Predator-Prey Mechanisms

Richard G. Coss

ANB 218B

Winter 2010

Levels of Organization

Steven Pepper’s Mechanism Construct

Heterochrony

Neotenous properties of the human face

Perceptual Aspects of Predator Recognition

• Developmental and neurobiological aspects of eyespot recognition by African jewel fish

• Genetic and experiential effects of eyespot recognition by paradise fish

• Crab predator recognition by climbing crabs• Development of ground squirrel recognition of

snake predators

Innate Eyespot Recognition by Jewel Fish

Eyespot Models

Jewel Fish Fry Pre-flight Position

Jewel Fish Fry Fleeing Eyespot Model

Generalization gradient of eyespot number

Juvenile Jewel Fish Model Presentation

Juvenile Jewel Fish Flight Distance Measure

Generalization gradient of eyespot number

Test of eyespot pattern orientation

Generalization gradient of eyespot orientation

Deprivation rearing of African jewel fish

Jewel fish inspecting blind cave fish

Jewel fish view of blind cave fish

Generalization gradients of rearing conditions

Neuroanatomical correlates of eyespot recognition by African jewel fish and ground squirrel antisnake behavior

• At 13 post-spawning days of age when fry first employ visually guided behavior to feed and recognize eyespots as dangerous, they also exhibit recognizable neurons in the optic tectum developmentally similar to those of adults.

• Developmental deprivation of jewel fish fry to when they are adults affects neuron development within the optic tectum and the retention of juvenile reactivity to eyespot patterns.

• Discussion of rat brain development when pups begin to see is relevant to understanding precocious snake predator recognition by ground squirrels pups.

Optic tectum development

Neurological effects of isolation rearing

Experimental study of eyespot pattern recognition by Asian paradise fish

Miklosi et al. 1997 Behavior Genetics

• Comparison of two larval strains in eyespot pattern recognition

• Comparison of two genetic strains that differ in eyespot pattern recognition

• Role of father in aiding the development of eyespot pattern recognition

Eyespot recognition by paradise fish

Miklosi et al. 1997 Behavior Genetics

Larva (10 mm long) tested at 20 days of age

Eyespot recognition by paradise fish

Genetic differences in eyespot recognition

Fathered group of paradise fish

Father fans egg mass for 5 post-spawning days.Larva in this group are tested at 20 days of age.

Role of egg-mass fanning by father

Perceptual aspects of crab predator recognition by climbing crabs

Cannicci et al. 2002 Anim. Beh.

Predator Models

1) Preserved crab Epixanthus dentatus in its typical ambush posture

2) Colored piece of wood with real E. dentatus claws attached to it

3) Colored piece of wood without claws

Predator crab recognition by climbing crab

Brachyuran predator

Cannicci et al. 2002 Anim. Beh.

Mangrove tree test bridge

Descending crab prey

Crab model

Responses of climbing crabs to models

Precocious development of snake predator recognition by California ground squirrels

Coss 1991 Ecol. Psych.

• Developmental onset of snake recognition in pre-emergent ground squirrel pups at 40-41 days of age.

• Precocious snake recognition is a by-product of high gene expression during the time of eye opening in pups.

• Gopher snake perceptual feature recognition. • Recognition of burrows as sit and wait snake ambush sites

after interactions with snakes in the field and lab.• Role of alarm calling in promoting snake recognition in

developmentally deprived ground squirrel adults.

Northern Pacific rattlesnake

Ground squirrel harassing rattlesnake

Pup recognizes rattlesnake immediately as it emerges the first time from its natal burrow

Pup confronts rattlesnake in artificial burrow

Pre-emergent ground squirrel pup recognizes gopher snake as dangerous the first day its uses vision at 40 days of age.

41 day-old pup cautiously investigates a textured strip resembling gopher snake scale markings the first day it uses vision.

Developmental changes in ground squirrel pup responsiveness to caged gopher snake and textured strip between 41 and

46 days of age.

Rat brain development when pups first see as an analog for ground squirrel neural development with the onset of vision

Effects of developmental deprivation in rats

Greenough et al.1972 Science

Cognitive Topography

Coss & Owings 1985

Coss & Goldthwaite 1995

• Ground squirrels appear to recognize what microhabitat features predators might use for sit and wait ambushing.

• Ground squirrels are deprived for 3 years after weaning for experimental study of alarm call recognition.

• Lab-born ground squirrels innately associate dark burrow entrances with snakes that use them for ambushing and thermoregulation.

Rock squirrel from New Mexico cautiously investigates a burrow entrance after a rattlesnake encounter

Historical risk of encountering rattlesnakes in shady areas

Historical risks of encountering rattlesnakes in burrow entrances

Rattlesnake resting in burrow entrance

Lab-born juvenile throws substrate into the dark entrance of its transfer box after encountering a caged gopher snake

Historical risks of avian and mammalian predatorsbased on distance from refuge

Effects of alarm call playbacks on surveillance during burrow exiting

Ground squirrels pausing during nestbox exciting to look upward and horizontally

Average duration of looking and sniffing after nestbox exiting following sound treatments

Lab-born ground squirrels shows concern for possible snake in nestbox following alarm call playbacks