Essay on The Predator Exclusion Refuge

Predator-Prey Refuge

Predator-prey refuge is an ecological and biological concept where an organism can obtain some protection from the predators by ensuring they hide in an area or location where it is difficult for them to be found or avoid some predation risks. The population dynamics necessitates that whenever there is the availability of the refuges, there is always significantly higher prey and predator populations. Cohabitation of the prey and predators ultimately leads to the existence of many species that can be supported in one given location or area.

Impacts of Predator-Prey Refuge

The presence of the predator-prey refuge has numerous substantial impacts on the prey and predator existence. The existence facilitates the promotion of stability of the given niche through some structures. The given balance of the niche helps in ensuring all the species of the organisms exists and there are no fears of one species facing extinction. The refuge also helps in the creation of some dynamic fluctuations because of the manner in which the existing prey utilizes the refuge to ensure their interaction with the predators (Berezovskaya, Faina, Baojun & Carlos p.1821). The dynamic fluctuations always make it hard for the predators to detect where the prey is, hence ensuring the survival of the given prey in the given niche. The previous studies conducted have always considered the refuge consequences through some various theoretical models, field observation, and laboratory experiments. The given examinations have always highlighted the refuge helps in the stabilization of the dynamics of the predator-prey of any given single population (Cressman, Ross & József p.250). It results to increment of the predator and prey persistence and increases the availability of the prey in the given niche population.

Relationship with Spatial Heterogeneity

The predator-prey refuge has some relationship with some spatial heterogeneity in any emigration or immigration rates of any given prey in a given niche. However, it also implies the existence of spatial predation heterogeneity (Hare & Rebaza p.370). Some harvested populations have always shown the distribution shifts in the predation response, whereby the organisms from the nearby areas or locations shifts their use of habitats to facilitate the taking advantage of some available resources which have been once utilized by the harvested organisms (Forrester, Graham & Mark p.1332). In the landscape context, refuge sometimes serves as the source habitat thus supports the self-sustaining populations that have net immigration. On the other hand, some areas or locations of the co-occurrence of the predator-prey serves as the sink habitats thus they always rely on the net emigration to ensure the maintenance of the populations of the given prey.

Source-Sink Dynamics

The refuge zones in the interactions of the prey and predator help in fostering some source-sink dynamics in the predators and prey between some hunted populations and the given populaces with no or little hunting have frequently been greatly inferred depending on the composition of demography, genetics, and densities. However, the results are not usually held in some systems which have natural predation (Kar & Tapan p.685). The suitability of various habitats is always a pre-requisite for the occurrence of the species. The non-random species distribution patterns across the ecological gradients affect the diversity of the assemblage and may make some non-Volant species to start selecting some microhabitats. The microhabitats help the small animal species to co-exist with the larger animals because they always use the given habitats as refuge zones thus avoiding the danger from the existing predators (Luza, André, et al. p.90). The diversity and stability of the assemblage are also achieved through other forms of refuge such as migration and predator exclusion from the given ecological niche.

Examples of Predator-Prey Refuge

There are various examples of the predator-prey refuge in the various ecological settings. The examples of the refuge zones include the coral reefs. The coral reefs usually help in the provision of the most dramatic aquatic refuge zone. The coral reefs always have many ocean species despite it being a small percentage of the surface area of the ocean. The coral reefs help in enhancing some non-local diversity through the provision of the spawning grounds and in some cases the refuge zone for the juvenile fishes which lives in the ocean. Additionally, some rainforests act as refuge zones for various rainforest species.

Predator Exclusion Refuge

The prey organisms usually ensure the maintenance of their large populations whenever there is a location or place they can physically hide or escape predation. For instance, the rats always uphold some high population whenever they have some refuge zones like some tall grass (Persson & Lennart p.40). The refuge allows the rats to hide or escape from the ecological predators like the cats and the owls. Additionally, the game reserves have always been utilized in the enhancement of the population of some large game animals such as deer for a long period (McNair & James p.40). The process occurs by the limitation of human hunting in some relatively smaller area or place thus allowing the rebounding of the entire population. The rebounding helps in maintaining the stability of the given animal population in the ecological niche. In the human-managed ecosystems such as fisheries and game reserves, the heavily hunted zones act as a sink area in which species die faster than their rate of reproduction, but there occurs the replacement by species migrating from some nature reserve that is protected.

Migration-based Refuge

Numerous prey organisms conduct some systematic migration between the predator-rich feeding places and refuge zones thus minimizing their given chances or probability of being caught by some existing predators (Berryman, Alan & Bradford p.194). An example is the European perch which undertakes some daily horizontal migration in some Finland lakes.

Size-based Refuge

Some strategies usually depend on the prey size. Some smallest organisms or species tucks themselves with much ease in various nearby cranny or holes. For example, the barnacles live in an exposed area but are less interest to some existing predators such as the starfish due to their smaller sizes (Sih & Andrew p.2). In the given situation, the size of the animal is a refuge strategy because it helps in enabling the barnacles to ensure the escaping of desiccation under some circumstances which are lethal to small individuals. Furthermore, the tidepool sculpin always hides in some small rock pools whenever the tide happens hence takes advantage of the smaller size and also avoids the large fish predators.

Consequences of Loss of Refuge Zones

The loss of the refuge zones from the landscape would have meant the eventual extinction of some prey species in the various ecological niches or even the reduction of the prey populations. The ultimate consequence would have been the instability of the given ecology due to a reduction in the number of the prey or even their extinction. The prey extinction would affect the predators as they would lack food forcing them to migrate to other areas or start dying from hunger.

References

Berezovskaya, Faina S., Baojun Song, and Carlos Castillo-Chavez. “Role of prey dispersal and refuges on predator-prey dynamics.” SIAM Journal on Applied Mathematics 70.6 (2010): 1821-1839.

Berryman, Alan A., and Bradford A. Hawkins. ”The refuge as an integrating concept in ecology and evolution.” Oikos 115.1 (2006): 192-196.

Cressman, Ross, and József Garay. ”A predator-prey refuge system: evolutionary stability in ecological systems.” Theoretical population biology

76.4 (2009): 248-257.

Forrester, Graham E., and Mark A. Steele. ”Predators, prey refuges, and the spatial scaling of density‐dependent prey mortality.” Ecology

85.5 (2004): 1332-1342.

Hare, A., and J. Rebaza. ”Dynamics of predator-prey models with refuge, harvesting, and dispersal.” Quaestiones Mathematicae 38.3 (2015): 369-383.

Kar, Tapan Kumar. ”Stability analysis of a prey-predator model incorporating a prey refuge.” Communications in Nonlinear Science and Numerical Simulation 10.6 (2005): 681-691.

Luza, André Luís, et al. ”Processes related to habitat selection, diversity and niche similarity in assemblages of non-volant small mammals at grassland–forest ecotones.” Natureza & Conservação 14.2 (2016): 88-98.

McNair, James N. ”The effects of refuges on predator-prey interactions: a reconsideration.” Theoretical population biology 29.1 (1986): 38-63.

Sih, Andrew. “Prey refuges and predator-prey stability.” Theoretical Population Biology 31.1 (1987): 1-12.

Persson, Lennart. ”Predator-mediated competition in prey refuges: the importance of habitat dependent prey resources.” Oikos (1993): 12-22.