Жануарлардың туған жерге қайта оралу тенденциясы

Tendency of animals to return to an area, especially to reproduce
Philopatry is the tendency of an organism to stay in or habitually return to a particular area. The causes of philopatry are numerous, but natal philopatry, where animals return to their birthplace to breed, may be the most common. The term derives from the Greek roots philo, "liking, loving" and patra, "fatherland",

Some of the known reasons for organisms to be philopatric would be for mating (reproduction), survival, migration, parental care, resources, etc In most species of animals, individuals will benefit from living in groups, because depending on the species, individuals are more vulnerable to predation and more likely to have difficulty finding resources and food. Therefore, living in groups increases a species' chances of survival, which correlates to finding resources and reproducing. Again, depending on the species, returning to their birthplace where that particular species occupies that territory is the more favorable option. The birthplaces for these animals serve as a territory for them to return for feeding and refuge, like fish from a coral reef. In an animal behavior study conducted by Paul Greenwood, overall female mammals are more likely to be philopatric, while male mammals are more likely to disperse. Male birds are more likely to be philopatric, while females are more likely to disperse. Philopatry will favor the evolution of cooperative traits because the direction of sex has consequences from the particular mating system. In colonial seabirds, it has been shown that nest fidelity depends on multi scale information, including the breeding success of the focal breeding pair, the average breeding success of the rest of the colony, and the interaction of these two scales. Breeding fidelity is also well documented among species that migrate or disperse after reaching maturity. Birds, in particular, that disperse as fledglings will take advantage of exceptional navigational skills to return to a previous site. Philopatric individuals exhibit learning behaviour, and do not return to a location in following years if a breeding attempt is unsuccessful. The evolutionary benefits of such learning are evident: individuals that risk searching for a better site will not have lower fitness than those that persist with a poor site. Philopatry is not homogenous within a species, with individuals far more likely to exhibit philopatry if the breeding habitat is isolated. Similarly, non migratory populations are more likely to be philopatric that those that migrate. In species that exhibit lifelong monogamous pair bonds, even outside of the breeding season, there is no bias in the sex that is philopatric. However, among polygynous species that disperse (including those that find only a single mate per breeding season), there is a much higher rate of breeding site philopatry in males than females among birds, and the opposite bias among mammals. Many possible explanations for this sex bias have been posited, with the earliest accepted hypothesis attributing the bias to intrasexual competition, and territory choice. Males generally invest little in the raising of offspring, and compete with each other for mates rather than resources. Thus, dispersing can result in reproductive enhancement, as greater access to females is available. On the other hand, the cost of dispersal to females is high, and thus they are philopatric. This hypothesis also applies to natal philopatry, but is primarily concerned with breeding site fidelity. A more recent hypothesis builds on Greenwood’s findings, suggesting that parental influence may play a large role. Because birds lay eggs, adult females are at risk of being cuckolded by their daughters, and thus would drive them out. On the other hand, young male mammals pose a threat to their dominant father, and so are driven to disperse while young.

This page discusses the evolutionary reasons for philopatry. For the mechanisms of philopatry, see Natal homing. Natal philopatry commonly refers to the return to the area the animal was born in, or to animals remaining in their natal territory. It is a form of breeding site philopatry. The debate over the evolutionary causes remains unsettled. The outcomes of natal philopatry may be speciation, and, in cases of non dispersing animals, cooperative breeding. Natal philopatry is the most common form of philopatry in females because it decreases competition for mating and increases the rate of reproduction and a higher survival rate for offspring. He argued that, since philopatry leads to the concentration of related individuals in their birth areas, and thus reduced genetic diversity, there must be some advantage to inbreeding – otherwise the process would have been evolutionary detrimental and would not be so prevalent. The major beneficial outcome under this hypothesis is the protection of a local gene complex that is finely adapted to the local environment. However, it is important to note that outbreeding depression becomes more detrimental the longer (temporally) that subpopulations have been separated, and that this does hypothesis does not provide an initial mechanism for the evolution of natal philopatry. A second is that philopatry provides a much higher chance of breeding success. Strict habitat requirements – whether due to a precisely adapted genome or not – mean that individuals that return to a site are more familiar with it, and may have more success in either defending it, or locating mates. Neither of these hypotheses is as widely accepted as the optimal inbreeding or dispersal hypotheses, but their existence indicates that the evolutionary causes of natal philopatry have still not been conclusively demonstrated.

A major outcome of multi generational natal philopatry is genetic divergence and, ultimately, speciation. Without genetic exchange, geographically and reproductively isolated populations may undergo genetic drift. Such speciation is most evident on islands. For mobile island breeding animals, finding a new breeding location may be beyond their means. In combination with a small population, as may occur due to recent colonisation, or simply restricted space, genetic drift can occur on shorter timescales than is observable in mainland species. The high levels of endemism on islands have been attributed to these factors. Substantial evidence for speciation due to natal philopatry has been gathered in studies of island nesting albatross. Genetic difference is most often detected in microsatellites in mitochondrial DNA. Animals that spend much of their time at sea, but which return to land to breed exhibit high levels of natal philopatry and subsequent genetic drift between populations. Many species of albatross do not breed until 6–16 years of age. Between leaving their birth island, and their return, they fly hundreds of thousands of kilometres. High levels of natal philopatry have been demonstrated via mark recapture data. For example, more than 99% of Laysan albatross (Phoebastria immutabilis) in a study returned to exactly the same nest in consecutive years. Such site specificity can lead to speciation, and has also been observed in the earliest stages of this process. The shy albatross (Thalassarche [cauta] cauta) was shown to have genetic differences in its microsatellites between three breeding colonies located off the coast of Tasmania. The differences are not currently sufficient to propose identifying the populations as distinct species; however divergence is likely to continue without outbreeding. Not all isolated populations will show evidence of genetic drift. Genetic homogeneity can be attributed to one of two explanations, both of which indicate that natal philopatry is not absolute within a species. Firstly, a lack of divergence may be due to founder effects, which explains how individuals that start new populations carry the genes of their source population. If only a short (in evolutionary timescales) period of time has passed, insufficient divergence may have occurred. For example, study of mitochondrial DNA microsatellites found no significant difference between colonies of black browed albatross (T. melanophrys) on the Falkland Islands and Campbell Island, despite the sites being thousands of kilometres apart. Observational evidence of white capped albatross (T. [cauta] steadi) making attempts to build nests on a south Atlantic Island, where the species had never been previously recorded, demonstrate that range extension by roaming sub adult birds is possible. Secondly, there may be sufficient gene exchange as to prevent divergence. For example, isolated (yet geographically close) populations of the Buller’s albatross (T. bulleri bulleri) have been shown to be genetically similar. Speciation through natal philopatry is a self reinforcing process. Once genetic differences are sufficient, different species may be unable to interbreed to produce viable offspring. As a result, breeding could not occur anywhere except natal island, strengthening philopatry and ultimately leading to even greater genetic divergence.

Philopatric species that do not migrate may evolve to breed cooperatively. Kin selection, of which cooperative breeding is a form, explains how individual offspring provide care for further offspring produced by their relatives. Animals that are philopatric to birthsites have increased association with family members, and, in situations where inclusive fitness is increased through cooperative breeding, may evolve such behaviour, as it will incur evolutionary benefits to families that do. Cooperative breeding is a hierarchical social system characterized by a dominant breeding pair surrounded by subordinate helpers. The dominant breeding pair and their helpers experience costs and benefits from using this system. Costs for helpers include a fitness reduction, increased territory defense, offspring guarding and an increased cost of growth. Benefits for helpers include a reduced chance of predation, increased foraging time, territory inheritance, increased environmental conditions and an inclusive fitness. For the breeding pair, costs include increased mate guarding and suppression of subordinate mating. Breeders receive benefits as reductions in offspring care and territory maintenance. Their primary benefit is an increased reproductive rate and survival. Cooperative breeding causes the reproductive success of all sexually mature adults to be skewed towards one mating pair. This means the reproductive fitness of the group is held within a select few breeding members and helpers have little to no reproductive fitness. With this system, breeders gain an increased reproductive, while helpers gain an increased inclusive fitness.

Migrating animals also exhibit philopatry to certain important areas on their route; staging areas, stop overs, molting areas and wintering grounds. Philopatry is generally believed to help maintain the adaptation of a population to a very specific environment (i. e., if a set of genes has evolved in a specific area, individuals that fail to return to that area may do poorly elsewhere, so natural selection will favor those who exhibit fidelity). The level of philopatry varies within migratory families and species. The term is sometimes also applied to animals that live in nests but do not remain in them during an unfavorable season (e. g., the winter in the temperate zone, or the dry season in the tropics), and leave to find hiding places nearby to pass the inactive period (common in various bees and wasps); this is not migration in the usual sense, as the location of the hiding place is effectively random and unique (never located or revisited except by accident), though the navigation skills required to relocate the old nest site may be similar to those of migrating animals.