environmental signals resource recruitment signals –costs and benefits –types –examples...
TRANSCRIPT
Environmental signals
• Resource recruitment signals– Costs and benefits– Types– Examples
• Predator detection signals– Types– Examples
Give Game
Why signal food location?
• Costs– Increases competition– Signal production takes time and energy
• Potential Benefits– Increasing number of foragers improves foraging
success and/or decreases predation risk– Increases reproduction of relatives– Food may allow long-term survival of group which
increases chance of discovering sites in future
Types of location signals
• Discoverer broadcasts signal from the resource and receivers recruit to the site
• Discoverer goes to receivers (often at nest or colony), communicates discovery, and then leads receivers to site
• Discoverer goes to receivers and provides directional information about site
Ravens recruit to carcasses
Cliff swallow recruitment calls
Food signalling by osprey
Males give display to females after catching preferred fish
Rhesus macaque food calls
Chimpanzee pant-hoots
Pant-hootsadvertise discoveryof divisible foodand are given bymales
Grunts are givenfor any amountof preferred food
Mole rats recruit to roots
Food recruitment in ants
Food recruitment in honey bees:dance angle indicates direction
Dance duration indicates distance
Dance divergence indicates patch size
Advertisement distance is constrained by dance duration
Bee dialects reflect foraging distances
Azimuth encoding in bee dances
Summary of food-associated signals
Vertebrates:Food signalling is rare.Most signals occur at food (except mole-rats)
Social insects:Food signalling is common.Signals to food from hive using pheromones or“language”
Predator alarm signals
• Cause– Alert conspecifics– Deter predator
• Types– Low risk - elicit scans– Predator inspection and mobbing signals – High risk - prompts escape– Distress signals
Private alarm calls
Benefits of alarm calls
Ground squirrel alarm calls
Alarm calls do not coordinate movements
Alarm calls differ by age and sex
Alarm calls and kinship
Referential signalling
• Do alarm calls convey information about predator type or just urgency associated with potential attack?
Vervet alarm calls
Alarm calls refer to predators
Development of vervet
alarm calls
Vervet calls, relatedness and dominance
Meerkat alarm calls signal predator class and urgency
Intertrophic level signalling
• Detection notification signals
• Condition notification signals
• Aposematic signals
• Distress signals
Predator notification
displays
Aposemitism
Prey advertise tasteto predators
Initial evolution requires kin groups
Can be invaded by mimics, but mustremain at low frequencies