Communication in Animals
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Animal communication allows for the transfer of information between animals. It can occur through visual, auditory, chemical, and mechanical channels. Visual signals include changes in coloration, posture, and facial expressions. Auditory signals involve the production of sounds through vocalizations or other noises. Chemical signals include pheromones that are detected by smell. Honest signals are more likely when the interests of the signaler and receiver are aligned, the signal reveals inherent qualities of the signaler that cannot be faked, producing the signal is costly, or dishonesty can be detected. Dishonest signals are more probable when the interests of the signaler and receiver differ or assessing signals is difficult.
Communication in Animals
- 1. B Y N A V E E D A K H T A R A S S I S T A N T P R O F E S S O R O F Z O O L O G Y Animal Communication
- 2. What is communication? Animal communication is the passage of information b/w two animals The animal which sends is called signaler and the animal that receives signal is called receiver. It benefits the signaler or an average to both partner. The transfer of information from a signaler to a receiver—in order to better understand animal behavior. Animal communication is also known as Biological communication A stereotyped sequenced of behaviors that has a signaling function is called Display. he study of animal communication is called Zoosemiotics The classical ethological view of communication was developed by Niko Tinbergen.
- 3. Animal Need of Communication .
- 6. Channels of Communication in Animals The pathway linking a signaler and the receiver of the signal is known as a channel. The term channel of communication is used to describe the various sensory modalities that are utilized by animals to facilitate effective communication Some such as the electrical sense are relatively rarely used because they can only operate in one specific environment These are the visual, auditory, chemical and mechanical channels
- 7. Each of these channels presents advantages and disadvantages to the user, and these may vary from environment to environment. For this reason individuals may rely upon a combination of them
- 8. 1. The Visual Channel (Vision)
- 13. Facial expressions are also used to convey information in some species. For instance, what is known as the fear grin—shown on the face of the young chimpanzee below—signals submission. This expression is used by young chimpanzees when approaching a dominant male in their troop to indicate they accept the male's dominance.
- 18. Sound signals have several advantages. They can be transmitted over long distances, especially in water. Although sound is transmitted more slowly than light, it still can be a rapid means of sending a message, particularly at close range For example, mammals use their larynx and birds use their syrinx to produce sound. The anatomical structure and location of these organs are different, but both allow production of complex sounds. Crickets, for example, produce sound by opening and closing their wings.
- 19. Some animals make sounds that humans cannot hear. For example, several groups of mammals, including cetaceans, bats, and rodents, produce and detect ultrasounds as part of echolocation Ultrasounds are sounds whose frequencies are above those audible to humans, which means frequencies greater than about 20 kHz Human hearing also has a lower limit: we typically cannot hear sounds whose frequencies are less than about 20 Hz, so sounds below this limit are called infrasound.
- 22. The advantages of chemical communication are not as immediately apparent as those offered by the visual and acoustic channels. To be effective the molecules that make up a chemical signal need to move from the sender to the receiver. In some cases this is achieved by the sender physically placing the signal onto the receiver, or by the receiver moving to a deposited signal to pick it up. More often it involves the movement of the chemical through air or water by the process of diffusion.
- 23. Some species of amphibians, reptiles, and mammals have a vomeronasal (or Jacobson’s) organ that is important in chemical communication between mates, parents and offspring, and rivals. t is anatomically separate from other chemosensory structures, and its neural wiring goes to brain regions different from those associated with the main olfactory system The vomeronasal organ is located in the roof of the mouth or between the nasal cavity and the mouth, so communicative chemicals must reach it through the nose, mouth, or both. B
- 24. Pheromones: Chemicals produced to convey information to other members of the same species are called pheromones. Some of these, releaser pheromones, have an immediate effect on the recipient’s behavior. A good example of a releaser pheromone is a sex attractant The most famous sex attractant is probably that of the female silk moth, Bombyx mori. She emits a minuscule amount, only about 0.01 microgram, of her powerful sex attractant, bombykol, from a small sac at the tip of her abdomen This pheromone, which is carried by the wind to any males in the vicinity, binds to the receptor hairs on the male’s antennae. As few as 200 molecules of bombykol have an immediate effect on the male’s behavior— he turns and flies upwind in search of the emitting female Trail Pheromones: Other examples of releaser pheromones in insects are trail pheromones, which direct the foraging efforts of others, and alarm substances, which warn others of danger.
- 25. Vertebrates also produce releaser pheromones. For example, lactating rabbits produce mammary pheromone, which stimulates their pups to search for and grasp onto a nipple Vertebrates also produce releaser pheromones. For example, lactating rabbits produce mammary pheromone, which stimulates their pups to search for and grasp onto a nipple 3. Primer pheromones exert their effect more slowly, by altering the physiology and subsequent behavior of the recipient.
- 26. In insect societies, queens control the reproductive activities of nest mates largely through primer pheromones. For example, a queen honeybee produces several compounds from her mandibular gland that ensure that she will remain the only reproductive indi
- 30. MULTIMODAL COMMUNICATION Animals do not always use a single channel when communicating. In fact, the displays of many animals contain signals from two or more sensory modalities. This type of communication is called multimodal communication, and the signaling in different channels can occur either simultaneously or sequentially
- 32. Characteristic's of different sensory Channel for Communication in Animals
- 33. Topic# 2 SIGNALS AND HONESTY SIGNALS AND HONESTY Four common circumstances under which we expect to see honest signals: (1) when senders and receivers share overlapping goals, (2) when signals indicate something about the sender that cannot be faked, (3) when signals are costly to produce, and (4) when dishonest signalers can be identified.
- 34. 1. If Senders and Receivers Share Overlapping Goals Sometimes both the sender and receiver share the same goal: the sender benefits by accurately transmitting information, and the receiver benefits by accurately interpreting it. The coordination of behaviors between animals that have chosen to mate provides an example. In cases like these, we expect that natural selection will favor unambiguous, honest signals.
- 35. Example: Begging chicks are quite obvious to predators as well as parents, so begging too much, when food is not needed, is a poor strategy Parents usually respond to the signal by providing food to those chicks that beg most vigorously
- 36. 2. If Signals Cannot Be Faked Sometimes signals are honest because they are tightly linked to a trait of the sender. Although the sender might benefit if it could lie, it simply is not possible to fake the signal. Size is usually a good predictor of fighting success, and many displays allow opponents to judge one another’s size. In some species, combatants can enhance their apparent size by puffing up their feathers, fluffing out their fur, or assuming an upright posture, but in other species, size is not so easily faked. In the threat display of male stalk- eyed flies
- 37. Other signals are honest because they are linked very strongly to an animal’s health and physiological wellbeing. For example, the bright reds and yellows of feathers, scales, or fleshy necks or combs of some birds depend on chemicals called carotenoids. These chemicals cannot be synthesized by vertebrates but must be obtained in the diet. 3. If Signals Are Costly to Produce Reliable signals will be favored in a population when signals are costly to the sender Handicap Principle
- 39. If Dishonest Signalers Can Be Identified A stable social unit also favors honest communication. One reason to expect honesty is that individuals will both send and receive signals at different times. The advantages of sending dishonest signals will be reversed when the animal is the receiver. Therefore, the advantages of receiving honest signals might outweigh the advantages of sending dishonest ones, and honesty might come to predominate in the population.
- 40. WHEN ARE DISHONEST SIGNALS LIKELY? If Senders and Receivers Have Different Goals Just as overlapping goals between senders and receivers favor honesty in signaling, different goals set the stage for deception If Signals Are Costly to Assess or Challenge Assessing signals can itself be costly. For example, a cricket assessing the quality of a singing male must invest time in listening and may risk attack by parasites or predators that are attracted to the male’s song.