Recent usage refers to animals returning to the same area to breed despite not being born there, and migratory species that demonstrate site fidelity: reusing stopovers, staging points, and wintering grounds.
The birthplaces for these animals serve as a territory for them to return for feeding and refuge, like fish from a coral reef.
Philopatry will favor the evolution of cooperative traits because the direction of sex has consequences from the particular mating system.
Such advantages are compounded among species that invest heavily in the construction of a nest or associated courtship area.
Nest fidelity is highly beneficial as reproducing is time and energy consuming (malleefowl will tend a mound for five to six months per year).
[9] Philopatric individuals exhibit learning behaviour, and do not return to a location in following years if a breeding attempt is unsuccessful.
[12] In species that exhibit lifelong monogamous pair bonds, even outside of the breeding season, there is no bias in the sex that is philopatric.
[13] 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.
A more recent hypothesis builds on Greenwood’s findings, suggesting that parental influence may play a large role.
[16] 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.
Outbreeding depression involves reduced fitness as a result of random mating, which occurs due to the breakdown of coadapted gene complexes by combining allele that do not cross well with those from a different subpopulation.
[17] 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.
[17] A second hypothesis explains the evolution of natal philopatry as a method of reducing the high costs of dispersal among offspring.
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.
[citation needed] A major outcome of multi-generational natal philopatry is genetic divergence and, ultimately, speciation.
[20] Substantial evidence for speciation due to natal philopatry has been gathered in studies of island-nesting albatross.
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.
[23] The differences are not currently sufficient to propose identifying the populations as distinct species; however divergence is likely to continue without outbreeding.
[25] 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.
[citation needed] Due to the dispersal capabilities of albatross, distance between populations does not appear to be a determining factor in divergence.
[24] Actual speciation is likely to occur very slowly, as the selective pressures on the animals are the same for the vast majority of their lives, which is spent at sea.
As a result, breeding could not occur anywhere except natal island, strengthening philopatry and ultimately leading to even greater genetic divergence.
[citation needed][32] Cooperative breeding causes the reproductive success of all sexually mature adults to be skewed towards one mating pair.
Over time, this may lead to the evolution of obligate cooperative breeding, as exhibited by the Australian mudnesters and Australo-Papuan babblers.
[citation needed] 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.