Animal Behavior Finals

Sensitive Periods

• Rapid change during development

• Revealed by large effects of small aberrations (inputs) during specific windows of time

• Sensitive periods can be:

  • Short or extended windows

  • Open/close gradually

  • Depend on the environment prior to and during the window

  • Variation among species

• Onset: internal and external factors

• Decline: Internal clock? or environmental feedback?

Filial Imprinting

• Imprinting with the first prominent character in the offspring’s life (parent)

• Immediate bond with the parent - stays close to the one thing that will protect and care for them

Sexual imprinting

• develop a preference for mates based on characteristics of individuals from early life (If it worked for my parents, it will work for me)

• acquisition, then consolidation

  • Initial learning phase (sensitive period), then applying that at a later time (mate choice)

Maternal imprinting

• Sensitive periods can occur in adults

• Mother forms attachment to offspring

Biological Clocks

• Persistent in constant conditions (behaviors are not dependent on the environment: “Free-running state”

• Rhythm entrained by an environmental que (synchronizes “free-running state” with the environment")

• Independent to temperature

Advantages of a biological clock

• Prepare for a change in the external environment

• Coordinate internal processes

• Synchronized with things that cannot be directly sensed

• Keeping time to adjust behavior (distance traveled)

Suprachiasmatic nucleus (SCN)

• Master clock

• Located in the hypothalamus

• Innervated by sensory cells of retina (affected by input from environment)

• Sensory cells change firing rate in response to prior light exposure

• Entrained SCN synchronizes oscillators (allows the body to be synchronized and function on the same time)

SCN gene expression

Negative feedback loop:

• BMAL1 and CLOCK proteins form a complex → nucleus

• BMAL1/CLOCK complex activates PER and CRY genes

• PER and CRY proteins leave nucleus, combine with TAU and together the complex suppresses the original BMAL1/CLOCK complex

• PER and CRY break down, allowing the BMAL1/CLOCK complex to become active

Communication

Information transferred from sender to receiver, benefitting the sender on average

Signal

communication that has evolved because it benefits the individual sending the information by altering the behavior of the receiver

Sign

Information transfer that did NOT evolve because of its benefits: Sender is not intentionally giving out this information

Sensory Channels

• Visual

• Auditory

• Chemical

• Tactile

• Electrical

Signals and space

Signals need channel space, different spaces encourage one channel over the other: sight is not useful if you cannot see, sound is not useful if environemnt to loud to hear

Frogs and waterfall: Waterfall too loud → frogs vocalize at much higher frequency only they can hear = created a new channel space

Redundant channels

Channels convey the same info

• Same Info is conveyed across multiple channels; if one channel is unavailable, it can still be received

• Utilizing extra energy to send out the same signals

Non-redundant channels

Channels convey different info

• Saves energy

• Hard to mistake signal for something else

• If that channel gets blocked → no way to send signal

Function of communication

• Mate attraction

• courtship

• pair bonding/social bonds

• alarms

• aggregation

• agonism

• species recognition

• Information about resources

Communication Origins

• Ritualization: ancestral behavior is modified to become stereotyped singal (dog moves lips so it can bite → showing teeth = aggression)

• Sensory exploitation: The Receiver possesses a bias for a particular signal, and it is exploited

  • non-sexual Survival benefit to the color red → red mates get more attention

How is communication maintained?

• Overlapping goals: Sender and receiver are trying to accomplish the same thing → parent and offspring want offspring to be fed → chirping when hungry

• Un-fake-ability: The signal that is being sent cannot be faked ie. ant’s eye stalks = body length

• Costliness: The more costly a signal is the more trustworthy it is: would not be done if cost outweighs the benefit

• Cheaters are identifiable

  • Dishonesty occurs:

    • Assessment/challenge is costly to the receiver: fighting for resources, looking bigger than you are to deter challenger (challenging in this case can lead to a fight which is costly)

    • Sender and receiver have different goals: experience different costs and benefits

    • Deceit is rare enough to be stable (happens so little you the receiver still reacts to it)

The ideal free distribution

Hoe animals should space themselves given perfect knowledge of environment and no interference

More competitors in a rich habitat is the same as less competitors in a poor habitat: what is this threshold of competitors and habitat? When resources per individual is the same

Defending territory

• Resource abundance: more resources=more likely to defend

• Resource distribution: Grouped together? easy to defend, free range (fish ball in ocean) hard to defend

• Intruder pressure: little intruders = easy to defend. Many intruders = harder to defend

Territory size decreases the richer the environment: benefit begins to level off while cost continues rising, Territory size = biggest difference in benefit from the environment and cost of defending it