Scientific Reports , 17 december December Evy van Berlo, Alejandra P. Skip to main content Menu. Yawning is also contagious in solitary animals Orangutans yawn when seeing others yawn 17 December Publication Experimental evidence for yawn contagion in orangutans Pongo pygmaeus.
Spontaneous yawns by standing elephants outside of arousal episodes within the group thus were extremely rare. This previous study, along with information about elephant-initiated interactions with people at the same study site 21 , provided the context for the current study.
One goal of the present study was to confirm and expand upon our previous descriptions of intraspecific contagious yawning among the same group of elephants, at a different time and with some changes in the group composition. The second goal was to determine if the human handlers that regularly interacted with the elephants during the day would evoke yawning from the elephants by yawning in a manner similar to that used in the studies of humans evoking yawns from dogs and captive chimpanzees.
These observations were conducted in the early morning, outside the nighttime enclosure, a time when spontaneous yawning would be highly unlikely. The setting of this study included videorecording of the behavior of the elephants freely moving at night; these recordings were available for perusal later by an investigator.
The structured interactions of the handlers with the elephants each morning were a daily routine. With elephants, where opportunities to record some behaviors is limited, but the behaviors are meaningful in understanding elephants' comparative behavior, a documented occurrence in just a few individuals is important. The parameters used in designating a yawn as contagious are presented in detail.
Recent examples of reports of just one or two instances of elephant behavior, where details are given, are of sleeping bouts in two wild African elephants in nature 22 and self-identification in a mirror by one elephant The trials with human handlers were integrated into a regular early morning handling procedure because this is soon after the arousal time for the elephants and the trials were part of their daily routine.
Participation of the handlers in the study was voluntary, and handlers were informed that they could withdraw their participation at any time with no repercussions. Permissions to conduct the experiment were granted by the Knysna Elephant Park management, and all aspects of the study were overseen by the on-site African Elephant Research Unit. Data were collected at Knysna Elephant Park, Western Cape, South Africa, from July to November , on ten captive African elephants seven adult females, one sub-adult female, and two sub-adult males , ranging in age from 9 to 27 years.
All ten elephants were part of the intraspecific yawning observations, and seven of the elephants were part of the interspecific trials. The elephants maintained a cohesive herd with a well-defined social hierarchy. Only two of these seven individuals are related mother and daughter.
The remaining three elephants not involved in the interspecific trials adult females were new to the park and did not yet take part in the daily routines of the other elephants with handlers and tourists. Observations over 13 nights took place between p. All 10 elephants were kept in an indoor-outdoor enclosure at night where the indoor section, measured 14 m x 14 m, and was illuminated by heat lamps at night.
Seven of the elephants could move freely between the indoor and outdoor sections 2 ha of the enclosure, while three elephants were kept in smaller enclosures 6 m x 4 m within the main indoor area, for management reasons unrelated to this research.
We reviewed the video footage with Hikvision iVMS software, scoring instances of intraspecific contagious yawning.
Results from the previous study 20 revealed when yawns were most likely to occur in this group of elephants, so observations on intraspecific contagious yawning were focused on final recumbent bouts of the night generally between a. We could then observe whether the yawn triggered a contagious yawn from any of the other elephants. Consistent with the previous study, for a yawn to be classified as contagious, the second elephant had to have a direct line of sight to the first elephant and the contagious yawn had to occur no more than two minutes after the end of yawning of the arousing elephant.
We made a distinction between contagious yawning by a standing elephant in response to a yawn from an arousing elephant, and yawning in an arousing elephant in apparent response to a yawn from another arousing elephant. Due to the prevalence of yawning associated with arousal, we cannot be certain that the latter is not two arousing elephants spontaneously yawning at around the same time.
Control observations from the previous study showed that spontaneous yawns were unlikely to occur outside of the two-minute period following arousal from a recumbency. As described in our previous study 20 , a yawn is characterized as a slow opening of the jaw, a brief frozen open posture and a quick closure of the jaw opening.
This behavior is seen most clearly in the attached video clip Supplementary Video 2 of the elephant yawning in response to a handler yawning. Between July and November , we conducted the trials testing for contagious yawning between handlers and the elephants. We tested seven elephants in this phase with two to three trials a week, dependent on handler availability.
Randomized trials took place during the scheduled morning training period, when the handlers worked directly with the elephants. Handlers often introduce new commands or forms of enrichment to the elephants during this period of the day and our trials were structured so that they would integrate as seamlessly as possible with the elephants' daily routine. Due to evidence of bonds between the elephants and their handlers 21 , it seemed that yawning between the elephants and the handlers could be influenced by the elephant's familiarity with the handler but in this instance all of the handlers who participated in this study had worked with these elephants for several years, and were very familiar to all the elephants.
Two trials were conducted on different elephants at the same time, but the trials were situated such that the two focal elephants in the trials were never adjacent to ensure that trials of one focal elephant did not influence trials of the other focal elephant.
During each trial, the focal handler walked around the elephant consistent with daily handling and when he was within eyesight of the focal elephant, he yawned.
These staged yawns were intended to be as realistic as possible. The handler was asked to yawn repeatedly, about 10 times, at 1-min intervals, depending on eye contact of the elephant. The number of yawns and the trial length were relatively consistent with similar studies on the chimpanzee contagious yawning 10 and the human-dog contagious yawning 11 — 13 trials. We conducted two other types of trials in addition to the yawning trials. In these trials the handler walked around the elephant, but instead of yawning, the handler exhibited a short gape.
Gapes differed from yawns in that they were shorter in duration, with a smaller opening of the mouth. Gapes also differed from yawns in that they consisted of a smooth opening and closing of the mouth, versus the slow opening and quick snap-shut characteristic of a yawn.
There were also control trials with no yawning or gaping where the handler walked around the elephant, as typical during a min morning session, and did not exhibit any yawning or gaping. Four yawning trials, two non-yawn gape trials, and two control trials were conducted for each of the seven elephants.
Since any type of trial took time away from normal morning training, we were limited in the number of trials we could run. We sought to maximize the number of yawning trials while still conducting the control trials we found to be necessary. All trials were recorded by video cameras hand-held by a recorder, for subsequent analysis.
The elephants and the handlers were recorded, when possible, from a side-view perspective from m away so as not to interfere with the trial. During yawn and gape trials, handlers were asked to make a fist each time they performed a yawn or gape so that a correct count of behaviors could be obtained if the handler was not facing the camera, or was partially obscured by the elephant. For intraspecific contagious yawning, the goal was to evaluate the incidence of a standing elephant in the enclosure at night spontaneously yawning within 2 min of a yawn by an arousing elephant.
As mentioned above, the rate of yawning by standing elephants, apart from arousal events, is extremely low 1 yawn in 18 h. For interspecific yawning, the goal was to assess whether trials with staged yawns by a handler would provoke a response of a contagious yawn by the elephant; trials with gapes and no special behavior by the handler were conducted for comparison. During the 13 nights with recorded videos, 17 spontaneous yawns were observed in association with arousal from a recumbency.
Alternatively use it as a simple call to action with a link to a product or a page. Contact MaryJaneS ethicalpet. Why Do Animals Yawn. Liz Bales. Facebook Twitter Pinterest Email. Older Post. Newer Post. Leave a comment Name. Close esc Popup. For instance, if two lions were lying down, and one yawned, the other yawned. Then the first yawner stood up, and so did the other animal.
The research supports the theory that contagious yawning may have evolved to boost group vigilance among animals that live cooperatively, such as wolves and chimps, says Andrew Gallup , director of the Adaptive Behavior and Cognition Lab at SUNY Polytechnic Institute in Utica, New York. He also agrees with Palagi that lions likely experience the same beneficial physiological impacts to the brain as humans.
Contagious yawning could serve multiple, and possibly yet unknown, functions in a cooperative animal group; for instance, gelada baboons have three distinct types of yawns that convey different messages, such as friendliness or aggression, Palagi says.
The role of empathy in contagious yawning is perhaps the most hotly debated area of yawn research, she says. Scientists have investigated empathy and yawning in only a handful of species, including humans, domestic dogs, wolves, and some primates. The results of that study—the first to show contagious yawning between species—may indicate that dogs are emotionally attuned to their humans, the authors said.
All rights reserved. Fair warning: Reading this story might make you yawn. But one of the biggest unsolved questions is why mammals yawn in response to one another. Catchy behavior For five months, Palagi and colleagues filmed 19 lions in two prides living at Makalali Game Reserve. Share Tweet Email. Read This Next Wild parakeets have taken a liking to London.
0コメント