BZ 300 1st Edition Lecture 11 Outline of Last Lecture Animal EmotionsExample of Perceiving Guilt with Owners and DogsCommunicationSignalNoiseAuto-communicationInformation ContentPublic InformationEvolution Of CommunicationCo-optionRitualizationStereotypyRedundancyModes of CommunicationChemical SignalsAdvantagesDisadvantagesPheromonesVolatilePersistentTactile SignalsOutline of Current Lecture: Audible Signals SoundDefinitionsSound Production MechanismsInfrasoundUltrasoundChorusesAuditory NoiseVisual SignalsThree Challenges in WaterThree Categories of Visual SignalsColorVisual NoiseThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Electrical SignalsMultimodal SignalingMating Signals Current Lecture: Audible Signals- Work really well in dark, do not linger in environment and are not strongly impeded by obstacles. Very energy intensive, and the distance the signal travels varies. It depends on the obstacles and the power given in the soundSound is the vibration. Physical characteristic through the medium influences how sound is used. Density of medium, affects the energy required to initiate signal and influences how fast that signal can actually travel.In dense media, sound requires a lot of energy but travels very fast. *Read about SOFAR- has to deal with water density, temperature and how it relates to marine communication. Definitions: Amplitude- Loudness or intensity of the soundDissipation- loss of intensity as sound travels. The further the sound travels the lower the energy. As sound travels, it dissipates.Pitch- Tone of sound (Frequency) number of oscillations per a unit time.Low pitched sounds have a lot of energy and carry wellHigh Pitch sounds do not have as much energy but are very good for echo-location. Reflection- bouncing of sound waves off a dense surface. Ex. Echoes are an example of reflection in the audible world. Refraction- waves does not bounce back and keeps going, but enters a medium of a different density so the frequency of the wave length changes and is somewhat distorted. Sound Production Mechanisms: Allow the pitch to be modulated so the sound can be different. Can regulate pitch and amplitude by altering the amount of energy invested. Adding a resonant structure can increase volume.Tymbal- vibrating the drums found often in cicadasStridulation- rubbing with scraper and pitch of sound depends on speedVibrating membrane in airflow and pushing membranes through air. Ex. BirdsHitting a substrate, external- example is beaversInfrasound Energetic and low sounds you normally can’t hearTravels really well in soil and waterVery good for long distance travel because it does not dissipateDistance between sound waves is relatively long, so you need a big receiver to sense these sounds. The animal to sense these sounds must be quite big itself. Important in wide-ranging animals. E.g., elephants, killer whalesGreat communication tool for animals that travel long distancesAn example is a contact signal which can last 4 to 5 seconds and can travel may kilometers in the soilMatrilineal- killer whales, males stay with mothers and females wander off and start own group.Calls work in pulses and calls are often time stereotype (very routine and standardized). On theother hand communication can be quite variable among groups and ages. Killer whales must actually learn some of the non-stereotypes. UltrasoundHigh Frequency= short high wavelengths require a miniature receiverLittle energy requiredDissipate rapidly, oftentimes rapid enough that they may not even be turned into a signal. Minimizes chances of communication primarily in echolocationOften times have thin membranes that act as transducersExtra bones in ears that guide the wavelengths towards the receptorTwo main contexts:Social- murids and bats use echolocation to sense certain amount of ripples in water to catch fishEcholocation- requires little energy; short wavelengths, likely to bounce back, reduces confusionChorusesFrogs, insects, bird males often sing to attract matesIt is an honest signal, you can either make that sound or can’t .If it requires energy it is a measure of fitnessWhy Chorus? Where everyone starts singing, it is a trigger in the environment where every maletries to be first. All males begin at about the same time and that is why it is called a chorus. Disadvantages of chorusingAuditory confusion in which specific male the female can hear, they all blend togetherAuditory Noise: animals must learn to deal with sounds in all the environments and sort out relevant and irrelevant information Three Coping strategies:Produce sounds limited range with certain pitches, and respond only to those pitches and nothing else (selective hearing)Cocktail party effect- even though there is a lot of conversation going on, there is the mental ability to screen that out and hear only what you want toPartition signaling by time of day works when trying to communicate with your same species, byworking at a specific time you eliminate all of the noise of the other timesA great concern is dealing with the artificial noise that humans have put into environment (anthropogenic noise). Animals have evolved to deal with noises in their own environment but have not evolved to deal with the anthropogenic noise.Visual Signals Work well in the presence of light and without impedimentsDo not work well in dark and with objects in the wayTravel very fast, inexpensive in energy, do not linger in environmentIn water, there are three challenges:Water absorbs light, so the deeper you are in water the darker it is to see the signalWater directly absorbs red, yellow, orange in particularDue to the density of the medium, refraction makes the interpretation quite difficultThree categories of visual signalsPatterns or pattern with color on surfaceMovement- waving hands, clapping, shaking head, etc. Bioluminescence- producing an animals own lightColorProduced byPigments and structureBioluminescencePigments are more common, they are on or in animal and reflect certain surfaces or colors. Examples are pterins, quinines, melanins, carotinoid (often dietary and produce orange, red, yellow). *Note: Look in book for more information.Bioluminescence- often produces blue or green colors (relatively rare compared to other colors)Fluorescent pigments are absorbed light by pigments and then the pigment retransmitted that didn’t even