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Animal Behavior Film Tonight - Winged Migration

DCL 1320

Modes of communication:

Visual- color, displays, sizeAuditory- song, callsChemical- pheromones, hydrocarbons, odors Vibrational- substrate, other individuals, webs Electrical- neural, “electric fish”

Forgot one:Temperature

Heat, another sensory modalityPit Vipers

Pit Organ

What do pit vipers eat?

What temp are they most sensitive?

Are they “tuned” to their prey?

Sensory Exploitation

Sensory bias of pre-existing perceptual mechanism

Current signal (context A) exploits a sensory system that evolved in a different context (for example foraging).

One hypothesis for the evolution of ornamentation in males(more on that later).

Evidence - preference may precede evolution of a signal!

Nancy Burley - found that zebra finches prefer males with red leg bands.

Kim Hughes and colleagues found that coloration in guppies in Trinidad may have evolved through exploitation of sensory bias for colors associated with preferred food.

Color patterns also influenced by the presence/absence of visually oriented predators.

“Honest signaling”-accurately conveys information

frequency of a call constrained by body size

length of display correlated with health, stamina

Handicap Principle (Zahavi)signals are expensive to produce, can be costly, are therefore accurately convey information about quality

Geoffrey Hill and colleagues showed that house finch color determined by carotenoids gotten from diet. Better foragers = brighter red.

crickets and phonotactic parasitoidsZuk et al. 1998 Evolution Increasing duration of chirps, # of chirps,

duration of song

Sensory Tuning – when the sensory perception of an animal is most sensitive to a particular (adaptive) range of stimulus.

Ormia sp. parasitic fly and its host,a calling male cricket (Gryllus sp.)

Range of Greatest Sensitivity

Garden Variety Fly = ultrasound (>20kHz)

Cricket Call = 4 kHz

Ormia Female Fly = 4kHz and ultrasound

Ormia Male Fly = ultrasound (>20kHz)

*Female Ormia are 100X moresensitive to calling male cricketsthan are female crickets!

C. Hopkins CORNELL UNIVERSITY

Sound Localization – the “sound shadow”

“Ears” of a female OrmiaMale’s ears are much smaller

Sound Source

Relative intensity of sound in each ear conveys directional information

Moreintense

Lessintense

C. Hopkins CORNELL UNIVERSITY

Sound Localization – the “sound shadow”

“Ears” of a female OrmiaMale’s ears are much smaller

Sound Source

Relative intensity of sound in each ear conveys directional information

Equallyintense

Equallyintense

Facial asymmetries:Left ear above midpoint of eyesRight ear below midpoint of eyes

Source: Ann Cook www.owlpages.com

For many (most?) types of communication, multiple modalities are involved.

reduce errors, increase honesty (information) of signal ?

Visual and olfactory (chemical) cuesVisual and auditory cues

Often, one modality overrides the other. Other times all are necessary.

Peter Nairns, UCLA

Which is more important, visual or auditory cues in frogs?

Peter Nairns, UCLA

Novel Sound Pathways in Amphibians. Using laser doppler vibrometry (LDV), discovered that the lateral body walls over the lungs of a frog vibrate in response to sound. Sound is then transfered from the lungs to the ears through the Eustachian tubes.

Rare Chinese frogs communicate by means of ultrasonic sound

first documented case of an amphibian being able to communicate like bats, whales and dolphins, said corresponding author Albert S. Feng, a professor of molecular and integrative physiology at the University of Illinois at Urbana-Champaign.

Feng continues to study frogs and bats to understand how the brain processes sound patterns, especially in sound-cluttered environments in which filtering is required to allow for communication.

BBCUnweaving the song of whales 28 February, 2005 Molly Bentley

Using old US Navy hydrophones once employed to track submarines, Cornell University researcher Christopher Clark has collected thousands of acoustical tracks of singing blue, fin, humpback and minke whales. His bioacoustics lab is now able to pinpoint the location of individual singers, and determine the length of their song. As a result, he's had to redraw the map of whale acoustics. Dr Clark has determined that whales' songs travel over thousands of kilometres and also that increasing noise pollution in the oceans impedes the animals' ability to communicate.

CNN103 whales found dead on beachNovember 24, 2003

HOBART, Australia -- More than 100 pilot whales have been found dead on a remote beach on the west coast of Tasmania in Australia. Pilot whales are particularly prone to mass strandings. Scientists have not established a reason for the strandings but some have suggested pilot whales live in large herds and because of this may simply follow, or get caught trying to help, one or two herd members.

CNNMilitary sonar may give whalesthe bendsOctober 8, 2003

Dozens of whales, dolphins and porpoises have washed up dead on shores around the world after exposure to military sonar. Researchers writing in the journal Nature say they may have found a link.

How to get around problems with signal transmittance…

Jellyfish – Cnidaria Brittle star - EchinodermataComb Jelly - Ctenophora

Shrimp - ArthropodaSquid - Mollusca

Fish - Chordata

Green Fluorescent Protein