Wait a second!
More handpicked essays just for you.
More handpicked essays just for you.
Predator-prey relationships scientific report
Don’t take our word for it - see why 10 million students trust us with their essay needs.
Recommended: Predator-prey relationships scientific report
Predation refers to the consumption of one organism known as the prey by another known as the predator in which the prey is alive when the predator first attacks it. Predation is beneficial to the predator and harmful to the prey. This is a broad group which covers a wide variety of interactions and numerous types of predators. For the purpose of this essay we will concentrate on classifying predators according to their individual taxonomic and functional responses.
When the predator and the prey meet they will interact with each other. Natural predators appear to regulate the numbers of prey. This brings us to a key question which this essay sets out to answer, if the number of prey increases, can the predator quickly adjust its rate of prey capture to take advantage of the situation?
Predators called prudent predators select prey of the highest quality and will switch prey when other foods become more profitable. Prudent predators show preference for the prey they consume, in order to maximise net energy gain per unit time. An important factor in predation-prey interactions is the rate at which individual predators can capture individual prey items. The response of the predator consumption rate to increases in prey density is called the functional response
Probably the simplest method of classifying predators is the taxonomic classification system. Carnivores are predators which consume animals. True predators kill their prey straight away after attacking them. During their lifetime they kill many prey. This is an takes in carnivores for example lions, snakes, seagulls and carnivorous plants. Even plankton eating large mammals, seed eating rodents and ants are included in this classification.
Grazers attack huge n...
... middle of paper ...
...w prey density. Examples include slugs feeding on grass. Handling time is the time taken to catch, kill, process, eat and digest the prey. Handling time varies with different prey types. As prey density increases finding prey becomes easy however handling the prey still takes up the same amount of time. Consumption rate reaches a maximum determined by the maximum number of handling times that can be fitted in to the total time.
Type three functional response occurs in predators which increase their search activity with increasing prey density. Initially there is a slow rise in predation rate at low prey densities then mortality increases with prey increasing density, and then declines. Examples include a fly feeding on sugar.
The graph shows the changes in the number of prey attacked per unit time by a single predator as the initial prey density is varied.
In 1927, Charles Elton took niche theory a step further and included food. He defined the niche of an animal as its place in the biotic environment and its relations to food and enemies (Elton, 1927). Grinnell also wondered if food was a limiting factor to the California Thrasher’s niche, but since the bird is omnivorous, it could find food in other habitats such as a forest floor or a meadow. There had to be other factors that restricted the bird to the chaparral bushes (Grinnel, 1917). Elton believes that the niche of an animal can be defined by its size and its food habits. It is important to study niches because it enables ecologists to see how different animal communities may resemble each other in the essentials of organization (Elton, 1927). For example, in a forest there could be a niche of owls that feeds on small animals such as rats. This same carnivore niche is filled with kestrels in the open grasslands. This carnivore niche is then dependent on the small animals in the herbivore niche (Elton, 1927). Hutchinson also discusses niche theory in his “Concluding Remarks” paper. His theory seems to combine some of the ideas
1) Inspiration: Grey wolves are considered as apex predators, meaning that they are at the top of the food chain. Grey
Predation could limit the prey distribution and decrease abundance. Such limitation may be desirable in the case of pest species, or undesirable to some individuals as with game animals or endangered species. Predation may also act as a major selective force. The effects of predator prey coevolution can explain many evolutionary adaptations in both predator and prey species. The effects of wolf predation on species of large ungulates have proven to be controversial and elusive.
All animals employ a vast array of behaviors that contribute to their ability to find resources, increase their chances of utilizing them efficiently, and therefore increase their overall fitness. One of the behaviors observed extensively throughout the animal kingdom to accomplish these tasks is aggression. Agonist conflict and aggressive behavior occurs both between species and within species. Curiously, within-species agonism is common in many animals because it can manipulate social hierarchies which can affect the distribution of resources within a population (Moore 2007 and Wofford 2013). Evaluating agonistic behavior is therefore a valuable means by which to examine expenditure of energy for resources (Moore 2007 and Wofford 2013).
Predators are biologically different and can be very dangerous compared to the common criminal. Predators have minimal or absent autonomic arousal, no conscious emotion, no imminent perceived threat, no displacement of target, and no time limited sequence. Predatory violence is planned and purposeful with variable goals, primarily cognitive, and predators have heightened and focused awareness. Predatory violence is different from other forms of violence because it is not defensive nor an appropriate or normal response.
People today use hunting as a sport. Of course, not everyone agrees with hunting, but those who like to hunt justify their actions by saying that they are helping with the overpopulation of animals, like deer. The truth is that we are affecting the population of animals. Animal overpopulation can be due to the loss of an animal’s natural predator. Predators are extremely important in an ecosystem, and they are nature’s way of controlling the animal population. In William Stolzenburg’s book, Where the Wild Things Were: Life, Death, and Ecological Wreckage in a Land of Vanishing Predators, he addresses the importance of predators in an ecosystem. He discusses an experiment done by a zoologist named Robert T. Paine. Paine decided to do an experiment to see what happens when one disrupts an ecosystem. He conducted his experiment on rocks along the shore in which a species of starfish was the top predator. Paine’s experiment consisted of grabbing the starfish off the rocks and throwing them into the ocean. His results showed that one single species has a tremendous effect on its ecosystem. After getting rid of the top predator, about half of the species that
The theory of “super-predators” was a prediction that never existed and became a myth to society and criminologist after the fact that the concept that revolves around the myth of super-predators had already create chaos that led many states throughout the country to implement laws in protection for what was to come. All the misconceptions of the exaggerated fear and concerns came to pass and the credits slowly dissipate when the violent wave of events did not exist as it was predicted by the experts. The prediction was never coming to pass, but the consequences that was put forth to the community of such myth lingers within the targeted community because it categorized such group of people as the main cause of the super-predators. So, what are super-predators?
For example, if the larger fish are removed than its prey begins to overpopulate, due to the lack of population control. The balance in the oceans is an urgent problem, with around 90% of predatory fish stocks depleted. The ripples can extend even further to land creatures like seagulls.
...his builds a relationship between the two causing the predator to consume its meat without looking away (Pollan 307). This causes that person to no want to know what they are eating because people are used to not knowing what they are eating.
Around the 1950’s, C.S. Holling decided to look into the reasoning of why predators can control their numbers of their prey. For example, when prey densities tend to increase, the predators respond by changing their rate of consumption for them to satisfy their hunger. This concept is also known as a functional response, and Holling created a method to reflect this model. His model consisted of blind folding human participants (considered as predators) and having them search for sand paper disks (prey) scattered throughout a board, to observe the responses of the participants to the disks. The participants’ reactions reflected a predator’s rate of discovery and handling time (reactions) to the amount of prey in a certain area. The predator’s responses usually reflect a Type II functional response, yet there are about three functional responses a predator may portray: Type I, Type II, and Type III.
For as prey is almost the unique subject of fighting among carnivorous animals, and as frugivorous ones live among themselves in continual peace, if the human race were of this latter genus it clearly would have had much greater ease subsisting in the state of nature, and less need and occasion to leave it. (Rousseau 188)
Invasive species, (also known as invasive alien species or simply alien species) are defined as any organism (plant, animal, pathogen, or other living thing) that is alien (non-native) to an ecosystem, which can cause adverse economical, ecological, or health effects to native species and/or humans. The roots of these problems all stem from the massive negative ecological impact these organisms are having on the environment (CBD, 2009). For all animal extinctions where the cause is known since the 1600’s, invasive alien species have been a contributing factor 40% of the time (CBD, 2006); the second most contributing factor to extinctions after loss of habitat (GC, 2013). By eliminating native species through competition for resources, predation, and transmittal of disease, invasive species continue to reduce biodiversity in almost all ecosystems around the world (CBD, 2009). In the future, this problem may worsen, and if no action is taken, could lead to a cascading ecological problem so large that whole communities or even ecosystems could collapse.
The. Pollan, Michael. A. The Omnivore's Dilemma. N. p. : Penguin Books, 2006.
Cannibalism is operationally defined as the ingestion of all or part of a conspecific, and is taxonomically widespread amongst many vertebrate and invertebrate groups; however, it is extremely infrequent in most species (Dawkins, 1976; Elgar and Crespi, 1992). It is believed that there are numerous fitness benefits to cannibalism, including better balance of nutrients from conspecifics over heterospecifics, and a competitive advantage of killing close competitors. There are also some fitness costs, which are believed to be associated with the rarity of cannibalism, including, increased risk of injury to the cannibal, diminishment of the indirect component of their inclusive fitness by killing relatives, and the heightened probability of acquiring deleterious pathogens and parasites above that experienced by non-cannibalistic predators (Dawkins, 1976; Elgar and Crespi, 1992; Hamilton, 1964; Pfennig, 1991, 1997; Sherman, 1981).
A successful natural enemy should have a high reproductive rate, good searching ability, victim specificity,