Eat the fruit earlier: Sakis (Pithecia chrysocephala) show enhanced temporal fruit resource access compared with squirrel monkeys (Saimiri sciureus) in an urban forest fragment in Brazil.

Fruit availability experienced by different primate species is likely to vary due to species-specific fruit use, even within the same habitat and timeframe. Pitheciines, primates of the subfamily Pitheciinae, particularly favor the seeds of unripe fruits. Researchers consider this dietary characteristic an adaptation to increase access to fruit resources. However, the relative advantages of pitheciines over sympatric non-pitheciine non-seed-eating primates regarding species-specific fruit availability is not well studied. In a 26-ha forest within the city of Manaus, Amazonian Brazil, we assessed the wild-food feeding behavior of free-ranging groups of golden-faced sakis (Pithecia chrysocephala) and sympatric common squirrel monkeys (Saimiri sciureus). We hypothesized that sakis would have greater and more consistent access to wild fruit due to (1) a wider variety of fruit species in their diet, and (2) longer consumption periods per fruit species. We recorded the plant species, part (pulp or seed), and developmental stage (ripe or unripe) of wild fruit consumed by both species. We also conducted monthly fruit censuses of 1000 trees and vines to estimate overall wild fruit abundance. As an indicator of fruit availability, we calculated the proportion of available fruiting trees and vines for each primate species separately based on their observed diet. Throughout the year, the proportion of available trees and vines was significantly higher and more temporally stable for sakis than for squirrel monkeys. This was because sakis used shared fruit species longer than squirrel monkeys by consuming both ripe and unripe fruit. Although sakis had a broader fruit repertoire than squirrel monkeys, it did not contribute to the higher fruit availability. Thus, the fruit feeding system of sakis identifies aspects of a niche that is less restricted in the timing of fruit consumption, which led to a relative advantage in fruit availability.

Evidence for adaptation of Rhagoletis pomonella (Diptera: Tephritidae) on large-thorn hawthorn, Crataegus macracantha, in Okanogan County, Washington State, USA.

The apple maggot fly, Rhagoletis pomonella (Walsh) (Diptera: Tephritidae), was introduced from eastern North America into western North America via infested apples (Malus domestica Borkhausen) about 44 yr ago, where it subsequently adapted to 2 hawthorn species, Crataegus douglasii Lindley and C. monogyna Jacquin. Here, we test whether R. pomonella has also adapted to large-thorn hawthorn, Crataegus macracantha Loddiges ex Loudon, in Okanogan County, Washington State, USA. In 2020, 2021, and 2022, fruit of C. macracantha were shown to ripen in late September and were infested at rates from 0.7% to 3.0%. In laboratory rearing studies, large-thorn hawthorn flies from C. macracantha eclosed on average 9-19 days later than apple flies from earlier ripening apple (August-early September), consistent with large-thorn hawthorn flies having adapted to the later fruiting phenology of its host. In a laboratory no-choice test, significantly fewer (64.8%) large-thorn hawthorn than apple flies visited apples. In choice tests, greater percentages of large-thorn hawthorn than apple flies resided on and oviposited into C. macracantha versus apple fruit. Large-thorn hawthorn flies were also smaller in size than apple flies. Our results provide further support for the recursive adaptation hypothesis that R. pomonella has rapidly and independently specialized phenologically and behaviorally to different novel hawthorn hosts since its introduction into the Pacific Northwest of the USA, potentially leading to host race formation.

Experts, peers, or celebrities? The role of different social endorsers on children's fruit choice.

This study investigates whether the source providing nutritional information matters for children's choice of fruit over candy. We conducted a between-subject experimental study with children (6-11 years; Mage = 8.20; N = 340). Children watched an audiovisual cartoon with nutritional messages provided by experts (expert condition), by celebrities (celebrity condition), or by typical consumers (peer condition). Additionally, we included a control group in which children were not exposed to any cartoon. As the dependent variable, we measured children's fruit choice over candy. As a mediator, measuring message processing we included children's argument awareness. Children's age was included as a moderator. The results indicate that the experimental conditions were equally effective in creating argument awareness for healthy eating compared to the control group. Children's argument awareness was generally rather low, and it did not influence children's fruit choice over candy. Nevertheless, there was a direct effect of the expert condition on children's fruit choice, pointing to an internalized "expert heuristic". No moderating effects of children's age were present. Our study indicates that using experts to present nutritional information within narrative media content is a potentially successful strategy to create argument awareness for healthy food and to impact children's selection of healthy food whereas peer and celebrity social endorsers are not.

Generalist birds promote tropical forest regeneration and increase plant diversity via rare-biased seed dispersal.

Regenerated forests now compose over half of the world's tropical forest cover and are increasingly important as providers of ecosystem services, freshwater, and biodiversity conservation. Much of the value and functionality of regenerating forests depends on the plant diversity they contain. Tropical forest diversity is strongly shaped by mutualistic interactions between plants and fruit-eating animals (frugivores) that disperse seeds. Here we show how seed dispersal by birds can influence the speed and diversity of early successional forests in Puerto Rico. For two years, we monitored the monthly fruit production of bird-dispersed plants on a fragmented landscape, and measured seed dispersal activity of birds and plant establishment in experimental plots located in deforested areas. Two predominantly omnivorous bird species, the Northern Mockingbird (Mimus polyglottos) and the Gray Kingbird (Tyrannus dominicensis), proved critical for speeding up the establishment of woody plants and increasing the species richness and diversity of the seed rain in deforested areas. Seed dispersal by these generalists increased the odds for rare plant species to disperse and establish in experimental forest-regeneration plots. Results indicate that birds that mix fruit and insects in their diets and actively forage across open and forested habitats can play keystone roles in the regeneration of mutualistic plant-animal communities. Furthermore, our analyses reveal that rare-biased (antiapostatic) frugivory and seed dispersal is the mechanism responsible for increasing plant diversity in the early-regenerating community.

Preferential consumption of larger fruits of Piper arboreum (Piperaceae) by Carollia perspicillata (Phyllostomidae) in the brazilian tropical dry forest / Consumo preferencial de frutos maiores de Piper arboreum (Piperaceae) por Carollia Perspicillata (Phyllostomidae) em uma floresta tropical brasileira

Frugivorous animals may use morphological traits of food items such as size, hardness, shape, color and smell as cues that allow them to assess cost-benefit relationship of foraging activity. Fruit size is an important trait that influences feeding behavior of most frugivores, since there is a functional correlation between fruit size and frugivores' body size. Therefore, size-based preference is fundamental to understand plant-frugivore interactions and seed dispersal. In this sense, we tested the hypothesis of preferential consumption of larger fruits of Piper arboreum by the short-tailed fruit bat Carollia perspicillata in the Brazilian tropical dry forest. Results showed considerable variation in fruit size among and within plants. There was also significant difference in fruit ripening time among plants, which was not related to fruit size. Average size of remaining fruits reduced as they were removed from plants by the bats, which indicates preferential consumption of larger fruits. On the other hand, plant phenology constrained consumption of bigger fruits. Only a small fraction of plant crop was available for consumption each night, regardless of fruit size, which probably coerced bats to feed on smaller fruits as the availability of larger ones decreased. Results suggest that bat preference on fruit size is mediated by plant phenological strategies.

Os frugívoros utilizam as características morfológicas dos frutos tais como tamanho, dureza, forma, cor e cheiro, como pistas para avaliar o custo-benefício da atividade de forrageio. O tamanho dos frutos é uma característica importante que influencia o comportamento alimentar dos frugívoros, já que existe uma correlação funcional entre tamanho do fruto e o do tamanho do frugívoro. Por isso, a seleção do fruto a partir do seu tamanho é um elemento fundamental para a compreensão das interações frugívoro-planta e da dispersão de sementes. Neste sentido, nós testamos a hipótese de consumo preferencial de frutos maiores de Piper arboreum pelo morcego Carollia perspicillata em uma floresta tropical brasileira. Os resultados mostraram ampla variação no tamanho do fruto entre e dentro das plantas parentais. Também houve diferença significativa no tempo de maturação dos frutos entre as plantas, o qual não esteve relacionado com o tamanho do fruto. O tamanho médio dos frutos restantes na planta após a remoção pelos morcegos decresceu, o que indicou o consumo preferencial dos frutos maiores. Por outro lado, a fenologia da planta restringiu o consumo destes frutos. Um número pequeno de frutos maduros esteve disponível para o consumo por noite, independentemente de seu tamanho, o que provavelmente limitou a escolha dos morcegos, obrigando-os a se alimentarem dos frutos menores conforme a disponibilidade dos maiores reduziu-se. Os resultados sugerem que a preferência dos morcegos pelo tamanho dos frutos é mediada pelas estratégias fenológicas das plantas.

The Crab-eating Fox (Cerdocyon thous) as a secondary seed disperser of Eugenia umbelliflora (Myrtaceae) in a Restinga forest of southeastern Brazil / O chachorro do mato (Cerdocyon thous) como dispersor secundário de Eugenia umbelliflora (Myrtaceae) em uma floresta de Restinga no sudeste do Brasil

The crab-eating fox (Cerdocyon thous) exhibits a very generalist habit and fruits compose a large proportion of its diet. However, few studies evaluated the importance of this animal as seed disperser. In the Restinga forest, in the Atlantic forest of Brazil, C. thous consumes fruits of Eugenia umbelliflora, a Myrtaceae species, which is dispersed chiefly by birds. This study evaluated the effects of gut transit on seed germination, and size selection of E. umbelliflora fruits by the crab-eating fox. We did not find differences on germination rates between seeds dispersed by foxes and control ones, but seeds dispersed by foxes germinated faster, which may be important for plant recruitment. Seeds consumed by C. thous were smaller than those available on the ground, indicating selection for small fruits. Regardless of the selection of small fruits, C. thous appears to be an important secondary disperser of E. umbelliflora, distributing large quantities of viable seeds of this Myrtaceae in the Restinga forest.

O cachorro do mato (Cerdocyon thous) tem um hábito bastante generalista e frutos compõem uma grande proporção de sua dieta. No entanto, poucos estudos avaliaram a importância deste animal como dispersor de sementes. Na floresta de restinga da Mata Atlântica brasileira C. thous consome frutos de Eugenia umbelliflora, uma espécie de Myrtaceae, que é dispersa principalmente por aves. Este estudo avaliou o efeito da passagem das sementes pelo tubo digestivo na germinação das sementes e a seleção de tamanho de frutos de E. umbelliflora pelo cachorro do mato. Não houve diferença nas taxas de germinação entre as sementes dispersas pelo cachorro do mato e as sementes controle, mas as sementes dispersas pelo cachorro germinaram mais rápido, o que pode ser importante para o recrutamento das plantas. As sementes consumidas pelo cachorro do mato foram menores do que as sementes disponíveis no solo, indicando seleção por frutos menores. Apesar de selecionarem frutos menores, o cachorro do mato parece ser um importante dispersor secundário de E. umbelliflora, distribuindo grandes quantidades de sementes viáveis desta espécie de Myrtaceae na restinga.