Island Monkeys Do Not Recognize Big Cat Calls

There were monkeys which resided on a particular island. They were not under any predation of big cats. These kinds of cats could be studied with dissection microscopes. Due to these cats’ absence, and which was quite understandable from a layman’s perspective, the monkeys did not illustrate any specific alarm whenever growls of tiger which were recorded were played towards them. This was a finding provided for by one graduate student of UC Davis. It was also observed that these langurs which were seen to be pig-tailed ran away whenever they could hear the voices of human beings.

Jessica Yorzinski was one graduate student in the field of animal behavior. She came from UC Davis. According to her, this could somehow provide contribution towards an increasing literature regarding the transformations of the behavior of animals under serene pressures of selection. The original text conveyed that langurs having tails like pigs were monkeys having medium structures which mostly spend sitting on the trees all the time. They were also seen to be in tiny assemblies nourishing on leaves. They also had relatives. Among their close ones resided on the Indonesia mainland. They were tigers’ and lelopards’ prey. However, on the islands of Mentawai, these monkeys, which could be investigated with dissection microscopes, had been put in isolation from cats which were huge. This transpired around half one million years had elapsed. It was Yorzinski who made these monkeys listened to recordings of the tiger as well as leopard bellows and snarls. Elephants’ sounds were also involved. This was done because monkeys did not know anything about elephants.

Also, pigs as well as birds’ sounds were also included. This was due to the reason that these animals did not nourish on monkeys even if the latter might know of their existence. The monkeys were also made to listen to conversing people because the latter would chase monkeys for their food. When the monkeys heard the noises, they would start looking around. After that, they would look at one another. Then, they would depart from the site. The monkeys did not illustrate any sign that they were alarmed upon hearing noises of big cats compared to when they heard elephant’ noises. When they heard the latter, they would eventually ran away in around four to up to five seconds. Meanwhile, when they heard voices of human beings, they would run away in a snap. It seemed then that they fear human beings the most. Lastly, upon hearing noises of birds or pigs, which could be further examined with dissection microscopes, no form of alarm had been witnessed.

Needless to say, during the course of the experiment, Yorzinski would stay hidden upon putting up the speakers and finding the monkeys. It would be impossible to experiment on the monkeys if the monkeys knew they were being studied. This study had been published in the year 2007, specifically in the month of December. Ethology journal has the details of this research undertaking.