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survey of alouatta caraya, the black-and-gold howler monkey, and alouatta guariba clamitans, the brown howler monkey, in a contact zone, state of rio grande do sul, brazil: evidence for hybridization.sympatry and natural hybridization between howler monkey taxa (alouatta spp.) has only recently being confirmed in the wild. surveys in areas of potential contact between the distribution of two taxa have shown that sympatry is rare, although more common than previously known. here we report the results of a survey conducted in a contact zone between the only two sexually dichromatic howler monkey taxa, alouatta caraya and a. guariba clamitans, in são francisco de assis, state of rio grande do s ...200818654738
infant hybrids in a newly formed mixed-species group of howler monkeys (alouatta guariba clamitans and alouatta caraya) in northeastern argentina.natural hybridisation between species has been reported in several primate taxa. in the neotropics, there is increasing evidence of this phenomenon in howler monkeys (genus alouatta) in contact zones between species. we describe the first known case of formation of a mixed-species group, and two cases of putative infant hybrids between the brown howler (alouatta guariba clamitans) and the black howler (a. caraya) in misiones, argentina. for 2 years, we followed a group consisting of one adult ma ...200818855099
sexual behavior across ovarian cycles in wild black howler monkeys (alouatta pigra): male mate guarding and female mate choice.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 durin ...200919016487
group size and composition of black-and-gold howler monkeys (alouatta caraya) on the upper paraná river, southern brazil.in social mammals, group size, sex and age-class composition are important parameters that are required to understand population dynamics and determine conservation strategies. these parameters are known only poorly for the black-and-gold howler monkey (alouatta caraya). here, we studied groups of a. caraya on islands and adjacent banks of the upper paraná river of southern brazil, to examine variability in group size and composition. this location is important for this species because of the hi ...200919034383
births in wild black and gold howler monkeys (alouatta caraya) in northern argentina.previous studies on births in nonhuman primates suggest that births are expected to occur at night to avoid predators. here, we describe birth-related behaviors in wild black and gold howler monkeys, alouatta caraya and address the various ideas proposed in the literature about the timing of births in group-living nonhuman primates. we collected data on females' birth-related behaviors through continuous focal observations and scan samples. focal observations on females giving birth were taken f ...200919048613
social and hormonal mechanisms underlying male reproductive strategies in black howler monkeys (alouatta pigra).we investigated the social and hormonal mechanisms underlying male reproductive strategies in two multimale-multifemale groups of black howler monkeys (alouatta pigra) during a 14-month study in palenque national park, mexico. fecal glucocorticoid (fgc) and androgen (fa) levels were analyzed for 343 fecal samples collected from 14 males during their presence in the study groups. neither immigrating males nor resident males that remained in the group had elevated fgc and fa levels during 11 obser ...200919712675
[diversity of wild and domestic mammal's intestinal helminths from the caatinga of the parque nacional serra da capivara, southeast of piauí, brazil].biodiversity studies allow ecosystem assessment and monitoring of environmental changes and impacts. parasite diversity could reflect the host/ parasite coevolutionary process and the environment changes that permit the loss, gain or maintenance of species. this survey used species/morphotypes of helminths eggs found in feces from seven wild mammal species (the groups dasypodidae and large cats, and tamandua tetradactyla, cebus apella, alouatta caraya, cerdocyon thous, pecari tajacu) and from tw ...200920040186
noninvasive collection of fresh hairs from free-ranging howler monkeys for dna extraction.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 ...200919125389
pheochromocytoma in six new world primates.six new world primates, including 2 golden lion tamarins (leontopithecus rosalia), 2 cotton-top tamarins (saguinus o. oedipus), 1 black howler monkey (alouatta caraya), and 1 black-handed spider monkey (ateles g. geoffroyi), were diagnosed with unilateral (4/6) or bilateral (1/6) adrenal or extra-adrenal (1/6) pheochromocytoma by light microscopy and immunohistochemical staining for chromogranin a. overt invasive behavior or metastases were not observed in any primate, and thus these neoplasms w ...200919276065
effects of habitat structure and fragmentation on diversity and abundance of primates in tropical deciduous forests in bolivia.habitat structure and anthropogenic disturbance are known to affect primate diversity and abundance. however, researchers have focused on lowland rain forests, whereas endangered deciduous forests have been neglected. we aimed to investigate the relationships between primate diversity and abundance and habitat parameters in 10 deciduous forest fragments southeast of santa cruz, bolivia. we obtained primate data via line-transect surveys and visual and acoustic observations. in addition, we asses ...201020949116
trabecular bone structure in the humeral and femoral heads of anthropoid primates.the functional significance of three-dimensional trabecular bone architecture in the primate postcranial skeleton has received significant interest over the last decade. some previous work has produced promising results, finding significant relationships between femoral head trabecular bone structure and hypothesized locomotor loading in leaping and nonleaping strepsirrhines. conversely, most studies of anthropoid femoral head bone structure have found broad similarity across taxonomic and locom ...201020235327
hybridization between alouatta caraya and alouatta guariba clamitans in captivity.hybridization between alouatta spp. has been suggested at contact zones of a. palliata and a. pigra in mexico and of a. caraya and a. guariba clamitans in brazil and argentina. whereas genetic data confirmed hybridization between the former pair of species, hybrid individuals of the latter pair have been putatively identified on the basis of a mosaic pelage color. in this paper, we describe the first confirmed cases of hybridization between a female a. guariba clamitans and a male a. caraya. one ...201020217179
are howler monkey species ecologically equivalent? trophic niche overlap in syntopic alouatta guariba clamitans and alouatta caraya.according to the principle of competitive exclusion, niche differentiation allows the stable coexistence of closely related species. we analyzed dietary profile and diversity, and dietary overlap between syntopic brown howlers (br; alouatta guariba clamitans) and black and gold howlers (blg; a. caraya) in the atlantic forest of ne argentina, with the objective of evaluating the degree of trophic niche overlap and potential interspecific competition for food. during 12 months, we collected data o ...201019953557
impact of yellow fever outbreaks on two howler monkey species (alouatta guariba clamitans and a. caraya) in misiones, argentina.two yellow fever outbreaks (yfos) occurred in northeastern argentina between november 2007 and october 2008, seriously affecting populations of two howler monkey species: the brown howler alouatta guariba clamitans and the black howler alouatta caraya. both howlers live syntopically in el piñalito provincial park, misiones, where four groups (36 individuals) were studied since january 2005. the first dead howlers were found on january 20, 2008, in el piñalito. systematic searches found 14 dead h ...201020095025
preliminary study of mother-offspring conflict in black and gold howler monkeys (alouatta caraya).parent-offspring conflict has been scarcely studied in neotropical primates. in this study, we explored mother-offspring conflict in a group of wild black and gold howler monkeys (alouatta caraya) in northeastern argentina. we used the all-occurrences technique to record behaviors, completing 712 h of observation. the results showed that all immature individuals between 2 and 23 months expressed conflict with regard to suckling or traveling with their mothers. successful suckling attempts negati ...201020165971
circulation of antibodies against yellow fever virus in a simian population in the area of porto primavera hydroelectric plant, são paulo, brazil.yellow fever (yf) is an acute viral infectious disease transmitted by mosquitoes which occurs in two distinct epidemiological cycles: sylvatic and urban. in the sylvatic cycle, the virus is maintained by monkey's infection and transovarian transmission in vectors. surveillance of non-human primates is required for the detection of viral circulation during epizootics, and for the identification of unaffected or transition areas. an elisa (enzyme-linked immunosorbent assay) was standardized for es ...201020305949
mating promiscuity and reproductive tactics in female black and gold howler monkeys (alouatta caraya) inhabiting an island on the parana river, argentina.in several primate species, females mate promiscuously and several adult males peacefully co-reside in the same social group. we investigated female mating behavior in two neighboring multimale-multifemale groups of alouatta caraya in northern argentina (27 degrees 20's-58 degrees 40'w). all adult individuals in each group were marked with identification anklets and ear tags, and followed for five consecutive full days per month during 20 consecutive months. we recorded 219 copulations for eight ...201020568080
observed infanticides following a male immigration event in black howler monkeys, alouatta pigra, at palenque national park, mexico.this study describes two cases of directly observed and one case of nearly observed infanticide after an adult male immigrated into a multimale-multifemale group of black howler monkeys (alouatta pigra) at palenque national park, mexico. the immigrant male entered the group alone, injured the central adult male, presumably evicted the noncentral adult male, and killed all three young infants present over the course of three consecutive days in february 2010. three weeks after the infanticide eve ...201020665226
parasites, primates, and ant-plants: clues to the life cycle of controrchis spp. in black howler monkeys (alouatta pigra) in southern belize.the purpose of this study was to investigate the prevalence, intensity, and possible transmission routes of the trematode, controrchis spp. (dicrocoeliidae), in a population of black howler monkeys (alouatta pigra) near monkey river, belize. alouatta pigra are arboreal primates that are typically folivorous and frugivorous. controrchis is a dicrocoeliid trematode and, as such, should require a gastropod and an ant (formicidae) intermediate host for transmission. from january to july 2005 and feb ...201020966290
influence of the landscape matrix on the abundance of arboreal primates in fragmented landscapes.composition of the landscape matrix of surrounding forest fragments is thought to be critically important to the survival of arboreal primates because it offers structures that help the animals move between fragments and other foraging sites. however, little is known about the composition of the matrix used by these animals. the aim of this study was to quantitatively assess the importance of the landscape matrix and its effects on primate abundance, using black howler monkeys (alouatta pigra) l ...201121210179
chromosome painting in two genera of south american monkeys: species identification, conservation, and management.cytogenetic studies showed that a number of new world primate taxa, particularly the genera alouatta, aotus, and callicebus, have highly derived karyotypes. cytogenetics in these primates, at every level of analysis, has contributed to the recognition of species and revealed that their number was certainly underestimated by researchers relying solely on traditional morphological data. further attention was drawn to alouatta and aotus because they are characterized by translocations of the y chro ...201121335958
potential distribution of mexican primates: modeling the ecological niche with the maximum entropy algorithm.we developed a potential distribution model for the tropical rain forest species of primates of southern mexico: the black howler monkey (alouatta pigra), the mantled howler monkey (alouatta palliata), and the spider monkey (ateles geoffroyi). to do so, we applied the maximum entropy algorithm from the ecological niche modeling program maxent. for each species, we used occurrence records from scientific collections, and published and unpublished sources, and we also used the 19 environmental cov ...201121404094
blood parameters are little affected by time of sampling after the application of ketamine in black howler monkeys (alouatta pigra).background ketamine hydrochloride is an anesthetic commonly utilized to obtain biological samples in various non-human primates. its application alters individual hematologic and biochemical values. the aim of this study was to analyze its effect on blood parameters of alouatta pigra. method we collected blood samples at 10 and 40 minutes after the application of ketamine in 12 adult female a. pigra living in free-ranging conditions. results the analysis showed that 40 minutes after applicati ...201121443563
cranial ontogeny and sexual dimorphism in two new world monkeys: alouatta caraya (atelidae) and cebus apella (cebidae).pattern of skull development and sexual dimorphism was studied in cebus apella and alouatta caraya using univariate, bivariate, and multivariate statistics. in both species, sexual dimorphism develops because the common growth trajectory in males extends and because of differences in growth rates between sexes. the expectation that the ontogenetic bases of adult dimorphism vary interspecifically is well substantiated by this study. a. caraya exhibits transitional dimorphism in its subadult stage ...201121484855
analysis of the hydrogenotrophic microbiota of wild and captive black howler monkeys (alouatta pigra) in palenque national park, mexico.intestinal methanogenesis is one of the major pathways for consumption of hydrogen produced by bacterial fermentation and is considered to affect the efficiency of host energy harvest; however, little information is available regarding the hydrogenotrophic pathways of nonhuman primates in the wild, in general, and of howler monkeys, in particular. microbial fermentation of plant structural carbohydrates is an important feature in wild howlers owing to the high fiber and low available energy cont ...201121557284
a comparative study of the recombination pattern in three species of platyrrhini monkeys (primates).homologous chromosomes exchange genetic information through recombination during meiotic synapsis, a process that increases genetic diversity and is fundamental to sexual reproduction. meiotic studies in mammalian species are scarce and mainly focused on human and mouse. here, the meiotic recombination events were determined in three species of platyrrhini monkeys (cebus libidinosus, cebus nigritus and alouatta caraya) by analysing the distribution of mlh1 foci at the stage of pachytene. moreove ...201121735165
reemergence of yellow fever: detection of transmission in the state of s+úo paulo, brazil, 2008.following yellow fever virus (yfv) isolation in monkeys from the s+úo jos+® do rio preto region and two fatal human autochthonous cases from the ribeir+úo preto region, state of s+úo paulo, brazil, two expeditions for entomological research and eco-epidemiological evaluation were conducted.201121739073
Variation in the Extraction Efficiency of Estradiol and Progesterone in Moist and Lyophilized Feces of the Black Howler Monkey (Alouatta pigra): Alternative Methods.Several fecal steroid extraction techniques have been developed to measure the ovary function in different species of mammals. However, regardless of the method of extraction and the sample type chosen, it has been observed that they can yield results with different percentages of recuperation. The objective of this study was to determine whether the type of substratum, solvent and extraction method used have any influence on the extraction efficiency in the feces of Alouatta pigra (black howler ...201122194723
black and gold howler monkeys (alouatta caraya) as sentinels of ecosystem health: patterns of zoonotic protozoa infection relative to degree of human-primate contact.exponential expansion of human populations and human activities within primate habitats has resulted in high potential for pathogen exchange creating challenges for biodiversity conservation and global health. under such conditions, resilient habitat generalists such as black and gold howler monkeys (alouatta caraya) may act as effective sentinels to overall ecosystem health and alert us to impending epidemics in the human population. to better understand this potential, we examined noninvasivel ...201120084672
Yellow fever outbreak affecting Alouatta populations in southern Brazil (Rio Grande do Sul State), 2008-2009.The natural transmission cycle of Yellow Fever (YF) involves tree hole breeding mosquitoes and a wide array of nonhuman primates (NHP), including monkeys and apes. Some Neotropical monkeys (howler monkeys, genus Alouatta) develop fatal YF virus (YFV) infections similar to those reported in humans, even with minimum exposure to the infection. Epizootics in wild primates may be indicating YFV circulation, and the surveillance of such outbreaks in wildlife is an important tool to help prevent human ...201222020690
the evaluation of enteric viruses in asymptomatic free-ranging non-human primates (alouatta guariba clamitans, alouatta caraya, callithrix spp., callithrix penicillata, and leontopithecus caissara) in southern brazil.this study evaluated the presence of rotavirus groups a, b, and c (rv-a, rv-b, and rv-c), sapovirus (sav), and norovirus (nov) in asymptomatic non-human primates (nhp).201222889190
squirrel monkey cytomegalovirus antibodies in free-ranging black howler monkeys (alouatta caraya), misiones, argentina.serum from four black howler monkeys (alouatta caraya) was screened for antibodies to seven viruses by dot immunoassay. cytomegalovirus antibodies were detected in three of four individuals and provide the first evidence of exposure by black howler monkeys to this virus.201222493133
isolation of yellow fever virus from mosquitoes in misiones province, argentina.yellow fever (yf) is a viral hemorrhagic fever endemic to tropical regions of south america and africa. from 2007 to 2009 an important epidemic/epizootic of yf was detected in different populations of howler monkeys (alouatta species) in misiones, a northeastern argentinian province. yellow fever virus (yfv) infection was researched and documented by laboratory tests in humans and in dead alouatta carayá. the objective of that research was to investigate the circulation of yfv in mosquitoes, whi ...201223025694
the role of minerals in food selection in a black howler monkey (alouatta pigra) population in belize following a major hurricane.as plants may contain low levels of some minerals including sodium, copper, and phosphorous, herbivores may become deficient in these nutrients. in 2001, hurricane iris hit the monkey river forest in belize causing substantial damage to the food supply of the black howler monkey population (alouatta pigra) living there. this included an 18-month absence in fruit production and a complete loss of figs that are high in calcium. in this article, we describe the post-hurricane diet of this monkey po ...201222851375
botfly parasitism and tourism on the endangered black howler monkey of belize.tourism imposes costs and benefits on wild primates. endangered black howler monkey (alouatta pigra) troops with high exposure to tourism had higher levels of botfly (alouattamyia baeri) parasitism. edge habitat and juvenile numbers did not seem to confound the observed relationship. to improve the cost/benefit ratio of tourism, we recommend further investigation.201222762861
free-ranging black howler monkeys, alouatta pigra, in southern belize are not parasitized by controrchis biliophilus.several coprological studies of alouatta pigra, the black howler monkey, inhabiting belize and mexico have been published in the past several years. trematodes, specifically controrchis biliophilus (dicrocoeliidae), have been detected in a. pigra from all locations in belize and mexico examined in those studies. a routine coprological survey of a. pigra was conducted in may and june 2010 as part of baseline data collection for an a. pigra population in punta gorda, toledo district, southern beli ...201222760693
hematological and biochemical blood values in wild populations of black howler monkeys (alouatta pigra) of campeche, méxico.the clinical analyses of free-ranging new world primates are extremely limited. the aim of this study was to obtain baseline data of blood chemistry and hematological values of free-ranging alouatta pigra.201222882076
genetic structure and kinship patterns in a population of black howler monkeys, alouatta pigra, at palenque national park, mexico.we investigated the genetic structure and kinship patterns of black howler monkeys (alouatta pigra) at palenque national park, mexico. fecal samples from 49 individuals residing in eight social groups were successfully genotyped for 19 polymorphic microsatellite markers known to be variable in other ateline primates. overall, genetic diversity was low (h(o) = 0.588) with an average of 4.2 alleles per loci (range = 2-8). we found that intergroup genetic variation among adults was relatively high ...201222707175
habitat degradation impacts black howler monkey (alouatta pigra) gastrointestinal microbiomes.the gastrointestinal (gi) microbiome contributes significantly to host nutrition and health. however, relationships involving gi microbes, their hosts and host macrohabitats remain to be established. here, we define clear patterns of variation in the gi microbiomes of six groups of mexican black howler monkeys (alouatta pigra) occupying a gradation of habitats including a continuous evergreen rainforest, an evergreen rainforest fragment, a continuous semi-deciduous forest and captivity. high thr ...201323486247
a comparison of scan and focal sampling for the description of wild primate activity, diet and intragroup spatial relationships.we used data collected during two concurrent studies of black howler monkeys (alouatta pigra) in palenque national park, mexico, to compare systematically three methods of behavioral data collection [group activity scan sampling (group scans), instantaneous focal individual sampling (instantaneous focals) and continuous focal individual sampling (continuous focals)] and three methods of proximity data collection [group proximity scan sampling (group proximity scans), focal individual proximity s ...201323548732
identification of bacterial infection in neotropical primates.emerging infectious diseases usually arise from wild animal populations. in the present work, we performed a screening for bacterial infection in natural populations of new world primates. the blood cell bulk dnas from 181 individuals of four platyrrhini genera were pcr screened for eubacterial 16s rrna genes. bacteria were detected and identified in 13 distinct individuals of alouatta belzebul, alouatta caraya, and cebus apella monkeys from geographically distant regions in the states of mato g ...201323797292
differential distribution of sperm subpopulations and incidence of pleiomorphisms in ejaculates of captive howling monkeys (alouatta caraya).the aim of this study was to develop an objective method to determine the incidence of pleiomorphisms and its influence on the distribution of sperm morphometric subpopulations in ejaculates of howling monkeys (alouatta caraya) by using a combination of computerized analysis system (asma) and principal component analysis (pca) methods. ejaculates were collected by electroejaculation methods on a regular basis from five individuals maintained under identical captive environmental, nutritional, an ...201323975115
hemotropic mycoplasma in a free-ranging black howler monkey (alouatta caraya) in brazil.hemotropic mycoplasmas are bacteria that infect erythrocytes and cause subclinical infections to life-threatening disease. we describe hemotropic mycoplasma infection in a free-ranging black howler monkey (alouatta caraya). this is the first molecular detection of a hemotropic mycoplasma in a nonhuman primate from brazil.201323778631
kin structure and parallel dispersal in the black-and-gold howler monkey alouatta caraya (platyrrhini, atelidae).we here investigated the kin structure and pattern of dispersal in the black-and-gold howler monkey (alouatta caraya, platyrrhini, atelidae) based on genotype differences at nine microsatellite loci of 48 individuals from eight social groups along the riparian forest of the tocantins river, brazil. the genetic diversity (he = 0.647) was similar to or higher than previously reported values in other alouatta species. given that no spatial kinship structure was detected, we found no evidence that d ...201324338396
scaling the primate lateral geniculate nucleus: niche and neurodevelopment in the regulation of magnocellular and parvocellular cell number and nucleus volume.new stereological assessments of lateral geniculate nucleus (lgn) neuron numbers and volumes in five new world primates (cebus apella, saguinus midas niger, alouatta caraya, aotus azarae, and callicebus moloch) and compiled lgn volumes for an additional 26 mammals were analyzed for a better understanding of visual system evolution. both the magnocellular (m)- and the parvocellular (p)-cell populations scale allometrically with brain volume in primates, p cells with a significantly higher slope s ...201424222647
male reproductive strategies in black and gold howler monkeys (alouatta caraya).behavioral and demographic factors such as group size, social structure, dispersal patterns, and mating systems affect male reproductive success. in the present study, we analyze the relationship between social structure, genetic relatedness of adult males and offspring paternity in one population of alouatta caraya inhabiting a continuous forest in northern argentina. after 14 months of behavioral studies and genotyping 11 microsatellites, we found that dominant or central males achieved greate ...201424014464
ganglion cell and displaced amacrine cell density distribution in the retina of the howler monkey (alouatta caraya).unlike all other new world (platyrrine) monkeys, both male and female howler monkeys (alouatta sp.) are obligatory trichromats. in all other platyrrines, only females can be trichromats, while males are always dichromats, as determined by multiple behavioral, electrophysiological, and genetic studies. in addition to obligatory trichromacy, alouatta has an unusual fovea, with substantially higher peak cone density in the foveal pit than every other diurnal anthropoid monkey (both platyrrhines and ...201425546077
detection of antibodies to toxoplasma gondii in wild animals in brazil.toxoplasmosis is a worldwide zoonosis caused by an obligate intracellular protozoan parasite, toxoplasma gondii, that affects all warm-blooded animals, including wild animals. the increased number of cases of parasitic infections is mainly due to the destruction of environmental conservation areas, which is driving wild animals out of their habitats and towards urban areas. in this study, the occurrence of t. gondii infection was investigated by the modified agglutination test (mat) in 26 differ ...201425278979
sero-epidemiological survey for brucellosis, leptospirosis, and toxoplasmosis in free-ranging alouatta caraya and callithrix penicillata from são paulo state, brazil.sera were tested for brucella spp., leptospira spp. and toxoplasma gondii antibodies in 68 free-ranging new world monkeys from a forest fragment of the brazilian cerrado.201424646216
serological evidence for saint louis encephalitis virus in free-ranging new world monkeys and horses within the upper paraná river basin region, southern brazil.saint louis encephalitis virus (slev) primarily occurs in the americas and produces disease predominantly in humans. this study investigated the serological presence of slev in nonhuman primates and horses from southern brazil.201425075477
detection of arboviruses of public health interest in free-living new world primates (sapajus spp.; alouatta caraya) captured in mato grosso do sul, brazil.a sero-epidemiological survey was undertaken to detect the circulation of arboviruses in free-living non-human primates.201424474008
molecular identification of trypanosomatids in wild animals.diverse wild animal species can be reservoirs of zoonotic flagellate parasites, which can cause pathologic chagas disease. the present study aimed to detect the natural occurrence of flagellate parasites through direct microscopic examination of the parasites in blood samples and through pcr of whole blood and blood culture (haemoculture) samples from 38 captive and 65 free-living wild animals in the centre for conservation of wild fauna (ccwf), an area endemic for leishmaniasis. for this study, ...201424636787
the role of gut microbes in satisfying the nutritional demands of adult and juvenile wild, black howler monkeys (alouatta pigra).in all mammals, growth, development, pregnancy, and lactation increase nutritional demands. although primate field studies tend to focus on shifts in activity and diet as mechanisms to compensate for these demands, differences in digestive efficiency also are likely to be important. because the gut microbiota can impact host digestive efficiency, we examined differences in activity budget, diet, and the gut microbial community among adult male (n = 4), adult female (n = 4), and juvenile (n = 5) ...201425252073
nutrition and foraging strategies of the black howler monkey (alouatta pigra) in palenque national park, mexico.food resources consumed by primates vary markedly in nutritional content. as a result, foragers must develop a feeding strategy to select resources that balance energy and macronutrient intake and reduce the consumption of fiber and toxins. in this study, we collected data on dietary patterns, rates of food consumption, and weight of food items consumed and combined them with published values of the nutritional content of neotropical foods to estimate energy and nutrient intake during a 10-month ...201424763976
black howler monkey (alouatta pigra) activity, foraging and seed dispersal patterns in shaded cocoa plantations versus rainforest in southern mexico.recent evidence has shown that primates worldwide use agroecosystems as temporary or permanent habitats. detailed information on how these primates are using these systems is scant, and yet their role as seed dispersers is often implied. the main objective of this study was to compare the activity, foraging patterns and seed dispersal role of black howler monkeys (alouatta pigra) inhabiting shaded cocoa plantations and rainforest in southern chiapas, mexico. we gathered data on three monkey grou ...201424668557
primates living outside protected habitats are more stressed: the case of black howler monkeys in the yucatán peninsula.the non-invasive monitoring of glucocorticoid hormones allows for the assessment of the physiological effects of anthropogenic disturbances on wildlife. variation in glucocorticoid levels of the same species between protected and unprotect areas seldom has been measured, and the available evidence suggests that this relationship may depend on species-specific habitat requirements and biology. in the present study we focused on black howler monkeys (alouatta pigra), a canopy-dwelling primate spec ...201425375243
physiological and analytical validations of fecal steroid hormone measures in black howler monkeys.the measurement of hormones in fecal samples allows for the noninvasive assessment of the endocrine status of free-ranging primates. however, procedures and techniques for hormone analysis in feces must be validated, both analytically and physiologically. few studies have addressed the endocrinology of black howler monkeys (alouatta pigra). due to its conservation status, direct handling of individuals from this species and invasive sample collection are highly regulated, and therefore tradition ...201424939341
the function of loud calls in black howler monkeys (alouatta pigra): food, mate, or infant defense?loud calling (i.e., howling) is the single most distinctive behavioral attribute of the social system of howler monkeys (alouatta spp.), yet no general consensus exists regarding its main function. during a 28-month study of five groups of black howler monkeys (alouatta pigra) at palenque national park, mexico, we examined whether howling mainly functioned in the defense of food resources, mates, or infants vulnerable to infanticide. we recorded 602 howling bouts. howling occurred more frequentl ...201424865565
variation in dietary breadth among groups of black howler monkeys is not associated with the vegetation attributes of forest fragments.habitat disturbance alters vegetation structure and composition. for example, in forest fragments, the rate of secondary plant species recruitment and mortality in species typical of old-growth forests are higher. for many arboreal primates, movement between fragments is infrequent and difficult, thus the dietary breadth of herbivorous primates that live in fragments is expected to change. it is likely that the ability of howler monkeys (alouatta spp.) to live in a large array of habitat types i ...201424842275
mammal assemblages in forest fragments and landscapes occupied by black howler monkeys.species assemblages in disturbed habitats vary as a function of the interaction between species requirements and the spatial configuration of the habitat. there are many reports accounting for the presence of howler monkeys in fragments where other mammals are absent, suggesting that they are more resilient. in the present study we explored this idea and predicted that if howler monkeys were more resilient to habitat loss and fragmentation than other mammals, mammal assemblages in fragments occu ...201424619385
factors affecting the drinking behavior of black howler monkeys (alouatta pigra).water is essential for animals, and is particularly critical for thermoregulation. animals obtain water from three main sources, free water, water contained in food, and water produced in the body during metabolism. howler monkeys (alouatta spp.) spend a small proportion of their time drinking water and some populations have not been observed drinking, suggesting they obtain most of their water requirements in food or by metabolism. however, when howler monkeys have been observed drinking there ...201424057696
foraging strategy of a neotropical primate: how intrinsic and extrinsic factors influence destination and residence time.most animals need to actively search for food to meet energetic requirements and live in heterogeneous environments where food resources have complex spatio-temporal patterns of availability. consequently, foraging animals need to find a balance between effort and resource allocation while accounting for intrinsic and extrinsic factors, which are often overlooked when modelling foraging behaviour. we identified the decision rules for foraging in black howler monkeys (alouatta pigra), according t ...201423957316
a diverse group of small circular ssdna viral genomes in human and non-human primate stools.viral metagenomics sequencing of fecal samples from outbreaks of acute gastroenteritis from the us revealed the presence of small circular ssdna viral genomes encoding a replication initiator protein (rep). viral genomes were ∼2.5 kb in length, with bi-directionally oriented rep and capsid (cap) encoding genes and a stem loop structure downstream of rep. several genomes showed evidence of recombination. by digital screening of an in-house virome database (1.04 billion reads) using blast, we iden ...201527774288
female participation in collective group defense in black howler monkeys (alouatta pigra).many group-living animals actively defend a home range against neighboring groups. in many of these societies, males are the primary participants during group defense, while female participation ranges from seldom to frequent. among howler monkeys (alouatta spp.), loud calls (i.e., howling) are often used in the context of intergroup spacing as a form of cooperative group defense. males initiate and lead these howling bouts, but females occasionally participate as well. during a 28-month study, ...201525704874
the gut microbiota appears to compensate for seasonal diet variation in the wild black howler monkey (alouatta pigra).for most mammals, including nonhuman primates, diet composition varies temporally in response to differences in food availability. because diet influences gut microbiota composition, it is likely that the gut microbiota of wild mammals varies in response to seasonal changes in feeding patterns. such variation may affect host digestive efficiency and, ultimately, host nutrition. in this study, we investigate the temporal variation in diet and gut microbiota composition and function in two groups ...201525524570
individual participation in intergroup contests is mediated by numerical assessment strategies in black howler and tufted capuchin monkeys.asymmetries in resource-holding potential between opposing groups frequently determine outcomes of intergroup contests. since both numerical superiority and high intergroup dominance rank may confer competitive advantages, group members should benefit from assessing the relative strength of rivals prior to engaging in defensive displays. however, differences in individual assessment may emerge when cost-benefit trade-offs differ among group members. we examine the influence of numerical superior ...201526503680
behavioural innovation and cultural transmission of communication signal in black howler monkeys.social traditions based on communication signals are widespread in birds, cetaceans and humans, but surprisingly rare in nonhuman primates known for having genetically-determined vocal repertoires. this study presents the first description of a singular case of behaviour associated with calling (placing a hand in front of the mouth while vocalizing: hfm) in black howler monkeys. we showed, first, that hfm was found only in a subset of the groups observed, at the same geographical location, and w ...201526303965
molecular typing of giardia duodenalis isolates from nonhuman primates housed in a brazilian zoo.giardia infections in captive nonhuman primates (nhp) housed at a brazilian zoo were investigated in order to address their zoonotic potential. fresh fecal samples were collected from the floors of 22 enclosures where 47 primates of 18 different species were housed. the diagnosis of intestinal parasites after concentration by sedimentation and flotation methods revealed the following parasites and their frequencies: giardia (18%); entamoeba spp. (18%); endolimax nana (4.5%); iodamoeba spp. (4.5% ...201524553608
how do demographic and social factors influence parent-offspring conflict? the case of wild black and gold howler monkeys (alouatta caraya).in this study, we examined the influence of demography and social context on mother-offspring conflict in wild black and gold howler monkeys (alouatta caraya) inhabiting two nearby sites in northern argentina, one comprising continuous forest and one fragmented forest. these sites differed in population density (3.25 vs. 1.04 individuals/ha), degree of home range overlap between neighboring groups (70 vs. 31%), and rate of intergroup encounters (2 vs. 0.02-1 encounters/day), though not in interb ...201525864875
comprehensive characterization of evolutionary conserved breakpoints in four new world monkey karyotypes compared to chlorocebus aethiops and homo sapiens.comparative cytogenetic analysis in new world monkeys (nwms) using human multicolor banding (mcb) probe sets were not previously done. here we report on an mcb based fish-banding study complemented with selected locus-specific and heterochromatin specific probes in four nwms and one old world monkey (owm) species, i.e. in alouatta caraya (aca), callithrix jacchus (cja), cebus apella (cap), saimiri sciureus (ssc), and chlorocebus aethiops (cae), respectively. 107 individual evolutionary conserved ...201527441227
hematological parameters and the variations resulting from stress of alouatta caraya during a wildlife rescue program in brazil.deforestation and habitat fragmentation are major threats to the conservation status of new world primates, such as the howler monkey (alouatta caraya) in brazil, where vegetation destruction is often associated with projects such as small hydro power plant (shp) construction. the resulting stress from the implementation of this type of enterprise may be a factor that influences individual susceptibility against pathogens and can determine the success or failure of mitigation measures proposed b ...201525231157
sperm morphology assessment in captive neotropical primates.the main objective of this study was to evaluate sperm morphology in four neotropical primate species to compare the sperm morphological traits and the sperm morphometric parameters as a basis for establishing normative sperm standards for each species. data from 80 ejaculates collected from four primate species, callithrix jacchus, callimico goeldii, alouatta caraya and ateles geoffroyi, were analysed for detection of sperm morphological alterations using subjective world health organization (w ...201627260333
sex differences in the behavior of wild alouatta caraya infants.several primates show sex-based differences in activity patterns and social interactions during infancy. these differences have been associated with adult social and reproductive functions of males and females and are related to male-male competition. our goal was to describe behavioral patterns of wild alouatta caraya male and female infants, a species with sexual dimorphism in body size and behavioral strategies during adulthood. we also examined the relationship between life history variables ...201627097805
determinants of daily path length in black and gold howler monkeys (alouatta caraya) in northeastern argentina.models used to explain the social organization of primates suggest that variation in daily path length (dpl) is a response to variation in resource distribution and the intensity of intragroup feeding competition. however, daily path length may be affected by a number of other factors including the availability and distribution of nutritionally complementary food items, temperature which can influence activity budget, patterns of subgrouping, and the frequency and function of intergroup encounte ...201627043938
medium- and large-sized mammals in a steppic savanna area of the brazilian pampa: survey and conservation issues of a poorly known fauna.the wildlife of the brazilian pampa is threatened by large-scale habitat loss, due in particular to the expansion of soybean cultivation and the conversion of grasslands areas into extensive areas of silviculture. it is essential to study how the mammal fauna copes with the highly fragmented, human-influenced, non-protected landscape. our study presents the results of a survey of the large- and medium-sized mammals of a typical human-influenced steppic savanna area of the pampa biome. the survey ...201626909626
medium- and large-sized mammals in a steppic savanna area of the brazilian pampa: survey and conservation issues of a poorly known fauna.the wildlife of the brazilian pampa is threatened by large-scale habitat loss, due in particular to the expansion of soybean cultivation and the conversion of grasslands areas into extensive areas of silviculture. it is essential to study how the mammal fauna copes with the highly fragmented, human-influenced, non-protected landscape. our study presents the results of a survey of the large- and medium-sized mammals of a typical human-influenced steppic savanna area of the pampa biome. the survey ...201626840582
cranial vault thickness in primates: homo erectus does not have uniquely thick vault bones.extremely thick cranial vaults have been noted as a diagnostic characteristic of homo erectus since the first fossil of the species was identified, but relatively little work has been done on elucidating its etiology or variation across fossils, living humans, or extant non-human primates. cranial vault thickness (cvt) is not a monolithic trait, and the responsiveness of its layers to environmental stimuli is unknown. we obtained measurements of cranial vault thickness in fossil hominins from th ...201626767964
molecular characterization of trypanosomatid infections in wild howler monkeys (alouatta caraya) in northeastern argentina.the transmission of trypanosoma cruzi by vectors is confined to the americas, and the infection circulates in at least two broadly defined transmission cycles occurring in domestic and sylvatic habitats. this study sought to detect and characterize infection by t. cruzi and other trypanosomes using pcr strategies in blood samples from free-ranging howler monkeys, alouatta caraya, in the northeastern argentina. blood samples were collected at four sites with variable levels of habitat modificatio ...201627617205
serological detection of hepatitis a virus in free-ranging neotropical primates (sapajus spp., alouatta caraya) from the paraná river basin, brazil.nonhuman primates are considered as the natural hosts of hepatitis a virus (hav), as well as other pathogens, and can serve as natural sentinels to investigate epizootics and endemic diseases that are of public health importance. during this study, blood samples were collected from 112 neotropical primates (ntps) (sapajus nigritus and s. cay, n = 75; alouatta caraya, n = 37) trap-captured at the paraná river basin, brazil, located between the states of paraná and mato grosso do sul. anti-hav igg ...201626910453
herpes simplex encephalitis in a captive black howler monkey (alouatta caraya).an 18-month-old captive black howler monkey (alouatta caraya) died after a 3-day history of neurologic signs. gross findings at autopsy were limited to bloody, yellow, and foul-smelling intestinal contents. histologically, there was extensive necrotizing meningoencephalitis predominantly in both cerebral hemispheres, and lymphohistiocytic, neutrophilic infiltrate expanded the subarachnoid and virchow-robbin space. in the most severely affected regions, neurons contained eosinophilic intranuclear ...201626699521
the loss of behavioral diversity as a consequence of anthropogenic habitat disturbance: the social interactions of black howler monkeys.to date, no study has investigated how human disturbance affects the size of the behavioral repertoire of a species. the aim of the present study is to illustrate how measurement of behavioral diversity assists in documenting biodiversity loss, demonstrating that human disturbance has a negative effect on behavioral diversity. we studied the social interaction repertoire of 41 adult black howler monkeys (alouatta pigra) belonging to 10 groups living in different habitats in campeche (mexico), an ...201626660682
fluctuations in daily energy intake do not cause physiological stress in a neotropical primate living in a seasonal forest.animals may face periods of nutritional stress due to short-term food shortage and/or low energy consumption associated with seasonal fluctuations in resource availability. we tested the hypothesis that periods of restricted macronutrient and energy intake result in energy deficits and physiological stress in wild black howler monkeys (alouatta pigra) inhabiting seasonal tropical semi-deciduous forests. we conducted full-day follows of focal animals recording feeding rates, time spent feeding, a ...201627681556
the effects of plant nutritional chemistry on food selection of mexican black howler monkeys (alouatta pigra): the role of lipids.understanding the nutritional basis of food selection is fundamental to evaluate dietary patterns and foraging strategies in primates. this research describes the phytochemical composition of the foods consumed by two groups of mexican black howler monkeys (alouatta pigra) during a 15-month field study, and examines how plant nutritional chemistry affected food choice. based on indices of selectivity that reflected seasonal changes in the amount of different phenophases of the most consumed plan ...201726713884
the missing fellow: first description of the trypanoxyuris pigrae male (nematoda:oxyuridae), a parasite of the black howler monkey (alouatta pigra) in mexico.the first morphological description of the male of trypanoxyuris pigrae solórzano-garcía, nadler, and pérez-ponce de león, 2016 is presented in this study. morphological data are supported by molecular data. specimens of t. pigrae were recovered after the necropsy of a roadkill black howler monkey (alouatta pigra) in southeastern mexico. males of t. pigrae are characterized by having 3 notched lips, and a long esophagus with a posterior bulb; they also show a single crested lateral alae, , a sin ...201728355111
metabolomic data suggest regulation of black howler monkey (alouatta pigra) diet composition at the molecular level.in addition to macronutrients, foods consist of a complex set of chemical compounds that can influence dietary selectivity and consumer physiology. metabolomics allow us to describe this complexity by quantifying all small molecules, or metabolites, in a food item. in this study we use gc-ms based metabolomics to describe the metabolite profiles of foods consumed by one population of mexican black howler monkeys (alouatta pigra) over a 10-month period. our data indicate that each food exhibited ...201727936282
patterns in gut microbiota similarity associated with degree of sociality among sex classes of a neotropical primate.studies of human and domestic animal models indicate that related individuals and those that spend the most time in physical contact typically have more similar gut microbial communities. however, few studies have examined these factors in wild mammals where complex social dynamics and a variety of interacting environmental factors may impact the patterns observed in controlled systems. here, we explore the effect of host kinship and time spent in social contact on the gut microbiota of wild, bl ...201728124727
vocal repertoire of free-ranging black howler monkeys' (alouatta pigra): call types, contexts, and sex-related contributions.alouatta species utter the most powerful primate vocalizations in the neotropics and are well-known for their loud and long-lasting male howling bouts. however, the diversity of acoustic structures used in these howling bouts, as well as in non-howling contexts, and the relative contribution of the different group members to the entire vocal repertoire, needed to be explored further. this report provides the first detailed description of the vocal repertoire of black howler monkeys (alouatta pig ...201728095604
contrasting time-based and weight-based estimates of protein and energy intake of black howler monkeys (alouatta pigra).two methods are commonly used to describe the feeding behavior of wild primates, one based on the proportion of time animals spent feeding on specific plant parts ("time-based" estimates) and one based on estimates of the actual amounts of different plant materials ingested ('"weight-based" estimates). however, studies based on feeding time may not be accurate for making quantitative assessments of animals' nutrient and energy intake. we analyzed the diet of two groups of alouatta pigra living i ...201727802361
the relative effects of reproductive condition, stress, and seasonality on patterns of parasitism in wild female black howler monkeys (alouatta pigra).parasitic infections in wildlife are shaped by host-related traits including individual reproductive condition. it has been argued that female primates are more susceptible to infectious diseases during pregnancy due to short-term changes in immune function that result in reduced ability to combat infections. likewise, lactation, which is the most energetically expensive state, may affect immunity and infection risk due to tradeoffs between milk production and maintenance of immune function. her ...201728407272
assessment of releases of translocated and rehabilitated yucatán black howler monkeys (alouatta pigra) in belize to determine factors influencing survivorship.rehabilitation and reintroduction have become important to the management and welfare of primates worldwide. however, the suitability and success of these practices must be evaluated to determine their effectiveness as well as to improve programs and methods, as little is known about the factors influencing survival of released individuals. between 2011 and 2014, 28 howler monkeys, alouatta pigra, were released at fireburn reserve, northern belize by the primate rehabilitation centre of belize: ...201728852885
biochemical and hematological evaluations of black howler monkeys (alouatta pigra) in highly degraded landscapes in mexico.loss and fragmentation of neotropical primates' habitat can alter the health and individual adaptation. physiological parameters reflect health status and individuals responses to the habitat conditions.201728703877
occurrence of hemotropic mycoplasmas in non-human primates (alouatta caraya, sapajus nigritus and callithrix jacchus) of southern brazil.hemoplasmas, the erythrocyte-associated mycoplasmas, have been detected in several primates, causing mostly subclinical infection. this study aimed to determine the prevalence of hemoplasma infection in captive and free-ranging monkeys from southern brazil, as well as factors and hematological abnormalities associated with infection. blood samples from 40 non-human primates (nhp) were tested for hemoplasmas and coinfections. an overall of 10/40 (25.0%) nhp tested positive for hemoplasmas using p ...201728673463
rabies virus exposure of brazilian free-ranging wildlife from municipalities without clinical cases in humans or in terrestrial wildlife.rabies is a zoonosis that causes thousands of animal and human deaths worldwide. serological studies provide information concerning rabies virus circulation among animals and humans. we evaluated the circulation of the rabies virus in wildlife in nine municipalities of são paulo state, brazil. we took blood samples from 27 terrestrial animals of nine different mammalian species in locations without cases of rabies in human and wild terrestrial mammals. sera were tested with the use of the rapid ...201728406757
flotation techniques (flotac and mini-flotac) for detecting gastrointestinal parasites in howler monkeys.analyses of environmental correlates of the composition of gastrointestinal parasite communities in black howler monkeys (alouatta pigra) have been hindered by inadequate calibration techniques of detection and quantification methods of the parasites. here we calibrate samples and compare the likelihood of parasite detection using two flotation techniques, flotac and mini-flotac, and compare flotation solution, preservation method and dilution ratio for egg detection and counts of the most commo ...201729169387
through the eyes of children: drawings as an evaluation tool for children's understanding about endangered mexican primates.this study seeks to understand children's perceptions and knowledge of endangered mexican primates. the black howler monkey (alouatta pigra) is a charismatic species endemic to southern mexico, northern belize, and guatemala and is a symbol of the region that fosters a sense of local pride. therefore, it can be considered a flagship species for the forests of southern mexico. we evaluated the perception and knowledge that 297 mexican elementary school children (8-10 years old) have about black h ...201729095512
genetic structure in the southernmost populations of black-and-gold howler monkeys (alouatta caraya) and its conservation implications.black-and-gold howler monkeys alouatta caraya, are arboreal primates, inhabitants of neotropical forests, highly susceptible to the yellow fever virus, considered early 'sentinels' of outbreaks, and thus, of major epidemiological importance. currently, anthropogenic habitat loss and modifications threatens their survival. habitat modification can prevent, reduce or change dispersal behavior, which, in turn, may influence patterns of gene flow. we explored past and contemporary levels of genetic ...201728968440
detection of the mosquito-borne flaviviruses, west nile, dengue, saint louis encephalitis, ilheus, bussuquara, and yellow fever in free-ranging black howlers (alouatta caraya) of northeastern argentina.several medically important mosquito-borne flaviviruses have been detected in argentina in recent years: dengue (denv), st. louis encephalitis (slev), west nile (wnv) and yellow fever (yfv) viruses. evidence of bussuquara virus (bsqv) and ilheus virus (ilhv) activity were found, but they have not been associated with human disease. non-human primates can act as important hosts in the natural cycle of flaviviruses and serological studies can lead to improved understanding of virus circulation dyn ...201728187130
detection of antibodies to oropouche virus in non-human primates in goiânia city, goiás.arboviruses are associated with human disease, and non-human primates (nhps) are important primary hosts. this study shows the detection of antibodies to oropouche virus (orov) in nhps either living in urban parks or acclimatized at the wild animal screening center, goiânia city.201727384834
validation of an enzyme immunoassay and comparison of fecal cortisol metabolite levels in black and gold howler monkeys (alouatta caraya) inhabiting fragmented and continuous areas of the humid chaco region, argentina.in the last years, the study of how environmental stimuli influence the physiology and specifically the endocrinology of an organism became increasingly important, relying mainly on the quantification of glucocorticoids to monitor animal welfare. most studies investigating cortisol levels in primates were focused on the impact of social stressors; however, a major concern for the conservation of howler monkeys is the increased habitat fragmentation led by the advancement of the agricultural fron ...201728100016
association between genomic instability and evolutionary chromosomal rearrangements in neotropical primates.during the last decades, the mammalian genome has been proposed to have regions prone to breakage and reorganization concentrated in certain chromosomal bands that seem to correspond to evolutionary breakpoints. these bands are likely to be involved in chromosome fragility or instability. in primates, some biomarkers of genetic damage may be associated with various degrees of genomic instability. here, we investigated the usefulness of sister chromatid exchange as a biomarker of potential sites ...201829905781
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