Animal Behavior ch11-12

Omnivores

unspecialized diet and digestive tract. can process plant and animal matter

• often are opportunistic, general feeders, which depend on a suitable mix of animal and plant food for long-term good health and reproduction

ex: humans, bears, pigs

suspension feeding

filter feeding - removal of small food particles that are suspended in the water

ex: Baleen whales, vampire squid, flamingos, clams/oysters

herbivores

diets are based on plant matter

• include frugivores, folivores, nectarivores, granivores, gramivores, palynivores, mucivores, and xylophages

Frugivores

feed on fruits ex: bats

folivores

feed on leaves ex: red panda

nectarivores

feed on nectar ex: humminbirds

granivores

feed on seeds

gramivores

feed on grass

palynivores

feed on pollen ex: bees

mucivores

feed on plant fluids (sap)

xylophages

feed on wood ex: ants

carnivores

animals whose diets are based on animal matter

aggressive mimicry

predator will mimic a signal that will either attract the prey or allow the predator to be ignored by the prey

Caudal Luring

Australian Viper snake uses tip of tail to lure lizards

Sensory Specializations

using various senses to detect prey

• mechanoreceptors - detect vibrations

• touch

• smell

• vision

• sound

• electricity

Which animals use mechanoreceptors to find prey?

some desert scorpions

which animals use touch to find prey?

star nosed mole

which animals use olfaction to find prey?

polar bears

which animals use vision to find prey?

hawks & eagles

which animals use sound to find prey?

owls

which animals use electricity to find prey?

lungfish & platypus

Foraging theory

branch of behavioral ecology that studies the foraging behavior of animals in response to the environment where the animals lives

• measured in calories gained

optimal foraging theory

idea in ecology that states organisms forage in such a way as to maximize their net energy intake per time

E/h

E - amount the energy (calories)

h - handling time; capture, killing, eating, and digesting

Optimal Diet Model

analyzes the behavior of a forager that encounters different types of prey and must choose which to attack

• goal is to identify the choice that will maximize fitness

Patch selection model

describes the behavior of a forager whose food is concentrated in small areas known as patches with a significant travel time between them

• seeks to determine how much time an individual will spend on one patch before deciding to move to the next patch

Central Place foraging theory

describes the behavior of a forager that must return to a particular place to consume food, or perhaps to hoard food or feed it to a conspecific

foraging innovation

animals using new foraging technique

• considered learning

Group foraging Pros

1. capture large and difficult prey

2. reduce danger of predation

Group foraging Cons

scramble & interference competition

Scramble Competition

each individual strives to get a portion of the shared resources

interference competition

presence of competitors prevents a foragers accessibility to resources

Crypsis

blending in with the background. involves disruptive coloration, countershading, transparency, etc.

Masquerade

whole animals looks like some other object. can be used to hide from predators or lure prey

polymorphism

occurs when two or more clearly different phenotypes exist in the same population of a species

Which animal is an example of Transparency in crypsis?

Glasswinged butterfly

decoration behavior

actively seek to make themselves cryptic by using materials from their environment, such as twigs, sand, or pieces of shell to conceal their outlines.

ex: Caddis fly and Decorator crab

countershading

involves pigments that are typically darkest on top, lightest below, making the counter shaded animal nearly invisible against a matching background.

chromatophores

cells that allow animals to rapidly change color and pattern

ex: seasonal coat color change; chameleons

counter illumination

producing light to match a background that is brighter than an animal’s body

ex: bioluminescence

motion camouflage

dynamic type of camouflage by which an object can approach a target while appearing to remain stationary from the perspective of the target.

ex: hoverflies and dragonflies

disruptive coloration

coloration designated to prevent the perception of an animal’s form.

uses strongly contrasting markings such as spots or stripes to break up an animal's outlines

dazzle pattern

disruptive coloration that actually works better when the animal is in motion. may cause confusion is a predator especially when the animals are in a group.

Aposematism

a warning signal is associated with the unprofitability of a prey item to potential predators. primarily visual and involve bright and contrasting colors

ex: skunks coloration, poison frogs

Mullerian Mimicry

form of mimicry when two or more poisonous species, that may or may not be closely related and share one or more common predators, have come to mimic each other's warning signals

• both species are poisonous

Batesian Mimicry

form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a common predator.

• harmful model organism and harmless mimic organism

Autotomy

act where an animal loses one or more of its own body parts usually as a self-defense mechanism designed to elude a predator's grasp

false heads

strategy of making a less vulnerable portion of the body look like its head. designed to fool primarily visual predators that focus their attack on the head.

mobbing behavior

occurs when members of a species drive away their predator by cooperatively attacking or harassing it.

dilution effect

phenomenon where individuals living in groups are safer from predators because the predator has more targets to choose from.

predator satiation

an antipredator adaptation in which prey occur at high population densities, reducing the probability of an individual organism being eaten.

Selfish Herd mechanism

considers the spatial arrangement of individuals within the group. In most groups centrally located animals are safer than would those be at the periphery. Idea is that animals do what they can to place themselves in greatest safety

confusion effect

technique in which a predator would be less successful targeting and capturing one prey item in a group. They are unable to single out and attack an individua