Among the vertebrate pollinated plants, the genus Erythrina includes tree species in which birds are the pollen vectors. Two groups in this genus may be distinguished: a) the hummingbird, and b) the perching bird pollinated species. Erythrina dominguezii is included in the second group and occurs in deciduous/semi-deciduous forests in the southwestern neotropics. I studied the exploitation of Erythrina dominguezii nectar by perching birds in a dry forest in western Brazil. Six perching bird species from two distinct groups (Psittacidae: Brotogeris chiriri, Nandayus nenday, Aratinga acuticaudata; Icterinae: Psarocolius decumanus, Icterus cayanensis, I. icterus) consumed its nectar. The two most important consumers were Brotogeris chiriri (51.5% of the flowers visited by birds) and Psarocolius decumanus (20%). While B. chiriri was a flower predator, P. decumanus removed the nectar without damaging the flowers which it opened by inserting its large bill between the standard and the keel. Nandayus nenday, Aratinga acuticaudata, and I. icterus exploited the nectar like P. decumanus, and presumably also contributed to pollen transfer. As the flowering in E. dominguezii was intense and synchronous during the dryest period of the year, and its nectar was highly consumed by birds, the present data suggest that the nectar of this species may be important as an alternative resource to frugivorous/omnivorous birds when other resources are scarce. Key words: bird pollination, parakeets, Icterinae, nectar exploitation, Erythrina. RESUMO Exploração de néctar em Erythrina dominguesii Hassl. (Fabaceae)por aves em uma mata seca do oeste brasileiro Dentre as plantas polinizadas por vertebrados, Erythrina inclui espécies arbóreas polinizadas por aves. Nesse gênero há dois grupos distintos: a) o de espécies polinizadas por beija-flores e b) o de espécies polinizadas por aves que não os beija-flores. Erythrina dominguezii está incluída no segundo grupo e é comum em matas decíduas e semidecíduas do sudoeste neotropical. Foi estudada a exploração de néctar em Erythrina dominguezii por aves em uma mata seca do oeste brasileiro. Seis espécies de aves de dois grupos distintos (Psittacidae: Brotogeris chiriri, Nandayus nenday, Aratinga acuticaudata; Icterinae: Psarocolius decumanus, Icterus cayanensis, I. icterus) consumiram o néctar dessa espécie arbórea. As duas espécies com maior consumo de néctar foram B. chiriri (51,5% das flores visitadas pelas aves) e P. decumanus (20%). Enquanto B. chiriri atuou como predador de flores, P. decumanus inseria seu grande bico entre o estandarte e a carena para abrir as flores e acessar o néctar, sem danificá-las. Dessa forma, P. decumanus potencialmente é um importante polinizador de E. dominguezii. Nandayus nenday, Aratinga acuticaudata e I. icterus acessaram o néctar de forma Braz. J. Biol., 62(4B): 877-883, 2002 878 RAGUSA-NETTO, J. similar a P. decumanus e presumivelmente contribuem para a polinização de E. dominguezii. A floração intensa nessa espécie arbórea foi aparentemente muito s...

Neotropical parrots usually forage in forest canopies for nectar, flowers, leaves, fruit pulp, and seeds. As they have no all-purpose territories, these birds usually exploit vegetation mosaics in order to use plentiful resources as they become available. In this study we examine the use of a gallery forest in the southern Pantanal (Brazil) by a diverse parrot community that ranged from Brotogeris chiriri (a small species) to Ara chloroptera (a large one). Plant food resources principally used by parrots were abundantly available during the rainy season (fleshy fruits), the annual floods (fleshy fruits), and the dry season (flowers). While both smaller and larger species foraged on fruits, parakeets largely consumed the pulp, while larger parrot species used pulp and seeds. In the dry season parakeets foraged extensively on nectar, especially Inga vera nectar that was abundantly available during the last two months of the dry season, the harshest period of the year. Among larger parrots, only Propyrrhura auricollis frequently harvested nectar. Fruits maturing during floods, despite being fish-or water-dispersed were extensively used by the parrots. Hence, unlike what happens in most other Neotropical dry forests, occurrence of a fruiting peak during the annual flooding, which occurs in the transition from the wet to the dry season, constitutes an extra and significant episode of food availability, since in this period, fruit production normally declines. Therefore, the unique and abundant availability of flowers and fruits in this gallery forest may account for the presence of large parrot populations in the southern Pantanal.Keywords: Psittacidae, parrot commuity, feeding ecology, gallery forest, canopy phenology, Pantanal. RESUMORecursos alimentares e dieta de uma comunidade de psitacídeos em uma mata ciliar no Pantanal Sul (Brasil) seca, período mais rigoroso do ano. Dentre as espécies maiores, apenas Propyrrhura auricollis utilizou substancialmente néctar. A intensa produção de frutos, tipicamente dispersos por peixes ou pela água durante a cheia anual, foi amplamente utilizada pelos psitacídeos. Portanto, ao contrário dos padrões de frutificação da maioria das matas secas neotropicais, a ocorrência de um pico de frutificação durante as cheias emerge como um evento marcante de disponibilidade de frutos, num período (transição da estação úmida para a seca) em que tipicamente tendem a declinar. Nesse sentido, a peculiar produção massiva de flores e frutos, nessa mata ciliar, potencialmente contribui para manutenção das grandes populações de psitacídeos, ainda presentes, no Pantanal Sul.

Figs are a remarkable food resource to frugivores, mainly in periods of general fruit scarcity. Although rainfall was highly seasonal, fruiting was aseasonal, since the monthly proportion of fruiting trees ranged from 4% to 14% (N = 50 trees). I recorded 22 bird species feeding on figs. In the wet season 20 bird species ate figs, while in the dry season 13 did. Parrots were the most important consumers. This group removed 72% and 40% of the figs consumed in the wet and dry seasons, respectively. No bird species increases fig consumption from dry to wet season. However, a group of bird species assumed as seed dispersers largely increases fig consumption from wet to dry season, suggesting the importance of this resource in the period of fruit scarcity. The results of this study points out the remarkable role that F. calyptroceras plays to frugivorous birds, in such a dry forest, since its fruits were widely consumed and were available all year round.

Unlike other toucan species, the Toco toucan (Ramphastos toco) -the largest Ramphastidae -usually inhabits dry semi-open areas. This conspicuous canopy frugivore uses a large home range that includes a variety of vegetation types, among which gallery forests are widely cited as important to this species. However, the factors relating to the occurrence of Toco toucans in such habitats are unclear. I studied the abundance of Toco toucans as well as the availability of fleshy fruit in a gallery forest in the southern Pantanal (sub-region of Miranda, Brazil), in order to assess the relationship between these parameters. Also, I examined toucan foraging activity to analyze its relationship with both toucan abundance and fruit availability. The presence of the Toco toucan was more common in the gallery forest from the middle to the end of the dry season and during the middle of the wet season. Toucans foraged for fleshy fruits, mainly Genipa americana, Ficus luschnatiana, and Cecropia pachystachya fruits, feeding mostly on G. americana (by far the favorite food resource) and F. luschnatiana fruits during the dry season, while C. pachystachya fruits were important in the wet season. Toco toucans foraged particularly heavily (> 80% of foraging activity) on G. americana fruits during the latter part of the dry season, when fleshy fruit availability declined sharply. Toco toucan abundance in the gallery forest was associated with the availability of the most commonly consumed fleshy fruits, and also with its foraging activity. This finding suggests that the Toco toucan moved to the gallery forest periodically in response to the availability of abundant food resources, especially the G. americana fruits widely available and exploited during the severely dry season. Therefore, these fruits potentially contribute to Toco toucan persistence in the South Pantanal during the harshest period of the year.Keywords: Ramphastidae, Ramphastos toco, phenology, gallery forest, frugivory, migration. RESUMO Abundância e exploração de frutos por tucano toco (Ramphastos toco) em uma mata ciliar no Pantanal SulDentre as espécies de tucanos, a maior delas, tucano toco (Ramphastos toco), é singular, uma vez que é muito comum em ambientes semi-abertos e/ou com manchas de florestas. As matas ciliares são citadas como ambientes em que essa espécie é comum. No entanto, os fatores relacionados com a ocorrência de R. toco, nesse tipo de vegetação, são desconhecidos. Estudei a abundância do tucano toco na mata ciliar do rio Miranda (Pantanal Sul), bem como a oferta de frutos carnosos, com o propósito de avaliar as relações entre esses parâmetros. Também examinei a exploração de frutos para avaliar as relações com a sua disponibilidade, bem como com a ocorrência do tucano toco na mata ciliar. Esse tucano foi mais comum de meados para o final da estação seca e em meados da estação chuvosa.

Parakeets usually forage for massive and ephemeral plant resources at forest canopies. Fruit pulp is widely cited as a major food resource for these birds, which often eat seeds and nectar. In this study, I assessed flower and fruit production at a gallery forest in the Pantanal flood plain (Brazil) in order to evaluate the relationship between food resource production and abundance of a common parakeet, Brotogeris chiriri. Also, I evaluated the relationship between food resource production and foraging activity. Parakeet abundance varied markedly along the year, coinciding with massive episodes of flower and fleshy fruit availability. Inga vera nectar, intensely used during the latter part of dry season, was by far the most exploited food item by parakeets when they were very abundant. The nectar comprised 34% of the parakeets' diet (N = 131 feeding records) at the gallery forest, while fleshy fruits made up the rest. Parakeets principally exploited fruits of Cecropia pachystachya and Ficus luschnathiana, besides palm fruits and Inga vera arils. The consistent relationship between foraging activity and parakeet abundance, as well as the coincidence between fluctuations of these parameters and availability of major food resources, suggests that food availability mostly influenced B. chiriri occurrence in the gallery forest. Furthermore, I found no evidence for gallery forest use for roosting and/or breeding, in spite of the fact that such factors usually influence local parakeet abundance.