9 research outputs found
Variation in the Meaning of Alarm Calls in Verreauxâs and Coquerelâs Sifakas (Propithecus verreauxi, P. coquereli)
The comprehension and usage of primate alarm calls appear to be influenced by social learning. Thus, alarm calls provide flexible behavioral mechanisms that may allow animals to develop appropriate responses to locally present predators. To study this potential flexibility, we compared the usage and function of 3 alarm calls common to 2 closely related sifaka species (Propithecus verreauxi and P. coquereli), in each of 2 different populations with different sets of predators. Playback studies revealed that both species in both of their respective populations emitted roaring barks in response to raptors, and playbacks of this call elicited a specific anti-raptor response (look up and climb down). However, in Verreauxâs sifakas, tchi-faks elicited anti-terrestrial predator responses (look down, climb up) in the population with a higher potential predation threat by terrestrial predators, whereas tchi-faks in the other population were associated with nonspecific flight responses. In both populations of Coquerelâs sifakas, tchi-fak playbacks elicited anti-terrestrial predator responses. More strikingly, Verreauxâs sifakas exhibited anti-terrestrial predator responses after playbacks of growls in the population with a higher threat of predation by terrestrial predators, whereas Coquerelâs sifakas in the raptor-dominated habitat seemed to associate growls with a threat by raptors; the 2 other populations of each species associated a mild disturbance with growls. We interpret this differential comprehension and usage of alarm calls as the result of social learning processes that caused changes in signal content in response to changes in the set of predators to which these populations have been exposed since they last shared a common ancestor
Communities of microscopic fungi in contaminated and reference Al-Fe-humus podzols and their influence on copper mobility
Structural and functional properties of actinomycetal communities in chernozems and saline soils of Ukraine
Actinomycetes in the prokaryotic complex of the rhizosphere of oats in a soddy-podzolic soil
Dieta de Micoureus demerarae (Thomas) (Mammalia, Didelphidae) associada Ă s florestas contĂguas de mangue e terra firme em Bragança, ParĂĄ, Brasil Diet of Micoreus demerarae (Thomas) (Mammalia, Didelphidae) associated with contiguous forests of mangrove and terra firme in Bragança, ParĂĄ, Brazil
A dieta de Micoureus demerarae (Thomas, 1905) foi estudada em bosques de mangue e terra firme atravĂ©s de amostras estomacais e fecais. O nĂșmero de indivĂduos capturados foi inversamente proporcional Ă disponibilidade de frutos e insetos, sendo Coleoptera e Hemiptera as ordens de artrĂłpodes mais consumidos e Passifloraceae e Arecaceae os frutos mais ingeridos. Desse modo, tanto a maior variabilidade de frutos como a alta produção destes durante a estação seca, parecem explicar o aumento da captura desses animais nos bosques de terra firme, dos quais sĂŁo originalmente provenientes. Os itens alimentares sugerem que esta espĂ©cie possui uma dieta do tipo onĂvora, independentemente da sazonalidade ou distribuição dos recursos disponĂveis.<br>The diet of Micoureus demerarae (Thomas, 1905) was studied in mangrove and terra firme stands by using stomachal and faecal samples. The number of captured individuals was inversely proportional to availability of fruits and insects, being Coleoptera and Hemiptera the most consumed arthropod orders and Passifloraceae and Arecaceae the most ingested fruits. Thus, either fruits variability or their high yield during the dry season seem to explain the increase of captured animals in the terra firme stands, where they originally come from. The food items suggest that this species has an omnivorous diet, independently of the seasonality or distribution of available resources