322,877 research outputs found
Sniffing behavior in Lemur catta: seasonality, sex and rank
No full textWe analyzed the role of direct olfactory investigation in relation to seasonality,
sex, and female rank via of a longitudinal study on 16 adult ring-tailed lemurs
living in two groups at the Pistoia Zoo (Tuscany, Italy). The observations took
place from May 1997 to March 1999 and lasted >1,500 h. Males were olfactorily
more active than females except for skin licking, which also appeared
to be associated with affiliative behaviors. Both sexes had peak frequency of
direct olfactory monitoring during the reproductive season; contrarily, skin
licking showed apparently random fluctuations. There is a significant positive
correlation between rank and sniffing genitals performed by females on
other females and a significant negative correlation between rank and sniffing
genitals received: high-ranking females are mostly actors, while low-ranking
females are mostly receivers. The continuous follow-up of the reproductive
conditions of potential competitors suggests that sniffing genitals might play
a role in female reproductive strategies
Immediate and delayed benefits of play behaviour: new evidences from chimpanzees (Pan troglodytes)
No full textEvidence for the anticipation of competition at feeding time has been
previously documented in both Pan species. Chimpanzees seem to cope with
competitive tendency through behavioural mechanisms of tension reduction, and
grooming is certainly one of these. Social play and grooming are often matched
because they bring animals into close physical contact for long periods, and they
have an important role in social cohesion. Our goal was to investigate the
occurrence of play behaviour during the pre-feeding period, before a basic
maintenance activity is about to take place, in the chimpanzee colony housed in
the ZooParc de Beauval (St Aignan sur Cher, France). The group was composed
of 10 adults and nine immature individuals. By scan animal sampling (344 h of
observation), we recorded play and grooming interactions in all age-class
combinations during four different periods (pre-feeding, feeding, post-feeding,
control). We found peak levels of grooming interactions among adults during the
pre-feeding time. A peak frequency at the pre-feeding time was also found in
social play between adults and unrelated immature subjects. This finding suggests
that during high tension periods, grooming and play might share similar functions
in conflict management. Like grooming, play might have an important role to
limit aggression and increase tolerance around food (immediate benefits).
Immature animals showed a higher frequency of play in the pre-feeding than in
any other condition (feeding, post-feeding, and control). During high excitement
periods social play probably represents a safe mechanism for immature subjects to
test their personal abilities (self-assessment), the strength/weakness of playmates,
and the degree of cooperation/competition with them (social-assessment). In the
light of this new evidence, we can assert that play behaviour is far from being a
purposeless activity, at least in the chimpanzee colony under study
Alcuni problemi relativi alle sepolture ad incinerazione della tarda età del bronzo in Italia centrale e meridionale affrontati a partire dalle determinazioni antropologiche.
No full textDiscussione delle determinazioni antropologiche dei resti cremati da Milazzo, necropoli di Piazza Roma e dintorni; valutazione generale dei problemi delle determinazioni antropologiche e discussione del significato dei risultati, rispetto ai comportamenti funerari dell'area e del periodo (facies Ausonia)
The neglected scent: On the marking function of urine in Lemur catta
No full textIn ring-tailed lemurs (Lemur catta) urine deposition
can be combined with two different tail configurations:
(i) tail held up in an evident display (urinate tail-up,
UT-up); (ii) tail slightly raised to avoid its impregnation
with urine (urinate tail-down, UT-down). We used both
signaller- and receiver-based approaches to search for functional
differences between these two kinds of urine deposition.
We predicted that UT-up might be a complex signal
combining olfactory and visual cues.We carried out observations
and scent tests on four captive groups of ring-tailed
lemurs. Group members sniffed/licked UT-up scents more
frequently than UT-down ones. Moreover, UT-up showed
peak levels during the mating season whereas UT-down
did not. These findings suggest that urine can play a role
in intra-group reproductive communication. Lemurs more
frequently performed UT-up in a fewdrops and UT-down in
streams. Recognition experiments clearly showed that individuals
can discriminate between urine of their own group
and urine from a foreign group (a necessary prerequisite for
the use of urine in inter-group communication). The possible
function of UT-up in inter-troop communication was
supported by the higher frequency of this pattern along a
fence separating two of the study groups. Moreover, in the
presence of a dummy, the frequency of UT-up increased
significantly. In conclusion, UT-up is a complex signal
with multiple characteristics. By using different sensory
channels, UT-up provides different types of information
(location and signaller quality) and contains multiple messages
directed both at group-members and neighbouring
groups
Short-term benefits of play behavior and conflict prevention in Pan paniscus
No full textMost theories on the function of play have focused on ultimate rather than
proximate benefits. Play peaks during juvenility but, in some species, it is
present in adulthood as well. In primates, social play and grooming often
show a matched pattern because they bring individuals into close contact and
favor social cohesion. In Pan, researchers have widely documented anticipation
of competition at feeding time. Chimpanzees limit aggression over food
by grooming (celebration), whereas bonobos use sociosexuality as a reassurance
mechanism. We examined the function of play in the context of conflict
prevention in the Apenheul bonobo colony. We analyzed the distribution of
social play, grooming, and sexual contacts in periods around feeding and in a
control condition. Adult-adult and adult-immature play frequencies were significantly
higher during prefeeding than in any other condition, thus not supporting
the commonly held view that social stress suppresses play. Further,
there is a significant positive correlation between adult-adult play and rates
of cofeeding. During feeding, adults engaged in their highest levels of sociosexual
behaviors, whereas an increase in grooming rates occurred in prefeeding,
though not significantly compared to the control rates. In conclusion,
bonobos apparently cope with competition and social tension via 2 different
mechanisms of conflict management: play to prevent tension, e.g., prefeeding,
and sociosexual behaviors as appeasement and reassurance mechanisms
once a tense situation emerges
Reconciliation and consolation in captive western gorillas
No full textWe studied post-aggression mechanisms in a captive group of western gorillas
(Apenheul Primate Park, The Netherlands) and compared them with
those of wild mountain gorillas (Gorilla beringei). We found the same trend
for reconciliation that wild mountain gorillas show: reconciliation occurred
only between adult male-female dyads, while it was absent in the other sexage
class combination. There were both solicited and nonsolicited contacts;
the latter finding is in contrast with the result obtained in wild mountain gorillas,
in which consolation was absent. Immature females were more likely
to offer consolation toward both related and unrelated individuals. Consolation
did not reduce the likelihood of further attacks among group members. It
may be that, as the α-male plays a fundamental role in preventing the spread
of conflicts throughout the entire group, triadic contacts become ineffective
for the function. The levels of consolation were higher in absence of reconciliation
than in its presence, suggesting that consolation may function as an
alternative mechanism in stress reduction of the victim
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
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