There is compelling evidence that inter-individual behavioural differences – here termed ‘behavioural distinctiveness’ – shape decision-making processes and interactions with the environment. Accordingly, we investigated whether behavioural distinctiveness influences the use of environmental enrichment (EE) components, with the aim of refining husbandry practices for yellow-breasted capuchin monkeys (Sapajus xanthosternos) in zoological settings. Employing the standard ethological approach of behavioural coding, we observed 20 capuchins housed in three groups comprising adult and juvenile males and females. Behavioural profiles were categorised into two distinctiveness dimensions: neuroticism and extraversion. To evaluate individual engagement with EE, we applied the ABA paradigm, wherein phases A1 and A2 (controls) represented standard zoo routines, while phase B corresponded to the implementation of an EE programme. Each phase spanned 10 days, and behavioural data were collected via focal animal sampling (10 minutes per animal per day), resulting in a total of 1,200 focal observations. During the environmental enrichment phase, capuchin monkeys displayed a reduction in aggressive behaviour alongside an increase in exploratory activity. However, contrary to our expectations, individuals with high neuroticism scores did not display a decrease in aggression following the introduction of EE components. Furthermore, unexpectedly, extraversion scores were not correlated with alterations in exploratory behaviour, behavioural diversity, abnormal/stereotypical behaviour, or inactivity in response to enrichment interventions. These findings suggest that environmental enrichment effectively reduced aggression and increased exploratory behaviour in yellow-breasted capuchin monkeys. However, measures of neuroticism and extraversion were not related to individual differences in behavioural change, indicating that individual behavioural profiles may not be reliable predictors of responses to enrichment interventions. The absence of aggression reduction in high neurotic individuals, coupled with the lack of an association between extraversion and exploratory behaviour, underscores the complexity of behavioural distinctiveness-enrichment interactions. Future research should explore additional factors, including social dynamics and prior experiences, that may influence behavioural responses to enrichment.

This study examines whether rock cavies (Kerodon rupestris), which are social rodents, modulate their alarm calls in response to various threat contexts. Conducted across four sample areas within two study sites in the Brazilian Caatinga region, alarm calls were collected using the ad libitum method. The acoustic responses of free-ranging rock cavies were then analyzed using discriminant function analysis, principal component analysis, and generalized mixed linear models to classify vocal types and assess differences in vocalization rates and acoustic parameters. The findings reveal that rock cavies produce both slow and fast alarm whistles in response to threats. Fast alarm whistles, emitted exclusively in response to nearby ocelots (Leopardus pardalis), exhibited a lower pitch (F1, 26.81=22.15, P<0.001), shorter duration (F1, 28.66=30.08, P<0.001), and shorter pulse intervals (F1, 29.30=9.95, P=0.004) compared to the slow alarm whistles. Slow alarm whistles were produced when rock cavies were threatened by distant ocelots, as well as by both distant and closer humans, dogs (Canis familiaris), marmosets (Callithrix spp.), tayras (Eira barbara), and birds of prey (Caracara plancus). The type of threat influenced the number of pulses (F6, 20.76=3.60, P=0.013) and pulse intervals (F6, 12.20=11.57, P<0.001) of slow alarm whistles. Rock cavies produced more pulses when threatened by dogs and birds of prey compared to humans (P<0.05) and shorter pulse intervals when threatened by ocelots compared to humans and dogs (P<0.05). Additionally, lower-pitched slow alarm whistles (F1, 19.84=7.46, P=0.013) with shorter pulse intervals (F1, 21.02=17.04, P<0.001) were emitted when threats were nearby compared to more distant threats. This study highlights the influence of various threats and their proximity on the modulation of rock cavy alarm calls, showcasing their behavioral adaptability. This crucial survival strategy not only enhances our understanding of rock cavies’ behavior but also has the potential to inspire research in other species and ecological contexts.

Empirical research indicates that interindividual behavioral variation among animals may significantly influence their behavioral expressions during pre-release training programs. Consequently, the present study seeks to examine the association between distinct personality traits exhibited by a cohort of 16 red-and-green macaws (Ara chloropterus)—comprising equal numbers of males and females—and their behavioral responses to pre-release training within the framework of a species reintroduction program. The behavioral distinctiveness of the macaws was assessed using the traditional ethological approach of behavioral coding, allowing for classification into three primary dimensions: exploration, aggressiveness, and sociability. Subsequently, the macaws underwent pre-release training, which encompassed environmental enrichment and anti-predator conditioning as preparatory measures for their reintroduction. As anticipated, environmental enrichment promoted heightened exploratory behaviors, while exposure to a predator model elicited vigilance and avoidance responses among the macaws. Consistent with expectations, individual behavioral traits did not serve as reliable predictors of vigilance or escape responses during anti-predator training. However, contrary to predictions, no significant correlation was identified between exploratory responses to novel food resources and individual scores for exploration and aggressiveness. These unexpected findings may be attributable to the shared origin of the macaws, as they were illegally captured from the wild and subsequently maintained in captivity. Under such conditions, individuals are subjected to inappropriate capture and handling practices, likely resulting in elevated stress levels and selective pressures that may favor the development of similar behavioral profiles. These findings highlight the critical role of individual history in avian reintroduction programs, emphasizing the necessity of accounting for the origins of birds when assessing their behavioral adaptability. Future research should further investigate the extent to which prior experiences and captive conditions influence behavioral traits and ultimately impact reintroduction success.

Empirical research indicates that interindividual behavioral variation among animals may significantly influence their behavioral expressions during pre-release training programs. Consequently, the present study seeks to examine the association between distinct personality traits exhibited by a cohort of 16 red-and-green macaws (Ara chloropterus)—comprising equal numbers of males and females—and their behavioral responses to pre-release training within the framework of a species reintroduction program. The behavioral distinctiveness of the macaws was assessed using the traditional ethological approach of behavioral coding, allowing for classification into three primary dimensions: exploration, aggressiveness, and sociability. Subsequently, the macaws underwent pre-release training, which encompassed environmental enrichment and anti-predator conditioning as preparatory measures for their reintroduction. As anticipated, environmental enrichment promoted heightened exploratory behaviors, while exposure to a predator model elicited vigilance and avoidance responses among the macaws. Consistent with expectations, individual behavioral traits did not serve as reliable predictors of vigilance or escape responses during anti-predator training. However, contrary to predictions, no significant correlation was identified between exploratory responses to novel food resources and individual scores for exploration and aggressiveness. These unexpected findings may be attributable to the shared origin of the macaws, as they were illegally captured from the wild and subsequently maintained in captivity. Under such conditions, individuals are subjected to inappropriate capture and handling practices, likely resulting in elevated stress levels and selective pressures that may favor the development of similar behavioral profiles. These findings highlight the critical role of individual history in avian reintroduction programs, emphasizing the necessity of accounting for the origins of birds when assessing their behavioral adaptability. Future research should further investigate the extent to which prior experiences and captive conditions influence behavioral traits and ultimately impact reintroduction success.

Several authors have proposed that using music as a sensory stimulation can positively impact animal welfare. We aimed to investigate the impact of classical music (classical music-300/Beethoven and Mozart) as environmental enrichment on the behavior of 25 white-lipped peccaries (Tayassu pecari) using an ABA design (A1/A2: control; B: enrichment). Over 63 hours of focal animal observation (5 minutes/individual) during five-day phases, we recorded affiliative, agonistic, inactive, and exploratory behaviors. Our results indicate that classical music significantly increased exploratory behaviors (P<0.05) and decreased inactivity (P<0.05) in peccaries, suggesting a positive welfare effect. While affiliative behavior showed no significant change, we observed a potential link between increased agonistic events and elevated exploratory behavior. These findings contribute to the ongoing debate regarding music as enrichment and highlight the need for further comprehensive research into the effects of auditory stimuli on this species.

Several authors have proposed that using music as a sensory stimulation can positively impact animal welfare. We aimed to investigate the impact of classical music (classical music-300/Beethoven and Mozart) as environmental enrichment on the behavior of 25 white-lipped peccaries (Tayassu pecari) using an ABA design (A1/A2: control; B: enrichment). Over 63 hours of focal animal observation (5 minutes/individual) during five-day phases, we recorded affiliative, agonistic, inactive, and exploratory behaviors. Our results indicate that classical music significantly increased exploratory behaviors (P<0.05) and decreased inactivity (P<0.05) in peccaries, suggesting a positive welfare effect. While affiliative behavior showed no significant change, we observed a potential link between increased agonistic events and elevated exploratory behavior. These findings contribute to the ongoing debate regarding music as enrichment and highlight the need for further comprehensive research into the effects of auditory stimuli on this species.

This study examines whether rock cavies (Kerodon rupestris), which are social rodents, modulate their alarm calls in response to various threat contexts. Conducted across four sample areas within two study sites in the Brazilian Caatinga region, alarm calls were collected using the ad libitum method. The acoustic responses of free-ranging rock cavies were then analyzed using discriminant function analysis and generalized mixed linear models to classify vocal types and assess differences in vocalization rates and acoustic parameters. The findings reveal that rock cavies produce both slow and fast alarm whistles in response to threats. Fast alarm whistles, emitted exclusively in response to nearby ocelots (Leopardus pardalis), exhibited a lower pitch (F1, 16.20 = 11.41, P = 0.004), shorter duration (F1, 22.59 = 14.93, P = 0.001), and shorter pulse intervals (F1, 21.29 = 6.08, P = 0.022) compared to the slow alarm whistles. Slow alarm whistles were produced when rock cavies were threatened by distant ocelots, as well as by both distant and closer humans, dogs (Canis familiaris), marmosets (Callithrix spp.), tayras (Eira barbara), and birds of prey (Caracara plancus). The type of threat influenced the pulse intervals (F6, 23.26 = 12.69, P < 0.001) and the high frequency (F6, 18.15 = 12.08, P < 0.001) of slow alarm whistles. Rock cavies produced shorter pulse intervals when threatened by ocelots, birds of prey, or tayras compared to humans and dogs (P<0.05) and higher-pitched slow alarm whistles when threatened by dogs, ocelots, humans, or birds of prey compared to capuchin monkeys and tayras (P<0.05). Additionally, shorter pulse intervals (F1, 25.73 = 28.87, P < 0.001) were emitted when threats were nearby compared to more distant threats. This study highlights the influence of various threats and their proximity on the modulation of rock cavy alarm calls, showcasing their behavioral adaptability. This crucial survival strategy not only enhances our understanding of rock cavies’ behavior but also has the potential to inspire research in other species and ecological contexts.

This study examines whether rock cavies (Kerodon rupestris), which are social rodents, modulate their alarm calls in response to various threat contexts. Conducted across four sample areas within two study sites in the Brazilian Caatinga region, alarm calls were collected using the ad libitum method. The acoustic responses of free-ranging rock cavies were then analyzed using discriminant function analysis and generalized mixed linear models to classify vocal types and assess differences in vocalization rates and acoustic parameters. The findings reveal that rock cavies produce both slow and fast alarm whistles in response to threats. Fast alarm whistles, emitted exclusively in response to nearby ocelots (Leopardus pardalis), exhibited a lower pitch (F1, 16.20 = 11.41, P = 0.004), shorter duration (F1, 22.59 = 14.93, P = 0.001), and shorter pulse intervals (F1, 21.29 = 6.08, P = 0.022) compared to the slow alarm whistles. Slow alarm whistles were produced when rock cavies were threatened by distant ocelots, as well as by both distant and closer humans, dogs (Canis familiaris), marmosets (Callithrix spp.), tayras (Eira barbara), and birds of prey (Caracara plancus). The type of threat influenced the pulse intervals (F6, 23.26 = 12.69, P < 0.001) and the high frequency (F6, 18.15 = 12.08, P < 0.001) of slow alarm whistles. Rock cavies produced shorter pulse intervals when threatened by ocelots, birds of prey, or tayras compared to humans and dogs (P<0.05) and higher-pitched slow alarm whistles when threatened by dogs, ocelots, humans, or birds of prey compared to capuchin monkeys and tayras (P<0.05). Additionally, shorter pulse intervals (F1, 25.73 = 28.87, P < 0.001) were emitted when threats were nearby compared to more distant threats. This study highlights the influence of various threats and their proximity on the modulation of rock cavy alarm calls, showcasing their behavioral adaptability. This crucial survival strategy not only enhances our understanding of rock cavies’ behavior but also has the potential to inspire research in other species and ecological contexts.

There is compelling evidence that inter-individual behavioural differences – here termed ‘behavioural distinctiveness’ – shape decision-making processes and interactions with the environment. Accordingly, we investigated whether behavioural distinctiveness influences the use of environmental enrichment (EE) components, with the aim of refining husbandry practices for yellow-breasted capuchin monkeys (Sapajus xanthosternos) in zoological settings. Employing the standard ethological approach of behavioural coding, we observed 20 capuchins housed in three groups comprising adult and juvenile males and females. Behavioural profiles were categorised into two distinctiveness dimensions: neuroticism and extraversion. To evaluate individual engagement with EE, we applied the ABA paradigm, wherein phases A1 and A2 (controls) represented standard zoo routines, while phase B corresponded to the implementation of an EE programme. Each phase spanned 10 days, and behavioural data were collected via focal animal sampling (10 minutes per animal per day), resulting in a total of 1,200 focal observations. During the environmental enrichment phase, capuchin monkeys displayed a reduction in aggressive behaviour alongside an increase in exploratory activity. However, contrary to our expectations, individuals with high neuroticism scores did not display a decrease in aggression following the introduction of EE components. Furthermore, unexpectedly, extraversion scores were not correlated with alterations in exploratory behaviour, behavioural diversity, abnormal/stereotypical behaviour, or inactivity in response to enrichment interventions. These findings suggest that environmental enrichment effectively reduced aggression and increased exploratory behaviour in yellow-breasted capuchin monkeys. However, measures of neuroticism and extraversion were not related to individual differences in behavioural change, indicating that individual behavioural profiles may not be reliable predictors of responses to enrichment interventions. The absence of aggression reduction in high neurotic individuals, coupled with the lack of an association between extraversion and exploratory behaviour, underscores the complexity of behavioural distinctiveness-enrichment interactions. Future research should explore additional factors, including social dynamics and prior experiences, that may influence behavioural responses to enrichment.

The rock cavy, a social rodent, emits alarm calls to signal danger. These calls are believed to be adjusted depending on the type of predator and the urgency of the threat. To confirm this, we aimed to compare the acoustic responses of free-range Kerodon rupestris in different threat contexts. The study was conducted in two conservation units located in the Brazilian semiarid region known as the Caatinga. All alarm calls were collected using the ad libitum method. Calls were classified through aural and visual inspection using Raven Pro software. Discriminant function analysis was applied to test the classification of vocal types. To assess differences in vocalization quantities and acoustic parameters, generalized mixed linear models were used, followed by Tukey post hoc tests when appropriate. Our results showed that rock cavies emitted two vocal types (alarm whistle and fast alarm whistle) in threat contexts. It was observed that both the type of threat and the proximity of the threat affected the intervals between pulses of the alarm whistles. Rocky cavies emitted alarm whistles with longer intervals between pulses when faced with threats from humans and dogs than birds of prey, tayra and ocelot. When the threat was closer, the rocky cavies emitted alarm whistles with shorter intervals between pulses. Fast alarm whistles were emitted only by rock cavy close to potential hunting predators. This study highlights that the distance from the threat and different threats influence adjustments in K. rupestris alarm calls. The rock cavy signals higher-degree dangers by emitting faster calls with shorter intervals between pulses.