An intended transfer of information from one organism to another. Purpose of communication: Location/position (food, sex, lost) Advertisement (quality quantity health) Defense (recruiting assistance, threatening, intimidating) Offence (tactical information for group hunting, herding prey) Social intent (dominance fear need help) Modes of communication: Chemical (olfactory, taste, Hormonal??) Visual (body language, plumage, skin pigmentation, physical augmentations) Auditory/mechanosensory (can be sub to ultrasonic) Vocalizations (songs, calls, barks, whistles etc.) Non vocal (stridulations/vibrations) Electric Communication

Modes of communication: Chemical (olfactory, taste, Hormonal??) Visual (body language, plumage, skin pigmentation, physical augmentations) Auditory/mechanosensory (can be sub to ultrasonic) Vocalizations (songs, calls, barks, whistles etc.) Non vocal (stridulations/vibrations) Electric

Senders and receivers of communications Intraspecific: within species Interspecific: between species Honest communicators Dishonest communicators (eavesdropping and lying) Predators Competitors Communication Given that communications can be exploited/misinterpreted how should evolution act on communication systems? Clear signals to intended receiver Cryptic signals to everyone else

Foraging Atta cephalotes Leaf-cutter ants Use chemical and subsonic communication to indicate food source and quality Chemical signal: methyl 4-methylpyrole-2-carboxlate 1 milligram of this pheromone properly laid down could lead a column of ants around the earth… 3 times Leaf-cutters only select younger leaves Fewer secondary compounds such as protease inhibitors and defensive toxins More sugar Selected leaves are striped to the stalk, the rest are left untouched

Foraging As the worker cuts a section of the leaf it will stridulate with its gaster Causes a vibration that recruits other workers to the leaf Also attracts Minim-workers Study1: Tough vs tender leaves that were sweetened vs not Percent stridulating by treatment: 40% tough 70% tender 100% sweetened Study2: Choice test between vibrating and silent leaves Workers preferred vibrating leaves

Mating and social dominance There are a variety of electric fishes each has a species-specific discharge pattern that is generated by the electric organ Used for: Stunning prey Stunning predators Communicating Carl D. Hopkins Some species can produce up to 600 volt discharges

Mating and dominance: Electric fish Electric fish can both produce electrical currents and detect electrical fields This forms the basis for communication

Mating and social dominance: Electric fish Males during breading season will produce longer discharge pulses In the presence of females discharges increase in frequency&duration Males exposed to androgens will produce longer discharge pulses When in groups social rank of males is determined by pulse duration These rankings can be a priori predicted based on ketotestosterone levels.

Ritualized battle safely establishes dominance (usually) These battles establish dominance using honest signals Size Strength Health Commitment to win

Raven yelling establishes dominance

Mating and social dominance: Ravens

Dishonest signals Used by predators and prey to deceive opponents Within species can be used to deceive reproductive opponents