Social odours, sexual arousal and pairbonding in primates

We describe the role of social odours in sexual arousal and maintaining pairbonds in biparental and cooperatively breeding primates. Social odours are complex chemical mixtures produced by an organism that can simultaneously provide information about species, kinship, sex, individuality and reproductive state. They are long lasting and have advantages over other modalities. Both sexes are sensitive to changes in odours over the reproductive cycle and experimental disruption of signals can lead to altered sexual behaviour within a pair. We demonstrate, using functional magnetic resonance imaging (fMRI), that social odours indicating reproductive state directly influence the brain areas responsible for sexual behaviour. Social odours also influence other brain areas typically involved in motivation, memory and decision making, suggesting that these signals have more complex functions in primates than mere sexual arousal. We demonstrate a rapid link between social odours and neuroendocrine responses that are modulated by a male's social status. Recent work on humans shows similar responses to social odours. We conclude with an integration of the importance of social odours on sexual arousal and maintaining pairbonds in socially biparental and cooperatively breeding species, suggesting new research directions to integrate social behaviour, neural activation and neuroendocrine responses

Predation on Alouatta guariba clamitans Cabrera (Primates, Atelidae) by Leopardus pardalis (Linnaeus) (Carnivora, Felidae)

There are a few studies about predation on primates. Howler monkeys, being relatively large animals, were believed to be preyed on successfully only by medium to large-sized carnivores and large birds of prey. Our study took place at Chácara Payquerê, which is situated in the municipality of Balsa Nova, State of Paraná, Southern Brazil. Fingers and nails from Alouatta guariba clamitans Cabrera, 1940 were founded in two faecal samples from Leopardus pardalis (Linnaeus, 1758). With our documentation large howler monkey remains in faeces, the possibility of ocelot being a potential predator of all Neotropical primates should be taken into consideration.<br>São poucos os estudos sobre a predação de primatas. Sendo os bugios animais relativamente grandes, acredita-se que somente médios e grandes carnívoros e grandes rapineiros possam lograr sucesso em sua predação. O estudo foi realizado na Chácara Payquerê, situada no município de Balsa Nova, Estado do Paraná, sul do Brasil. Dedos e unhas de Alouatta guariba clamitans Cabrera, 1940 foram encontradas em duas amostras fecais de Leopardus pardalis (Linnaeus, 1758) que foram coletadas. Com este registro de grande primata em fezes, a possibilidade de a jaguatirica ser um potencial predador de todos os primatas neotropicais pode ser levada em consideração

Feeding associations between capybaras Hydrochoerus hydrochaeris (Linnaeus) (Mammalia, Hydrochaeridae) and birds in the Lami Biological Reserve, Porto Alegre, Rio Grande do Sul, Brazil

Feeding associations between capybaras Hydrochoerus hydrochaeris (Linnaeus, 1766) and some bird species were registered in the Lami Biological Reserve, southern Brazil, through observations in a set of transects established in the five major vegetation types of the study area: shrubby and herbaceous swamps, wet grasslands, sandy grasslands and forests. Data included: date and time, vegetation type, bird species, number of individuals (birds and capybaras), type of prey consumed, foraging strategy of the birds and the behavior of the capybaras in relation to the presence of birds. Five species of birds were registered: Caracara plancus (Miller, 1777), Furnarius rufus (Gmelin, 1788), Machetornis rixosus (Vieillot, 1819), Milvago chimachima (Vieillot, 1816) and Molothrus bonariensis (Gmelin, 1789). The interactions were observed in the shrubby swamp (M. bonariensis), forest (C. plancus) and wet grassland (F. rufus, M. rixosus, M. chimachima). The foraging strategies were: (1) use of the capybara as a perch, hunting from its back (M. rixosus, M. bonariensis); (2) use of the capybara as a beater, hunting in the ground (F. rufus, M. rixosus, M. bonariensis); (3) foraging in the skin of the capybara, by picking the ectoparasites (C. plancus, F. rufus, M. chimachima). Strategies (1) and (2) were employed to catch arthropods flushed from the vegetation. Sometimes, capybaras lay down and exposed the abdomen and lateral areas of their bodies to facilitate cleaning by M. chimachima, but the presence of other bird species seemed to be neutral to capybaras.<br>Foram registradas associações alimentares entre capivaras Hydrochoerus hydrochaeris (Linnaeus, 1766) e aves na Reserva Biológica do Lami, sul do Brasil, por meio de observações em um conjunto de transecções estabelecidas nos cinco principais tipos de vegetação existentes na área: banhado arbustivo, banhado herbáceo, campo úmido, campo arenoso e mata. As informações coletadas foram: data, horário, tipo de vegetação, espécie de ave, número de indivíduos (para aves e capivaras), tipo de presa consumida e estratégia de forrageamento das aves e comportamento das capivaras em relação à presença das aves. Cinco espécies de aves foram registradas: Caracara plancus (Miller, 1777), Furnarius rufus (Gmelin, 1788), Machetornis rixosus (Vieillot, 1819), Milvago chimachima (Vieillot, 1816) and Molothrus bonariensis (Gmelin, 1789). As interações foram observadas no banhado arbustivo (M. bonariensis), na mata (C. plancus) e no campo úmido (F. rufus, M. rixosus, M. chimachima). As estratégias de forrageamento registradas foram: (1) uso da capivara como "poleiro"; (2) uso da capivara como "batedor"; (3) forrageio no pêlo da capivara, para captura de ectoparasitas. As estratégias (1) e (2) foram empregadas pelas aves para capturar artrópodos que saltavam da vegetação pela movimentação das capivaras. Foi observado que as capivaras, em algumas ocasiões, apresentavam comportamento de exposição do abdômen e partes laterais do corpo para facilitar a retirada de ectoparasitas por M. chimachima. A presença das demais espécies de aves não interferiu no comportamento das capivaras