The Maintenance of Traditions in Marmosets: Individual Habit, Not Social Conformity? A Field Experiment

Social conformity is a cornerstone of human culture because it accelerates and maintains the spread of behaviour within a group. Few empirical studies have investigated the role of social conformity in the maintenance of traditions despite an increasing body of literature on the formation of behavioural patterns in non-human animals. The current report presents a field experiment with free-ranging marmosets (Callithrix jacchus) which investigated whether social conformity is necessary for the maintenance of behavioural patterns within groups or whether individual effects such as habit formation would suffice.Using a two-action apparatus, we established alternative behavioural patterns in six family groups composed of 36 individuals. These groups experienced only one technique during a training phase and were thereafter tested with two techniques available. The monkeys reliably maintained the trained method over a period of three weeks, despite discovering the alternative technique. Three additional groups were given the same number of sessions, but those 21 individuals could freely choose the method to obtain a reward. In these control groups, an overall bias towards one of the two methods was observed, but animals with a different preference did not adjust towards the group norm. Thirteen of the fifteen animals that discovered both techniques remained with the action with which they were initially successful, independent of the group preference and the type of action (Binomial test: exp. proportion: 0.5, p<0.01).The results indicate that the maintenance of behavioural patterns within groups 1) could be explained by the first rewarded manipulation and subsequent habit formation and 2) do not require social conformity as a mechanism. After an initial spread of a behaviour throughout a group, this mechanism may lead to a superficial appearance of conformity without the involvement of such a socially and cognitively complex mechanism. This is the first time that such an experiment has been conducted with free-ranging primates

Temporal consistency and ecological validity of personality structure in common marmosets (Callithrix jacchus): A unifying field and laboratory approach

Personality in animals has been extensively researched in recent decades. Temporal consistency of behaviors is almost always part of the personality definition and is usually explored in several different testing sessions or observation periods. However, it is still unclear whether the obtained personality constructs are stable across several years, which might be especially important for long-living animals, such as primates. Further, little is known on whether the personality structures obtained in the laboratory reflect the structures obtained under ecologically relevant conditions in the wild. Therefore, we conducted a battery of personality tests on common marmosets (Callithrix jacchus) (N = 27), compared it with a test battery conducted 4 years beforehand on a subset of animals in captivity (N = 13) and ran an adapted version under field conditions at Baracuhy Biological Field Station, Brazil (N = 18). Under captive conditions, we found a remarkably similar personality structure across 4 testing years. Further, we found high long-term temporal consistency in the first two personality components, Boldness and Exploration; however, monkeys that changed their social (i.e., breeding) status between the two testing periods showed a significant increase in Boldness scores. Under field conditions, we found a somewhat similar personality structure as compared to the laboratory, which to some extent corroborates ecological validity of our personality test design. Nevertheless, whether the structure in the wild is suppressed or expanded in comparison to captivity, and in which way the social setting influences personality structure, should be further explored. Taken together, our results contribute to the discussion about the reliability and ecological validity of personality structures in nonhuman primates

Behavioral Adjustments by a Small Neotropical Primate ( Callithrix jacchus

We provide the first information on the behavior of a small primate (Callithrix jacchus) inhabiting a semiarid Caatinga environment in northeastern Brazil. We observed behavioral variations in response to temperature fluctuation throughout the day. Due to the high temperatures, low precipitation, and resource scarcity in the Caatinga, as well as the lack of physiological adaptations (e.g., a highly concentrated urine and a carotid rete to cool down the brain) of these primates, we expected that the common marmosets would exhibit behavioral adjustments, such as a prolonged resting period or the use of a large home range. During the six-month period, we collected 246 hours of behavioral data of two groups (10 individuals) of Callithrix jacchus. Most of the observed behavioral patterns were influenced by temperature fluctuation. Animals rested longer and reduced other activities, such as foraging, when temperatures were higher. Both study groups exploited home ranges of 2.21–3.26 ha, which is within the range described for common marmosets inhabiting the Atlantic Forest. Our findings confirm that common marmosets inhabiting the Caatinga adjust their behavioral patterns to cope with the high temperatures that characterize this environment and highlight their ability to survive across a wide range of different environmental conditions

Qualidade das águas cinza tratada com fitorremediação em unidades de produção agrícola

Irrigation is an activity that requires large amounts of water, the treatment of greywater from a public laundry in semi-arid regions for reuse becomes a means of survival in this environment and conducive to sustainable economic development. In this context, the research was conducted in the district of the municipality of Ribeira Cabaceiras - PB aiming to evaluate the quality of gray water treated with phytoremediation in agricultural production units. Two treatments (Tank 2) and without phytoremediation (Tank 1) were performed, the culture used was purple elephant grass. Monthly samples were collected and analyzed the following physicochemical parameters: turbidity, pH, electrical conductivity (Ce), Chemical Oxygen Demand (COD) and Total Fostoro. For the turbidity values of the treatments were over 1,000 UNT. In chemical oxygen demand, the minimum value was 311mg / L (in September) and a maximum of 438mg / L (October) in tank 2 however in tank 1 the minimum value was 354mg / L (in September) and a maximum of 618mg / L (October). Treatment with phytoremediation has a higher efficiency of COD reduction.A irrigação é uma atividade que necessita de grande quantidade de água, o tratamento de águas cinzas provenientes de uma lavanderia pública em regiões semiáridas para reuso passa a ser uma alternativa de sobrevivência neste ambiente e favorável no desenvolvimento econômico sustentável. Nesse contexto, a pesquisa foi realizada no distrito de Ribeira no município de Cabaceiras - PB objetivando-se avaliar a qualidade da água cinza tratada com fitorremediação nas unidades de produção agrícola. Foram realizados dois tratamentos com(Tanque 2) e sem fitorremediação(Tanque 1), a cultura utilizada foi o capim elefante roxo. Foram coletadas amostras mensais e analisadas os seguintes parâmetros fisicoquimicos: Turbidez, pH, Condutividade elétrica (Ce), Demanda Quimica de Oxigenio(DQO) e Fostoro Total. Para a turbidez os valores dos tratamentos foram acima de 1.000 UNT. Na demanda química de oxigênio, o valor mínimo foi de 311mg/L (setembro) e máximo de 438mg/L (outubro) no tanque 2 em contrapartida no tanque 1 o valor mínimo foi de 354mg/L (setembro) e máximo de 618mg/L (outubro). O tratamento com fitorremediação teve uma maior eficiência na redução de DQO

Eficiência na remoção de coliformes em águas cinza através da fitorremediação

The semiarid region is characterized by irregularities storm water and treatment of gray water for reuse in agriculture with ecological technology is a way to cope with the drought in these regions. In this context, the research was conducted in the district of the municipality of Ribeira Cabaceiras / PB aiming to evaluate the efficiency of removal of total and fecal coliforms in treated wastewater in agricultural production units through phytoremediation. Two treatments with and without phytoremediation were performed, the culture used was purple grass. The gray water was provided from the public laundry. Monthly samples were collected and analyzed total and fecal (Escherichia coli) coliforms. On the treatment without phytoremediation, total coliforms ranged from 1.583 x 103 to 2.0224 x103 (UFC/100 ml) and when the treatment had purple grass, with phytoremediation then total coliforms ranged from 1.354 x 103 to 2, 0224 x 103 (UFC/100 mL). There was a significant reduction of Escherichia coli in the treatment with phytoremediation. The use of phytoremediation in greywater treatment reduced the presence of total and fecal coliforms, making it a viable alternative treatment, providing an increased in water quality.O semiárido é caracterizado pelas irregularidades pluviais e o tratamento de águas cinza para reuso na agricultura com tecnologia ecológica é uma forma de conviver com a seca nessas regiões. Nesse contexto, a pesquisa foi realizada no distrito de Ribeira no município de Cabaceiras/PB objetivando-se avaliar a eficiência da remoção dos coliformes totais e fecais do efluente tratado nas unidades de produção agrícola através da fitorremediação. Foram realizados dois tratamentos com e sem fitorremediação, a cultura utilizada foi o capim roxo. As águas cinza eram provenientes de uma lavanderia pública. Foram coletadas amostras mensais e analisadas os coliformes total e fecal (Escherichia coli). No tratamento sem fitorremediação, os coliformes totais variaram de 1,583 x 103 a 2,0224 x 103 (UFC/100 mL) e quando o tratamento tinha o auxílio do capim roxo, ou seja, com fitorremediação os coliformes totais oscilaram de 1,354 x 103 a 2,0224 x 103 (UFC/100 mL). Ocorreu uma redução significativa de Escherichia coli no tratamento com fitorremediação. A utilização da fitorremediação no tratamento de águas cinza reduziu a presença de coliformes totais e fecal, sendo assim uma alternativa viável de tratamento, proporcionando um aumento da qualidade hídrica

Foraging networks and social tolerance in a cooperatively breeding primate ( Callithrix jacchus )

International audienc

Temporal consistency and ecological validity of personality structure in common marmosets (Callithrix jacchus): A unifying field and laboratory approach

Personality in animals has been extensively researched in recent decades. Temporal consistency of behaviors is almost always part of the personality definition and is usually explored in several different testing sessions or observation periods. However, it is still unclear whether the obtained personality constructs are stable across several years, which might be especially important for long-living animals, such as primates. Further, little is known on whether the personality structures obtained in the laboratory reflect the structures obtained under ecologically relevant conditions in the wild. Therefore, we conducted a battery of personality tests on common marmosets (Callithrix jacchus) (N = 27), compared it with a test battery conducted 4 years beforehand on a subset of animals in captivity (N = 13) and ran an adapted version under field conditions at Baracuhy Biological Field Station, Brazil (N = 18). Under captive conditions, we found a remarkably similar personality structure across 4 testing years. Further, we found high long-term temporal consistency in the first two personality components, Boldness and Exploration; however, monkeys that changed their social (i.e., breeding) status between the two testing periods showed a significant increase in Boldness scores. Under field conditions, we found a somewhat similar personality structure as compared to the laboratory, which to some extent corroborates ecological validity of our personality test design. Nevertheless, whether the structure in the wild is suppressed or expanded in comparison to captivity, and in which way the social setting influences personality structure, should be further explored. Taken together, our results contribute to the discussion about the reliability and ecological validity of personality structures in nonhuman primates