Behavioral ecology
This term, derived from economic game theory, became prominent after John Maynard Smith (1982)[1] recognized the possible application of the concept of a Nash equilibrium to model the evolution of behavioral strategies.
The two sharers would then move out of phase with one another, resulting in decreased feeding rate but also increased defense, illustrating advantages of group living.
[9] One example of this is with the grayling butterfly (Hipparchia semele), where males engage in complex flight patterns to decide who defends a particular territory.
[9] First, the good genes hypothesis suggests that female choice is for higher genetic quality and that this preference is favored because it increases fitness of the offspring.
[17] The sensory bias hypothesis states that the preference for a trait evolves in a non-mating context, and is then exploited by one sex to obtain more mating opportunities.
This mechanism is thought to explain remarkable trait differences in closely related species because it produces a divergence in signaling systems, which leads to reproductive isolation.
[34] Similarly the neriid fly Derocephalus angusticollis demonstrates mate guarding by using their long limbs to hold onto the female as well as push other males away during copulation.
Male scorpionflies usually acquire mates by presenting them with edible nuptial gifts in the forms of salivary secretions or dead insects.
In other cases, parental care is indirect, manifested via actions taken before the offspring is produced, but nonetheless essential for their survival; for example, female Lasioglossum figueresi sweat bees excavate a nest, construct brood cells, and stock the cells with pollen and nectar before they lay their eggs, so when the larvae hatch they are sheltered and fed, but the females die without ever interacting with their brood.
This is most likely because females are internally fertilized and so are holding the young inside for a prolonged period of gestation, which provides males with the opportunity to desert.
[50] Evidence suggests that the sperm evolved to prevent female waltzing flies from mating multiply in order to ensure the male's paternity.
[citation needed] Lack's hypothesis posits an evolutionary and ecological explanation as to why birds lay a series of eggs with an asynchronous delay leading to nestlings of mixed age and weights.
This competition for the mother's milk is especially fierce during periods of food shortage such as an El Niño year, and this usually results in the older pup directly attacking and killing the younger one.
In the blue-footed booby, for example, the first egg in a nest is hatched four days before the second one, resulting in the elder chick having a four-day head start in growth.
Studies show that the common cuckoo uses vocal mimicry to reproduce the sound of multiple hungry host young to solicit more food.
[80] Monogamy is the mating system in 90% of birds, possibly because each male and female has a greater number of offspring if they share in raising a brood.
[87] Some birds, such as the phalaropes, have reversed sex roles where the female is larger and more brightly colored, and compete for males to incubate their clutches.
[90] John Maynard Smith coined the term in 1964,[92] although the concept was referred to by Charles Darwin who cited that helping relatives would be favored by group selection.
[98] That is, the effect an individual's behaviors have on: being personally better-suited to reproduce offspring, and aiding descendant and non-descendant relatives in their reproductive efforts.
[103] Similarly, individuals of the stingless bee species Trigona fulviventris can distinguish kin from non-kin through recognition of a number of compounds, including hydrocarbons and fatty acids that are present in their wax and floral oils from plants used to construct their nests.
Laboratory tests[106] indicate that females can discriminate between kin and nonkin, close and distant relatives and, within-litters, between full-siblings and maternal half-siblings.
[121] The species of wasp Polybia rejecta and ants Azteca chartifex show a cooperative behavior protecting one another's nests from predators.
Spiteful behavior is favored if the actor is less related to the recipient than to the average member of the population making r negative and if rB-C is still greater than zero.
Sterile soldier wasps also develop and attack the relatively unrelated brother larvae so that the genetically identical sisters have more access to food.
This has led to the suggestion that kin selection may be a driving force in the evolution of eusociality, as individuals could provide cooperative care that establishes a favorable benefit to cost ratio (rB-c > 0).
Another suggested benefit is the possibility of "fortress defense", where soldier castes threaten or attack intruders, thus protecting related individuals inside the territory.
The natural world is replete with examples of signals, from the luminescent flashes of light from fireflies, to chemical signaling in red harvester ants to prominent mating displays of birds such as the Guianan cock-of-the-rock, which gather in leks, the pheromones released by the corn earworm moth,[138] the dancing patterns of the blue-footed booby, or the alarm sound Synoeca cyanea make by rubbing their mandibles against their nest.
[139] Yet other examples are the cases of the grizzled skipper and Spodoptera littoralis where pheromones are released as a sexual recognition mechanism that drives evolution.
Although the potential benefits of deceit could be great in terms of mating success, there are several possibilities for how dishonesty is controlled, which include indices, handicaps, and common interests.
Prime examples of dishonest signals include the luminescent lure of the anglerfish, which is used to attract prey, or the mimicry of non-poisonous butterfly species, like the Batesian mimic Papilio polyxenes of the poisonous model Battus philenor.
