RESUMO

Partindo da abordagem evolucionista objetivou-se identificar efeitos da imprevisibilidade familiar na infância e das diferenças em função do sexo sobre propensão ao risco, expectativa de futuro e percepção de exposição à violência. Participaram 233 jovens (117 homens, M=18,96 anos). O grupo com maior imprevisibilidade na infância apresentou maior risco de competição e expectativa de vida. Homens apresentaram maiores taxas de propensão ao risco e exposição direta à violência; mulheres maiores taxas de exposição indireta à violência. Concluiu-se que imprevisibilidade familiar e diferenças em função do sexo não apresentaram efeitos lineares sobre as variáveis estudadas, como previsto a partir da abordagem evolucionista. Aponta-se a necessidade de integrar teorias biológicas, psicológicas e sociais e de desenvolver instrumentos adaptados para a população brasileira(AU)

Assuntos

RESUMO

Parent-offspring vocal communication, such as the isolation call, is one of the essential adaptations in mammals that adjust parental responsiveness. Thus, our aim was to test the hypothesis that the function of the capybara infants' whistle is to attract conspecifics. We designed a playback experiment to investigate the reaction of 20 adult capybaras (seven males and 13 females) to pups' whistle calls recorded from unrelated offspring or to bird song, as control. The adult capybaras promptly responded to playback of unrelated pup whistles, while ignoring the bird vocalisation. The adult capybaras took, on average, 2.6 ± 2.5 seconds (s) to show a response to the whistles, with no differences between males and females. However, females look longer (17.0 ± 12.9 s) than males (3.0 ± 7.2 s) toward the sound source when playing the pups' whistle playback. The females also tended to approach the playback source, while males showed just a momentary interruption of ongoing behaviour (feeding). Our results suggest that capybara pups' whistles function as the isolation call in this species, but gender influences the intensity of the response.(AU)

A comunicação vocal entre pais-filhotes, tal como os chamados de isolamento, é uma das adaptações essenciais nos mamíferos para o ajuste da resposta parental. Assim, nosso objetivo foi testar a hipótese de que a função do chamado de assobio em filhotes de capivara é para atrair co-especificos. Delineamos um experimento via playback para investigar a reação de 20 capivaras adultas (sete machos e 13 fêmeas) ao chamado de assobio de filhotes não aparentados e como controle usamos o chamado de um pássaro. As capivaras adultas prontamente responderam ao playback de assobios de filhotes não aparentados, enquanto ignoraram as vocalizações de pássaro. As capivaras levaram, em media 2,6 ± 2,5 segundos (s) para mostrar a resposta para os assobios, não havendo diferença entre machos e fêmeas. No entanto, fêmeas permanecem mais tempo (17,0 ± 12,9 s) do que os machos (3,0 ± 7,2 s) para retornar da fonte sonora após o playback de assobio iniciar. As fêmeas também tendem a aproximar-se da fonte sonora, enquanto os machos fazem uma breve interrupção do comportamento que estão engajados (comendo). Os resultados sugerem que a função do chamado de assobio de filhotes de capivaras é um chamado de isolamento na espécie e que o gênero influencia a intensidade da resposta.(AU)

Assuntos

RESUMO

Parent-offspring vocal communication, such as the isolation call, is one of the essential adaptations in mammals that adjust parental responsiveness. Thus, our aim was to test the hypothesis that the function of the capybara infants' whistle is to attract conspecifics. We designed a playback experiment to investigate the reaction of 20 adult capybaras (seven males and 13 females) to pups' whistle calls - recorded from unrelated offspring - or to bird song, as control. The adult capybaras promptly responded to playback of unrelated pup whistles, while ignoring the bird vocalisation. The adult capybaras took, on average, 2.6 ± 2.5 seconds (s) to show a response to the whistles, with no differences between males and females. However, females look longer (17.0 ± 12.9 s) than males (3.0 ± 7.2 s) toward the sound source when playing the pups' whistle playback. The females also tended to approach the playback source, while males showed just a momentary interruption of ongoing behaviour (feeding). Our results suggest that capybara pups' whistles function as the isolation call in this species, but gender influences the intensity of the response.

Assuntos

RESUMO

In several rodent species, an increase or recovery of sexual behavior can be observed when sexually satiated males are placed in contact with a novel mate. In order to assess the influence of female novelty on the courtship behavior of guinea pigs (Cavia porcellus), four adult males were observed during four daily 15-min sessions while interacting with the same pregnant female (same-female sessions). A new female was presented during the fifth session (switched-female session). The duration of behavioral categories was obtained from videotape records using an observational software. From the first to the second session, all males decreased the time allocated to investigating (sniffing and licking), following, and mounting the female, and that response did not recover by the end of the same-female sessions. No similar decreasing tendencies were detected in the circling or rumba categories. A marked increase of investigating occurred in all males from the last same-female session (8.1, 11.9, 15.1 and 17.3 percent session time) to the switched-female one (16.4, 18.4, 37.1 and 28.9 percent session time, respectively). Increases in following and circling were recorded in three of four males, and full-blown recovery of mounting in one male. No consistent changes in the females' responses to males (following or attacking) were observed throughout testing. These results are consistent with the hypothesis that guinea pig males recognize individual females and that courtship responses may suffer a habituation/recovery process controlled by mate novelty.

Assuntos

RESUMO

In several rodent species, an increase or recovery of sexual behavior can be observed when sexually satiated males are placed in contact with a novel mate. In order to assess the influence of female novelty on the courtship behavior of guinea pigs (Cavia porcellus), four adult males were observed during four daily 15-min sessions while interacting with the same pregnant female (same-female sessions). A new female was presented during the fifth session (switched-female session). The duration of behavioral categories was obtained from videotape records using an observational software. From the first to the second session, all males decreased the time allocated to investigating (sniffing and licking), following, and mounting the female, and that response did not recover by the end of the same-female sessions. No similar decreasing tendencies were detected in the circling or rumba categories. A marked increase of investigating occurred in all males from the last same-female session (8.1, 11.9, 15.1 and 17.3 percent session time) to the switched-female one (16.4, 18.4, 37.1 and 28.9 percent session time, respectively). Increases in following and circling were recorded in three of four males, and full-blown recovery of mounting in one male. No consistent changes in the females' responses to males (following or attacking) were observed throughout testing. These results are consistent with the hypothesis that guinea pig males recognize individual females and that courtship responses may suffer a habituation/recovery process controlled by mate novelty.

Assuntos