Animal Behaviour

Animal behviour

Everything an animal does and why and how it does it

Behavioural ecology

How adaptive behaviours can contribute to the differential survival and reproductive success of organisms, may be simple or complex 

Te hī ika

Māori fishing, experts knew when the good fishing days were

George romanes

comparative psychology, similarity in the cognitive processes of humans and animals

Behavioural science with rigour

Animal behaviour was describable, descriptions of behaviours were found to be quantifiable, experiments were successfully repeated with consistent results

Ethogram 

Objective descriptions of behaviours

Ethology

Study of the functional significance of behaviours to evolution, behavioural traits are subject to natural selection and so influence the evolution of an animal 

Behavioural psychology and physiology 

Study of behaviours controlling behaviours, sensations, perception, learning processes, behavioural genetics 

Proximate Questions 

How the behaviour happens

Proximate questions 1-2

What environmental or internal stimulus triggers a particular behaviour and what mechanism leads to this? How does the animal experience during growth and development influence the response?

Ultimate question

Why does the behaviour occur?

Ultimate question 3-4

How does the behaviour aid survival and reproduction? What is the evolutionary history of that behaviour?

Fixed Action Patterns

Behavioural responses to well-defined stimuli, triggered by a sign stimuls or releaser, genetically-based, once started, continues to completion, adaptive

Imprinting 

Innate and learned components, includes both innate and learning components, critical or sensitive period, irreversible 

Spatial learning

Using cues in the environment to locate nest

Associative learning

Association between two stimuli, or a behaviour and stimulus, is learned

Classic conditioning 

Previously neural stimulus is repeatedly presented together with a reflex-eliciting stimuli until eventually the neutral stimulus will elicit a response on its own 

Operant conditioning

Trial and error, voluntary behaviour is either reinforced or punished which results in an altered probability that the behaviour will happen

Kinesis

A change in activity in response to a stimulus, no specific direction, not an orientated movement

Taxis 

Movement towards, positive, or away from, negative, some stimulus 

Rheotaxis

Orientation with river stream

Geotaxis 

Orientation with earth 

Phototaxis

Orientation towards light

Migration

Regular, long-distance movement or change of location, frequently involving the movement of many animals together

Why Migrate?

avoid unfavourable seasonal conditions, find water or seasonal foods, congregate to find mates and or raise young 

To navigate, animals use…

Sun and stars, scents and sounds, visual stimuli, magnetic fields

Behavioural rhythms

Circadian rhythms, 24 hrs, circannual rhythms, linked to annual cycles, circa tidal rhythms, tide cycles 

Zeitgebers 

Environmental stimuli trigger these behaviours, internal biological clocks maintain them, environmental cues fine tune and maintain these inbuilt rhythms over long periods of time 

Social behaviour

The interaction of two or more animals of the same species

Benefits of living in groups

Capture large prey, Predator detection, help raising young, locate scarce resources

Costs of living in groups

Disease, share resources, predator detection, compete for resources

Predator avoidance 

predator detection, dilution effects, vigilance, the selfish herd 

Dilution effects

chances that any one individual will be attacked decreases rapidly with increasing group size

Vigilance

May change with increasing group size, individuals spend less time scanning in a flock compared to when they are alone

Selfish herd

predators are more likely to take individuals from the edge of a group, Competition for central positions, members of group seek cover behind each other 

Group defence 

Prey animals are better able to defend themselves

Foraging benefit

Sharing information, catching difficult prey

sharing information

Colonies and roosts may act as an information centres

Foraging costs

Competition for food

Social hierarchy 

Ethogram defined, establish hierarchy by ritualised aggressive interactions, maintain hierarchy by ritualised posturing

innate responses 

Fixed action processes, reflexes, ritualized behaviours 

Learned responses

Language, cultural traditions, conditioned behaviours

How do scientists measure heritability of traits

Measure, quantify, shared traits between individual of shared genes. the more similarity the higher the estimated heritability 

r

probabiltiy that a gene in one individual is an identical copy, by descent of a gene in another individual  

On average full siblings share how many genes

50%

Domestication

Artificial selection for specific traits

Altruism 

Behaviour of an animal that benefits another at its own expense 

Reciprocal altruism

exchange of aid between individuals

Kin selection

Evolutionary effects on both parental aid given to offspring and altruism to relatives other than offspring

Alturism is more likely to evolve when…

Benefits to the recipient are great, cost to the act is low, participants are closely related

Hamiltons rule 

rB-C>0, b is benefits, c is costs, r is coefficient of relatedness 

Where altruism occurs… 

it is likely to be between closely related individuals 

Hymenoptera

Insect order, females develop from fertilized diploid, males from haploid unfertilized eggs, females workers are reproductively sterile, males do not engage in colony tasks

Defining eusociality

Overlap of generations, reproductive division of labour, cooperative brood care

r for haplodiploid species sisters

Full sisters share 75% of genes, sisters share 25% of genes with brothers

r for haplodiploid species brothers

Brothers share 50% of genes with sister, brothers share 50% of genes

Certainity of paternity 

As certainty of paternity increases ao does probability to engage in parental care

Sexual selection

When individuals of one sex gain an advantage over other individuals in obtaining mates

Intra sexual selection

competition with one sex for access to members of the opposite sex

Intersexual selection 

Choice by individuals of one sex for particular members of the opposite sex 

Female reproductive sucess

Frequency of copulation beyond the first does not effect reproductive success, greater consistency of success 

Male reproductive success 

directly proportional to their frequency of copulation, greater variation in success 

Female parental investment 

Egg is expensive so cost limits number made, most variation in reproductive success is a function of variation in female condition

Male parental investment

One male could fertilize may females, sperm are relatively inexpensive

Parental investment theory

Investment by parent in a individual offspring that increases the offsprings chnaces of surving at the cost of the parents ability to invest in other offspring

Polygyny

Single male, many females 

Polyandry

A single female with many males

Monogamy

1 male and 1 female

Polygyny advantages 

allows fit males to maximise reproductive success, females only mate with fittest males 

Polygyny disadvantages

huge variation in male reproductive success, lots of energy used defending resources

Polyandry Benefits

gain gifts, enlist several males to help raise young, fertility insurance

Polyandry disadvantages

Males may provide less nest defence, higher risk of disease and parasitism

monogamy advantages 

less time finding mate, both parents raise young 

monogamy disadvantages

if one of the pair is deserted redproductive output is reduces and more time is spent finding a new partner

Inprinting related to mate preference

Parental appearance affects mate preference in offspring, independent of genetic influence

Female choice in mate

Selection for ability to detect parasite load

Mate choice male strategies

Mate competition, variation in mating strategies 

Communication involves a 

Sender and receiver 

Process of communication

sender produces signal, signal is transmitted and is detected by receiver, receiver makes a decision about how to responds

The recievers response in communication …

Affects the fitness of the sender as well as its own, in true communication they both benefit

Channals of communication

Chemical, electrical, vibratory, acoustic, visual

Signals are conatrained by…

The environment, the physiological capabilities of the sender and receiver 

Visual communication properties

Medium distance, fast rate of change, poor around obstacles, high locatability, low energy cost, no night use, persistence transient

Chemical communication properties

Long distance, slow rate of change, good around obstacles, variable locatability, low energy cost, yes night use, persistence long

Acoustic communication properties

long distance, fast rate of change, good around obstacles, medium locatability, high energy cost, yes night use, persistence transient

Visual signals are characterised by

colour, brightness, intensity, spatial characteristics

Limitations of visual communication

Only useful with sufficient ambient light, only useful in a straight line

Semiochemical

Specific chemical signals

Pheremones

intra-specific

allomones 

interspecific chemical communication, allomones are emitters, kairomones are receptors 

Acoustic communication species specific receptors

vertebrate have the inner ear, arthropods vary, legs, thorax, abdomen