Activity budget of a group of black-horned capuchin monkeys (Sapajus nigritus) in an urban environment / Orçamento de atividades de um grupo de macacos-prego-pretos (Sapajus nigritus) em ambiente urbano

Urban growth and human impacts on the environment have forced animals to adjust to habitat fragmentation and reduced home ranges. Capuchin monkeys are known for their great social and behavioral flexibility, occupying even highly urbanized environments in a way that the time budget of this primate in synanthropic situation may be affected by the area they inhabit. This study aims to analyze the activity budget of a group of Sapajus nigritus living in an anthropized area, 1) comparing the behavioral frequencies in urbanized areas and forest fragments; 2) comparing behavioral frequencies in different sex-age classes. During the study, the number of individuals ranged from 35 to 40 individuals identified based on sex-age classes. Behavioral data were collected using the instantaneous scan sampling method, for two minutes with eight-minute intervals. We obtained 319 scans over 28 days, distributed between November 2021 and June 2022, with eight hours per day. We compared the behaviors different areas and between sex-age classes using the Kruskal-Wallis's test. Overall, the group performed a higher frequency of traveling (21.22%), followed by foraging (18.07%), feeding (16.57%) and vigilance (15.61%). The frequency of behaviors varied between areas, with vigilance, social, resting, interaction with humans and self-activity more frequent in urbanized areas compared to forest fragments. We also found variation between the sex-age classes, primarily with juveniles foraging more and adults performing more vigilance. The differences in the behaviors performed by the group express the behavioral flexibility of S. nigritus, adapting its activity pattern according to the area occupied.

O crescimento urbano e os impactos humanos no ambiente forçaram os animais a se adaptarem à fragmentação de hábitat e à redução da área de vida. Os macacos-prego são conhecidos por sua flexibilidade social e comportamental, ocupando até mesmo ambientes altamente urbanizados, sendo que seu padrão de atividades pode ser afetado pela área que habitam. Este estudo teve como objetivo analisar o padrão de atividades de um grupo de Sapajus nigritus vivendo em área antropizada, com base em: 1) comparação das frequências comportamentais em áreas urbanizadas e fragmentos florestais; e 2) comparação das frequências comportamentais em diferentes classes sexo-etárias. Durante o estudo, o número de indivíduos variou entre 35 e 40 indivíduos, identificados a partir de classes sexo-etárias. Os dados comportamentais foram coletados pelo método scan sampling, durante dois minutos com intervalo de oito minutos. Foram obtidos 319 scans ao longo de 28 dias (entre novembro de 2021 e junho de 2022), por oito horas diárias. Comparamos os comportamentos em diferentes áreas e entre classes sexo-etárias através do teste de Kruskal-Wallis. Em geral, o grupo apresentou frequência maior de deslocamento (21,22%), seguido de forrageio (18,07%), alimentação (16,57%) e vigilância (15,61%). A frequência dos comportamentos variou entre áreas (vigilância, social, descanso, interação com humanos e autoatividade foram mais frequentes em áreas urbanizadas) e classes sexo--etárias (principalmente com os juvenis forrageando mais e os adultos realizando mais vigilância). As diferenças nos comportamentos realizados pelo grupo expressam a flexibilidade comportamental de S. nigritus, adaptando seu padrão de atividade conforme a área ocupada.

Grounding Context in Embodied Cognitive Robotics.

Biological agents are context-dependent systems that exhibit behavioral flexibility. The internal and external information agents process, their actions, and emotions are all grounded in the context within which they are situated. However, in the field of cognitive robotics, the concept of context is far from being clear with most studies making little to no reference to it. The aim of this paper is to provide an interpretation of the notion of context and its core elements based on different studies in natural agents, and how these core contextual elements have been modeled in cognitive robotics, to introduce a new hypothesis about the interactions between these contextual elements. Here, global context is categorized as agent-related, environmental, and task-related context. The interaction of their core elements, allows agents to first select self-relevant tasks depending on their current needs, or for learning and mastering their environment through exploration. Second, to perform a task and continuously monitor its performance. Third, to abandon a task in case its execution is not going as expected. Here, the monitoring of prediction error, the difference between sensorimotor predictions and incoming sensory information, is at the core of behavioral flexibility during situated action cycles. Additionally, monitoring prediction error dynamics and its comparison with the expected reduction rate should indicate the agent its overall performance on executing the task. Sensitivity to performance evokes emotions that function as the driving element for autonomous behavior which, at the same time, depends on the processing of the interacting core elements. Taking all these into account, an interactionist model of contexts and their core elements is proposed. The model is embodied, affective, and situated, by means of the processing of the agent-related and environmental core contextual elements. Additionally, it is grounded in the processing of the task-related context and the associated situated action cycles during task execution. Finally, the model proposed here aims to guide how artificial agents should process the core contextual elements of the agent-related and environmental context to give rise to the task-related context, allowing agents to autonomously select a task, its planning, execution, and monitoring for behavioral flexibility.

Urine washing in urban robust capuchin monkeys (Sapajus sp.): The relation with visitors.

In primates, urine washing (UW) is a behavior in which individuals intentionally deposit urine on their bodies. Social and nonsocial hypotheses have been proposed to explain the adaptive function of this behavior. For capuchins, different functions have been assigned for UW, suggesting it as a flexible behavior, but studies have been mainly in captivity. However, no investigations have been performed in urban environments, where these animals can modify their behavior. Our goal was to study UW in a semi-provisioned group of an introduced unknown robust capuchin species (Sapajus sp.) living in a tiny urban fragment in Foz do Iguaçu, Brazil, where they have contact with humans. We assessed the influence of social (sexual, agonistic, and anointing behaviors) and environmental (temperature, relative air humidity, height of the monkeys in the trees, number of people present in the fragment, and human-monkey interactions) variables, the influence of behavior before and after UW, and the influence of sex-age classes, on the frequency of UW. We observed 75 records of UW in 300 h of observations, where urine was mostly deposited on hands and passed on to feet (95%). There were no significant differences in the frequency of the behavior between sex-age classes nor in the behaviors before and after UW. Around 50% of UW took place in the late morning and we found no correlation between UW and temperature, relative air humidity, nor the heights of the monkeys in the trees. However, we found a significant association between UW and the daily number of people in the fragment, but not between UW and human-monkey interactions, anointing, agonisms, and sexual behavior. Our study increases the scope of UW flexibility by identifying the presence of visitors affecting the occurrence of this behavior. We discussed different possibilities through which people could influence the capuchins to display UW.

Animal Creativity as a Function of Behavioral Innovation and Behavior Flexibility in Problem-solving Situations.

A natural approach of animal creativity through insightful problem-solving may offer a panel of how physiological, contextual, cultural and developmental variables related to each other to produce new behaviors. The spontaneous interconnection of acquire behaviors is an Insightful Problem-Solving model based on the new combination and/or chaining of behaviors that were previously and independently trained. This model seems to offer an integrative alternative for the studies of Innovation and Behavioral Flexibility because it allows the research on innovation in a scenario in which the response that solves the problem situation is not available by trial-and-error. Measuring task-appropriateness by behavior flexibility and novelty by behavior innovation under insightful problem-solving paradigm can contribute for the integration of decades of evidence in Cognitive Psychology, Neuro-ethology, Behavior Analysis and Behavioral Neurosciences. The Insightful Problem-Solving allows the independent test of behavioral innovation and behavioral flexibility as it measures the behavioral innovation inside insightful test and tests if the BF depends on variables arranged in the problem-situation and/or on the previous training (e.g. familiarity with access to appetitive stimulus in the pre-test, the number of distinct behaviors trained, and contingency changes in the post-test).

Innovative problem-solving in a threatened gull species, the Olrog's Gull (Larus atlanticus).

Innovation, a process that plays an important role in the ecology and evolution of species, is considered an expression of behavioral flexibility in animals. Here we analyzed innovative problem-solving ability and performance enhancement through learning in the Olrog's Gull (Larus atlanticus), under controlled processes and experimental conditions. Trials were undertaken with nine adult individuals captured at a highly urbanized coastal area of Argentina. Each individual was presented with a Plexiglas box that could be opened by pushing or pulling two lids, each lid leading to a separated food reward. We measured problem-solving ability through consumption latency and the number of solved lids. As explanatory variables, we measured contact rate, as a measure of persistence, and the number of effective contacts. The results showed that the contact rate and effective contacts did not affect variables related to problem-solving ability during the first confrontation of the individuals with the closed box. Consumption latency decreased significantly throughout the trials, and with increasing contact rate and effective contacts. The number of solved lids increased through the trials independently of the contact rate and the total effective contacts with the box. Although persistence did not influence individuals' performance during the problem-solving test; this variable affected individuals' ability to solve the task throughout trials. Learning was evidenced by the decrease in the resolution time across experiments, suggesting that successful individuals improved their performance probably through a trial-and-error process. Evaluation of behavioral responses of a threatened seabird to a novel problem-solving task adds knowledge to previous field studies and provides a better understanding of the ability of individuals to adjust their foraging behavior in highly urbanized areas used during the non-breeding season.

Araneophagy as an alternative foraging tactic to kleptoparasitism in two Argyrodinae (Araneae: Theridiidae) species.

Kleptoparasitism is assumed to be the main foraging strategy in some animal groups, such as the spiders of the subfamily Argyrodinae (Theridiidae). However, some species may also feed on silk threads, egg sacs, or even their hosts. The conditions determining these alternative foraging tactics remain unknown for most species. We performed field observations, stable isotope analysis and laboratory experiments to investigate kleptoparasitism and araneophagy of Argyrodes elevatus and Faiditus caudatus in webs of Manogea porracea (Araneidae). We evaluated the following hypotheses: (1) both species exhibit higher trophic positions than their hosts and closest to an araneophagic sympatric species; (2) host web selection is influenced by the presence of alternative resources (adult male and female, and egg sacs); and (3) they preferentially consume egg sacs instead of stored prey items. Both argyrodines showed higher trophic positions than their female hosts and closest to an araneophagic spider species. The invaders were found mainly on host webs with one adult and egg sacs and with egg sacs only. Finally, A. elevatus preferred to feed on prey captured by the host spider instead of egg sacs. We discussed the factors that can potentially determine the choices between foraging exclusively as kleptoparasites and consuming the hosts.

Flexibility in the integration of environmental information by Dinoponera quadriceps Kempf during foraging

Abstract Foraging behavior requires animals' behavioral flexibility to exhibit efficient strategies that result in the successful search for food. The navigation of ants enables long distance trips back and forth from the nest, using orientation cues. We analyzed the flexibility of Dinoponera quadriceps workers in integrating information introduced into the environment. We studied workers from two colonies in an area of secondary Atlantic Forest, with the use of a physical obstacle placed in front of the entrance of the nest with no fixed angular position. There was no significant difference in the resolution time workers to bypass the obstacle, in the angles between trips when exiting and returning to the nest, or in the positioning angles when returning to the nest. However, we found an increase in positioning angles when leaving the nest to search food, from the second contact onwards. They overcame the new obstacle as they would any other natural one. The presence of the obstacle did not prevent workers from maintaining route fidelity to individual areas. The behavior of D. quadriceps workers indicates that they have the flexibility to incorporate new information in a familiar environment. They likely use multimodal cues, which prevent them from wandering outside the familiar area.

Effect of the Endocannabinoid System in Memory Updating and Forgetting.

Most memories of life experiences will be forgotten or modified over time. Although several studies have investigated the processes underlying memory formation, the mechanisms behind memory updating and forgetting remain unclear. The endocannabinoid system has been shown to be closely involved in various memory processes such as consolidation, destabilization, and extinction. Here, we investigate the role of the endocannabinoid system in memory updating, behavioral flexibility, and forgetting. We found that the hippocampal infusion of CB1 antagonist prevented memory updating in the immediate footshock (context pre-exposure facilitation effect) and reversal learning. Also, CB1 antagonist accelerated forgetting in inhibitory avoidance. Thus, by indicating the important role played by the endocannabinoid system, our results extend current knowledge of the mechanisms underpinning memory updating and forgetting.

Perturbations in the Activity of Cholinergic Interneurons in the Dorsomedial Striatum Impairs the Update of Actions to an Instrumental Contingency Change.

The striatal cholinergic system is key in detecting changes in instrumental contingencies. While recent evidence supports this vision, cell type-specific online control on the activity of the cholinergic striatal neurons is necessary to empirically test it. In this study, we performed optogenetic manipulations of the activity of striatal cholinergic interneurons (CINs) to evaluate their contribution to the updating of a previously learned instrumental contingency. By modulating the activity of CINs, we identified that the inhibition of CINs impairs the update of actions to a contingency change. Remarkably, a manipulation that perturbs the activity of CINs, rather than inhibiting them also impaired the encoding of the change in contingency. These results emphasize that beyond an increase in the activity of CINs, the intact activity of these cells is required for the identification of an instrumental contingency change.

Supplemented howler monkeys eat less wild fruits, but do not change their activity budgets.

Research on the influence of food supplementation on primate behavior has focused on terrestrial and semiterrestrial species. Its effects on highly arboreal species are poorly known. We assessed the influence of food supplementation on the feeding behavior and activity budget of four adult female and two adult male brown howler monkeys (Alouatta guariba clamitans) belonging to two groups (JA and RO) that inhabited periurban forest fragments in southern Brazil. We used the "focal-animal" method during 6-8 full days per month from March to August 2017 (916 h of observation) to record the behavior of the study subjects. The feeding events of the focal individual were recorded using the "all occurrences" method. The supplementation was unevenly distributed during the day and accounted for 5-6% of all feeding events of male and female howlers, respectively. JA always received fruit in a platform, whereas RO had access to fruits and processed foods on roofs and directly from humans. The mean biomass of wild foods ingested by each adult per day was >300% higher than the ingested biomass of supplemented foods (females: 395 vs. 109 g/day; males: 377 vs. 120 g/day), but the ingestion rate of supplemented foods was ca. 400% higher than that of wild foods (females: 17 vs. 4 g/min; males: 19 vs. 5 g/min). The activity budgets of females and males were dominated by resting (66-72%) followed by feeding (18-14%), moving (12-11%), and socializing (2%). We found that food supplementation reduced the ingestion of wild fruits, but it did not affect the howlers' need to ingest a given amount of leaves per day and the time spent resting, feeding, moving, and socializing.

Surviving in the urban-rural interface: Feeding and ranging behavior of brown howlers (Alouatta guariba clamitans) in an urban fragment in southern Brazil.

Wild primates that live in urban areas face extreme threats that are less frequent in nonurban fragments, such as the presence of dangerous matrix elements (e.g., roads, power lines, buildings, and a high density of domestic dogs near food patches), that could influence their movements, feeding behavior, and survival. However, the scarcity of studies addressing this issue hinders our understanding of the behavioral adjustments that favor the survival of primates in urban areas. For 12 months, we studied a six-individual group of brown howlers (Alouatta guariba clamitans) in an urban fragment to determine (i) their diet richness and its relationships with food availability, (ii) their daily path length (DPL) and the matrix elements used during movement, and (iii) the main ecological drivers of the DPL. Sampling effort totaled 72 days, 787 hr, and 3,224 instantaneous scans. We found that the diet of brown howlers contained 35 plant species (including seven cultivated crops) belonging to 33 genera and 21 families. The consumption of fruits and young leaves was directly related to their temporal availability. The average DPL (446 m) was smaller than that reported for groups of howlers inhabiting large nonurban fragments. To move between food patches, animals used three main matrix elements: trees, power lines, and roofs. The number of plant species used during the day was the main driver of DPL. Our findings highlighted that the generalist-opportunistic diet of brown howlers and their ability to move across the anthropogenic matrix using artificial elements such as power lines, roofs, and wildlife crossings represent a remarkable part of their behavioral repertory in Lami. However, there are potential costs associated with these strategies, namely, electrocution and predation by domestic dogs. Thus, it is urgent to further investigate how these behaviors could affect the long-term survival of these animals.

Lack of Pannexin 1 Alters Synaptic GluN2 Subunit Composition and Spatial Reversal Learning in Mice.

Long-term potentiation (LTP) and long-term depression (LTD) are two forms of synaptic plasticity that have been considered as the cellular substrate of memory formation. Although LTP has received considerable more attention, recent evidences indicate that LTD plays also important roles in the acquisition and storage of novel information in the brain. Pannexin 1 (Panx1) is a membrane protein that forms non-selective channels which have been shown to modulate the induction of hippocampal synaptic plasticity. Animals lacking Panx1 or blockade of Pannexin 1 channels precludes the induction of LTD and facilitates LTP. To evaluate if the absence of Panx1 also affects the acquisition of rapidly changing information we trained Panx1 knockout (KO) mice and wild type (WT) littermates in a visual and hidden version of the Morris water maze (MWM). We found that KO mice find the hidden platform similarly although slightly quicker than WT animals, nonetheless, when the hidden platform was located in the opposite quadrant (OQ) to the previous learned location, KO mice spent significantly more time in the previous quadrant than in the new location indicating that the absence of Panx1 affects the reversion of a previously acquired spatial memory. Consistently, we observed changes in the content of synaptic proteins critical to LTD, such as GluN2 subunits of N-methyl-D-aspartate receptors (NMDARs), which changed their contribution to synaptic plasticity in conditions of Panx1 ablation. Our findings give further support to the role of Panx1 channels on the modulation of synaptic plasticity induction, learning and memory processes.

Neophobia is negatively related to reversal learning ability in females of a generalist bird of prey, the Chimango Caracara, Milvago chimango.

In an ever-changing environment, the ability to adapt choices to new conditions is essential for daily living and ultimately, for survival. Behavioural flexibility allows animals to maximise survival and reproduction in novel settings by adjusting their behaviour based on specific information and feedback acquired in their current environments. However, a growing body of evidence indicates that an individual's personality type can limit the extent to which the individual might behave flexibly, by influencing the way an individual pays attention to novelty and how much information it collects and stores, which in turn affects the individual's decision-making and learning process. In this study, the behavioural flexibility of a generalist predator, the Chimango Caracara, Milvago chimango, was analysed using the reversal learning paradigm, focusing on the comparison between age classes, and the relation of learning flexibility with a personality trait, the level of neophobia. Due to the low number of male individuals captured, this study was carried out only with female birds. The results showed that age had no significant effect either on the acquisition of a stimulus-reward association, or on the capacity of reversing this previously learned association. Reversal of the response was a harder task for these birds in comparison with the initial acquisition process. The individual's performances in the learning tasks seemed to be uncorrelated with each other, suggesting that they involve different neural mechanisms. Contrary to the general pattern observed in the majority of previous work on personality and cognition in non-human animals, the level of neophobia did not correlate with the initial associative learning performance in both adults and juveniles, yet it showed a significant negative relationship with reversal learning ability, mainly in the regressive phase of this task, for the two age classes. Our results suggest that the predatory and generalist lifestyle of female individuals of M. chimango along with the selective pressures of the environment of the individuals studied might play a critical role in the degree and direction of the linkage between novelty response and learning flexibility observed in this study.

Tool use in urban populations of capuchin monkeys Sapajus spp. (Primates: Cebidae)

Capuchin monkeys, Sapajus Kerr, 1792, are known for their flexible behavior, including tool use, and their ability to survive in urban forests. We observed capuchin juveniles using wood as hammer and anvil and different materials as sponges (four tool-use events) in two geographically distinct urban populations in Brazil, in 2012: two in Goiânia, Central Brazil and two in Foz do Iguaçu, Southern Brazil. In Goiânia, a male used a detached tree branch as a hammer and a buttress root as an anvil to pound a seed of Terminalia Linnaeus. Another male used a small branch with leaves as a dipping tool to access water inside a tree trunk hole. In Foz do Iguaçu, the capuchins used a small branch and a piece of bread to obtain water by dipping them into tree trunk holes. This latter event might be interpreted as a case of self-control, with a familiar food item used as a tool to reach a resource that is difficult to access otherwise. Our observations contribute to the knowledge on the tool-kit of capuchins and we propose that these urban populations should be conserved for scientific evaluations of behavioral flexibility in non-human primates.(AU)

Tool use in urban populations of capuchin monkeys Sapajus spp. (Primates: Cebidae)

Capuchin monkeys, Sapajus Kerr, 1792, are known for their flexible behavior, including tool use, and their ability to survive in urban forests. We observed capuchin juveniles using wood as hammer and anvil and different materials as sponges (four tool-use events) in two geographically distinct urban populations in Brazil, in 2012: two in Goiânia, Central Brazil and two in Foz do Iguaçu, Southern Brazil. In Goiânia, a male used a detached tree branch as a hammer and a buttress root as an anvil to pound a seed of Terminalia Linnaeus. Another male used a small branch with leaves as a dipping tool to access water inside a tree trunk hole. In Foz do Iguaçu, the capuchins used a small branch and a piece of bread to obtain water by dipping them into tree trunk holes. This latter event might be interpreted as a case of self-control, with a familiar food item used as a tool to reach a resource that is difficult to access otherwise. Our observations contribute to the knowledge on the tool-kit of capuchins and we propose that these urban populations should be conserved for scientific evaluations of behavioral flexibility in non-human primates.

Activity pattern of Cuniculus paca (Rodentia: Cuniculidae) in relation to lunar illumination and other abiotic variables in the southern Brazilian Amazon

Understanding what influences the activity of organisms is important for both ecological understanding and species conservation. Using data from 2,707 camera trap days distributed across 24 forest sites, we present quantitative analyses of the activity pattern of Cuniculus paca (Linnaeus, 1766) in southern Amazonia. We compared the activity pattern of this species across four designated subsets of the 24-hours diel cycle (dawn, dusk, day and night). Using linear regression models we tested the influence of season, temperature and rainfall on the activity patterns of C. paca (paca). We also evaluated the nocturnal photos of paca (N = 111) as a function of the degree of lunar illumination in order to test the prediction that pacas minimize their activity during moon phase when illumination is brighter. Pacas were not recorded during the day but were active at dawn, dusk and night time. We found differences in the influence of the abiotic variables on the nocturnal activity of pacas in the study area. There was no significant difference between the observed (expressed as the frequency of total counts of independent photos over the five classes of lunar illumination) and the expected activity of pacas, based on the frequency of days in the lunar cycle with different classes of lunar illumination, whereas lunar illumination had a weak negative influence on the timing of paca activity (i.e. pacas were active closer to sunset with increasing lunar illumination). However, the timing of nocturnal activity in pacas was not influenced by season, temperature or rainfall. Our findings highlight the ecological plasticity of this Neotropical rodent which has a key function in the maintenance of Neotropical forests.

Coordinated feeding tactics of the Guiana dolphin, Sotalia guianensis (Cetacea: Delphinidae), in Ilha Grande Bay, Rio de Janeiro, Brazil

Differences in distribution, prey species, season and social learning opportunities influence the feeding tactics used by marine mammals. Here, we analyze the coordinated feeding behavior of the Guiana dolphin, Sotalia guianensis (Van Bénéden, 1864, Delphinidae) and its relation to seasonality and the presence of calves. In a total of 201 feeding bouts, we observed four types of coordinated feeding tactics, which differed in frequency and in mean number of engaged individuals. Tactics in which dolphins used their bodies to herd and capture prey were the most frequent, presenting a higher frequency and engaging a higher number of individuals, suggesting that these tactics are better for capturing fishes which form larger schools. Furthermore, the seasons influenced the feeding behavior used by dolphins. During spring-summer, a longer duration of bouts and a larger number of individuals engaged in the feeding tactics was observed, which may be related to the seasonal spawning of larger schooling fish, such as Sardinella brasiliensis (Steindachner, 1879). Calves were present in 95% of all coordinated feeding tactic occurrences. This study indicates a complete preference of dolphins for coordinating their actions to capture prey and for the first time reports the presence of calves in the coordinated tactics and jumps. This broadens the current knowledge of the Guiana dolphin feeding tactics.