Two-thirds of 258 fruit species from Peruvian tropical forest belong to one of two classes: large orange, yellow, brown, or green fruits with a husk; or small red, black, white, blue, purple, or mixed-color fruits without a husk. The characteristics of the two fruit classes match the size, visual ability, and jaw morphology of mammals and birds, respectively, and the animals also prefer to eat one class of fruits. Thus, most plants in this forest seem to be adapted to seed dispersal by either of two distinct broad arrays of animal taxa.

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Two approaches were used to examine the relationship between seed size and typical establishment conditions in woody species of tropical rain forests. First we compared seed masses of 36 mature tropical forest tree species with differing light-gap requirements for establishment. The 14 species that become established beneath a closed canopy or in small gaps were found to have higher mean seed masses than the species that require large gaps. Though species were divided into two types of establishment requirements, plotting the mean seed masses produced a continuous unimodal distribution rather than a bimodal distribution, suggesting that either intermediate establishment conditions are most common in tropical rain forests or that other biotic or abiotic conditions confound the relationship between establishment conditions and seed mass. Second, we compared seed masses of 203 early and late successional woody plants in one Peruvian forest. Seed masses of mature forest species were found to be significantly larger than those of pioneer species, even when the effects of tree height, dispersal syndrome, and growth form were controlled for statistically. Thus, both analyses demonstrated a relationship between large seed size and establishment in shady, stable plant associations. Additional analysis of the Peruvian forest data demonstrated that mammals tend to disperse larger seeds than birds do, trees tend to have larger seeds than vines, and taller plants of a given growth form tend to produce larger seeds than shorter plants of the same growth form.

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Aim Capuchin monkey species are widely distributed across Central and South America. Morphological studies consistently divide the clade into robust and gracile forms, which show extensive sympatry in the Amazon Basin. We use genetic data to test whether Miocene or Plio-Pleistocene processes may explain capuchin species' present distributions, and consider three possible scenarios to explain widespread sympatry.Location The Neotropics, including the Amazon and Atlantic Coastal Forest.Methods We sequenced the 12S ribosomal RNA and cytochrome b genes from capuchin monkey specimens. The majority were sampled from US museum collections and were wild-caught individuals of known provenance across their distribution. We applied a Bayesian discrete-states diffusion model, which reconstructed the most probable history of invasion across nine subregions. We used comparative methods to test for phylogeographic association and dispersal rate variation.

and Summary The mating system of wild brown capuchin monkeys, Cebus apella, was studied during four years in Peruvian rainforest. The most striking feature of estrus is active continuous solicitation of males by females. During the first three to four days, the female continuously follows the dominant male of the group, approaching him with grimaces, distinctive vocalizations, and submissive‐like postures. Although the female frequently attempts to initiate copulations by touching the male and running away, he rarely copulates with her more than once a day. On the next to last day of estrus, the female no longer follows the dominant male closely, and begins to solicit copulations from subordinate males. The dominant male then begins following the female and aggressively preventing other males from approaching her; during the remainder of the estrous period, male‐male aggression is infrequent compared to other polygamous primates. After another half a day, the dominant male stops following the estrous female, who then rapidly solicits and copulates with up to six subordinate males in a single day. Estrous behaviors disappear after 5 to 6 days. The frequency and intensity of female pre‐ and post‐copulatory behaviors are significantly greater with dominant than subordinate males. Copulation duration is significantly longer in dominant males than subordinates. The dominant male has a greater frequency of copulation than any subordinate male and furthermore may have almost exclusive access to the female during the most probable days of ovulation. The strong active solicitation by the female of the dominant male may be explained by direct benefits that she or her offspring might receive from him. Because the dominant male controls access to many food sources during periods when food is scarce, his tolerance of a particular female or her offspring could be an important component of fitness for them. It may be possible to extend this correlation between ecology and mating system to other primate species. Zusammenfassung Während der ersten drei oder vier Brunsttage folgen weibliche Kapuzineraffen (Cebus apella) ununterbrochen dem dominanten Männchen ihrer Gruppe und nähern sich ihm mit besonderen Gesichtsausdrücken, Lautgebungen und Gesten. Das dominante Männchen kopuliert mit einem Weibchen selten öfter als einmal pro Tag, auch wenn es häufiger zur Paarung aufgefordert wird, indem das Weibchen ihn berührt und wegläuft. Etwa ab dem vierten Brunsttag folgt das Weibchen dem dominanten Männchen nicht mehr, sondern beginnt rangtiefere Männchen zur Kopulation aufzufordern. Jetzt aber folgt ihm das dominante Männchen und hindert andere Männchen daran, sich dem Weibchen zu nähern. Am Ende des vierten Tages jedoch hört das dominante Männchen auf, dem Weibchen zu folgen. Darauf kann das brünstige Weibchen bis zu 6mal am Tag rangtiefere Männchen zur Paarung auffordern. Das typische Brunstverhalten endet nach vier bis sechs Tagen. Das brünstige Weibchen zieht das dominante Männchen den rangtieferen Männchen vor (in der Häuf...

In addition to being frugivorous, Cebus and Saimiri stand out among the New World primates of similar body size in being heavily dependent on animal matter for protein (faunivory). A detailed description of the morphology and behavior of the two genera is presented with the object of evaluating the interaction and respective contributions of morphological and behavioral adaptations to foraging patterns. Our conclusions include the following: First, body size is extremely important in explaining the observed variation in diet. Second, the emphasis on faunivory is facilitated more by behavioral than by morphological specialization. Third, whatever morphological specializations are present, particularly in Cebus, are probably favored by diet at the most food-depauperate time of year. Fourth, although morphology may well reveal what a primate may potentially eat, to map this potential onto actual diet requires a detailed knowledge of its natural ecosystem. Finally, we consider whether the behavioral data support the tenuous morphological evidence for grouping Cebus and Saimiri within the clade Cebinae.