Question

Ecology:

How might flight-initiation distance change with changing distance to cover? (For example, if both the distance from the predator to the prey, and the distance from the prey to the safe zone, were different.) Be sure to relate your answers in terms of effects on foraging efficiency (in our demonstration, number of nutrition points) and predation rates (in our demonstration, how many prey die).

Answer 1

Escape is the behaviour that starts from a critical distance assessed by a prey tracking its predator.The prey msust determine the predator's positiin and behaviour and estimate the risk of remaining at the given site.Monitoring is assiciated with the vigilance that occurs before predator detection,allowing the prey to elaborate its desicion to escape.This decision is based on the fitness costs and benefits of the behavioral alternatives in this situation,the desicion to remain and take risk vs.the decision to avoid the predator and ensure immediate survival.

Individuals face trade offs in relationship to the disturbances caused by a potential threat that may increase or decrease their fitness.The timely decision of an animal to escape may directly influence the feeding success because early escape decreases foraging efficiency(increasing the risk of starvation) and the delayed departure may increase the risk of death by predation.The costs(lose of foraging opportunities and risk of being predated)are balanced to achieve an optimal fligh distance ,thus ensuring individual reproductive success,meaning that a balance costs and benifits has been reached in the context of effective feeding and predator avoidance.

Flying is one of the most widespread anti predator responses in birds and the distance at which the animal starts to fly due to an approaching predator is known as "initial flight distance".Several factors are known to influence the initial flight distance.These factors include taxonamic level,predator and prey size,levels of human intervention,hunting history,number and orientation of predators approaching ,the size of the social group with which the potential prey is associated,the breeding season,latitudinal gradients,and the animal's levels of hunger,which may vary accross seasons as well as during the day.

The flight distance of animals is often estimated as a way of assessing the human impacts on natural environments either in urban and non urban areas.Approach by humans may be identified by birds as a predatory approach and is therefore through to exert strong influence on animal behaviour sometimes resulting in decreased reproductive success.If the initial flight distance becomes shorter when the level of human disturbance increases,this behaviour can provide a rapid and easy way to evaluate the species tolerance to human interference and to monitor the degree of disturbance in a given environment.

A standard measure of risk taking is the distance at which animals flee from an approaching predator including humans,the so called Flight initiation distance.Flight initiation distance(FID) potentially constitutes a general proximate factor reflecting the risks that individual take.Because animals continuously have to take risks to fulfill their daily requirements,in particular when reproducing,FID can be considered the behavioral basis for proximate and ultimate factors determining life histories and life history trade offs.FID varied between individuals and sites,and it increased over time as climate amelioreted.FID shows the U shaped relationship with the age,with young and very old individuas having the longest FIDs.

Given that animals escape by physiological and morphological means,we could expect that FID was correlated with such variables at the individual,population and species levels.

FID changes due to many factors,of which predation risk plays the larger role in both the decision of the predator and prey.In a study of incubatin birds and variable predation risk,it was discovered that male bird could detect increased predation and would visit its incubating nest less frequently as a result .The instance of predator would take off,the prey would would attempt to grab food while deciding to initiate running without looking at the predator,observe predators closing distance and begin running once,and increased vigilance throughout foraging resulting in several starved prey.Similar observations were seen in FID of different prey and their responses,immediate flight or cost benifit of staying and fleeing seems to be a recurring trend.Increased predator speeds or experience would resulting in less effecient foraging for both populations.In some studies,the speed of the predator would only increase the FID when the strting distance was increased -a formula for which was derived where the FID was affected by approach speed and starting distance.Foraging decisions such as when and what to eat would result in less time spent foraging leading to less acquired resources.The predation rate at which the proportion of prey killed by predation would have also been effected had the risk of predation been the variable.Had a certain distance been set as aa constant where most prey would notice the presence of the predator and not flee immediately,the mean FID would have been larger as a result of increased speed.

Distance to cover is another important aspect of predation in terms of the prey foraging for resources.The results of one study indicate that the FID is related to the benifit of flight value in relation to the cost of flight-the greater value of the two resulting in response of fleeing or staying.