1,721,076 research outputs found
Response of captive lowland gorillas (Gorilla gorilla gorilla) to different housing conditions: testing the aggression/density and coping models
No full textThe aim of this study was to thoroughly
investigate social play and its modalities among adult
bonobos. We evaluated how play intensity varies according
to the sex-class combination of the playmates and
we also performed an analysis on social locomotor-rotational
movements (L-R play) and contact interactions (C
play). Rough and gentle play sessions were performed
with comparable frequencies by male–female and
female–female adult dyads, with play signals unlikely
when the playmates strongly differed in age and in
rank position. L-R play rates did not differ according to
the sex-combination of the players; in contrast, C play
sessions were particularly frequent among females.
Play faces (play signals) were significantly higher during
C play than L-R play sessions, thus suggesting that
playmates assess reciprocally yet safely their relationships
by using facial displays to avoid any kind of misunderstanding.
Play was positively correlated with
grooming and contact sitting interactions, suggesting
that it may be used as a social enhancer. Finally, we
found no correlation between both play contexts (L-R
and C play) and age, size and rank differences of the
players. In conclusion, we suggest that bonobos with
their egalitarian society, peculiar social structure, and
playful tendency represent an attractive testing subject
to examine empirically many emerging hypotheses on
adult play behavior
Postconflict third-party affiliation in Canis lupus: do wolves share similarities with the great apes?
No full textUnsolicited third-party affiliation is defined as the first postconflict affinitive contact directed by
bystanders to victims. To date, it has been found in apes and children but not in monkeys. We investigated
the occurrence of unsolicited postconflict third-party affiliation in wolves, Canis lupus, and verified
some functional hypotheses using a comparison with solicited contacts. Unsolicited affiliations were
more frequent between individuals sharing good relationships and were reciprocated between partners
(victims and third parties), thus suggesting the reciprocal nature of this mechanism (mutualistic
behaviour). At an immediate level, in wolves unsolicited contacts provided benefits to the victim by
breaking off aggression and restoring victims’ social cohesiveness. The incidence of unsolicited interactions
was affected by the presence of previous reconciliation. This result mirrors what has been found
for the great apes, in which consolation may function as a partial alternative to reconciliation. Even
though the cognitive skills at the basis of conflict resolution in canids still have to be investigated in
detail, our study shows an unexpected similarity between wolves and the great apes
Being a victim or an aggressor: Different functions of triadic post-conflict interactions in wolves (Canis lupus lupus)
No full textAnimals adopt different behavioral strategies to cope with the conflict of interests coming from the competition over limited resources. Starting from the study on chimpanzees, post-conflict third-party affiliation (the affiliative contact provided by a third-party toward the victim—VTA—or the aggressor—ATA) was investigated mainly in primates. Later, this post-conflict mechanism has been demonstrated also in other mammals, such as wallabies, horses, dolphins, domestic dogs, and wolves. Here, we present data on triadic post-conflict affiliation in wolves (Canis lupus lupus) by exploring some of the hypotheses already proposed for primates and never tested before in other social mammals. In this carnivore species, the study of VTA and ATA revealed that these strategies cannot be considered as a unique behavioral category since they differ in many functional aspects. VTA serves to protect the victim by reducing the likelihood of reiterated attacks from the previous aggressor and to reinforce the relationship shared by the third-party and the victim. On the other hand, ATA has a role in bystander protection by limiting the renewed attacks of the previous aggressor toward uninvolved group-members (potential third-parties). In conclusion, exploring VTA and ATA gives the opportunity to concurrently demonstrate some functional differences in triadic post-conflict affiliation according to the different targets of bystanders (victims or aggressors). The data comparison between primates and other social mammals should permit to open new lines of research
Reconciliation in wolves (Canis lupus): new evidence for a comparative perspective
No full textSocial animals gain benefits from cooperative behaviours. However,
social systems also imply competition and conflict of interest. To cope
with dispersal forces, group-living animals use several peace-keeping
tactics, which have been deeply investigated in primates. Other taxa,
however, have been often neglected in this field research. Wolves (Canis
lupus) with their high sociality and cooperative behaviour may be a
good model species to investigate the reconciliation process. In this
study, we provide the first evidence for the occurrence of reconciliation
in a group of zoo-kept wolves. The conciliatory contacts were uniformly
distributed across the different sex-class combinations. We found a linear
dominance hierarchy in the colony under study, although the hierarchical
relationships did not seem to affect the reconciliation dynamics.
Moreover, both aggressors and victims initiated first post-conflict affinitive
contact with comparable rates and both high- and low-intensity
conflicts were reconciled with similar percentages. Finally, we found
that coalitionary support may be a good predictor for high level of conciliatory
contacts in this species
Fair play and honest signals in immature chimpanzees.
No full textIn primates, specific facial displays (PF, play face; FPF,
full play face) often accompany play bouts and are considered an integral
part of play development. In humans, laughter, a universal expression
of joy, seems to derive from non-human primate play faces
and pant-like vocalizations. Playful facial displays may represent
honest signals that express the non-agonistic intent of players in order
to maintain the session at a later time. Here, we examine the
possible roles of facial displays during play sessions of immature
chimpanzees (Pan troglodytes). Infants and juveniles performed PF
and FPF with comparable frequency to maintain the playful mood.
However, the use of playful expressions was fine-tuned in relation
to the asymmetry of the session and of the receiver’s identity. In infants,
whose play sessions were the most unbalanced, we found a
positive correlation between the play face frequency and the asymmetry
degree that characterizes each single session. On the other
hand, in juveniles, we found that the most of the facial signals was
directed towards peers. This result is not surprising also considering
the high complexity and competition levels characterizing juvenile
play in chimpanzees. Probably, when play becomes more competitive,
as it occurs in juvenile chimpanzees and adolescent humans,
clear and fair signals are essential to maintain the session and to
avoid it turning into aggression. Therefore, like human laughter,
playful expressions do not give simple information, but positively
influence the receiver’s reaction. Independently of the playmate age,
in chimpanzees, play facial signals, may have a role in advertising cooperative
dispositions and intentions thus increasing the likelihood
of engaging in honest social relationships. In social play, there are
codes of conduct that regulate what is permissible and what is not.
The existence of shared codes in immature individuals might contribute
in developing some traits of social morality in adults
Possible roles of consolation in captive chimpanzees (Pan troglodytes)
No full textEmpathy is a necessary prerequisite for
the occurrence of consolation. The term ‘‘consolation’’
contains a hypothesis about function, which is distress
alleviation. The present study aims to confirm the
occurrence of consolation in captive chimpanzees via the
post-conflict/matched-control method (PC-MC) and to
suggest its possible roles. We collected 273 PC-MC pairs
in the group of Pan troglodytes housed in the ZooParc
de Beauval (France). We confirmed the presence of consolatory
contacts (mean level of consolation, 49.5% 6
22.3% SEM) in the colony. Consolation rates were significantly
higher than reconciliation levels (mean level
of reconciliation, 28.9% 6 16.8% SEM). The level of consolation
was greater in the absence of reconciliation
than in the presence of it, suggesting that consolation
might be an alternative behavior. As friendship and
relatedness did not influence the occurrence of consolation,
they did not seem to be the best prerequisites for
this behavioral mechanism, at least in this chimpanzee
colony. Affinitive contacts with third parties were significantly
more frequent when the victim called attention
to itself during severe aggressions by screaming. These
high-pitched sounds seem to be useful in eliciting aid
from conspecifics, as occurs in young humans. The
occurrence of consolation reduced the likelihood of further
attacks among group-members. From this perspective,
both victims and consolers most likely gain potential
advantages by interacting with each other when
aggression is particularly severe, reconciliation is not
immediate, and consequently social stress reaches high
levels
Peaceful post-conflict interactions between aggressors and bystanders in captive lowland gorillas (Gorilla gorilla gorilla)
No full textWe observed a colony of lowland gorillas in order to assess the occurrence of Peaceful Post-Conflict
Interactions between Aggressors and Bystanders (PPIAB). We compared the dynamics of PPIAB with
those of Peaceful Post-Conflict Interactions between Victims and Bystanders (PPIVB), which are
directed toward victims. We confirmed the occurrence of PPIAB (mean Triadic Contact Tendency:
41.7%716.2% SEM) at frequencies comparable to PPIVB. Immature gorillas were responsible for most
PPIAB. PPIAB occurred when the bystander was unrelated to either the aggressor or the victim, and
when it was a relative of the aggressor. However, affinitive contact rates were higher in the former case.
Unlike PPIVB, PPIAB significantly reduced the likelihood of further aggressions within the group,
suggesting that they work at an immediate level. Our data also suggest that bystanders decide when a
peaceful contact may be too risky; in fact, neither PPIAB nor PPIVB occurred after high-intensity
aggressions
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