Ants in their plants:Pseudomyrmexants reduce primate, parrot and squirrel predation onMacrolobium acaciifolium(Fabaceae) seeds in Amazonian Brazil

Abstract

Although plant-inhabiting ants are known to act as effective deterrents to a variety of vertebrate and invertebrate herbivores, this has been reported only once before for primates, a group better known for their predation of ants. In the present study, we investigated the effects that colonies of Pseudomyrmex viduus ants living in individual Macrolobium acaciifolium (Fabaceae) trees have on the rates of visitation and fruit removal by four taxa of seed-predating vertebrates: the primate Cacajao melanocephalus ouakary; macaws (Ara spp.); large parrots (Amazona spp.); and the Northern Amazonian red squirrel (Sciurus igniventris). We found that ant presence significantly reduced both rates of visitation and of fruit removal by C. m. ouakary. The same pattern of reduced fruit removal was also observed for other seed predators (parrots, macaws, and squirrels) but not for visitation rates (although this may be a result of the small sample size). This appears to be only the second-known demonstration of the repellent effect of ants on primates and, indeed, the first for squirrels and psittacine birds.

Trait-mediated indirect interactions of ant shape on the attack of caterpillars and fruits

“…Here, we reaffirm that ant presence on fruits can repel potential visually oriented fruit dispersers and we expand this vision not only for specialized myrmecophytic species as previously proposed [8]. Some plants that secrete extrafloral nectar on their fruits to attract protective ants decrease nectar secretion at the end of fruit maturation in order to minimize the negative effect of ants on fruit dispersal [20].…”

“…On the other hand, plants visited by ants are less attacked by insect herbivores and mutualistic ant-plant interactions are well known and documented [5]. However, in some cases, ants are harmful plant partners; this occurs when ants offer enemy-free space for ant-associated herbivorous (mainly trophobiont insects) or when the ant disrupts the visit by other mutualistic partners, such as pollinators and seed dispersers [6][7][8][9][10]. Ants have become models for a variety of organisms that have evolved to visually mimic them as defence from predation [11].…”

Juggling options: Manipulation ease determines primate optimal fruit‐size choice

“…For the fruits that had their seeds consumed, the feeding debris, composed of large fallen fragments of freshly removed husk, were retrieved by a member of the field team from beneath feeding trees immediately after the uacaris had left, then pieced together to reconstitute the lumen in which the single seed had rested. Retrieval was aided by the very slow current in flooded igapó (less than 0.2 m/h ‐1 : Barnett, Almeida, et al, 2015), besides few fruits are consumed by tree. Size measurements were made with SPI dial calipers (Swiss Precision Instruments, Garden Grove, CA, USA), and weights measured with Pesola balances (precision: 0.01g).…”

Buds, Bugs and Bienniality: The Floral Biology of Eschweilera tenuifolia (O. Berg) Miers in a Black-Water Flooded Forest, Central Amazonia

“…Data were collected from three areas within the park: (i) a macacaricuizal near the village of Seringalzinho; (ii) the area near the village of Patuá bounded by six 0.25 ha plots used to monitor igapó phenology during the 2006-2008 study; (iii) the remainder of the 2000 ha area used to study the ecology of the golden-backed uacari in 2006-2008 [12,51,87] (Figure 3; Table 3). In total, data were gathered from 194 individual E. tenuifolia trees (originally N = 197, but three trees were excluded when they did not flower).…”