A predictive framework for the ecology of species invasions requires that we learn what limits successful invaders in their native range. The red imported fire ant (Solenopsis invicta) is invasive in the United States, Puerto Rico, Australia, New Zealand, and China. Solenopsis invicta appears to be a superior competitor in its introduced range, where it can cause the local extirpation of native species, but little is known about its competitive ability in its native range in South America. Here we examine the competitive ability of S. invicta for food resources in three widely separated Brazilian ant communities. Each of these communities contains 20-40 ant species, 8-10 of which were common and frequently interacted with S. invicta. S. invicta at all three sites was attacked by several species-specific phorid parasitoids, and at one site, two other species were attacked by their own specialized parasitoids. We examined interactions in these local communities for evidence that trade-offs among ant species between resource dominance and resource discovery, and between resource dominance and parasitoid vulnerability facilitate local coexistence. The trade-off between resource dominance and resource discovery was strong and significant only at Santa Genebra, where parasitoids had no effect on the outcome of confrontations at resources. At Bonito, parasitoids significantly reduced the ability of S. invicta, which was the top-ranked behavioral dominant, from defending and usurping food resources from subordinate species. In the Pantanal, S. invicta ranked behind three other ant species in a linear hierarchy of behavioral dominance, and lost the majority of its interactions with a fourth more subordinate species, Paratrechina fulva, another invasive species. Parasitoids of S. invicta were uncommon in the Pantanal, and did not affect its low position in the hierarchy relative to the other two sites. Parasitoids, however, did affect the ability of Linepithema angulatum, the top-ranked behavioral dominant in this community, from defending and usurping resources from behavioral subordinates. These results indicate that both interspecific competition and trait-mediated indirect effects of phorid parasitoids affect the ecological success of the red imported fire ant in its native range, but that the relative importance of these factors varies geographically.
-(Effect of nectar secretion rate on pollination and seed production by Passiflora speciosa Gardn. flowers (Passifloraceae) in the Pantanal). We verified the effect of nectar secretion rate (NSR) on the pollinator frequency and the number of seeds per Passiflora speciosa Gardn. flowers in the Pantanal Wetlands. The plant was pollinated by hummingbirds and presented self-incompatibility. The NSR varied as a function of flower diameter, and number of hummingbird visits was a function of flower diameter. The number of seeds per flower of P. speciosa increased with the number of pollinator visits. The frequency of nectar thieves had no significant effect on seed set, but total number of hummingbird visits was negatively correlated with the total number of visits by nectar and/or pollen thieves. The overall results indicate that flower size affects NSR, which could determine the number of pollinator visits and the success of seed set per Passiflora speciosa flowers.Key words -flower size, foraging, hummingbird, nectar secretion, seed set RESUMO -(Efeito da taxa de secreção de néctar sobre a polinização e a produção de sementes em flores de Passiflora speciosa Gardn. (Passifloraceae) no Pantanal). Foi determinado o efeito da taxa de secreção de néctar (TSN) sobre a freqüência de visitas dos polinizadores e o número de sementes por flor de Passiflora speciosa Gardn. no Pantanal. A planta foi polinizada por beija-flores e apresentou auto-incompatibilidade. A TSN variou em função do diâmetro da flor, e o número de visitas dos beija-flores foi função do diâmetro da flor. O número de sementes por flor de P. speciosa foi maior com o aumento do número de visitas dos polinizadores. A freqüência de pilhadores de néctar não apresentou efeito sobre a produção de sementes, mas o número total de visitas dos beija-flores foi negativamente correlacionado com o número de visitas dos pilhadores de néctar e/ou pólen. Os resultados indicam que o tamanho da flor afeta a TSN, que por sua vez pode determinar o número de visitas dos polinizadores e o sucesso da produção de sementes em flores de P. speciosa.Palavras-chave -beija-flores, forrageamento, produção de sementes, secreção de néctar, tamanho da flor
Species of Vampyressa Thomas, 1900 are locally uncommon and widespread in the Neotropics. They are known to occur from southern Mexico to southern Amazon basin and from southeastern South America to Paraguay. Vampyressa pusilla (Wagner, 1843) and V. thyone Thomas, 1909 -previously considered one species -show a disjointed distribution. The former is considered endemic to the Atlantic forest and the other occurs from northwestern South America to southern Mexico. In addition, V. pusilla has been registered in savanna (Cerrado) and dry forests (Chaco). We report here the occurrence of V. pusilla in the Pantanal wetlands, western Brazil. It is probably the first record of the genus Vampyressa in such an ecosystem, increasing the geographical range of V. pusilla to western Brazil, towards the V. thyone distribution limits.Keywords
Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non‐detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non‐governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer‐reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non‐detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio‐temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large‐scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data.
Feeding of Pitangus sulphuratus (Tyrannidae) nestlings have been poorly studied. Here we describe the foraging behavior of a P. sulphuratus pair and the searching and offering time of food items to nestlings in the Pantanal, Brazil. Data collection was carried out over 25 days on the outskirts of the Base de Estudos do Pantanal building, inhabited by insectivorous bats. Records were based on direct observations with the help of binocular. The pair required little time for searching for small insects and fruits, but these items comprised a little amount of food per event of capture. Some large prey was more time-costly for searching, but the long period that these food items were offered to nestlings overcompensated the searching time. Considering the time of feeding nestlings (benefit) in relation to the searching time by the parents (cost), bats and snails are the most advantageous items for P. sulphuratus parents feeding nestlings at the study site.Keywords: feeding behavior, foraging strategy, nestling diet, parental care, predation. Forrageamento de bem-te-vis (Pitangus sulphuratus) e itens alimentares oferecidos para ninhêgos no Pantanal ResumoA alimentação de ninhêgos de Pitangus sulphuratus (Tyrannidae) tem sido pouco estudada. Descrevemos, neste estudo, o comportamento de forrageamento de um casal de P. sulphuratus e o tempo para busca e oferta de itens aos ninhêgos, no Pantanal, Brasil. A coleta de dados foi realizada durante 25 dias nas proximidades do prédio da Base de Estudos do Pantanal, habitada por morcegos insetívoros. Os registros foram baseados em observações diretas com auxílio de binóculo. O casal demandou pouco tempo de busca para a captura de pequenos insetos e frutos, porém esses itens representaram pouca quantidade de alimento por evento de captura. Algumas presas grandes demandaram mais tempo para busca, mas o longo período que esses itens foram oferecidos aos ninhêgos sobrecompensou o tempo de busca. Considerando-se o tempo de alimentação dos ninhêgos (benefício) em relação ao tempo de busca pelos pais (custo), morcegos e caramujos são itens mais vantajosos para os pais de P. sulphuratus alimentar ninhêgos no local de estudo.Palavras-chave: comportamento alimentar, cuidado parental, dieta de ninhêgos, estratégia de forrageamento, predação.
Great Kiskadees (Pitangus sulphuratus) are found in a variety of habitats from Argentina north to the United States and are the most generalist tyrant flycatcher in both foraging behavior and food habits. These kiskadees are known to occasionally prey on small vertebrates, but, to our knowledge, bats have never been reported as a prey item. We observed a breeding pair of Great Kiskadees preying on bats (Myotis spp.) at the field station Base de Estudos do Pantanal (BEP) in the southern Pantanal, Brazil. At BEP, there are fissures under the building's floor slabs that allow two species of bats, black myotis (Myotis nigricans) and silver-tipped myotis (M. albescens), to access internal galleries and use them as day roosts. We found that bats, insects, and fruits were the most common food items fed to nestlings by adult kiskadees. Bats (N = 10) were captured when kiskadees landed on ground below a building, looked up through a fissure, and then reached through the fissure and captured a bat in their bill. On one occasion, a kiskadee flew from a perch and captured a bat in flight. Our observations provide further evidence of the opportunistic feeding behavior of Great Kiskadees. RESUMEN. Depredación de murciélagos por Pitangus sulphuratusLos pitogués (Pitangus sulphuratus) se encuentran en una amplia variedad de hábitats desde Argentina hasta los Estados Unidos, y se le considera el más generalista de los tiránidos tanto en conducta de forrajeo como en su dieta. Se sabe que estas aves ocasionalmente depredan pequeños vertebrados, pero según nuestro conocimiento, nunca habían sido informados depredar murciélagos. Observamos un par de pitogués depredando murciélagos (Myotis spp.) en la estación de campo Base de Estudos do Pantanal (BEP) en el Pantanal sur, Brasil. En el BEP, hay fisuras bajo las planchas del suelo de los edificios que permiten que dos especies de murciélagos, Myotis nigricans y M. albescens, utilizen las galerías internas como lugares para pasar el día. Encontramos, que los murciélagos, insectos y frutas fueron los artículos alimentarios mas comúnmente utilizados para alimentar a los pichones. Los murciélagos (N = 1) fueron capturados cuando los pitogués aterrizaron en el suelo, miraron dentro de las fisuras y a través de estas alcanzaron a los murciélagos. En una de las ocasiones, una de las aves voló de una percha y capturo a un murciélago a vuelo. Nuestras observaciones proveen evidencia adicional sobre la conducta alimentaria oportunista del pitogué.
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