PSY 2364 Animal Communication Extra credit …assmann/PSY2364/ancom_lec...10/14/2019 1 PSY 2364...

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PSY 2364Animal Communication

Luna Moth (Actias luna)

Extra credit assignment

• Extra credit assignment (up to 5%). Optional extra credit assignment on a topic of your choice (topic must be cleared with instructor).

• Submit proposed extra credit topic (one paragraph) via eLearning by Monday Oct 14.

• Report due on the same day as the final exam (Dec 11).

Extra credit proposal

• Title

• Project topic – research problem addressed

• References – cite relevant source(s)– Literature search

• https://www.ncbi.nlm.nih.gov/pubmed/

– Integrative approach

Chemical communication

• Pheromones - chemicals that operate

externally to facilitate communication with

other members of the same animal species

(conspecifics).

Functions of pheromones

1. Territory defense2. Aggregation3. Alert others to food sources4. Alert others of danger5. Sexual attraction6. Parent-offspring bonds7. Dominance status

Human pheromones?

• Electrical activity in VNO tissue in response to chemical stimulation

Vomeronasal organ

Vomeronasal nerves

Hippocampus

Olfactory nerves

Olfactory tract

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Human pheromones?

• Chemicals found in sweat and other human secretions appear to affect mood

• Infants appear to distinguish breast pads worn by their mothers from other mothers

• Menstrual “synchrony” seen in women who live or work together

Pheromones and immune system

• Major Histocompatibility Complex (MHC)

• Mice (even highly inbred mice) tend to

choose mates that differ from them in terms

of the MHC.

• Animals probably detect information about MHC through odors or odor-pheromone mixture

Sex pheromone mimicry

• “Sex pheromone mimic lures two moths to their doom” (Science, 24 June 2002)

• Bolas spiders – do not build webs, but sling a single strand of silk across a gap and a second strand with a sticky end.

• Chemicals are released that mimic the sex pheromones of female moths. When a male moth approaches the spider uses its silk line as a lasso.

Chemical communication

Comparison with acoustical and visual signals

• Directionality

• Speed

• Temporal pattern

• Spectrum

Short‐necked oil beetle

• Last seen in 1948; rediscovered this year in Devon, England

• Produces highly toxic oil secretion when threatened

• Adults live for three months, lay up to 1000 eggs that hatch the following spring

http://news.bbc.co.uk/2/hi/uk_news/england/devon/6464531.stm

Short‐necked oil beetle

• After hatching, the larvae crawl onto vegetation (often flowers) where they wait to hitch a ride on a mining bee.

• The bee returns to its nest with the hitchhiker.

• There the larvae devour the bee's eggs and its protein rich pollen stores.

http://news.bbc.co.uk/2/hi/uk_news/england/devon/6464531.stm

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Lancet liver fluke (Dicrocoelium dendriticum)

• The lancet liver fluke is a parasite that spends its adult stage in the liver of a host animal, usually a sheep or goat.

• Their eggs are deposited in the host’s feces.

http://www.weichtiere.at/Mollusks/Schnecken/parasitismus/dicrocoelium.html


• Snails eat the feces and are infected with the larval parasites. The larvae drill through the wall of the snail's gut and settle in its digestive tract.


• Eventually the snail excretes the parasite in a ball of slime, which it leaves in the grass. Ants eat the slime ball, loaded with juvenile lancet flukes. (It is believed that the mucus contains pheromones that makes it highly attractive to ants).


• The parasites settle in a cluster of nerve cells under the ant’s esophagus. Somehow they manipulate the nervous system of the ant, and this produces complex changes in its behavior.


• The infested ant finds itself compelled to climb to the top of a stem of grass every evening until eventually a grazing animal comes along and eats the blade of grass with the ant attached, and the cycle is repeated.

Tactile communication

• Limited to close range communication

• Functions:– Courtship

– Pair bonding

– Parent-young interactions

– Play

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Tactile communication

• Chacma baboons spend a significant amount of time in “social grooming.”– Cleans fur, removing parasites– Reinforces social bonds between animals– Releases endorphins, lowers stress hormones

Grooming in primates

• Grooming keeps fur clean of dirt, dead skin, and parasites

• Social grooming serves as a tactile signal to maintain and strengthen social bonds and resolve conflicts

Whirligig beetles (family Gyrinidae)

• Named for their habit of swimming rapidly in circles when alarmed

• Aggregation (rafting) • Territorial behavior (same-sex

competition)• Tactile cues generated by ripples

on water surface allow whirligig beetles to monitor and repel rivals

Treehoppers (family Membracidae)

• Vibrations produced in the plant tissues are felt by other treehoppers and function as an alarm signal or promote aggregation

Tactile Communication

• Advantages– Instantaneous transmission

and reception

– Individual recipient

– Effective in darkness

Tactile Communication

• Disadvantages– Limited to immediate vicinity of recipient

– Organisms must stay in direct contact

– Only one receiver at a time

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Weak electric fields• Duck-billed platypus (Ornithorhynchus

anatinus)

Lateral line organ

• Lateral line organ – mechanoreceptors – sense of touch

• Ampullary lateral line organ– electroreceptors – electrical sensitivity

THE BIG PICTURE

http://news.bbc.co.uk/nol/shared/spl/hi/pop_ups/07/sci_nat_enl_1187693729/img/1.jpg

\

http://news.bbc.co.uk/nol/shared/spl/hi/pop_ups/07/sci_nat_enl_1187693729/img/1.jpg

http://www.youtube.com/watch?v=iNRHy‐XCh1E

Lateral line organ Electric organs and electroreceptors

• African electric fish (family Mormyridae) produce complex electric signals using a specialized electric organ in the slender part of their tails. They also have specialized electroreceptors on their skin to pick up electrical signals.

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Electric organs and electroreceptors

• Electrical signals are used for object recognition, species recognition, sex identification, territorial behavior, advertisement of status or reproductive condition, and possibly in group hunting (prey probing and size estimation).

Weakly electric fish

Glass knife fish, Eigenmannia virescens

Weakly electric fish

• Electrical organ discharge (EOD)

• “jamming avoidance response”

• EOD range of up to 1 meter

Signal Properties Chemical Acoustical Visual Tactile

Range Long Long Medium Very short

Transmission rate Slow Fast Fast Fast

Flow around barrier Yes Yes No No

Night use Yes Yes No Yes

Fadeout time Slow Fast Fast Fast

Locatability of sender Difficult Fairly easy Easy Easy

Cost to sender (energy expense)

Low High Low to moderate

Low










Low










Low

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Low










Low










Low










Low










Low

• Natural & Sexual Selection– https://youtu.be/RxHdzw7E0wU

• Female Choice and the Birds-of-Paradise– http://www.birdsofparadiseproject.org/content.php?page=112

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Midterm exam

• Look over the exam carefully

• Mandatory: return the exam when finished

• Extra credit point when the exam is returned

• Posted letter grades include exam + quizzes

Midterm exam grades

Mean=77.5%STD=12.8%

PSY 2364 Animal Communication Extra credit …assmann/PSY2364/ancom_lec...10/14/2019 1 PSY 2364...

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