Studying the causes of parasite geographic distribution is relevant to understand ecological and evolutionary processes that affect host populations as well as for species conservation. Temperature is one of the most ...Studying the causes of parasite geographic distribution is relevant to understand ecological and evolutionary processes that affect host populations as well as for species conservation. Temperature is one of the most important environmental variables affecting parasite distribution, as raising temperatures positively affect development, reproduction, and rate of transmission of both endo- and ectoparasites. In this context, it is generally accepted that, in mountains, parasite abundance decreases with elevation. However, empirical evidence on this topic is limited. In the present study, we analyzed the elevational variation of hemoparasites and ectoparasites of a lizard, Psammodromus algirus, along a 2,200-m elevational gradient in Sierra Nevada （SE Spain）. As pre- dicted, ectoparasite （mites, ticks, mosquitoes, and sandflies） abundance decreased with elevation. However, hemoparasite prevalence and intensity in the lizard augmented with altitude, showing a pattern contrary to their vectors （mites）. We suggest that tolerance to hemoparasites may increase with elevation as a consequence of lizards at high altitudes taking advantage of increased body condition and food availability, and reduced oxidative stress. Moreover, lizards could have been selected for higher resistance against hemoparasites at lowlands （where higher rates of replication are expected）, thus reducing hemoparasite prevalence and load. Our findings imply that, in a scen- ario of climate warming, populations of lizards at high elevation may face increased abundance of ectoparasites, accompanied with strong negative effects.展开更多
Communication relies on signals that can be produced via different sensory modalities to modify receivers’behavior.During social interactions,the possibility to perceive subtle visual cues enhances the use of facial ...Communication relies on signals that can be produced via different sensory modalities to modify receivers’behavior.During social interactions,the possibility to perceive subtle visual cues enhances the use of facial expressions to exchange information.One of the most appropriate fields to explore the specific design features of visual signals is play fighting.Here,we explored the production and potential role of Relaxed Open Mouth(ROM)and Head Bobbing(HB)in regulating play fighting of wild spotted hyenas Crocuta crocuta,a highly hierarchical carnivore species.In accordance with the assumptions of the signal optimization theory,wild hyenas produced ROM and HB almost exclusively when the sender was in direct visual contact with the receiver thus suggesting that senders were attentive to the playmates’face.Contrary to HB,the sequential analysis revealed that ROM often anticipated offensive patterns such as play biting thus supporting the hypothesis that ROM,but not HB,is a metacomunicative signal.Moreover,when the offensive patterns were biased toward one of the 2 players,the session was punctuated by a higher number of ROMs.Our findings support the general hypothesis that these 2 visual signals can play different roles in the management of play fighting in this carnivore species.The complementary use of ROM and HB would suggest that spotted hyenas are highly competent and fast in processing facial displays of different nature to correctly“read others’intentions”and respond with appropriate motor actions to avoid misunderstanding during one of the most multifaceted and risky social interaction.展开更多
Female primates can emit vocalizations associated with mating that can function as honest signals of fertility.Here,we investigated the role of mating calls and visual signals in female geladas(Theropithecus gelada).B...Female primates can emit vocalizations associated with mating that can function as honest signals of fertility.Here,we investigated the role of mating calls and visual signals in female geladas(Theropithecus gelada).Because females have a central role in the gelada society and seem to solicit sexual interactions,we answered whether they emit vocalizations in conjunction with gazing to increase mating success probability.Before and during copulations,females can emit pre-copulation calls and copulation calls.For the first time,we identified a new female vocalization emitted at the final stage of copulations(end-copulation call),possibly marking the occurrence of ejaculation.We found that longer pre-copulation call sequences were followed by both prolonged copulations and the presence of end-copulation calls,thus suggesting that females use pre-copulation calls to ensure successful copula completion.Moreover,we found that different combinations of female vocal types and gazing had different effects on male vocal behavior and motivation to complete the copula.The analysis of the vocal and visual signals revealed a complex inter-sexual multimodal chattering with the leading role of females in the signal exchange.Such chattering,led by females,modulates male sexual arousal,thus increasing the probability of the copula success.展开更多
The increasing interest in the study of spontaneous(SY)and contagious yawning(CY)was so far focused on several taxa,especially primates.Here,we focused on SY and CY in horses,a suitable species due to their complex so...The increasing interest in the study of spontaneous(SY)and contagious yawning(CY)was so far focused on several taxa,especially primates.Here,we focused on SY and CY in horses,a suitable species due to their complex social dynamics that has been largely overlooked in research on these phenomena.By analyzing videos of 48 horses on pasture,we identified 2 yawning morphologies:Covered(Y_(CT))and Uncovered Teeth(Y_(UCT)).Using EquiFACS,we quantitatively demonstrated that Y_(CT) and Y_(UCT) differ in terms of muscle recruitment.Moreover,we provide the first evidence for the presence of CY by comparing 2 different conditions:chewing-yawn-chewing versus chewing-chewing-chewing.Supporting the Social Modulation hypothesis,in our mares,CY was more prominent among subjects sharing good relationships.Moreover,subjects responded more rapidly to kin compared with non-kin and kin frequently grooming each other responded even more rapidly to each other yawns.The high familiar yawn sensitivity can provide selective advantages increasing behavioral synchronization and group cohesion.展开更多
Dogs engage in play behavior at every age and the play bow is their most iconic playful posture.However,the function of this posture is still under debate.Here,we selected the Czechoslovakian Wolfdog(CWD)as a model br...Dogs engage in play behavior at every age and the play bow is their most iconic playful posture.However,the function of this posture is still under debate.Here,we selected the Czechoslovakian Wolfdog(CWD)as a model breed to clarify the function of the play bow.We analyzed frame-by-frame 118 sessions of 24 subjects and recorded 76 play bow events.We found that all the play bows were performed in the visual field of the playmate suggesting that the sender takes into account the attentional state of the receiver when releasing the signal.By drawing survival curves and using log-rank test we found that play bow was mainly performed during a short pause in an ongoing session and that its performance triggered the playmate’s reaction again.These findings show that play bow functions in restoring the partner motivation to play.Finally,by using a sequential analysis and a generalized mixed model,we found no evidence supporting the metacommunicative function of the play bow.The signal did not necessarily precede a contact offensive behavior(e.g.,play biting and play pushing)and it was not affected by the level of asymmetry of the play session.In conclusion,in CWDs play bow can be considered a visual signal useful to maintain the motivation to play in the receiver.Therefore,we suggest that the mismatched number of play bows emitted by the 2 players in a given session can be predictive of their different motivations to play.展开更多
n nonhuman animals,the phenomenon of rapid facial mimicry(RFM)—the automatic,involuntary,and rapid(<1 s)replication of others’facial expressions—has been mainly investigated in the playful domain.In immature low...n nonhuman animals,the phenomenon of rapid facial mimicry(RFM)—the automatic,involuntary,and rapid(<1 s)replication of others’facial expressions—has been mainly investigated in the playful domain.In immature lowland gorillas Gorilla gorilla gorilla both play face(PF)and full PF(FPF)are rapidly mimicked between the players.This makes the species suitable to test hypotheses on the factors influencing RFM during play.The observations on 3 captive groups of lowland gorillas(N=27)revealed that contrary to expectations,the closeness of social bond negatively influenced the occurrence of RFM but it did not affect either RFM latency or its overlapping index(OVERLAP).RFM was affected by the degree of symmetry of play fighting:the more balanced the session,the higher the occurrence of RFM.Players of the same sex class responded faster than players of different sex.These findings suggest that RFM may help synchronizing behaviors of playmates matching in size(same-sex)and promote symmetric playful interactions.“Laughing together”(measured by the RFM OVERLAP)lasted longer when the responder perfectly mirrored the partner expression(PF→PF;FPF→FPF).If PF and FPF convey information on the different play roughness degree,through“laughing together”the players could coordinate their actions and share positive moods and playful intensity.If the perfect congruency in the motor resonance,also known as social sensitivity,can foster a possible emotional dialogue between gorillas remains to be investigated.展开更多
文摘Studying the causes of parasite geographic distribution is relevant to understand ecological and evolutionary processes that affect host populations as well as for species conservation. Temperature is one of the most important environmental variables affecting parasite distribution, as raising temperatures positively affect development, reproduction, and rate of transmission of both endo- and ectoparasites. In this context, it is generally accepted that, in mountains, parasite abundance decreases with elevation. However, empirical evidence on this topic is limited. In the present study, we analyzed the elevational variation of hemoparasites and ectoparasites of a lizard, Psammodromus algirus, along a 2,200-m elevational gradient in Sierra Nevada （SE Spain）. As pre- dicted, ectoparasite （mites, ticks, mosquitoes, and sandflies） abundance decreased with elevation. However, hemoparasite prevalence and intensity in the lizard augmented with altitude, showing a pattern contrary to their vectors （mites）. We suggest that tolerance to hemoparasites may increase with elevation as a consequence of lizards at high altitudes taking advantage of increased body condition and food availability, and reduced oxidative stress. Moreover, lizards could have been selected for higher resistance against hemoparasites at lowlands （where higher rates of replication are expected）, thus reducing hemoparasite prevalence and load. Our findings imply that, in a scen- ario of climate warming, populations of lizards at high elevation may face increased abundance of ectoparasites, accompanied with strong negative effects.
文摘Communication relies on signals that can be produced via different sensory modalities to modify receivers’behavior.During social interactions,the possibility to perceive subtle visual cues enhances the use of facial expressions to exchange information.One of the most appropriate fields to explore the specific design features of visual signals is play fighting.Here,we explored the production and potential role of Relaxed Open Mouth(ROM)and Head Bobbing(HB)in regulating play fighting of wild spotted hyenas Crocuta crocuta,a highly hierarchical carnivore species.In accordance with the assumptions of the signal optimization theory,wild hyenas produced ROM and HB almost exclusively when the sender was in direct visual contact with the receiver thus suggesting that senders were attentive to the playmates’face.Contrary to HB,the sequential analysis revealed that ROM often anticipated offensive patterns such as play biting thus supporting the hypothesis that ROM,but not HB,is a metacomunicative signal.Moreover,when the offensive patterns were biased toward one of the 2 players,the session was punctuated by a higher number of ROMs.Our findings support the general hypothesis that these 2 visual signals can play different roles in the management of play fighting in this carnivore species.The complementary use of ROM and HB would suggest that spotted hyenas are highly competent and fast in processing facial displays of different nature to correctly“read others’intentions”and respond with appropriate motor actions to avoid misunderstanding during one of the most multifaceted and risky social interaction.
基金Department of Life Sciences and Systems Biology(Italy)via Compagnia di San Paolo(Torino,Italy)(grant 879660)Erasmus KA1 mobility funds(Ethiopia_2019)the EAZA via the University of Pisa,Natural History Museum(No.Protocol 0000384/2018).
文摘Female primates can emit vocalizations associated with mating that can function as honest signals of fertility.Here,we investigated the role of mating calls and visual signals in female geladas(Theropithecus gelada).Because females have a central role in the gelada society and seem to solicit sexual interactions,we answered whether they emit vocalizations in conjunction with gazing to increase mating success probability.Before and during copulations,females can emit pre-copulation calls and copulation calls.For the first time,we identified a new female vocalization emitted at the final stage of copulations(end-copulation call),possibly marking the occurrence of ejaculation.We found that longer pre-copulation call sequences were followed by both prolonged copulations and the presence of end-copulation calls,thus suggesting that females use pre-copulation calls to ensure successful copula completion.Moreover,we found that different combinations of female vocal types and gazing had different effects on male vocal behavior and motivation to complete the copula.The analysis of the vocal and visual signals revealed a complex inter-sexual multimodal chattering with the leading role of females in the signal exchange.Such chattering,led by females,modulates male sexual arousal,thus increasing the probability of the copula success.
文摘The increasing interest in the study of spontaneous(SY)and contagious yawning(CY)was so far focused on several taxa,especially primates.Here,we focused on SY and CY in horses,a suitable species due to their complex social dynamics that has been largely overlooked in research on these phenomena.By analyzing videos of 48 horses on pasture,we identified 2 yawning morphologies:Covered(Y_(CT))and Uncovered Teeth(Y_(UCT)).Using EquiFACS,we quantitatively demonstrated that Y_(CT) and Y_(UCT) differ in terms of muscle recruitment.Moreover,we provide the first evidence for the presence of CY by comparing 2 different conditions:chewing-yawn-chewing versus chewing-chewing-chewing.Supporting the Social Modulation hypothesis,in our mares,CY was more prominent among subjects sharing good relationships.Moreover,subjects responded more rapidly to kin compared with non-kin and kin frequently grooming each other responded even more rapidly to each other yawns.The high familiar yawn sensitivity can provide selective advantages increasing behavioral synchronization and group cohesion.
基金Hashtag Formazione e Benessere grant number:360-HASHTAG-200213-D043-24000.
文摘Dogs engage in play behavior at every age and the play bow is their most iconic playful posture.However,the function of this posture is still under debate.Here,we selected the Czechoslovakian Wolfdog(CWD)as a model breed to clarify the function of the play bow.We analyzed frame-by-frame 118 sessions of 24 subjects and recorded 76 play bow events.We found that all the play bows were performed in the visual field of the playmate suggesting that the sender takes into account the attentional state of the receiver when releasing the signal.By drawing survival curves and using log-rank test we found that play bow was mainly performed during a short pause in an ongoing session and that its performance triggered the playmate’s reaction again.These findings show that play bow functions in restoring the partner motivation to play.Finally,by using a sequential analysis and a generalized mixed model,we found no evidence supporting the metacommunicative function of the play bow.The signal did not necessarily precede a contact offensive behavior(e.g.,play biting and play pushing)and it was not affected by the level of asymmetry of the play session.In conclusion,in CWDs play bow can be considered a visual signal useful to maintain the motivation to play in the receiver.Therefore,we suggest that the mismatched number of play bows emitted by the 2 players in a given session can be predictive of their different motivations to play.
文摘n nonhuman animals,the phenomenon of rapid facial mimicry(RFM)—the automatic,involuntary,and rapid(<1 s)replication of others’facial expressions—has been mainly investigated in the playful domain.In immature lowland gorillas Gorilla gorilla gorilla both play face(PF)and full PF(FPF)are rapidly mimicked between the players.This makes the species suitable to test hypotheses on the factors influencing RFM during play.The observations on 3 captive groups of lowland gorillas(N=27)revealed that contrary to expectations,the closeness of social bond negatively influenced the occurrence of RFM but it did not affect either RFM latency or its overlapping index(OVERLAP).RFM was affected by the degree of symmetry of play fighting:the more balanced the session,the higher the occurrence of RFM.Players of the same sex class responded faster than players of different sex.These findings suggest that RFM may help synchronizing behaviors of playmates matching in size(same-sex)and promote symmetric playful interactions.“Laughing together”(measured by the RFM OVERLAP)lasted longer when the responder perfectly mirrored the partner expression(PF→PF;FPF→FPF).If PF and FPF convey information on the different play roughness degree,through“laughing together”the players could coordinate their actions and share positive moods and playful intensity.If the perfect congruency in the motor resonance,also known as social sensitivity,can foster a possible emotional dialogue between gorillas remains to be investigated.
