and threatened community. Thus, understanding hummingbird-plant pollination dynamics becomes fundamental to the conservation of the campos rupestres.(AU)

A comunidade de flores visitadas por beija-flores em habitats abertos de montanhas da Serra do Espinhaço, sudeste do Brasil foi estudada por dois anos (de agosto de 2007 a julho de 2009) no Parque Nacional da Serra do Cipó (19° 15′ S e 43° 31′ W). As características florais e o período de floração das plantas visitadas foram registradas mensalmente ao longo de trilhas localizadas em três tipos vegetacionais: (1) campos rupestres típicos (TCR), (2) campos abertos (OPF), e (3) capões de mata (CAM). Foram observadas visitas de beija-flores a 51 espécies de plantas: 22 ornitófilas e 29 não-ornitófilas. O TCR apresentou o maior número de espécies visitadas (N = 38), seguido pelo OPF (N = 18) e CAM (N = 17). Seis espécies de beija-flores foram observadas visitando as flores: Augastes scutatus, Campylopterus largipennis, Colibri serrirostris, Chlorostilbon lucidus, Eupetomena macroura e Phaethornis pretrei. A riqueza de espécies e o número de espécies ornitófilas visitadas pelos beija-flores, neste estudo, foi mais similar à comunidades de plantas visitadas por beija-flores na Floresta Atlântica, que as comunidades do Cerrado, bem como de outras comunidades de ambientes abertos do Brasil. As famílias com maior número de plantas visitadas pelos beija-flores foram Bromeliaceae e Asteraceae. Apesar da família Asteraceae, raramente ser utilizada como fonte alimentar pelos beija-flores em outras comunidades, nas áreas amostradas neste estudo esta família foi utilizada, principalmente, pelo beija-flor endêmico A. scutatus. Nós registramos grande sobreposição de floração ao longo do ano entre as espécies visitadas pelos beija-flores. Portanto, a disponibilidade de néctar mantem os beija-flores residentes. Este estudo, demonstrou também, que a comunidade de plantas visitadas pelos beija-flores nesta área é composta por muitas espécies endêmicas dos campos rupestres da Serra do Espinhaço, algumas das quais consideradas em perigo de extinção, constituindo assim uma comunidade única e ameaçada. Portanto, o entendimento da dinâmica de polinização desta comunidade é fundamental para a conservação dos campos rupestres.(AU)

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Hummingbird abundance varies with plant bloom phenology used for feeding. However, the information on hummingbird-flower interaction is limited for tropical mountain environments. We evaluated hummingbird abundance using mist nest and estimated monthly flowering phenology visited by hummingbirds in three different habitats (oak forest, cloud forest and bush) from January to August 2010 in Huitepec Ecological Reserve. We recorded four hummingbird species (Hylocharis leucotis, Lampornis amethystinus, Lamprolaima rhami and Eugenes fulgens), and their abundance varied among habitats (H3.8=14.8, p=0.001). Seven plant species were visited for hummingbirds and showed the highest number of flower species during dry season. Bush had the highest blossom. Fuchsia paniculata had the highest blossom period but only was visited by H. leucotis. Passiflora membranacea was the only species visited for all hummingbird species. The only positive association was E. fulgens abundance with P.a membranacea bloom (rS=0.93, p=0.02). Hummingbird abundance fluctuations in this study are determined for interactions with floral resources and their habitat distribution.

La abundancia de los colibríes puede variar por la fenología de floración de las plantas de las que se alimentan. Sin embargo, la información sobre la interacción colibrí-flor es limitada en ambientes tropicales de montaña. En este estudio se evaluó la abundancia de colibríes con redes de niebla y se registró la fenología de floración mensual de las flores visitadas por los colibríes en tres ambientes (bosque de encino, de neblina y matorral) en la Reserva Ecológica Huitepec, Chiapas, México de enero a agosto 2010. Cuatro especies de colibríes (Hylocharis leucotis, Lampornis amethystinus, Lamprolaima rhami y Eugenes fulgens) se registraron y sus abundancias variaron entre ambientes (H3.8=14.8, p=0.001). Siete especies de plantas fueron visitadas por los colibríes, y presentaron una mayor floración formando parches durante la temporada de secas. En el matorral se concentró el mayor número de especies de plantas con flores. Fuchsia paniculata presentó el mayor periodo de floración aunque solo fue visitada por H. leucotis. Passiflora membranacea fue la única especie visitada por las cuatro especies de colibríes. La única asociación positiva fue la abundancia de E. fulgens con la floración de P. membranacea (rS=0.93, p=0.02). Las fluctuaciones de las abundancias de colibríes en este estudio están en cierta forma determinadas por las interacciones del recurso floral y su distribución en el ambiente.

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The temporal and spatial resource use among hummingbirds was studied over 13 months in an urban forest remnant (Prosa State Park: PSP) in Campo Grande, Mato Grosso do Sul, Brazil. Hummingbird visitation was recorded at three ornithophilous and eleven non-ornithophilous species. Flower density was roughly constant during the study period, with the density of non-ornithophilous flowers being higher than that of ornithophilous ones. Mean values of nectar volume and concentration were similar between ornithophilous and non-ornithophilous species. Eight hummingbird species were observed at PSP: Amazilia fimbriata, Anthracothorax nigricollis, Chlorostilbon lucidus, Eupetomena macroura, Hylocharis chrysura, Florisuga fusca, Thalurania furcata and an unidentified species. Hummingbird visit frequencies to ornithophilous and non-ornithophilous flowers were similar. However, some non-ornithophilous species received a higher number of visits, which seems to be related to their large number of open flowers per plant per day. The number of feedings bouts of hummingbirds increased with the total number of flowers observed per focal plant. All recorded species of hummingbirds visited non-ornithophilous flowers, predominantly melittophilous and generalised entomophilous flowers. Hummingbird species recorded at PSP may be viewed as generalists, visiting a large number of non-ornithophilous species. Despite being an urban forest, PSP is relatively rich in hummingbird species, suggesting that it provides important shelter and foraging sites for hummingbirds in such an environment.

O uso temporal e espacial de recursos por beija-flores foi estudado ao longo de 13 meses em um remanescente florestal urbano (Parque Estadual do Prosa: PSP) em Campo Grande, Mato Grosso do Sul, Brasil. As visitas dos beija-flores foram registradas em três espécies ornitófilas e 11 não ornitófilas. A densidade de flores foi mais ou menos constante durante o período de estudo, com a densidade de flores não ornitófilas sendo maior que a de flores ornitófilas. Os valores médios de volume e concentração do néctar foram similares entre as espécies ornitófilas e não ornitófilas. Oito espécies de beija-flores foram observadas no PSP: Amazilia fimbriata, Anthracothorax nigricollis, Chlorostilbon lucidus, Eupetomena macroura, Hylocharis chrysura, Florisuga fusca, Thalurania furcata e uma espécie não identificada. A frequência de visitas dos beija-flores foi similar entre as espécies ornitófilas e não ornitófilas. Entretanto, algumas espécies não ornitófilas receberam um alto número de visitas, o que parece estar relacionado ao alto número de flores abertas por planta por dia. O número de turnos de visitas dos beija-flores aumentou com o número total de flores observadas por planta focal. Todas as espécies de beija-flores visitaram flores não ornitófilas, predominantemente flores de espécies melitófilas e entomófilas generalistas. Os beija-flores observados no PSP podem ser considerados generalistas, visitando um grande número de espécies não ornitófilas. Apesar de o PSP ser um fragmento florestal urbano, possui riqueza de espécies de beija-flores relativamente alta, sugerindo ser importante sítio de abrigo e forrageamento para os beija-flores neste ambiente.

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The temporal and spatial resource use among hummingbirds was studied over 13 months in an urban forest remnant (Prosa State Park: PSP) in Campo Grande, Mato Grosso do Sul, Brazil. Hummingbird visitation was recorded at three ornithophilous and eleven non-ornithophilous species. Flower density was roughly constant during the study period, with the density of non-ornithophilous flowers being higher than that of ornithophilous ones. Mean values of nectar volume and concentration were similar between ornithophilous and non-ornithophilous species. Eight hummingbird species were observed at PSP: Amazilia fimbriata, Anthracothorax nigricollis, Chlorostilbon lucidus, Eupetomena macroura, Hylocharis chrysura, Florisuga fusca, Thalurania furcata and an unidentified species. Hummingbird visit frequencies to ornithophilous and non-ornithophilous flowers were similar. However, some non-ornithophilous species received a higher number of visits, which seems to be related to their large number of open flowers per plant per day. The number of feedings bouts of hummingbirds increased with the total number of flowers observed per focal plant. All recorded species of hummingbirds visited non-ornithophilous flowers, predominantly melittophilous and generalised entomophilous flowers. Hummingbird species recorded at PSP may be viewed as generalists, visiting a large number of non-ornithophilous species. Despite being an urban forest, PSP is relatively rich in hummingbird species, suggesting that it provides important shelter and foraging sites for hummingbirds in such an environment.(AU)

O uso temporal e espacial de recursos por beija-flores foi estudado ao longo de 13 meses em um remanescente florestal urbano (Parque Estadual do Prosa: PSP) em Campo Grande, Mato Grosso do Sul, Brasil. As visitas dos beija-flores foram registradas em três espécies ornitófilas e 11 não ornitófilas. A densidade de flores foi mais ou menos constante durante o período de estudo, com a densidade de flores não ornitófilas sendo maior que a de flores ornitófilas. Os valores médios de volume e concentração do néctar foram similares entre as espécies ornitófilas e não ornitófilas. Oito espécies de beija-flores foram observadas no PSP: Amazilia fimbriata, Anthracothorax nigricollis, Chlorostilbon lucidus, Eupetomena macroura, Hylocharis chrysura, Florisuga fusca, Thalurania furcata e uma espécie não identificada. A frequência de visitas dos beija-flores foi similar entre as espécies ornitófilas e não ornitófilas. Entretanto, algumas espécies não ornitófilas receberam um alto número de visitas, o que parece estar relacionado ao alto número de flores abertas por planta por dia. O número de turnos de visitas dos beija-flores aumentou com o número total de flores observadas por planta focal. Todas as espécies de beija-flores visitaram flores não ornitófilas, predominantemente flores de espécies melitófilas e entomófilas generalistas. Os beija-flores observados no PSP podem ser considerados generalistas, visitando um grande número de espécies não ornitófilas. Apesar de o PSP ser um fragmento florestal urbano, possui riqueza de espécies de beija-flores relativamente alta, sugerindo ser importante sítio de abrigo e forrageamento para os beija-flores neste ambiente.(AU)

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RESUMO

O conhecimento das interações entre plantas e seus polinizadores tem-se destacado como ferramenta na biologia da conservação de ambientes degradados, como a Mata Atlântica e no estudo da evolução de características morfológicas que medeiam estas interações. Neste estudo são apresentadas informações sobre a biologia reprodutiva e as interações com os visitantes florais de Sophora tomentosa e Crotalaria vitellina (Fabaceae), espécies comuns em áreas de restinga na Mata Atlântica no Núcleo Picinguaba, Parque Estadual da Serra do Mar, Ubatuba - São Paulo. Estas espécies são sincronopátricas, possuem flores amarelas dispostas em racemos e oferecem néctar como principal recurso. Ambas as espécies são autocompatíveis, mas dependem de polinizadores para formação de frutos e sementes. Xylocopa brasilianorum e Megachile sp.1 foram os polinizadores de S. tomentosa, ao passo que C. vitellina, além destas espécies, também foi polinizada por Bombus morio, Centris labrosa e mais duas espécies de Megachile. Estas espécies de abelhas possuem comprimento da língua compatível com as dimensões das câmaras nectaríferas, acessando o néctar por visitas legítimas. As inflorescências de S. tomentosa foram mais visitadas (0,62 visitas/inflorescência/dia) do que as de C. vitellina (0,37 visitas/inflorescência/dia). Entretanto, em condições naturais, a frutificação em S. tomentosa (33 por cento) é semelhante à de C. vitellina (42 por cento), provavelmente devido às diferenças na eficiência de cada polinizador. Espécies de Trigona e de Augochlora não têm acesso ao néctar em visitas legítimas, pois não possuem comprimento da língua compatível com as dimensões das câmaras nectaríferas. Portanto, as dimensões das câmaras nectaríferas de S. tomentosa e C. vitellina funcionam como barreira seletiva às espécies de abelhas com língua curta, assegurando maior oferta de néctar aos polinizadores. Ainda, os polinizadores destas leguminosas são comuns na restinga e atuam como vetores de pólen de diversas espécies neste ecossistema. Portanto a manutenção destas leguminosas é importante para a diversidade da fauna de abelhas e essencial para a comunidade de plantas.

The study of plant-pollinator interactions is a major tool for conservation biology of fragmented habitats like the Atlantic Rain Forest and for the study of evolutionary traits that rule these interactions. Information on reproductive biology and floral visitor interactions of Sophora tomentosa and Crotalaria vitellina (Fabaceae) is presented in this study. Both species are common in the restinga formation of the Atlantic Rain Forest in the Núcleo Picinguaba, Parque Estadual da Serra do Mar, Ubatuba - São Paulo. These species occur in the same areas, the flowering period is the same for both and they have yellow flowers that offer nectar as the major reward. Both are self-compatible, although fruit and seed set depend on the pollinators. Xylocopa brasilianorum and Megachile sp.1 were pollinators of S. tomentosa, whereas C. vitellina was pollinated by both the aforementioned bees and Bombus morio, Centris labrosa and two separate species of Megachile. All these bees have long tongues and are able to reach nectar at the bottom of the nectar chamber by legitimate visits. The inflorescences of S. tomentosa received more visits (0,62 visits/inflorescence/day) than the inflorescences of C. vitellina (0,37 visits/inflorescence/day). However, the fruit set of S. tomentosa (33 percent) is similar to that of C. vitellina (42 percent) in natural conditions, probably due to different pollinator efficiency. Having shorter tongues, Trigona and Augochlora bees have no access to the nectar chamber by means of legitimate visits. Hence, the dimensions of the nectar chamber of S. tomentosa and C. vitellina act as a selective barrier to short-tongued bees, thus guaranteeing more nectar to the long-tongued visitors. These legume pollinators are very common in the restinga forest, and they act as pollen vectors of other species in this ecosystem as well. The preservation of these legume plants is important to the diversity of bees and essential to the plant community.

RESUMO

In the eastern Andes of Colombia, the shrub Befaria resinosa (Ericaceae) has peaks of flowering that are separated by extended periods of low flower production. The effect that these fluctuations in flower production have on pollen flow was investigated by using fluorescent dye as a pollen analog. Dye applied to open flowers was dispersed over long distances more often during low flower production than during high flower production. Whether enhanced pollen dispersal during flowering lows is of benefit to individual plants is not clear. The proportion of flowers that set fruit is positively correlated with flower abundance, negating the possibility that increased pollen dispersal results in a higher rate of fruit production due to outbreeding effects. It is also difficult to attribute the pattern of fruit production to changes in pollinator visitation rates, which are negatively correlated with flower abundance in the case of hummingbirds and not correlated at all with flower abundance in the case of insects. An opportunistic, large-bodied hummingbird (Colibri coruscans) visits B. resinosa during high flowering and may be a particularly effective pollinator, accounting for some of the increase in the proportion of flowers setting fruit. Rainfall is positively correlated with flower production and may be an important factor in shaping flowering phenology, but it is not significantly correlated with the proportion of flowers setting fruits. The possibility that low-level flowering may counteract inbreeding that results from peak flowering is discussed.