Worldwide Distribution of Antagonistic-Mutualistic Relationships Between Parrots and Palms

Palms, like all plants, show coevolutionary relationships with animals that have been traditionally categorized as mutualistic (seed dispersers and pollinators) or antagonistic (seed predators). This dual perspective, however, has prevented a full understanding of their true interactions with some animal groups, mainly those that do not ingest entire fruits. One clear example is parrots, which have been described to use palm species as feeding resources, while their role as seed dispersers has been largely neglected. Here, we combined fieldwork data with information from the literature and citizen science (i.e., naturalists and nature photographers) on parrot foraging ecology worldwide to evaluate the spatial and taxonomic extent of parrot-palm interactions and to identify the eco-evolutionary factors involved. We identified 1,189 interactions between 135 parrots and 107 palm species in more than 50 countries across the six realms where palms are present as natives or introduced. Combining this information, we identified 427 unique parrot-palm interacting pairs (i.e., a parrot species interacting with a palm species). Pure antagonistic interactions (i.e., parrots just preying on seeds or eating or destroying their non-reproductive parts) were less common (5%) than mutualistic ones (i.e., parrots benefiting by partially preying on the seed or fruit or consuming the pulp of the fruit or the flower but also contributing to seed dispersal and, potentially, pollination; 89%). After controlling for phylogeny, the size of consumed seeds and parrot body mass were positively related. Seed dispersal distances varied among palm species (range of estimated median dispersal distances: 9–250 m), with larger parrots dispersing seeds at greater distances, especially large fruits commonly categorized as megafauna anachronisms (>4 cm length). Although parrot-palm interactions are widespread, several factors (e.g., social behavior, predation fear, food availability, or seasonality) may affect the actual position of parrots on the antagonism-mutualism continuum for different palm species and regions, deserving further research. Meanwhile, the pervasiveness of parrot-palm mutualistic interactions, mainly involving seed dispersal and pollination, should not be overlooked in studies of palm ecology and evolution.

Potential impact of mammal defaunation on the early regeneration of a large-seeded palm in the Brazilian Atlantic Forest

Defaunation, the decline in animal species and populations, is biased towards large-bodied animals that have unique roles as dispersers of large seeds. However, it is speculated that these roles may still be performed by smaller animals, such as small mammals like rodents and marsupials, that thrive in defaunated sites. We investigated if small mammals can disperse the large-seeded palm Attalea dubia. We performed the study in a well-conserved Atlantic Forest remnant in southeast Brazil that still harbours large mammals, such as tapirs. Focal observations showed that capuchin-monkeys consumed the mesocarp of the fruits and dropped the seeds beneath the plant crown thereafter. Mammals preyed on ca. 1% and removed ca. 15% of the fallen fruit/seed and deposited them up to 15 m away. Amongst them, small mammals (< 1 kg), such as the squirrel Guerlinguetus brasiliensis and non-identified nocturnal Sigmodontinae, as well as the marsupial Philander frenatus performed the bulk of interactions. Dispersal enhances recruitment, but the short distances of seed removal did not match the current spatial distribution of palm seedlings and juveniles. Recaching rates of hoarded seeds were small (2%) and unlikely to increase distances of seed dispersal achieved. Short distances of dispersal would increase plant clumpiness and negative density-dependent effects with time. Although small mammals can provide legitimate dispersal, they cannot fully replace larger frugivorous mammals and maintain long-distance seed dispersal that feeds plant metapopulation dynamics and seed gene flow.

Patch occupancy and activity pattern of the spotted paca (Cuniculus paca Linnaeus, 1766) in a protected area of the Atlantic Forest, Brazil

The spotted paca Cuniculus paca (Linnaeus, 1766) is a medium-sized caviomorph rodent of the Cuniculidae family that mainly inhabits tropical forests, but may occur in other habitat types, often associated with water bodies. We aimed to verify which factors influence the spatial and temporal distribution of C. paca in the Vale Natural Reserve (VNR), Espírito Santo, Brazil. We used 39 camera traps to model occupancy and detectability and to estimate the species activity period. The spotted paca showed high occupancy at low distances from water resources and high densities of palm species. The species avoided areas with high poaching intensity, and activity frequency was reduced by extreme temperature and by a higher intensity of poaching. We conclude that in the VNR, the C. paca is a nocturnal species and that it is necessary to assess other elements that could potentially affect the spatial and temporal distribution of the spotted paca in the Atlantic Forest.

Living and lost mammals of Rio de Janeiro's largest biological reserve: an updated species list of Tinguá

Abstract: The Tinguá Biological Reserve (TBR) is the largest protected area of this category in Rio de Janeiro state. Here, for the first time, we present the historical composition of terrestrial mammals' assemblage of TBR region. An inventory was conducted using transect surveys, nonstandard transects, survey of museum specimens and informal reports. Considering all the data, eighty-five species were recorded, placing TBR as the second one in the number of mammals recorded in "Serra do Mar" ecoregion of Atlantic Forest and in the Rio de Janeiro state. Among the species with historical records are the jaguar (Panthera onca) and the golden-lion-tamarin (Leontopithecus rosalia) while the current presence of the maned wolf (Chrysocyon brachyurus) was recorded for the first time. Priority studies should focus on Chiroptera, Rodentia and Didelphimorphia orders, especially in the most remote areas of the reserve, and long-term surveys of endangered species. Besides hunting, fragmentation of its interior by roads, pipelines and transmission lines and exotic species, TBR is also threatened by the urban growth around it and the pressure to reduce its area and its protection category, demanding greater attention by the high levels of governance of protected areas in Brazil.

Frugivoría y dispersión de semillas de la palma <i>Oenocarpus bataua</i> en dos regiones con diferente estado de conservación

Se comparó la frugivoría y dispersión de semillas de Oenocarpus bataua en dos áreas en Colombia, con diferente estado de conservación: Porce (departamento de Antioquia), bosque subandino alterado, fragmentado con baja conectividad y defaunado; y Reserva Las Unamas (departamento del Meta), bosque continuo, menos alterado y con presencia de especies de fauna, principalmente mamíferos desaparecidos en áreas transformadas. Se realizaron observaciones focales, fototrampeo y registro de distancias de dispersión. Cuatro de cinco frugívoros en Porce fueron pequeños mamíferos, mientras que en Las Unamas se registraron cuatro especies de tamaño mediano, y de acuerdo a registros de fauna en el área, hasta 24 especies podrían consumir los frutos. El número de semillas dispersadas, las distancias de dispersión y las distancias de semillas y plántulas al árbol parental más cercano, fueron mayores en Porce. Estos resultados sugieren intensa actividad de roedores pequeños, principalmente las ardillas, que posiblemente han aumentado, como producto de la ausencia de depredadores y competidores desaparecidos por cacería y fragmentación del hábitat. Estos roedores ejercen alta presión sobre los frutos de O. bataua, pero a la vez cumplen una función de dispersión de semillas. A pesar de la limitada dispersión de O. bataua, en ambas áreas estudiadas, esta palma es una especie abundante, fuente casi permanente de alimento para la fauna silvestre y un elemento estructurante del bosque. Este tipo de estudio es significativo debido a que permite reconocer la importancia de la conservación de áreas que sustentan interacciones ecológicas, como la dispersión de semillas y en general la funcionalidad de los ecosistemas que están siendo amenazados por la defaunación y fragmentación del hábitat.