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Black Howler Monkeys (black + howler_monkey)
Selected AbstractsSeed Dispersal and Ingestion of Insect-Infested Seeds by Black Howler Monkeys in Flooded Forests of the Parana River, ArgentinaBIOTROPICA, Issue 4 2008Susana Patricia Bravo ABSTRACT All howler monkey species (Alouatta spp.) have a folivorous,frugivorous diet. Howler monkeys are reported to be seed dispersers in several areas, including black howlers (Alouatta caraya), which are important seed dispersers in northern Argentinean forests. The goal of this work was to study the three-way interaction between insects, seeds, and black howlers, and assess the functional significance of this tri-trophic interaction for seed dispersal. I determined through direct observation that fruits of species with a high proportion of insect infestation were important components of howler monkey diet. Ocotea diospyrifolia seeds from fresh faeces of black howlers contained dead larvae, but seeds were still able to germinate. Seeds in which larvae had reached an advanced stage of development did not germinate. Larvae of infested Eugenia punicifolia fruits were killed by digestion when they occurred in the pulp early in the fruiting season, but were dispersed alive with seeds later in the season. Banara arguta fruits contained both healthy and infested seeds; infested seeds were destroyed during digestion, while healthy seeds were dispersed. Black howlers' ingestion of infested fruits could result in the: (1) killing of larvae and dispersion of healthy seeds; (2) spread of larvae; or (3) destruction of infested seeds. This will depend on the relationship between the time at which fruit is consumed by black howlers, the time at which insect infestation occurs, and also probably on the hardness of the seed coat and the seed,insect size ratio. RESUMEN Todas las especies de monos aulladores (Alouatta spp.), poseen dietas folívoro-frugívoras. Los monos aulladores han sido reportados en varias ocasiones como dispersores de semillas, incluído Alouatta caraya, el cual es un importante dispersor de semillas en las selvas del norte de Argentina. El objetivo de este trabajo fue estudiar la interacción triple insectos,semillas,Alouatta caraya y determinar su significado funcional para el proceso de dispersión de semillas. Se determinó por observación directa que el consumo de frutas de las especies que poseían una alta infestación por insectos representaba una alta proporción de la dieta. Las semillas de Ocotea diospyrifolia colectadas de heces frescas de A. caraya contenían larvas muertas y su capacidad germinativa intacta. Las semillas en las cuales las larvas habían alcanzado un avanzado estado de desarrollo ya no podían germinar. Al principio de la estación de fructificación las larvas que infestaban las frutas de Eugenia punicifolia se encontraban en la pulpa y morían al ser ingeridas por A. caraya, pero cuando, avanzada la fructificación, las larvas se movían hacia las semillas, eran dispersadas vivas dentro de las mismas. Las frutas de Banara arguta contenían tanto semillas infestadas como sanas; las infestadas fueron destruidas por la digestión mientras que las sanas eran dispersadas. La ingestión de frutas infestadas por parte de A. caraya puede llevar a: (1) la muerte de las larvas y la dispersión de semillas sanas, (2) la dispersión de larvas o (3) la destrucción de las semillas infestadas. Esto depende de la relación entre el tiempo en que es ingerida la fruta por A. caraya y el tiempo en que se produjo la infestación, probablemente también sea importante la dureza de la cubierta de la semilla y la relación entre el tamaño de la semilla y el de la larva. [source] Behavioral effects of introducing pied tamarin (Saguinus bicolor) to black howler monkey (Alouatta caraya) and white-faced saki (Pithecia pithecia) in a zoological parkAMERICAN JOURNAL OF PRIMATOLOGY, Issue 5 2008Lydia Gentry Abstract Mixed-species primate exhibits are becoming more common in zoological parks as a means to display a diverse array of animals both more naturalistically and with more economy of space. Here, we describe behavioral changes during the introduction process of a pair of pied tamarins (Saguinus bicolor) to an established group of black howler monkeys (Allouatta caraya) and white-faced saki monkeys (Pithecia pithecia). Data were collected during six phases, representing introductions among the various species and to exhibit space and off-exhibit holding. The pied tamarins were consistently the most active of the three species. Although activity levels of the howler and saki monkeys remained constant throughout, that of the tamarins declined as the introduction progressed. Several episodes of aggression between the tamarins and the sakis were observed, but did not coincide with patterns predicted by previous intra-specific introductions. The three-species mix remained stable for several months; however, escalating aggression ultimately led to the removal of the sakis from the mixed-species exhibit. Despite our mixed results, we contend that only through continued trials, coupled with careful and systematic monitoring, can we ultimately identify stable mixes of species. Am. J. Primatol. 70:505,509, 2008. © 2008 Wiley-Liss, Inc. [source] Noninvasive collection of fresh hairs from free-ranging howler monkeys for DNA extractionAMERICAN JOURNAL OF PRIMATOLOGY, Issue 4 2009Monica Améndola-Pimenta Abstract The use of noninvasive collected samples as source of DNA in studies of wild primate populations has increased in recent years. Fresh-plucked hairs represent an important source of DNA, with relatively high quality and concentration. In this study, we describe a low-cost noninvasive technique for collecting fresh-plucked hairs used to obtain DNA samples from free-ranging black howler monkey populations (Alouatta pigra). We designed and manufactured darts made of wooden dowels, with the anterior part smeared with glue, which were projected with blowpipes to trap howler monkey hairs. All of the materials to make the darts are inexpensive and are available locally. We collected 89 samples from 76 individuals residing in 15 troops, and the total number of hairs obtained was 754. We found no differences in the number of hairs collected among sex,age classes or among localities but the percentage of darts recovered with sample varied among localities. Preliminary results indicate that over 96% of samples yielded DNA suitable for polymerase chain reaction-based microsatellite marker analysis. The technique proved successful for collecting fresh-plucked hairs of free-ranging black howler monkeys without any trauma to the animals and can be easily adapted to obtain samples from other wild primate and mammal species. Am. J. Primatol. 71:359,363, 2009. © 2009 Wiley-Liss, Inc. [source] Sexual behavior across ovarian cycles in wild black howler monkeys (Alouatta pigra): male mate guarding and female mate choiceAMERICAN JOURNAL OF PRIMATOLOGY, Issue 2 2009Sarie Van Belle Abstract We studied two multimale,multifemale groups of black howler monkeys (Alouatta pigra) during a 14-month study (June 2006,July 2007) in Palenque National Park, Mexico to evaluate the ways in which their sexual behavior changes across ovarian cycles. We analyzed 231 fecal samples, collected every 2.2±1.4 days from five females. For four females, estradiol and progesterone profiles revealed an average (±SE) cycle length of 18.3±1.4 days. Copulations occurred significantly more frequently during the periovulatory period (POP), defined as the estimated day of ovulation ±3 days (N=18). This was largely the result of cycling females soliciting sexual interactions during their POPs. Females directed their solicitations significantly more often toward "central" males of their group, who had close spatial associations with females at other times, compared with "noncentral" males, who did not associate closely with females. Central males rarely solicited sexual interactions, but instead monitored the females' reproductive status by sniffing their genitals, and maintained significantly closer proximity to females during their POPs, suggesting male mate guarding when conceptions are most likely to occur. Our findings indicate that the reproductive strategies of black howler central males and females coincide, highly skewing mating opportunities toward central males. Black howler females, however, occasionally choose to copulate with noncentral resident males or extra-group males during their POPs, undermining the ability of central males to monopolize all reproductive opportunities. Am. J. Primatol. 71:153,164, 2009. © 2008 Wiley-Liss, Inc. [source] Behavioral effects of introducing pied tamarin (Saguinus bicolor) to black howler monkey (Alouatta caraya) and white-faced saki (Pithecia pithecia) in a zoological parkAMERICAN JOURNAL OF PRIMATOLOGY, Issue 5 2008Lydia Gentry Abstract Mixed-species primate exhibits are becoming more common in zoological parks as a means to display a diverse array of animals both more naturalistically and with more economy of space. Here, we describe behavioral changes during the introduction process of a pair of pied tamarins (Saguinus bicolor) to an established group of black howler monkeys (Allouatta caraya) and white-faced saki monkeys (Pithecia pithecia). Data were collected during six phases, representing introductions among the various species and to exhibit space and off-exhibit holding. The pied tamarins were consistently the most active of the three species. Although activity levels of the howler and saki monkeys remained constant throughout, that of the tamarins declined as the introduction progressed. Several episodes of aggression between the tamarins and the sakis were observed, but did not coincide with patterns predicted by previous intra-specific introductions. The three-species mix remained stable for several months; however, escalating aggression ultimately led to the removal of the sakis from the mixed-species exhibit. Despite our mixed results, we contend that only through continued trials, coupled with careful and systematic monitoring, can we ultimately identify stable mixes of species. Am. J. Primatol. 70:505,509, 2008. © 2008 Wiley-Liss, Inc. [source] | ||||||||||