Bare Minimum for Communication - Biology of Animals - Lecture Slides, Slides of Biology

Download Bare Minimum for Communication - Biology of Animals - Lecture Slides and more Slides Biology in PDF only on Docsity! Bare Minimum for Communication SENDER produces a stimulus e.g. movement odor sound display etc. RECEIVER sensory neurons detect the stimulus e.g. vision olfaction audition etc. Receiver brain interprets signal PNS CNS Docsity.com "What is communication"? Not a trivial question … 1) Must communication signals be intentional? 2) Does the sender have to be intentionally "behaving"? 3) Must they be beneficial? To whom? 4) Is communication only INTRAspecific? Docsity.com Comments about using the model: 1) Sending or receiving does not have to be conscious, voluntary, or "neural". 2) Sender/receiver usually same species but may not be. 3) The signaling is normally advantageous to sender – may or may not be to the receiver. 4) Upon receiving a signal, the receiver's behavior changes in some way. 5) Signals have receiver-specific meaning Docsity.com SOURCE OF MEANING?? What is it about a signal that confers meaning?? SIGNAL MODULATION Dictionary Def. Modulate – to vary the amplitude, frequency, or phase of a signal Docsity.com Signals are varied … or MODULATED … which gives information richness. Modulated signals would include those that are … i) DISCRETE (binary = 2-state = digital) ii) GRADED (analog) iii) COMPOSITE (of discrete & graded) Docsity.com Graded signals may vary qualitatively or quantitatively. EXAMPLE: bird song qualitative = pitch variation (low ……to ……..high) quantitative = volume (soft …….to ……….loud) Docsity.com Composite signals combine discrete & graded. EXAMPLE: greeting & threat displays in zebras. Docsity.com FUNCTIONS OF COMMUNICATION We'll discuss only 2: alarm communication communicating food location I) ALARM COMMUNICATION - group-living animals alert group members to danger (major advantage of group-living) “Danger" is usually the presence of a predator. meerkatsprairie dog Docsity.com b) Alarm Sound?? c) Alarm Visual Display Docsity.com Alarm Calls: Mobbing Behavior in Birds Communication to the Community? Docsity.com Different birds living in the same area have evolved very similar alarm calls … why does this make sense? Docsity.com Round Dance Sequence 1) Starting point: Worker discovers a food source … she feeds & then labels the flower with her scent. 2) Upon returning to the hive, she will communicate in a variety of ways with her sisters. If a food source has been discovered nearby, the discoverer will return & do a "round dance". Docsity.com 3) Round dances stimulate interest in the dancer -- an audience forms. 4) Audience smells flower odor – begins search for that odor. Docsity.com Waggle Dance Sequence * If food more distant, dancer does a "waggle dance". * More complex that the round dance. * Dance is a figure 8 -- waggling done in the straight section of the 8. Docsity.com Docsity.com (A) No osprey returns with prey = 10 Departures 4 5 Departures e 1 Departure An osprey returns with alewife BEBE HE BeBe eP a oe e Orientation of departing ospreys ‘©2001 Sinauer Associates, Inc Docsity.com (B) 40 Hi Naive ospreys Hi Informed ospreys w oS Number of birds 8 KR So 0 == © Ca = 0 20 40 60 80 Time to capture alewife (minutes) © 2001 Sinauer Associates, Inc @) Docsity.com Explanation: Ravens are territorial & live in pairs - Territorial pairs will drive single transient birds away - If a transient finds a carcass, it yells to recruit other transients - Large groups of transients can’t be intimidated by the territorial pair Docsity.com Yelling raven communication about food location … Appears to be altruistic … transients helping other transients Actually, yellers are manipulative and selfish!! Docsity.com