Plant and Animal responses internal instructions including inter - - PDF document

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Plant and Animal responses

AS 3.4 Animal Behaviour and Plant Responses

How, when and why plants and animals respond to external stimuli and internal instructions including inter and intraspecific relationships in

• rder to ensure successful survival

and reproduction.

Thinking hats on….

Can you think of a stimulus and its corresponding behavioural response for an animal and a plant? Can you give the main difference between how animals and plants deal with a stimulus?

What is a habitat?

An organism’s habitat is the physical place in which it lives.

Lichens are found on rocks, trees, and bare ground. Most frogs, like this leopard frog, live in or near fresh water, but a few can survive in arid habitats.

What does a habitat provide?

The habitat provides

• rganisms with the

following resources: Food and water sources Mating sites Nesting sites Shelter

Whereas the habitat does not change, the environment does. The environment is everything that affects an organism eg biotic and abiotic factors.

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Abiotic (physical) Factors

The abiotic factors influence the habitat in which an organism

• lives. These include:

humidity sunlight temperature salinity pH (acidity) exposure altitude Depth

Each abiotic (or physical) factor may be well suited to the

• rganism or it may present it with problems to overcome.

Biotic (living) Factors

The biotic factors influence the habitat in which an organism lives. These include:

Food supply predator prey parasites Competition

Quick quiz

1) How can a tree be both a biotic and abiotic factor? Food source and shelter. Resources are factors that are competed for whereas conditions are factors that influence

• rganisms without being used up.

2) Can you identify a factor that is both a resource and a condition? Light.

Law of Tolerance

The law of tolerancestates that “For each abiotic factor, an organism has a range of toleranceswithin which it can survive.”

Examples of abiotic factors that influence size of the realized niche: Tolerance range Optimum range Unavailable niche Marginal niche Number of organisms Preferred niche Marginal niche Unavailable niche

Ecological Niche

The ecological niche describes the position of an

• rganism in its environment.

A niche comprises:

the habitat in which the organism lives. the organism’s activity pattern: the periods of time during which it is active. the resources it obtains from the habitat.

Adaptations Physical conditions Activity patterns Presence of other

• rganisms

Habitat

What could cause the difference between the fundamental and realised niche?

The fundamental niche of an

• rganism is described by the

full range of environmental conditions (biological and physical) under which the

• rganism can exist.

The realised niche of the

• rganism is the niche that is

actually occupied. It is narrower than the fundamental niche.

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Gause’s Principle

“No two species can occupy the same ecological niche in the same place at the same time. One species will either die, shift away (emigrate) or change its niche.”

In the zone of overlap, interspecific competition is the most intense.

Zone of overlap Species B Resource use as measured by food item size Amount eaten Species A

Liebig’s Law of the Minimum

“The essential environmental factor present in the least amount will limit the functioning of the organism.”

• Ex. North Island farms lacked cobalt in the

1930s.

14

Immediate Orientation in Animals

Behaviours come in two categories Learned Innate

Imprinting: normally

and not so normally

A learned response: behaviour soon after birth is triggered by something and then doesn’t change

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Behaviours come in two categories Learned

• Advantage: learned behaviours

give animals more adaptability to the environment

• Imprinting: means young

recognise their parent and their species

Innate Other learned behaviours

• Habituation: learning that a stimulus is of no

importance (eg stock by a road) prevents an

• rganism being in a constant state of alarm
• Conditioning eg learning to do things without

“thinking” about it eg walk

• Trial and error: learning what is useful eg food

sites, water holes, nest building materials, cat and hot stove.

Behaviours come in two categories Learned

• Advantage: learned behaviours

give animals more adaptability to the environment

• Imprinting: means young

recognise their parent and their species Eg: Imprinting, Habituation, Conditioning, Trial and Error

Innate Behaviours come in two categories Learned

• Advantage: learned behaviours

give animals more adaptability to the environment

• Imprinting: means young

recognise their parent and their species

• Usually involves vertebrates

Eg: Imprinting, Habituation, Conditioning, Trial and Error

Innate

• Inherited
• Automatic responses to a stimuli
• Much of invertebrate behaviour

is innate

Stimulus: The red belly of the invading male. Innate behaviour: Sticklebacks attacked nonfish-like models with red on the ventral surface.

Innate behaviour

Example: Parent/young feeding behaviour in birds. Sign stimulus: Parent landing at the nest, colour of beak. Innate behaviour: The begging behaviour of newly hatched chicks (raised heads, open mouths, and loud cheeps).

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Instinctive behaviour

• A series of innate responses co-ordinated to achieve a certain result

eg making a nest

• Often one action is the releaser for the next
• Same in the whole species (may be sex differences)
• Often if the sequence is broken, have to start again = “non thinking”

process

Behaviours – big picture/ recap

• https://www.youtube.com/watch?v=6hREwakXmAo

Taxes

A taxis is a movement of an organism towards

• r away from a stimulus.

They are named according to the kind of stimulus and the direction of the response. How are stimuli detected by animals? What are the main effectors of a response?

What’s the taxis?

Negative phototaxis Cockroach scuttles away from light

• Woodlice show a negative phototaxis.
• This would will result in them moving away from bright conditions

towards darker regions. Brighter conditions tend to be drier and warmer than dark conditions so this behaviour will again result in decreased desiccation.

What’s the taxis?

Clam digs towards gravity Positive gravitaxis/ geotaxis

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What’s the taxis?

Land snail moves upwards when disturbed Negative gravitaxis/ geotaxis

What’s the taxis?

Mayfly nymph swims against a water current Positive rheotaxis

What’s the taxis?

Mosquito attracted to heat Positive thermotaxis

What’s the taxis?

Male silk moth attracted by pheromones Positive chemotaxis

What’s the taxis?

Moth flies towards light Positive phototaxis

phototaxis

Euglena and moths are positively phototactic

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Thigmotaxis – movement in response to touch. Hydrotaxis – movement in response to water. Klinotaxis – side-to-side movement in response to stimulus (blowfly larvae) Tropotaxis – straight line movement in response to stimulus due to pairs of sensory organs on either side of organism.

Kinesis

• A kinesis is non-directed orientation – moves, but not towards or

away from a stimulus.

• The amount of movement is related to the intensity of the stimulus

Orthokinesis

Intensity of stimulus determines the speed of movement. e.g. slaters move slower in damper air.

Klinokinesis

Intensity of stimulus determines the frequency of turning. e.g. flatworms turn more often in light making more likely they will turn back into the dark.

Klinokinesis is a change in the rate of turning

• Slaters show both an increased speed of movement

and increased rate of turning in dry conditions and slower rates of movement in more humid conditions.

• This response will result in them accumulating in

more humid regions and so will not lose water from their bodies.

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• What is the stimulus with thigmokinesis and what would you

expect to see?

• Stimulus is touch.
• Increased touch would mean more/less movement.
• Slaters show a positive thigmokinesis. This means

they are less active when more of their body surface is in contact with other objects (including other woodlice). They will move around so that the maximum amount of their body is in contact with

• ther objects.
• This behaviour results in woodlice forming groups or

clumps and also means they will tend to congregate in cracks and crevices. In all these cases they will have better protection from desiccation and also predators.

Starter

• Recap Taxes and Kineses
• Workbook pg 50-53

This weeks workbook pages

• Timing responses – pg 43-49
• Due Monday
• And: remember to keep an eye on the blog page for the glossary

words (will go up every lesson or 2).

Animal Behaviour - Timing

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Animal Behaviour – Timing http://www.britannica .com/science/biological

• rhythm

Many animals show daily or seasonal rhythms in activity

• Daily (diurnal, nocturnal or crepuscular)
• Tidal
• Lunar
• Annual (hibernation, migration)

Rhythms may be behavioral (eg active or asleep) or physiological (eg changes in body temperature). Diurnal, nocturnal or crepuscular?

Tidal Rhythm Vs.

Why do tides affect animal behaviour? Link to their survival.

Semilunar Rhythm

Why do tides affect animal behaviour? Link to their survival.

Lunar Rhythm

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Length Rhythm Free running rhythm example 12.4 hours tidal Circatidal crab activity

• n shoreline

14.8 days semilunar Circasemi- lunar Marine reproduction 29 days lunar Circalunar marine reproduction 365 days annual Circannual rutting in deer 24 hours daily Circadian sleep-wake cycle.

The Environmental Cues

The Earth's Spin. results in the solar day (approximately 24 hours). This is responsible for the light-dark cycle. Result - many organisms are active in the day or at night. Orbit of the Earth around the Sun. Results in the year. Earth’s elliptical orbit and its tilted axis causes the seasons as the Earth tilts towards and away from the sun. Result - seasons dictate when animals can breed and when some must enter hibernation or migrate. Orbit of the Moon around the Earth. This generates the lunar month (24.53 days) and the lunar day (24.8 hours). Result - many organisms have rhythms that correspond to these periods. The gravitational pull of the moon also causes the tides : generally 2 tides per lunar day i.e. every 12.4 hours. Result - these can govern when tidal zone organisms can feed. The combined effects of the sun and moons pull causes neap and spring tides which occur every 14.79 days. Result - for some marine organisms these may control when they reproduce.

• Organisms must be able to sense these rhythmic changes so

that their behaviour is synchronised with it

• Is the cause of the synchronising internal or external?

Synchronisation may be:

• Exogenous: rhythm is controlled by an external

environmental stimuli. Removing the stimulus removes the rhythm.

e.g. a barnacle's cilia will beat whenever the tide is in.

• Endogenous: rhythm is controlled by an internal

biological clock.

• A combination of both exogenous and endogenous

factors.

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How do we know if there is a biological clock?

It maintains a rhythm even when conditions are constant eg always dark, or always light, or constantly covered in water (tidal clocks). Therefore the rhythmic behaviour must be driven from within the organism ie must be endogenous.

It maintains a rhythm even when conditions are constant ie always dark

• However, without an external cue, and in

constant conditions, the timing of this free running endogenous rhythm gets slowly out

• f synchronisation.
• This is because the period of the free

running endogenous rhythm has a frequency that is not exactly the same as if the external cue is present.

• A free running rhythm has no external cues

and is under constant conditions.

• This cannot continue indefinitely and

endogenous rhythms will eventually cease.

Human Activity Actogram

When free running Zeitgebers could be:

• Circannual:
• Circamonthly:
• Circadian:

_____ or ______ or _______.

• Circatidal:

tidal flow, position of moon and earths rotation.

• Circasemilunar:
• highest and lowest tides.

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Daily physiological rhythms

If the rhythm continues in the absence of external zeitgebers it is called a Biological clock.

Define the following terms…

• Environmental cue
• Endogenous rhythm
• Free running rhythm
• Exogenous rhythm

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Since free running endogenous rhythms are not exactly synchronous with those of the environment there must be constant resetting or entrainment of the biological clock by an external cue known as the

• zeitgeber. The zeitgeber is usually dawn, dusk or

water turbulence. Essential for adjusting to seasonal changes and migration. The shift in activity in response to a zeitgeber, is known as a phase shift . Entrainment is the process of shifting the rhythm. We suffer jet lag until this phase shift

• ccurs.

Biological clocks:

• Control daily rhythms of the body: eg sleep, pulse, blood

pressure, temperature, blood cell count, alertness,

• Prepare for migration: eg eating a lot
• Prepare for winter: eg storing food,
• Development of winter coat, hibernating.
• Enable solar or stellar navigation.

Biological Clocks in Humans

It is believed that the biological clock in humans is located in the Hypothalamus (the part of the brain that regulates the basic drives such as hunger, thirst and sexual desire.)

How?

• The hypothalamus area of the brain and its pineal gland can

sense light in animals

• This secretes melatonin, a hormone which regulates sleep-

wake cycles, fluctuations in body temperature, heart rate and blood pressure.

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Advantages of biological clocks

• They prepare a plant or organism for an event –

daily, or seasonal or tidal eg hibernation, feeding, migration

• Eg time reproduction: eg animals come on heat

about the same time, carry out courtship rituals, release eggs or sperms.

• Clocks register local time which may be important if

there is a certain time when it is best to feed or best to hide. actograms

Human Activity Actogram

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Fiddler crabs live on estuary mudflats. The actogram below shows the activity pattern of a fiddler crab in normal environmental conditions.

Describe how many periods the crab has in a 24-hour period. 2 Explain why the crab’s activity starts later each day.

• Tides. The period between tides is slightly over 12 hours (12.4)/

tide gets later each day. (NO reference to biological clock – this negates answer

Another fiddler crab was placed under constant environmental conditions in the laboratory. The activity pattern is shown. Explain what these results suggest about the control of the activity pattern in this crab.

The results suggest that the activity is controlled by a biological clock (endogenously). Because the periods are later each day under constant conditions.

Calculate the period of the rhythm under constant environmental conditions in the laboratory.

12.5 – 14 hours

Explain the type of biological rhythm exhibited by the fiddler crabs.

Circatidal because it occurs once every 12 hours

• The activity of many organisms is controlled by an internal

biological clock. Describe one benefit an internal biological clock provides an individual, compared with relying on external environmental cues

• An animal can anticipate or predict correct time for a specified

activity eg feeding, sleeping, migrating if environmental cues are

• bscured or not available

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Practice questions

The chart below shows the activity of a weta kept in a laboratory at 20OC. From day 1 to 11 the weta was exposed to 12 hours light followed by 12 hours dark.

From day 12 it was kept in constant dark.

Free running period

• The time between repeats of behaviour in CONSTANT

conditions

• In this case the behaviour starts later and later every

“day” so it must be slightly longer than 24 hours

Daily rhythm = circadian rhythm

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Expla plain the he acti tivity ty patte tern rn show hown n by the he weta over the 30 days

• It was regularly active during periods of light during the first 12 days
• But it started progressively later when in constant conditions

BECAUSE although it has a biological clock that keeps the rhythm, there is no zeitgeber to keep it in time. The endogenous free running period is slightly longer than 24 hours which is why it started activity later each day.

Endogenous or exogenous

• Endogenous because the rhythmic behaviour continued after being

put in constant conditions

• This actogram was incorrectly labelled. (You knew that weta is

nocturnal)

• This is how it should have looked

Light phase Light phase

Day 1

Light phase

Day 2

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Light phase

Day 2 again

Light phase

Day 3

Light phase

Day 3 again This makes for easier comparisons

coc cockroaches

The diagram above records the spontaneous activity of two species of cockroaches over several days. The dark phase is shaded. (a) Compare and nd con

• ntr

trast t the he beha haviou

• ur

r of the he two

• species.

How are they the same? How are they different?

A B

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(c) Discuss what you would observe if C. subcorticaria had a biological clock and C. undulivitta did not. If C. sub had a biological clock I would observe that its behaviour in the constant conditions would . . . . . . . . … because _ _ _ _. However the rhythm _ _ _ _ _ ___ If C. und did not have a biological clock I would observe that its behaviour in the constant conditions would _ _ _ __ _ __ __. This is because _ _ _ __

Animal behaviour

Great migrations: https://www.youtube.com/wa tch?v=kHGRtPYj0D0 Canada Geese - http://video.nationalgeograp hic.com/video/goose_canada ?source=relatedvideo Godwits - http://sciencelearn.org.nz/Co ntexts/Flight/Sci- Media/Video/Godwits-in- flight

Recap: Explain how you could find out if rhythmic behavior was driven endogenously or exogenously. Endogenous means ……. Exogenous means ……. I would put them in ___________ conditions. If the rhythmic behaviour continued it is driven ________________ which means it has a ___________ _________

As the plains dry up, wildebeest (gnu) move north and west, to more permanent water and grazing, and return as rain returns to the south.

Migration

Migration is the seasonal movement from one location to another It is active, predictable, preemptive, long distance and towards breeding/feeding sites.

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Humpback Whale

Most shining cuckoos over-winter in the Solomon Islands and near Papua New Guinea, returning to New Zealand in September.

light blue: breeding yellow: going north

• range: wintering grounds and going south

Longest Animal Migration Measured: Flies 64000 km a year

Sooty Shearwaters

Migration tracks of Bar-tailed Godwits determined using satellite telemetry.

southbound heading north

Wrybill Plover August to February Breed in river beds February to August In tidal areas and estuaries in NI

Why migrate?

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Advantages of Migration

• food
• energy
• size
• offspring
• variation
• predation
• colonisation
• plenty of food (away during

winter)

• less energy required to keep

warm

• those that migrate grow larger
• produce more offspring
• more genetic mixing
• reduces predation
• May lead to new colonisation

Disadvantages of Migration

• get lost
• eaten
• starve
• use too much energy and become exhausted
• can bring back new parasites or pests

Why would diurnal birds be nocturnal migrants?

• safer from predators
• more time during day freed up for foraging
• reduced threat of over heating/ dehydration
• wind direction is more stable at night
• Migrating birds are important

ecologically as a food source for

• ther animals.
• They also transport plankton,

seeds etc, parasites such as ticks and lice, which can carry micro-

• rganisms harmful to human

health.

What instigates migration?

• maturation – salmon, eels
• day length getting shorter is the most common – sensed

through skin by pineal gland in birds

• cooler temperatures
• can be innate

Navigation

Moving a particular course toward a specific destination This requires a

• map sense (aware of latitude/longitude)
• sense of timing (internal clock)

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Methods of Navigation

• visual (landmarks, solar, light, stellar)
• magnetic fields (homing pigeons)
• chemicals (salmon)
• sound (bats)

Visual – Using landmarks

Some organisms use landmarks.

Must be able to sense TIME of day too and adjust course accordingly

Visual – Solar Navigation – the position of the Sun

NB: diagram is for N hemisphere where sun is to the south Desert ants use the position of the sun for short distances

Some use a sun compass to orient themselves.

Why must they be sensitive to more than just the sun?

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• Bees use a sun compass to indicate

the direction of a source of food

• And polarised light on overcast days

Some birds use the patterns of the stars This is learned behaviour

Stellar Navigation

Sound (sonar) navigation

Bats (ultrasound) and whales (infrasound) interpret sound waves that reflect off objects around them. Some use earth’s magnetic field to navigate

Magnetic Fields

Some have an inbuilt magnetic compass: magnetite found in cells of some species.

Sunny day Overcast day Magnets on their back disoriented them No magnets

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Pages on timing responses (43-49)

• Comments? Questions?

This week pg 53-63

• Navigation, Migration, Homing

Chemical Navigation Sockeye salmon use smell to find their home stream

Homing

The ability of certain animals to return to a given place when displaced from it, often over great distances. May be daily eg roosting birds, or seasonal eg nesting

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Homing

• Limpets return to the same spot on the rock just before

the tide recedes.

• Shell shape grows to precisely match the contours of the

rock forming a better seal to the rock protecting from either predation or desiccation.

• It is thought that they follow pheromones in the mucus

left as they move to find their way back.

Advantages of Homing

• back to a place of

warmth, shelter protection from predators

• to return to offspring after feeding

Interspecific relationships

Relationships between members of different species

Predator-prey relationship

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• Advantages to the predator?
• Advantages to the prey?
• Advantages to the environment?

Which is the predator / prey? Predation

sea star

chitons limpets fan worms anemones snails barnacles mussels snails

competition for space predation

Predation

species richness time

chitons, limpets, snails, fan worms, anemones, barnacles, mussels… A mixture… gooseneck barnacles, mussels…

• nly competitively superior

species predators removed

What strategies can prey employ to increase their chances of survival?

Cryptic colouration: a form of camouflage

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Aposematic colouration is bright colouration that acts as a warning of effective physical or chemical defence.

Mullerian mimicry In this type of mimicry two or more unpalatable species resemble each other. Both gain additional advantage since predators learn more quickly to avoid prey with this colouration.

BOTH HARMFUL!

Batesian mimicry In this type of mimicry the palatable/harmless species mimics an unpalatable/harmful species Sounds may also be copied

HARMLESS! HARMFUL!

Behavioural Defences Structural Defences Chemical Defences

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Monarch butterfly larva Predator-prey Coevolution

• As predators have evolved to exploit their prey, prey have evolved to

protect themselves.

• A genetic change in one leads to a genetic change in the other
• E.g. mammalian predators vs their prey….
• Plant has chemicals to deter insects so insects develop chemicals to

neutralise the chemical so the plant develops another nasty chemical . . . .

Interspecific competition

Conclusion from these experiments? What principle do they illustrate? Both species are harmed to a certain degree

Gause’s Principle

• Also known as the competitive exclusion principle or

Gause’s Principle.

• Two species cannot compete for the same limiting

resource for long.

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Write a simple explanation of why this shows Gause’s Principle

• It means that two organisms cannot occupy

exactly the same niche.

Exploitation : Herbivory + -

• Animal eats plant
• Plant loses biomass and energy

The organism feeding on the

• ther is called the

parasite

The parasite usually does not kill the host

Parasitism + -

• Parasites can be

endoparasites (inside the body) or

• ectoparasites (living
• utside the body)

Tick ectoparasite on bird wing Many birds and mammals use dust bathing to rid themselves of external parasites

Ectoparasites

Bed bug (Cimex lectularis) Human flea (Pulex irritans) Head louse (Pediculus humanus) Mosquito vector for Dengue fever (Aedes albopictus)

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Endoparasites

Taenia scolex (head region) Taenia proglottid (reproductive segment) Horse gut nematode Sheep liver fluke

• Don’t look if squeemish!
• Obligate parasites cannot survive without a host, e.g….
• Facultative parasites can survive without a host,
• Much easier to imagine in non-animal species.
• e.g…Common examples are fungi like candida (causes

thrush) and Amarilla (honey fungus – parasitizes trees)

• Which of these two types is less likely to kill its host?

Parasitoid

• Only a parasite for a while then kills its host and survives

independently – it has a free living stage in its life cycle.

• National Geographic - Body Invaders

https://www.youtube.com/watch?v=vMG-LWyNcAs

Plant Parasite

plants that live on other plants. Can be hemi-parasites.

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Social Parasites

Takes advantage of hosts behaviour.

Co-existence

Competition between two species may be reduced by one or both species modifying a characteristic (i.e. evolving) e.g. feeding time, food type.

E.g. pipis are found near the high tide mark but cockles found near the low tide mark. Mutualism (symbiosis) ++

Both organisms benefit from the relationship

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Facultative mutualism

Mutual relationship that is not essential for the survival of either species.

Obligate mutualism

The relationship is essential for the survival of one or both species. nitrogen fixing bacteria in the roots of legumes such as clover, pea, gorse and beans. Eg

Many plants have mutualistic associations with fungal mychorrhizae. Mychorrhizae increase the capability of plant roots to absorb nutrients. In return, the host provides support and a supply of carbohydrates. Lichens are a fungal-algal mutual association. (symbiosis.) The fungus provides a protected habitat for the algae, and takes up water and nutrients for the algae. In return, the algae provide food for the fungus.

Lichens

Why an example of mutualism?

Herbivores have bacteria in their gut that can digest the cellulose of the plant cells they eat. In return they provide the bacteria with food and a safe, warm home.

Many flowers are adapted to be pollinated by specific

• rganisms

What is this an example of? coevolution

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Commensalism +0

• Commensalism occurs when one species

benefits and the other is unaffected.

Epiphytes

• Epiphytes gain brighter

light for photosynthesis while the host plant is unharmed.

Amensalism 0-

A relationship between two species in which one is harmed but the other is not affected. For example, squashing insects while walking along It is opposite to commensalism

• Eg an epiphyte

drops from its tree and damages plants below.

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This week: Workbook pages 64-75

Antibiosis +-

• An organism produces a chemical that keeps
• thers out of its space so reducing competiton

Eg Bacteria are inhibited by the antibiotic secreted by the penicillin fungus Allelopathy - plant produces chemicals to prevent being eaten or stop competitors seeds germinating in its space Plants produce toxins that inhibit the growth of competing species.

Macrocarpa.

Relationship Species A Species B Example Predation +

• Lion and Antelope

Antibiosis & Allelopathy +

• Grazing

+

• Competition
• Mutualism

+ + Commensalism + Parasitism +

• Amensalism
• What type of

relationship?

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• Pea crabs living inside
• shellfish. The crabs gain

shelter and food scraps while the mollusc is unharmed.

• Grazing mammals trample and destroy vegetation around

waterholes, creating bare zones. The mammals are unaffected by the loss as they go there primarily to drink and not to feed.

• On flax leaves, ‘notch’

caterpillars chew the leaf edges while ‘window’ caterpillars eat holes in the middle of the leaf. they occupy different niches.

Relationships occur between some birds (such as oxpeckers) and large herbivores (such as zebra, Cape buffalo, and rhinoceros). The herbivore is cleaned of parasites and the

• xpecker gains access to

food

Cape buffalo and oxpecker birds

• Barnacles growing on the

shells of mussels.

Interspecific competition

may be reduced by:

Zonation Stratafication Succession

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zonation

Eg vegetation zones up a mountain from lowland bush to shrubs, to grassland to herbs to true alpine plants. The animals alter accordingly.

zonation A community changes over a geographic gradient because… they are adapted for distinct geographic conditions eg temperature. Zonation reduces interspecific competition because….

Stratification

reduces interspecific competition because… birds feeding at different levels eg kiwi on ground, fantail just above the ground, pigeon up high. Grasslands show stratification too

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Eg on rock scraped clean by a glacier:

lichens (pioneer community) mosses grasses small shrubs bigger shrubs small trees big trees (climax community)

time

Sand dunes are stabilised by pioneer plants like marram grass or pingao and replaced by grasses, shrubs and trees as water and nutrient content is built up in the sand.

Succession

Over time one community gets replaced by another until it reaches a community that does not change – the climax community. Disruption (due to erosion, eruption, fire, glacial erosion), results in a distinct series of seral community stages that slowly develop back to the climax community.

Succession…

…reduces interspecific competition because

species are not present at the same time.

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Succession occurs as a lake slowly fills in time

Species Percentage frequency Mean height of each plant species (cm) Start of 3 year period End of 3 year period Fescue grasses (Festuca spp.) 51 32 5.1 Sedges (Carex spp.) 11 8 3.7 Creeping bent grass (Agrostis) 10 5 1.4 Wild thyme (Thymus drucei) 15 4 0.7 Gutierrezia sarothrae 13 45 18.6 Cirsium flodmanii 6 25.9 Mean height

• f

vegetation (cm) 2.3 17.5 An investigation was carried out to find out the effects of grazing by deer on an area of grassland they frequented. From within the 22 year study period, a three year period was chosen when the deer population was small (as indicated by low catch numbers). During this three year period, the percentage frequency of a number of plant species was determined, as well as the mean height of the vegetation. The results are shown in the table below. Species Percentage frequency Mean height of each plant species (cm) Start of 3 year period End of 3 year period Fescue grasses (Festuca spp.) 51 32 5.1 Sedges (Carex spp.) 11 8 3.7 Creeping bent grass (Agrostis) 10 5 1.4 Wild thyme (Thymus drucei) 15 4 0.7 Gutierrezia sarothrae 13 45 18.6 Cirsium flodmanii 6 25.9 Mean height

• f

vegetation (cm) 2.3 17.5 a) Describe the effect of the reduction in deer numbers on the mean

height of the vegetation over the three year study period and explain how the change in deer numbers caused this change.

(b) Explain the decrease in the percentages of the grass species over the three year period. Species Percentage frequency Mean height of each plant species (cm) Start of 3 year period End of 3 year period Fescue grasses (Festuca spp.) 51 32 5.1 Sedges (Carex spp.) 11 8 3.7 Creeping bent grass (Agrostis) 10 5 1.4 Wild thyme (Thymus drucei) 15 4 0.7 Gutierrezia sarothrae 13 45 18.6 Cirsium flodmanii 6 25.9 Mean height

• f

vegetation (cm) 2.3 17.5 (c) Describe how the vegetation in the area might change further if the deer numbers remained low over the next ten to twenty years. Species Percentage frequency Mean height of each plant species (cm) Start of 3 year period End of 3 year period Fescue grasses (Festuca spp.) 51 32 5.1 Sedges (Carex spp.) 11 8 3.7 Creeping bent grass (Agrostis) 10 5 1.4 Wild thyme (Thymus drucei) 15 4 0.7 Gutierrezia sarothrae 13 45 18.6 Cirsium flodmanii 6 25.9 Mean height

• f

vegetation (cm) 2.3 17.5 (d) Name the community pattern that is seen in this study.

• Intraspecific interactions are…

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How Animals Communicate

An organism cannot live in isolation - it needs to be able to communicate with

• ther organisms, either of the same

species or of different species. For an animal, communication can mean the difference between life or death.

Why communicate?

Create a table with a column for ‘why’ and a second column for ‘how’

Visual displays can deter predators, attract predators (to lead them away) or attract mates Some animals produce repellent chemicals to keep predators away.

Fighting is harmful to the species so many species have displays that reduce aggression.

24/07/2016 41

The positioning and intensity of the waggle dance in bees indicates to other bees the direction of food.

Chicks are often different colours to the

• adult. This may stimulate parental behavior

from the adults, so that they do not see the young birds as competitors for mates or nesting sites.

Birds communicate by sound: eg to indicate this is their territory, or as an alarm

Chemical Stimuli

Animals use chemical stimuli for different activities such as mating, marking territories, setting trails and identifying young.

24/07/2016 42

Many animals rub objects in their habitat, depositing pheromones that mark their presence

Cats detect smells in the roof of their mouth

• Female moths, which are active at night,

use chemicals to attract mates.

• Males use their antennae to pick up its

presence in the air.

• These chemicals are called pheromones

The spawning of mussels in a mussel bed is regulated by a chemical stimulus so that all of the mussels liberate their eggs and sperms into the water at the same time. Ants

Relationships

Intraspecific or Interspecific And Negative (Agnostic), Neutral or Co-operative

24/07/2016 43

Intraspecific Relationships

Intraspecific relationships are aggressive or co-operative interactions between members of the same species

Communication continued….

• Choose some vids
• http://www.bbc.co.uk/nature/adaptations

How do animals communicate?

• What do you remember???

Communication

Why do animals need to communicate….

• With the competition?
• With prospective mates?
• With peers?
• With offspring?

Some stimuli are only given out by animals and plants at certain times of the year, generally in the breeding season Many males change their behaviour in a way which will attract females, or vice versa: courtship behaviour Some male birds develop colourful plumage so that the females will be attracted by a visual stimulus as well as by sound.

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Courtship displays https://www.youtube .com/watch?v=d_yYC 5r8xMI

The blue footed booby

The blue-footed booby is distributed among the continental coasts of the eastern Pacific

• cean from California to the Galapagos islands down to Peru. It is strictly a marine bird. Its
• nly need for land is to breed and rear young, which it does along the rocky coasts of the

eastern Pacific. Foot facts:

• Blue feet indicate the current health condition of a booby.
• Brightness of feet decreases with age.
• Chicks cared for by fathers with brightly coloured feet had brighter coloured feet.
• Both parents share incubation and chick rearing responsibilities – they use their feet to

keep the eggs warm.

• Females put less energy into egg production when cared for by males with duller

coloured feet. Explain why this might be.

Group living Solitary organisms

• Live alone most of the

time.

• May only mix with others

during breeding

Orangutans are unusual in that unlike most other primates, they are solitary.

Many species of animals are found living in large groups

24/07/2016 45

Hunting as a group and hunting by oneself. Sentinels means less time is spent looking for danger The group works together to protect young

These animals stay in large groups for their

• wn protection.
• A carnivore is more likely to see a large group of

herbivores feeding together than a single herbivore.

• BUT it is much more likely that the carnivore will be

seen by one of its members.

• This means that each herbivore is able to spend more

time eating and less time looking around for danger.

Young are placed in the centre of the circle

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• A solitary gnu has little chance of

escaping from a predator.

• If a herd of gnu are attacked by a

predator, each individual has less chance of being caught.

Also, the predator is often "confused" with so much

• choice. If the predator hesitates over its choice of

prey, the prey may gain enough time to escape. Confusing the predator Clumping can reduce heat and water loss They are together in the same place because it offers each one of them better protection (safety in numbers), an available mate when the mating season comes around. Colonial species form a group at nesting time. Safety in numbers: particularly if your nest is to the centre By all producing young at the same time, predators can’t eat them all, so improving the survival rate.

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In order for a group of animals to be truly social it has to show co-operation between its members and a division of labour. Division of labour means that the jobs to be done are given to different members of the group. This makes the group more efficient and successful and provides protection to the individual members of the group.

Social groups

In a beehive, different individuals are adapted to carry out different roles, together working for the benefit of the hive.

Honey bees

• The colony has only one queen whose function is to lay eggs
• The workers are all sterile females. Their functions are to

feed and care for the larvae, build, clear and guard the hive and search for food. The workers change their jobs according to their ages. Worker Bee's Activities

Day 1and 2: Cleaning the honeycomb cells and keeping the eggs and the larvae warm. Days 3 to 6: Feeding the older larvae with beebread. Days 7 to 11: Feeding the younger larvae with royal jelly. Days12 to 17: Making beeswax and building honeycombs; moving food around the hive. Days18 to 21: Guarding and ventilation the entrance to the hive. Days 22 to 34: Visiting flowers to collect pollen and nectar. Days 35 to 45: End of the life of a worker bee.

• The drone's only function is

to mate with the young queen.

Disadvantages of living in a group

• Disease and parasites spread more readily
• There is competition for the resources they all need
• Crowded conditions increase conflict

24/07/2016 48

Other amazing animal groups

Lets talk about sex….or at least the before and after:

• Courtship behaviour
• Pair bonds/ family groups
• Reproductive strategies

https://www.youtube.com/wa tch?v=d_yYC5r8xMI

Intraspecific Interactions - Cooperative Behaviour

• Courtship behaviour
• Pair-bond formation
• Parental care
• Discuss
• Define
• Give the reasons and
• Advantages of these three behaviours
• Courtship pre mating behaviour to attract mate, select best

mate, reduce aggression and allow mating, ensures same species are involved

• Pair bond - two organisms pair for a breeding season or for

life, ensures survival of offspring, female cannot incubate and feed herself and offspring by herself.

• Parental behaviour Overcomes natural aggression to allow

reproduction and care of young - young have good chance of survival

R strategy -typically oviparous (produce eggs)

• Many offspring and hope some survive on their
• wn
• Eg fish, frogs, insects, turtles
• Survival may be assisted by jelly or shell

covering the egg, burying them or building a case to protect them and adding food source to egg eg yolk

Reproductive strategies

24/07/2016 49

Reproductive strategies

K strategy - typically viviparous (young develop inside parent)

• Produce fewer offspring, have parental care

and putting some effort into their survival. Eg mammals and birds and some reptiles. More care needed if young are helpless (can’t walk or fly) or carnivorous (have to learn how to hunt)

Cut and order Mating systems

monogamy (pair bonding) Male stays with one female for the season – most birds (some for life eg albatross) She cant produce his offspring without him; she can’t feed herself and incubate or feed young.

Gibbons are monogamous

polygamy

• Mate with several others in the season
• Male mates with lots of females in the season =

polygyny

• Female mates with lots of males in the season =

polyandry (rarer)

• Several males and females mate with each other

= polygynandry eg pukekos

• https://www.youtube.com/watch?v=fQI5KUfM2xc

Synchronised spawning

When eggs and sperms are released at the same time by lots of organisms eg

• coral spawns just after full moon for a couple of days

in November

• salmon return to river of origin to spawn at the same

time

Grunions spawn just after full moon from march to august

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Synchronised spawning advantages…

• Increases chances of fertilisation
• Too many adults / eggs / young at once for predators to get

them all

Courtship

• http://humoncomics.com/archive/animal-lives
• This parental care requires behaviour to change from

aggressive (competing for food) to co-operative.

• Normally it is the female that cares for the young but not

always eg male seahorse gets pregnant!

• Stimuli called sign stimuli are of

significance to cause this behaviour change Eg - round face of some young primates, gaping mouth of chicks, colour of young penguins

Parental Care

Cooperative Parenting

• More than just the parents look after the eggs and the

young eg the helpers in a pukeko group, or all lionesses look after all young

Kin-selection

• favouring members of one's genetic family
• eg the pukeko helpers may not breed, but they are

encouraging the survival of their family genes

Social insects

• Insect groups such as bees and ants
• Different groups have different roles.
• Generally some are sterile - they care for the reproductive

members – but all are offspring of the same queen so they are ensuring the family genes are being passed on successfully.

24/07/2016 51

“In ornithology, monogamy is necessary for the provision of bi

• ding period to hatching, evolution has favoured the mutual support of the couple.”

Reproductive strategies

• What is meant by each of the following terms:
• r strategy and k strategy
• mating systems: monogamy, polygyny,

polygamy, polyandry, polygynandry, synchronised spawning

• co-operative breeding kin – selection
• social insects

Questions from last week – 64-75 This week – 90-94 + 86-90

Territories and Home ranges Territory

An area around an animals home base that is defended from members of the same species

Home range

The area around a territory in which an animal searches for food and other resources but is undefended.

24/07/2016 52

The home range is the area that provides food, mates and other resources. It is undefended and may overlap with the home range of other populations.

Territory is defined and defended by…

Pheromones Song (birds) or other sound eg howler monkeys Display Scratched bark Urine and dung piles

Communication: defining a territory

• Visual or Oral/ Aural displays
• Scent marking – cats
• Aggressive displays and fighting

Within the home range is the territory. This area is for nesting, mating and/or feeding. Territoriality is defence of the territory.

• Territories may be

held by an individual, a pair or a group.

An Adélie penguin's territory is its nest.

The size of the home range and territory are determined by….

• availability of resources – more resources means a smaller

territory.

• density of population
• aggression /place in hierarchy of the individual or group
• competition with other species for the same resources

24/07/2016 53

Aside: Fit for purpose

• A territory may not be maintained all year round, and it may change

depending on the needs of the animal.

Advantages

• f

territoriality Each animal has enough food, safe breeding and nesting sites

Reduces the spread

• f disease

and parasites

Successful males have best territory so best genes are handed

• n

Become familiar with resource locations Unsuccessful males have no territory and no mate Territories act as population control. Intruders and defenders know their roles. Reduces intraspecific competition

A pride of lions Lions live together in a group called a pride. The pride is made up of

• ne dominant male,

between 4 to 12 lionesses and their cubs.

• The territory of the pride is between 15km2

and 100km2.

• The male marks the boundaries of the

territory by placing a mixture of scent and urine on bushes and twigs.

• He also roars loudly to let other animals know

that he is there. Other lions are not allowed to hunt in the marked territory.

• The male cubs are chased out of the territory

by the dominant male when they are between 2 and 3 years old. The young males then have to look after themselves.

• When they are fully grown they can challenge

a dominant male. If the younger male wins, the dominant male is chased out of the territory and any cubs which he fathered are killed.

• The lionesses co-operate in hunting for the pride. All of the lions

eat together and the cubs have to fight to get their share. When food is scarce the lionesses eat and their cubs starve. In general, about half of the cubs survive and grow into adults. The females will not have another litter until the cubs are between 18 and 24 months old and are able to look after themselves.

• This prevents overcrowding within the territory.
• The females share the task of looking after the cubs. The lionesses

will suckle cubs which are not their own.

• Note, however, that the females and the cubs are all related to

each other.

24/07/2016 54

Advantages and disadvantages of territories

Benefits Costs Note – territory cards

Advantages and disadvantages of territories

Benefits Costs

• Defending resources
• Access to mates
• Energy to defend it
• Energy to mark it

What is the ultimate cost or benefit to that individual or species– how does this strategy help or hinder the animals survival? How does it help or hinder the ‘improvement’ of the species.

Wekas (Gallirallus australis) are endemic flightless New Zealand

• birds. The diagram below shows the relative sizes of territories held

by male wekas in two separate study locations; Kapiti Island bird sanctuary, and a regenerating native bush area at Double Cove close to Picton in the Marlborough Sounds. Territory size on Kapiti Island averaged 1.96 hectares, while at Double Cove territory sizes ranged between 2.6 and 15.8 hectares.

Kapiti Island weka territories Double Cove weka territories Scale 1:100 000 (both diagrams)

• The researcher also observed that

territorial birds were found up to 200 m into neighbouring territories at Double Cove, something never seen at Kapiti Island.

(a)Define territory. (b) Describe TWO ways in which wekas might maintain their territories. (c) Suggest TWO reasons why the territories in the two locations vary in size. d) Why would a territorial weka be found in a neighbouring territory at Double Cove, yet not at Kapiti Island?

• While the weka is territorial all year round,

many other common New Zealand birds such as sparrows and starlings come together in flocks after the breeding season. Often all the flock roosts in one tree.

• (e) Give TWO possible advantages of this

flocking behaviour to an individual in the flock.

An albino weka

24/07/2016 55

The African hunting dog lives in a group called a pack. The pack shows a wide variety of social behaviour. The territory of the pack can be up to 520km2. The dominant male marks the boundary with urine. No other pack is allowed to hunt in the

• territory. The pack consists of between 8 to 20 members including both

males and females.

African hunting dogs The Twelve-wired Bird of Paradise finds a new mate each season. In comparison Albatrosses mate for life. (g) Discuss how each bird species benefits from its mating strategy

(

State TWO reasons why some animals have a territory. For each reason, describe the benefits this gives to the population. Gannets nest virtually only a peck apart and defend their territories by calling and pecking at each other. Territories are a characteristic of certain populations such as gannets.

This is a population

• f

Australian gannets in New Zealand.

The Twelv lve-wired Bi Bird d of Paradi dise se is a territ itor

• ria

ial bird.

• d. For most of

the year, the male le bird d does not allow low othe her birds ds, incl clud udin ing females, s, int nto

• his

is territ itor

• ry.
• a. Suggest ONE reason why the male

Twelve-wired Bird of Paradise defends his territory.

• b. Explain why neighbouring birds have

different songs. The males use song to mark their territory and warn off other birds. The songs from birds occupying neighboring territories will

• ften be slightly different.

The Twelve-wired Bird of Paradise is a sexually dimorphic species. The female is predominantly brown with patches of black. The male in comparison has a conspicuous colouration with velvety black iridescent wings, sulphur yellow wing plumes and coral pink legs. His tail has 12 long wire-like feather shafts. Females of many bird species often select the most colourful males as mates. What does this suggest about the suitability of such males as mates?

• Once mating has taken place only the female

incubates the eggs and rears the young. The male takes no part in parental care.

• Discuss how the different roles of males and females

in reproduction helps explain the differences in coloration of the two sexes.

24/07/2016 56

During the males elaborate courtship display the male sways his body rhythmically exposing his bright plumage and brushing his 12 tail plumes across the female. (e) Describe TWO purposes of courtship behaviour. Agnostic behaviour: Conflict between members of the same species.

Aggressive and Submissive Behaviours

(Hierarchies and Territories)

Hierarchies

• https://www.youtube.com/watch?v=V0u5RK_IL6s
• What other animals do you know of that have hierarchies?
• What’s the best place to be in a hierarchy?

Hierarchies

A linear order of dominance within a social group. Hierarchies are usually controlled by aggressive and submissive behaviours rather than fighting in order reduce the chance of injury to individuals

a.k.a – Pecking order Biozone – pg 66-68

Tell me about Hierarchies…..

24/07/2016 57

Tell me about Hierarchies…..

• Linear order of dominance
• Means there is a “top dog” or alpha and at the other end an omega
• Usually dominance or submission is shown through displays rather

than fighting.

• What animals do you know that form hierarchies?

Usually, the number 1 animal (dominant) has the first choice of food and mates and can chase away the number 2 animal (subordinate). Likewise the number 2 takes priority over number 3. This means that each member of the group has a specific position on the social ladder.

Who gets to be “top dog”?

• Older
• Stronger
• Aggressive
• Larger
• Healthy
• Have offspring – kin alliance
• Know the territory
• Usually male

Who gets to be “top dog”?

Animals that hold higher positions in a hierarchy tend to have 'better genes. Why is this a good thing…

• For individuals?
• For the group?
• For the species?
• A linear hierarchy has a ___
• rganism ("alpha") which ______

the whole group

• the second in line ("beta")

dominates all but the _____ and so on.

• The "beta" is therefore

________ to the "alpha”.

Advantages of living in a social hierarchy: For the species

• 1. Reduces fighting and tension in the group
• 2. Reduces competition once established
• 3. Often results in only dominant individuals

reproducing (passing on the strongest genes)

For the individual

1. Increased survivorship because weaker protected by stronger 2. Better and safer access to resources and mates

24/07/2016 58

Social hierarchies only work when…

• Each animal recognises
• every other member of the group.
• various displays from other members
• The group is stable over a long period of time.

Social hierarchies exist because…

• There is advantage to the individual – protection, resources

and mates.

• Hierarchies reduce fighting and competition within a group

Changes in the pecking order take place if

• ne animal

successfully challenges another

• ne.

Aggressive Vs Submissive

Costs + Benefits Costsand Benefits Cost:

• Costs energy
• Risk of death or injury

Costs:

• Less resources
• Poor access to mates

Benefits:

• Better access to resources
• Better quality mates

Benefits:

• Save energy
• Less risks associated with fighting (sometimes)

What’s the point?

Pukeko and Weka

Describe the behaviour Is it Aggressive or Submissive?

• Raised feathers/ feet?
• Upright stance?
• Pointed forward?
• Beak High?
• Tail feathers/ vulnerable parts showing
• Turning away
• Head down
• Body lowered

Aggressive Vs Submissive

Displaysof aggressive behaviour Displays of submissivebehaviour

• Raised feathers/ feet
• Tail feathers/ vulnerable parts showing
• Upright stance
• Turning away
• Pointed forward
• Head down
• Beak High
• Body lowered

How can we, and other members of your species tell? If I were a Pukeko……. (NB: there are some great examples of wolf dominant and submissive behaviour on your one note). Biozone – pg 62 NB: more on animal communication next week Biozone – pg 60

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Costs and benefits

Advantages of maintaininga hierarchical social group Disadvantages of maintaininga hierarchical social group

Costs and benefits

Advantages of maintaining a hierarchical social group Disadvantages of maintaining a hierarchical social group The alpha male is the strongest, largest, fittest animal and he has mating rights to the females. This ensures that his genes are the ones that are being passed on to the offspring. The species benefits because the offspring are genetically fitter. The less fighting over food and other resources. More dominant individuals have the rights to resources, ensuring they are in the best physiological state for reproduction. It also means that less individuals get hurt in fighting over food resources. Individuals at the bottom of the pecking order survive on scraps and leftovers. They therefore receive less nutrition and are in poorer physiological state. Fighting is inevitable, especially when challenging for higher positions on the pecking order. This can lead to injury which may prevent certain individuals from reproducing.

The term pecking order originates from studies of relationships among hens. The following set of data shows the interactions of six free range hens. 1) Write the letters of the hens in order from most dominant to least dominant 2) Which hen appears to be challenging for a higher position in the hierarchy? 3) Hens are female. Describe two factors (besides sex) that could influence an individual’s position in the hierarchy. 4) Many other bird species and most primates exhibit hierarchical behaviour. Describe three advantages of this type of social organisation to either the group or the individual.

24/07/2016 60

Hierarchies in wolves

Wolves are found in the wild only in northern Europe, Canada and the northern states of the USA. They are very social animals, living in family packs of up to 20 wolves. The pack is well organised with a dominant animal, generally a male, as the alpha wolf. Next is the beta wolf who acts as the disciplinarian to reinforce the alpha’s decisions. The omega wolf is the lowest ranking member of the pack. The other wolves rank between the beta and the omega wolves. Describe the social structure seen in wolf packs Wolves are often seen grooming each other and taking part in play fights

• 2. Describe how the following behaviours are important in maintaining the social structure of the pack

Grooming Play fighting Young males will often leave the pack to find a mate and form a new pack

• 3. Explain how this benefits the wolf species.

The images show two behaviours commonly seen in wolves

• 4. Which behaviour is associated with the omega wolf?
• 5. Explain why the omega wolf would display this behaviour

The omega wolf is the last to get access to food and may be chased away from areas favoured by the dominant wolves. Despite this the omega wolf remains within the pack. Describe two advantages to the omega wolf remaining within rather than leaving the pack. Wolf packs in Europe are generally much smaller than those in Canada

• 2. Explain why pack sizes might be smaller in Europe?

Practice Question: Olive Baboons

Home ranges and daily ranges have been recorded for some olive baboon troops in

• Africa. The data for troops in four areas is recorded in the table.
• Explain what the term home range means.
• Explain how environmental factors impact on BOTH the home range size and the

daily range of olive baboons.

• You must include the given information in your explanations.

Area Approximate home range size (km2) Approximate daily range (km) Average troop size Habitat Yearly rainfall (mm) Bole Valley, Ethiopia 0.745–1.12 0.3–2.0 15–24 Mixed forest and grassland 2000 Ishasa, Uganda 3.88–5.18 0.2–2.4 60 Forest and shrub- land 1100–1600 Gilgil, Kenya 19.7 2.2–7.8 49 Open grassland and shrub-land 500–1000 Laikipia Plateau, Kenya 43.8 5.64 100 Dry grassland 400–600

QUESTION ONE: BEHAVIOUR IN AUSTRALASIAN GANNETS Australasian gannets, Morus serrator, are known as colonial breeders. During the summer, large colonies of birds can be found within gannet colonies, where breeding pairs fiercely defend their individual nesting territories. However, recent studies have shown that when foraging at sea, the same birds show no territorial behaviour across their chosen feeding areas, and yet they appear to maintain largely separate foraging areas at sea, specific to the particular colonies they belong to when nesting on land. Gannets display territorial behaviour when nesting on land, but not when foraging at sea. Discuss the reasons why Australasian gannets appear to behave as described above. In your answer:

• describe territorial behaviour
• use biological ideas to explain why the territorial behaviour provides adaptive advantages

for the gannets

• justify possible reasons why the Australasian gannets appear to maintain separate

foraging areas when at sea.

24/07/2016 61

Review:

• Members of the same species have the same requirements = have

the same ecological niche.

• Competition within a species for resources is called intraspecific

competition.

• Hierarchies and Territories partition resources within a species.

Build a class Hierarchy

• Use your epic arm-wrestling skills to create a class Hierarchy
• Winners play winners, losers play losers to work out an “order of

dominance”

Build a class Hierarchy

• Use your epic arm-wrestling skills to create a class Hierarchy
• Winners play winners, losers play losers to work out an “order of

dominance”

• Was there anything other than physical prowess on display (ie smack talk/

posturing)?

• Is it a good idea to show dominance through physical conflict?

Why? Or Why not?