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Brain hemispheres have different functions and control the movements of the contralateral side of the body. One of these functions is the process of emotions. The right hemisphere hypothesis suggests that the right hemisphere of the brain is responsible for emotional processing, and so the left side of the body is activated in emotive contexts such as social interactions. In contrast, the valence hypothesis proposes that both hemispheres are involved in emotional processing, with the left hemisphere processing positive emotions and the right hemisphere dealing with negative emotions. As sociality can influence emotional states, studying behavioral lateralization in social contexts, and the effect of rank on laterality should help to clarify the role of brain hemispheres in social responses. The aim of this study was to investigate whether and how target animacy (interaction with inanimate and animate targets) affected manual laterality in 12 zoo-housed Barbary macaques (Macaca sylvanus). We focused on both the direction and the strength of hand preference and tested the effect of social rank on lateralization. We used continuous focal animal sampling to record bouts of hand preference when interacting with inanimate targets and animate targets (during social and self-directed behaviors). and recorded social interactions to measure the rank. For inanimate targets, 14 15-minute sessions were done. For animate targets, 14 2-hour morning sessions and 14 90-minute afternoon sessions were done. At the individual level, six of nine lateralized macaques were significantly right-handed when interacting with inanimate targets, whereas only three subjects showed a significant (right) lateralization when interacting with animate targets. Thus, inanimate targets seem to elicit manual laterality to a greater extent than animate targets. However, we found no group-level hand preference for actions directed toward inanimate or animate targets in general. However, we found a group-level right-hand bias for affiliative behaviors, whereas no effects of social rank on lateralization was present. Based on our results, both hemispheres seem to process emotions, influencing hand preference during social interactions, as suggested by the valence hypothesis. Despite the limitations due to the small sample size, these findings suggest that Barbary macaques show hand preference patterns similar to those found in great apes and other catarrhines in interactions with both inanimate and animate targets

Bifidobacteria represent one of the main bacterial groups occurring in the gut of primates and other animals and are well known for their positive role on host health. Moreover, bifidobacteriaceae are used in coevolution studies since they are maintained within host lineages across hundreds of thousands of host generations. Therefore, the discovery of bifidobacterial diversity in the gastrointestinal tract together with the isolation and characterization of novel bacterial taxa in different hosts is essential. Until now no evidence has been reported about the occurrence of bifidobacteria in bats which are a crucial part of the ecosystem and are ecologically and economically advantageous to humans especially frugivorous ones. This study aimed at the investigation of bifidobacteria in bats belonging to Rousettus aegyptiacus species which were born in Egypt and hosted in Natura Viva Garda Zoological Park (Bussolengo, Verona, Italy). Faecal samples were serially diluted and plated on selective medium MRS supplemented with 0.05 % (w/v) cysteine, 100 mg/l norfloxacin, 2 mg/l cycloheximide, 50 mg/l mupirocin and 1 ml/l acetic acid. Strains were typed by BOX-PCR. Representative isolates of each cluster were identified sequencing 16S rRNA gene and studied for phylogenetical relationship with other Bifidobacteriaceae. Similarities among profiles were calculated by clustering the Pearson‟s correlation matrix using UPGMA algorithm. A total of 13 bifidobacteria were isolated and two of them belonged to new bifidobacterial species according to 16S rRNA gene analysis. The majority of strains revealed a phylogenetic relationship with bifidobacteria isolated from non-human primates. This evolutive link of bifidobacterial microbiotas between bats and non-human primates will be further investigated studying bifidobacteria characterizing Rousettus aegyptiacus bats from Egypt in order to offer new insights about bats origin.

La preferenza manuale è l’asimmetria comportamentale più evidente nell’uomo; lo studio della lateralizzazione manuale nei primati non-umani può rappresentare una strategia ottimale per comprendere le origini evolutive e il valore adattativo della preferenza manuale nella nostra specie. Lo scopo di questo progetto è stato valutare la preferenza manuale in azioni semplici e complesse in 32 scimmie del Vecchio Mondo e 26 scimmie antropomorfe, confrontandola poi fra i due gruppi; inoltre, si è andati a considerare l’effetto di sesso ed età sulla preferenza manuale. Questo progetto si compone di 3 diversi studi: un low-level task (scimmie del Vecchio Mondo e scimmie antropomorfe), un high-level task (scimmie del Vecchio Mondo) e un tool-use task (scimpanzé). Nel low-level task, sono stati raccolti dati relativi alla preferenza manuale in azioni semplici e spontanee (foraging, manipolazione e locomozione). Nell’high-level task e nel tool-use task, invece, sono stati raccolti dati circa la preferenza manuale durante l’interazione con degli apparati sperimentali (compito complesso). Nel low-level task, è emersa una preferenza per l’uso della mano destra a livello di gruppo; inoltre, l’uso preferenziale della la mano destra a livello di gruppo è stato riscontrato anche nell’ambito di manipolazione e locomozione. Per quanto riguarda sesso ed età, gli H-index per la manipolazione sono risultati essere significativamente più elevati nei maschi rispetto alle femmine nelle scimmie del Vecchio Mondo; inoltre, è stata trovata una correlazione positiva significativa fra i valori degli H-index per la manipolazione e l’età dei soggetti. Per quanto riguarda il confronto fra i due gruppi, gli H-index per la manipolazione sono risultati essere significativamente maggiori nelle scimmie antropomorfe rispetto che in quelle del Vecchio Mondo. Questi risultati suggeriscono che fattori quali postura e complessità del compito sembrano avere un ruolo importante nell’evoluzione della preferenza manuale dei primati; inoltre, anche il sesso e l’esperienza individuale dei soggetti potrebbero essere rilevanti nella determinazione della lateralizzazione manuale dei soggetti. Per quanto riguarda high-level task e tool-use task, non è emersa una preferenza manuale significativa in alcuna delle azioni considerate. Tuttavia, gli ABS-HI (forza della preferenza manuale) per recupero del cibo e manipolazione sono risultati essere significativamente più elevati in high-level task e tool-use task rispetto che nel low-level task. Pertanto, la complessità del compito sembra giocare un ruolo fondamentale nella determinazione di una preferenza manuale, anche se unicamente a livello individuale. Handedness is the most obvious behavioural asymmetry in humans: the study of manual lateralization in non-human primates could represent an optimal way to investigate the evolutionary origin and the adaptive value of handedness in our species. The aim of this project is to investigate and compare the hand preference in 32 Old World monkeys and 26 apes during simple and complex tasks, assessing the effect of sex and age on primate handedness. Three different studies were done: a low-level task (Old World monkeys and apes), an high-level task (Old World monkeys) and a tool-use task (chimpanzees). In the low-level task, data about simple and spontaneous actions (foraging, locomotion and manipulation) were collected. In the high-level task and in the tool-use task, data about the hand preference during the interaction with an experimental apparatus (complex task) were collected. In the low-level task, a significant group level right hand preference was found. Furthermore, a strong bias toward right hand use for starting locomotion and for manipulation were reported. Considering the effect of sex and age, in the Old World monkey sample, the H-index for manipulation were significantly higher in females than in males. Furthermore, a positive correlation between the H-index for manipulation and the age of the subjects was found. Regarding the comparison between the different groups, the H-index for manipulations were significantly higher in apes than in Old World monkeys. These results suggest an important role of factors such as posture and task complexity in the evolution of primate manual lateralization; in addition, the sex as well as the individual experience of the subjects seem to be relevant in the determination of primate hand preference. In the high-level and the tool-use tasks, no significant hand preference for any of the actions considered was reported. However, the ABS-HI (strength of the hand preference) for food retrieval and manipulation were significantly higher in the high-level and in the tool-use tasks than in the low-level task. Therefore, task complexity seems to play a key role in the determination of hand preference, although only at the individual level.

Although some studies investigated lateralization in reptiles, little research has been done on chelonians, focusing only on few behaviours such as righting response and escape preference. The aim of this study was to investigate lateralization in Aldabra giant tortoises (Aldabrachelys gigantea), focusing on asymmetrical positioning of the limbs and the head during resting behaviour, called sleep-like behaviour, involving both wild tortoises and individuals under human care. Subjects of the study were 67 adult Aldabra tortoises (54 free ranging on Curieuse, 13 under human care in Mahè Botanical Garden). For each tortoise observed during sleep-like behaviour, we recorded the position of the head (on the left, on the right or in line with the body midline) and we collected which forelimb and hindlimb were kept forward. Moreover, the number of subjects in which limbs were in a symmetrical position during the sleep-like behaviour was recorded. Based on our results, the number of tortoises with asymmetrical position of head and limb was higher (head: 63%; forelimbs: 88%; hindlimbs: 70%) than the number of tortoises with symmetrical position of the head and the limb. Regarding the head, throughout the subjects found with the asymmetrical position of the head during sleep-like behaviour, tortoises positioning the head on the right (42%) were more than those sleeping with the head on the left (21%). We found a relationship between the position of the forelimbs and hindlimbs during sleep-like behaviour. We reported no differences between Mahè (under human care) and Curieuse (wild) tortoises. Findings of this preliminary study underlined traces of group-level lateralization in head positioning during the sleep-like behaviour, possibly due to a left-eye/right-hemisphere involvement in anti-predatory responses and threatening stimuli as reported in reptiles and other vertebrates. This study aims at adding data on brain lateralization, often linked to lateralized behaviours, in reptiles, especially in chelonians.

Tamarins and marmosets are small‐bodied social callitrichines. Wild callitrichines feed on exudates, such as sap and gum; particularly, marmosets are mainly gummivores, while tamarins consume gums only occasionally and opportunistically. Zoo marmosets and tamarins are usually provided with gum arabic as an alternative to the exudates normally found in the wild. The aim of this study was to evaluate the effects of a gum feeder on the behavior and well‐being of four zoo‐managed callitrichines. We studied four cotton‐top tamarins (Saguinus oedipus), four red‐handed tamarins (S. midas), two pygmy marmosets (Cebuella pygmaea), and three Geoffroy's marmosets (Callithrix geoffroyi) housed at Parco Natura Viva (Italy). We conducted the study over two different periods, a baseline (control, without the gum feeder) and then a gum feeder (when the gum feeder was provided) period. We used continuous focal animal sampling to collect behavioral data, including durations of social and individual behaviors. We collected 240 min of observations per period per study subject, with a total of 3,120 min for all the subjects in the same period and of 6,240 min in both periods. We analyzed data by using nonparametric statistical tests. First, we found that the gum feeder promoted species‐specific behaviors, such as exploration, and diminished self‐directed behaviors, suggesting an enriching effect on tamarin and marmoset behavior. Moreover, in red‐handed tamarins, the provision of the gum feeder reduced the performance of self‐directed and abnormal behavior, specifically coprophagy. These results confirm that gum feeders are effective foraging enrichment tools for zoo marmosets and tamarins.