Animal Responses Flashcards
What is an adaptive advantage?
Any trait that results in an organism having a greater chance of surviving to an age where it can reproduce
What is taxis?
Directional movement of an animal toward or away from a stimulus
What is negative phototaxis?
Movement of an animal away from light
What is positive phototaxis?
Movement of an animal toward light
What is positive chemotaxis?
Movement of an animal toward a chemical stimulus
What is negative chemotaxis?
Movement of an animal away from a chemical stimulus
What is positive geotaxis?
Movement of an animal with the direction of gravity
What is negative geotaxis?
Movement of an animal away from the direction of gravity
What is kinesis?
Non directional movement of an animal in response to a stimulus. They end up moving toward or away from the stimulus by chance.
What is orthokinesis?
The speed of an animal is proportional to the intensity of the stimulus causing the movement.
What is klinokinesis?
The rate of turning is related to intensity of stimulus. Turning increases when the animal is in an unfavourable environment, turning rate decreases when the animal is in a favourable environment.
What is migration?
Long distance mass movement of animals of the same species to a different environment, usually seasonal, to a predetermined location with better resources.
What are migration cues?
Change in daylight (photoperiod), change in temperature (season), food/water availability, internal biological clock, low fat reserves, sexual maturity
What are migration risks?
Predators waiting on route, getting lost (poor orientation), storm events, run out of energy, not enough preparation, mistiming.
What is magnetic field sensing?
The use of Earth’s magnetic field to navigate. Innate and common in birds. Does not require signals.
What are migration benefits?
Warmer weather, safer habitat for breeding, arrive as a group (better chance of mating), more food in new environment
What is navigation?
The ability of an animal to stay on a desired course / find a desired location using external environmental cues.
What is a sun compass?
The use of the sun for orientation during navigation or homing. Can only occur during the day when the weather is good.
What are landmarks?
Use of familiar landmarks to check orientation along a migration or homing route. Learnt behaviour only.
What is homing?
The ability of an animal to repeatedly return to its home location after travelling away from it to get resources e.g food.
What is an innate behaviour?
Behaviours from birth, controlled by genes inherited from parents.
What is an exogenous rhythm?
A pattern that only occurs in response to external cues and disappears when cues are removed
What is an endogenous rhythm?
A rhythm that continues without any external cues
What is a learnt behaviour?
Behaviour that can be changed or improved with repeated experience.
What is a chemoreceptor?
Detects certain chemical stimuli in the environment, such as those found in the nose and on the tongue
Why do organisms respond to their environment?
Find favourable environment - find shelter, avoid harsh climate or moult in safe place.
Food - find food or essential nutrients
Reproduction - To search for a mate, to give birth, lay eggs or raise young
Predation - avoid being eaten
Competition - reduce intraspecific (same species) or interspecific (different species) competition
What is a zeitgeber?
An external or environmental cue that entrains an organism biological rhythm.
What is a thermoreceptor?
Responds to temperature
What is a photoreceptor?
Responds to changes in light
What is a mechanoreceptor?
Responds to mechanical stress or strain
What is a magnetoreceptor?
Allows an organism to sense direction, altitude or location by detecting a magnetic field.
Thigmo?
Touch
What is solar navigation?
Animals are able to use the sun’s position to navigate. For long journeys, animals must compensate for the movement of the sun by using some form of biological clock or other navigation.
Food?
Tropho
What is stellar navigation?
Animals travelling at night may orientate to a particular constellation or to a celestial pole.
What are some external migration cues?
Photoperiod: Longer days in the summer or shorter days in the winter. Less sunlight means lower rates of photosynthesis, less food, lower temperatures.
Shifting seasons: In many cases the temperatures and levels of precipitating change
Food and/or water availability: Lack of food or water as a result of extreme temperature, lack of precipitation or population pressure.
What are some internal migration cues?
Circadian rhythm: the ‘internal calendar’ in an animals nervous system can help an animal know when to migrate.
Fat reserves: Low fat reserves may cue some species to move in search of food
Sexual maturity: When an animal reaches sexual maturity, hormones may trigger an innate desire to migrate to breeding grounds.
What is a circadian rhythm?
An endogenous rhythm with a free-running period of approximately 24 hours that is generally entrained by a zeitgeber.
What is a circatidal rhythm?
Cycles synchronised by the tides. 12.4 hours.
What is a circaannual rhythm?
Seasonal migration. 365 days.
What is a free-running period?
The time between the onset of one activity and the next, in the absence of any environmental cue.
