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Animal Behaviour and Plant Responses. 3.4. Orientation. A behaviour in which an animal positions itself in a certain way in relation to its surroundings. Orientation Behaviour. Taxis Kinesis Migration Homing. Taxis ( Taxes pl ). Describe taxis.
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Orientation A behaviour in which an animal positions itself in a certain way in relation to its surroundings.
Orientation Behaviour • Taxis • Kinesis • Migration • Homing
Describe taxis The movement of the whole animal towards or away from a stimulus coming from one direction.
Describe kinesis • The random movement of an organism where the rate of movement depends on the intensity of the stimulus. • Eg. Slaters in dry conditions move faster than in humid conditions
Types of kinesis • Orthokinesis • The intensity of the stimulus determines the speed of movement.
Types of kinesis • Klinokinesis • The intensity of the stimulus determines the rate of turning. • Eg Some flatworms, which prefer darkness turn more quickly in light. • Why ?
This increases their chances of finding darkness again so increases their chances of survival.
Explain why kinesis is an advantage to a named animal. • When slaters are dry, it is important to move quickly to encounter optimum environmental conditions ie moisture to prevent dehydration as their gills depend on water for gas exchange. • It is important to move randomly to increase the chances of finding humid conditions.
Fun Spot • http://www.youtube.com/watch?v=EQ1HKCYJM5U&NR=1
Migration • Migration is an active movement of populations of animals from one area to another, for a specific purpose such as breeding, avoiding bad weather or seeking food. • Migrations usually involve long distances, a return journey, and occur at regular times.
Triggers (environmental cues) for migration • Shortened photoperiod (day length)Eg birds –godwits and shining cuckoos • Decrease in air temperature eg butterflies • Lack of food eg wilderbeest • Maturing sex organs eg eels and salmon • Decrease in water temperature eg whales
Link between reproductive success and migration • Animals that migrate, compared with ones of the same species that do not migrate, grow larger and have better reproductive success. • Eg Salmon that migrate grow to an average 100cm compared with 20cm for animals that do not migrate. • Also migratory salmon produce 125 times the number of eggs.
Advantages & Disadvantages of Migration • Why Migrate? • Examples to back up ideas? • Pg 54 Meg Bailey – bullet points.
How long distance migration could have evolved Continental drift As the land masses moved apart, birds that fed on one landmass, but bred in another area, may have continued to fly between each place, with the journeys getting longer as the continents drifted apart.
How long distance migration could have evolved Ice Ages Ice ages and interglacial periods both change the flora and fauna of habitats. These changes may have forced animals to move over long distances to find sufficient food or breeding grounds.
Identify the issues that would drive the continuation of migratory behaviour. P12a. • The availability of food, mates, nesting sites and warmer temperatures drive the continuity of migration. • If migration results in higher reproductive success, then migration is worthwhile. • Overall, migration is a successful strategy for certain species as the benefits outweigh the risks.
Migration of Godwits • E7!
NCEA Question 2005 Cuckoo • The cuckoo does not have to spend any energyrearing its young, so it can put more energy into producing eggs. It is able to produce more eggs as it has timeto feed itself and remain in peak condition for egg production. • The host bird expends energyrearing the cuckoo instead of its own young. This means that the grey warbler numbers are fewer than there could be, so this could endanger the species in adverse conditions.
NCEA Question 2005 Cuckoo • The host bird has less time to feed itself and therefore will not be in such good condition and possibly health at the end of the breeding season. • Overall, the strategy of the cuckoo benefits this species but has a negative impact on the grey warbler species.
Cockoo • http://www.youtube.com/watch?v=dAU5MTXmAPY&feature=related
Homing • The ability of an animal to find its way to a home site, after it has been away looking for food, water or mates. • Homing may also take place over unfamiliar territory after an animal has been displaced. • Eg Homing pigeons
Reasons for homing • To feed young eg blackbirds • For warmth and shelter eg a kiwi burrow • For protection from predators eg birds roost in groups in the same trees, which they know are safe.
Homing in Salmon • Salmon travel from the river of their birth out to sea where they grow to maturity. • When they are ready to reproduce, they may travel hundreds of Kms in open sea to the river where they hatched.
To navigate at sea they may use a magnetic compass and polarised light. • To find their own river, they use the taste and smell of the water at the river mouth. • Chemicals from vegetation and rocks give each river a different taste.
http://www.youtube.com/watch?v=-7ijI-g4jHg • Short • http://www.teachersdomain.org/asset/tdc02_vid_beenavig/ Long
Methods of navigation used in homing • 1. Using familiar landmarks
Solar navigation in birds • The bird thinks it is 9.00AM • Therefore the sun should be 45o on its left. • So it turns WEST to position sun on its left. • It now thinks it is flying south.