Sérgio Luiz Gama Nogueira-Filho

Assessing social structure is fundamental for the management of group-living animals under human care because social instability can compromise animal welfare, increase aggression, and reduce the success of group formation. However, in species with flexible dominance hierarchies, such as the collared peccary (Dicotyles tajacu), it remains unclear whether commonly used methods provide consistent information for evaluating social structure and informing management decisions. We evaluated whether complementary approaches to assessing social structure provide consistent or contrasting interpretations of social structure and its relationship with physiological stress. We combined multiple dominance-ranking methods, social network analysis, and non-invasive measurements of fecal glucocorticoid metabolites (fGM) to characterize the social structure of three captive groups of collared peccaries. Only one group exhibited a significant linear dominance hierarchy, whereas the remaining groups showed no evidence of a linear dominance structure. Although the different ranking methods generally agreed in identifying the highest- and lowest-ranking individuals, they differed in the ranking of intermediate individuals and, in one group, even in the identification of the dominant individual. Dominant individuals consistently occupied more central positions in agonistic networks, whereas associations between dominance rank, affiliative integration, body weight, and fGM concentrations varied among groups, indicating that the relationship between social status and physiological stress was context dependent. Interestingly, introduced males generally occupied the lowest dominance ranks but were among the most central individuals in affiliative networks, suggesting that affiliative interactions may facilitate social integration after introduction. Our findings demonstrate that captive collared peccaries exhibit flexible rather than consistently linear social organization. Integrating complementary dominance-ranking methods, social network analysis, and non-invasive physiological indicators provides a more robust framework for evaluating social stability, interpreting the integration of newly introduced individuals, and supporting evidence-based, welfare-oriented management.

Individual behavioural variation or temperament, is a key determinant to understand how animals perceive and cope with captive environments. Therefore, we investigated whether stable temperament traits in collared peccaries (Dicotyles tajacu) modulate behavioural and physiological responses to novel environmental stimuli. Eleven adult animals (6 males, 5 females) were subjected to standardized challenge tests (novel environment, human approach, and forced contact). Ethological observations were applied for temporal repeatability and reduced via Principal Component Analysis (PCA) to find individual scores along a bold-shy continuum. Subsequently, animals were exposed to three environmental modifications (hanging sisal rope, whole coconuts, and a hay-filled box) in a crossover design. Each phase lasted four days, with behavioural budgets recorded via focal animal sampling (1.680 minutes/animal), and faecal samples were collected to monitore glucocorticoid metabolite (FGM). The PCA identified a dominant behavioural axis (98.8% of variance), where bold individuals were characterized by high exploration and low inactivity, while shy individuals showed the opposite pattern. Linear mixed-effects models revealed that temperament was the primary predictor of behaviour across all phases (p < 0.001), with bold and shy profiles remaining highly stable regardless of the stimulus. In contrast, FGM concentrations were driven by environmental phase (p < 0.001) rather than individual behavioural variation (p = 0.88), with the rope stimulus inducing the highest physiological arousal in both groups. While bolder individuals maintained stable activity, shy individuals were more sensitive to environmental changes, significantly increasing inactivity when faced with novel stimuli (p < 0.05). These results suggests that while physiological reactivity is a generalized plastic response to environmental complexity, behavioural engagement is strictly governed by stable individual behavioural traits. Management strategies must therefore move beyond standardized protocols toward temperament-tailored enrichment to ensure effective welfare outcomes for all individuals.

Systems that farm non-typical (wild) species for human consumption are on the rise globally, in contrast to more typical livestock production. In some instances, wildlife farming may arguably help alleviate poverty, provide sustainable animal protein, and be a useful strategy for conservation through reducing wildlife poaching or breeding some animals on farms for reintroduction. However, it is unclear whether farming non-typical species within variable and often unregulated systems truly offers these benefits or outweighs the costs including animal welfare implications, public health concerns, and normalising or intensifying the consumption of wild animals. A previous study proposed a sentiocentric ethical decision-making framework for the farming of wild species. In the present study we invited academic ‘key informants’ with specialised knowledge about farming non-typical species to pilot the framework via an online survey using a species of their choice and requested their feedback on its strengths and weaknesses. Thirteen respondents applied ten different mammalian, reptilian, insect, and avian species to the framework, spanning all continents. Ultimately, the framework outcome for 11 appraisals was that the chosen species may be suitable for farming. However, erroneous responses were likely in places, and there was some uncertainty over definitions of framework terminology. We publish resultant amendments to the ethical framework to clarify meaning and suggest that it can be applied proactively or reactively by different stakeholders (e.g., governments, businesses, and NGOs). We reflect our informants’ views, acknowledging the need to solicit expertise from additional stakeholders (e.g., farmers) and the role of cultural significance and rural communities when considering farming non-typical species.

Understanding how environmental enrichment influences behavioural time allocation is particularly important for threatened primate species maintained under human care. Accordingly, we investigated whether environmental enrichment (EE) influences behavioural time allocation in yellow-breasted capuchin monkeys (Sapajus xanthosternos), aiming to inform evidence-based husbandry practices 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. We recorded behavioural categories including: aggressive, exploratory, affiliative/play, general activity, alert, inactivity, and abnormal behaviour. To evaluate individual engagement with EE, we applied the ABA paradigm, wherein phases A1 and A2 (controls) represented standard zoo conditions, 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 (2 × 10 min focal sessions per animal per day), resulting in a total of 1200 focal sessions. Behavioural time allocation was analysed using a multivariate generalized linear mixed modelling approach that accounted for the interdependence among behavioural categories. Based on previous studies, we predicted that environmental enrichment may promote higher levels of play and exploration and lower aggression and inactivity. However, despite by-eye suggestions of increases in play and decreases in activity during enrichment, when behavioural categories were analysed simultaneously within the multivariate framework, overall behaviour time budgets and behavioural diversity were found not to change significantly across experimental phases. There were also no sex or age effects on behaviour. This indicates that for S. xanthosternos, the enrichment protocol used here did not provide sufficient novelty or complexity to alter established activity patterns. Integrated analytical approaches are needed to further evaluate the effectiveness of enrichment strategies to ensure they are tailored to specific cognitive and social needs of complex species; future studies could explore how social dynamics, enclosure design, and environmental complexity interact to shape behavioural responses to enrichment.

Background: Medical ozone is used in various treatments due to its oxidising properties. Objective: We aimed in this study to evaluate the impact of intrarectal ozone therapy on haematological and biochemical parameters, as well as the pain induced by the procedure in sport horses. Study design: In vivo experiment with 12 Quarter Horses (3 males and 9 females) used as their own controls to assess the effects of ozone therapy. Methods: Blood samples were collected before treatment (Control), 24 h after ozone therapy (24 h post‐treatment), and 7 days after the last day of ozone therapy (7 days post‐treatment). These samples were analysed for haematological and biochemical parameters. Pain assessment, clinical evaluation, and the measurement of heart rate (HR) and respiratory rate (RR) were conducted before and during ozone therapy. Results: Ozone therapy significantly affected haemoglobin ( F _2,20 = 5.55; p = 0.012), mean corpuscular haemoglobin concentrations (MCHC) ( F _2,20 = 16.01; p < 0.001), and aspartate aminotransferase (AST) activity ( F _2,20 = 20.49; p < 0.001). Specifically, haemoglobin concentration decreased 24 h after ozone therapy, MCHC levels increased 7 days post‐ozone therapy, and AST activity decreased 7 days post‐ozone therapy. Blood smears taken 24 h post‐treatment revealed red blood cells with membrane deformities, which normalised by 7 days post‐treatment. None of the animals exhibited clinical symptoms, although pain scores increased, although pain scores increased (before: 4.2 ± 0.4; during: 5.3 ± 0.4; F _1,107 = 5.20; p = 0.025). The reduction in haemoglobin was likely due to oxidative damage, which stimulated the production of erythrocytes with higher haemoglobin content. Lower AST levels suggested an absence of liver damage. The increase in pain scores suggests that using lower concentrations or doses in future studies might alleviate discomfort in the animals. Main limitations: The study's applicability is limited by the small sample size, particularly the number of males, yet the findings provide valuable insights. Conclusions: Overall, the administration of intrarectal ozone therapy over a 7‐day period in horses was associated with favourable haematological modifications, which may suggest an enhancement in systemic tissue oxygenation.

Resting sites are essential for many species, because they provide protection from adverse weather conditions, predators, and environmental disturbance. The characteristics of these sites and how they are used remain poorly understood for several Neotropical species, including the southern tamandua, also known as the lesser anteater (Tamandua tetradactyla). We aimed to describe the structural and environmental characteristics of resting sites used by southern tamanduas on two islands in the coastal zone of the Parnaiba River Delta, northeastern Brazil. We characterized resting-site type, height, vegetation cover, structural protection, and habitat context, and compared these characteristics among habitat types and between dry and rainy seasons. We recorded 29 resting sites for the 12 southern tamanduas. Individuals used tree canopies and tree hollows, with additional records in branch forks, burrows constructed by other mammals, an arboreal coati nest, and uncovered ground sites. Resting sites in mangrove areas were generally higher than those in restinga and anthropized environments, and records were unevenly distributed between seasons. These findings suggest that structurally complex habitats, particularly mangrove areas, may provide important shelter opportunities for southern tamanduas in coastal landscapes. These results provide baseline information on resting-site use by southern tamanduas in coastal landscapes and highlight the importance of considering habitat structure and seasonality in future studies of shelter use in this species.

We aimed to assess whether object play can be used as a positive emotional state indicator for farmed spotted pacas (Cuniculus paca) by examining its association with other positive welfare markers including affiliative behavior and low-amplitude vocalizations. We submitted six groups of spotted pacas (one male/two females per group) (N = 18) to an ABA experimental design (A₁/A₂: without ball; B: with three boomer balls). Object play behavior occurred only during phase B (mean = 35.5 s, SE = 6.4). The spotted pacas spent more time in affiliative and exploratory behaviors and less time engaging in agonistic interactions during phase B than in both control phases (A₁ and A₂) (p < 0.05). Moreover, the spotted pacas emitted more low-amplitude bark vocalizations during phase B than during either control phase (p < 0.05), and such vocalizations have previously been shown to indicate a positive affective state and low arousal level. Because the expression of object play was associated with a decrease in aggression, an increase in affiliative behavior, and an increase in low-amplitude barking, we suggest that object play can be used as a non-invasive indicator of positive emotional state in this species.

We aimed to assess whether play behavior can be used as a welfare indicator for farmed spotted pacas (Cuniculus paca) by examining its association with other positive welfare markers including affiliative behavior and low-amplitude vocalizations. We submitted six groups of spotted pacas (one male/two females per group) (N=18) to an ABA experimental design (A1/A2: without ball; B: with three boomer balls). Play behavior occurred only during phase B (mean=35.5s, SE=6.4). Spotted pacas spent more time in affiliative and exploratory behaviors, while they spent less time engaging in agonistic interactions during phase B than in both control phases (A1 and A2) (P<0.05). Moreover, spotted pacas emitted more low-amplitude bark vocalizations during phase B than during either control phase (P<0.05), which have previously been shown to indicate a positive affective state and low arousal level. Because the expression of play was associated with a decrease in aggression, an increase in affiliative behavior, and an increase in low-amplitude barking, indicating thus a positive state, we suggest that play behavior can be used as a non-invasive indicator of positive welfare in this species.

Monitoring the concentration of glucocorticoid metabolites (GCMs) in faecal samples is a non-invasive tool for physiological stress evaluation, particularly useful when studying wild species. However, both negative and positive stimuli (distress and eustress, respectively) can lead to a rise in glucocorticoids. Thus, besides validating whether GCM concentration in faeces reflects endogenous adrenal activity, we also need to identify behavioural indicators of distress to avoid misinterpretation. Therefore, we submitted four adult male spotted pacas (Cuniculus paca) to an exogenous adrenocorticotropic hormone (ACTH) challenge-test in a Latin square design (4 × 4) to monitor changes in the GCM concentration in faeces. We also aimed to describe behaviours potentially indicative of distress. We collected excreted faeces and video-recorded the animals’ behaviours for five consecutive days, one day before and four days after application of the following four treatments: 1st control (no-handling); 2nd control (intra-muscular [IM] injection of saline solution); low-dose ACTH (IM injection of 0.18 ml ACTH); and high-dose ACTH (IM injection of 0.37 ml ACTH). There was a peak in the concentration of GCM in faeces collected 24 h after the injection of the high-dose ACTH treatment. Additionally, independent of the treatments, spotted pacas spent less time on exploration and feeding states, while spending more time in the inactive but awake (IBA) state following the treatment application (challenge day). The use of GCM concentration in faecal samples together with the behavioural changes (less exploration and feeding, and more IBA) showed to be efficient as a non-invasive tool for welfare assessment of farmed spotted paca.

In this study we aimed to examine whether the ‘redundancy’ (a backup function to ensure the signal transmission) or ‘multiple messages’ (sensory communication system in combination) hypothesis would explain the function of multimodal communication of white-lipped peccaries (Tayassu pecari–WLPs). We also aimed to assess the individual factors (the social rank and sex of the sender) influencing the production of, and responses to unimodal and multimodal signals. We determined the social rank of 21 WLPs living in two captive groups and quantified the production of unimodal and multimodal signals when displaying threatening and submissive behaviors. WLPs most often produce multimodal signals independent of a previous unimodal signal failure, which suggests that they were adding more information, such as the sender’s size, rather than merely increasing efficacy by engaging a different receiver’s sensory channel. There was no effect of the sender’s sex in the production of, and responses to, multimodal signals. However, the higher the sender’s social rank, the greater the production of multimodal signals when WLPs were displaying threatening behaviors; whereas the lower the sender’s social rank, the greater the production of multimodal signals when displaying submission behaviors. Multimodal signals elicited more non-aggressive responses than did the unimodal signals when displaying a threat. Moreover, the higher the sender’s social rank, the greater the occurrence of non-aggressive responses to multimodal signals when displaying a threat; whereas the opposite occurred when displaying submission. Our findings support the ‘multiple messages’ hypothesis to explain the function of multimodal signaling during agonistic interactions in WLPs. Additionally, both the production of, and responses to, multimodal signals are related to the sender’s social rank. These results allow us to suggest that the production of multimodal signals may have a key role in mitigating conflict and thus promoting group cohesion among white-lipped peccaries.