University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Eileen Hebets Publications Papers in the Biological Sciences 2010 Mate Choice and Learning Eileen Hebets University of Nebraska-Lincoln, [email protected] Laura Sullivan-Beckers University of Nebraska-Lincoln, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/bioscihebets Part of the Behavior and Ethology Commons Hebets, Eileen and Sullivan-Beckers, Laura, "Mate Choice and Learning" (2010). Eileen Hebets Publications. 46. https://digitalcommons.unl.edu/bioscihebets/46 This Article is brought to you for free and open access by the Papers in the Biological Sciences at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Eileen Hebets Publications by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Published in Encyclopedia of Animal Behavior, edited by Michael D. Breed and Janice Moore. Amsterdam: Elsevier B.V., 2010, vol. 2, pp. 389-393. Copyright © 2010 Elsevier Ltd. Used by permission. Mate Choice and Learning E. A. Hebets and L. Sullivan-Beckers, University of Nebraska–Lincoln, Lincoln, NE, USA Introduction choice learning. For example, the use of public informa- tion relieves an individual from personally gathering While an individual’s genetic framework is a major con- information and could minimize costs typically associ- tributor in determining its eventual mate choice, the role ated with mate assessment such as exposure to preda- of the environment in further influencing mating deci- tors or decreased time devoted to other important ac- sions has long been recognized. Animals gather informa- tivities such as foraging. Mate-choice learning more tion from the environment throughout life, and in some generally permits flexibility in mate choice, which could cases, may apply this information to increase their odds be extremely important in a changing environment. In of obtaining a high-quality mate. In short, these individu- the following text, examples of different forms of mate- als learn. Moreover, such learning can have a social com- choice learning will be provided and the state of re- ponent. “Social learning” is a general term that describes search in this area summarized. any learning based on observing, interacting with, and/ or imitating others in a social context. Social learning can Private (Personal) Information transmit information vertically, generation to generation (e.g., parent to offspring) and/or horizontally, within a Juvenile Experience: Mate-Choice Imprinting generation (as individual to individual). This form of in- formation transfer is generally referred to as “cultural “Mate-choice imprinting” refers to the learning process, transmission.” This entry will focus on social learning or processes, by which young individuals acquire sex- that relates to mate choice – mate-choice learning. ual preferences based on their observation of adults. Mate-choice learning can be separated into two broad Several specific forms of imprinting exist and the gen- categories: learning based on personal experiences with eral tenet was first described by Douglas Spalding in others (referred to as “private” or “personal informa- the nineteenth century as he recounted his observations tion”) or learning that results from the observation of of newly hatched chicks following random moving ob- others (referred to as “public information”). Learning jects. Despite its early description, however, the notion from private experiences can occur at the juvenile or of imprinting was not popularized until the 1930s by adult stage and may include encounters with conspe- the pioneering work of the Nobel Prize winning Aus- cifics or heterospecifics, same sex or opposite-sex indi- trian ethologist, Konrad Lorenz. Similar to other forms viduals (Figure 1). Mate-choice imprinting, for exam- of imprinting (e.g., filial imprinting), sexual imprinting, ple, demonstrates how an early experience based on or mate-choice imprinting, typically takes place during private information shapes subsequent mate choice. a sensitive period early in life. Historically, it has most Conversely, public information refers to any informa- frequently been observed in species with parental care, tion gained through the observations of other individ- where the young use the parent of the opposite sex as ual’s experiences. An example of the use of public in- the model upon which they base their future mating formation is mate-choice copying, for example, when a preferences. This kind of early mate-choice imprinting female mimics the mating decision of another female in is thought to function to ensure conspecific matings, en- the population. Mate choice that is influenced by private abling individuals to avoid presumably costly hetero- information is sometimes termed “independent mate specific matings. Nonetheless, it is now clear that mate- choice,” whereas mate choice based on public informa- choice imprinting is not always restricted to an early tion is “nonindependent mate choice.” sensitive period and that preferences often continue to Mate-choice learning, whether it is through the acqui- be modified throughout development. sition of private or public information, balances various Crossfostering experiments are one of the primary costs and benefits. For example, the process of learning means by which scientists study early mate-choice im- itself can be costly, a topic covered in depth elsewhere. printing and such studies are most easily, and frequently, Additionally, costs can come in the form of imprinting conducted with birds. In crossfostering experiments, off- on the wrong species (which could lead to reduced fit- spring are raised by parents of either another phenotype ness), or from copying another individual that has cho- (e.g., a different color morph) or another species and, sen poorly itself. Nonetheless, the prevalence of mate- subsequently, their adult mate choice is examined. Us- choice learning across taxonomic groups suggests that ing crossfostering experiments, mate-choice imprinting there are significant benefits associated with mate- has been demonstrated in numerous bird species includ- 389 390 HEBETS & SULLIVAN-BECKERS IN ENCYCLOPEDIA OF ANIMAL BEHAVIOR (2010) Figure 1. Mate-choice learning as influenced by social environment. This diagram depicts the various sources of social information that can impact mate-choice learning; the various life stages during which learning might be important; and some of the documented outcomes of mate-choice learning. Sections marked with “***” indicate topics for which research is lacking or nonexistent, and we suggest that these might be potentially fruitful areas for future focus. ing, but not confined to snow geese, zebra finches, Ben- mathematical models have been constructed to examine galese finches, great tits, blue tits, and red jungle fowl. In the various aspects of mate-choice imprinting. For ex- mammals, reciprocal crossfostering of sheep and goats ample, population genetic models have been used to ex- has demonstrated a role of maternal imprinting on sub- plore the evolution of different forms of imprinting. In sequent sexual preferences. Similarly, in Lake Victoria these models, Tramm and Servedio compared the evo- fishes, females of some species appear to imprint on the lution of paternal, maternal, and oblique imprinting and phenotype of their mother. Crossfostering experiments found that paternal imprinting was the most likely to supporting a process of mate-choice imprinting are prev- evolve. Their results suggest that the success of a partic- alent, yet studies do exist for which such early experi- ular imprinting strategy is most influenced by the group ences have not influenced adult mate choice—raising in- of individuals that are imprinted upon (termed the “im- teresting questions about species-level differences in the printing set”). potential for, and importance of, mate-choice learning. Traditional examples of mate-choice imprinting, as Juvenile Experience: Mate Selectivity outlined earlier, are often restricted to species in which young spend significant time with their parents, thus, Mate-choice imprinting involves juvenile individuals enabling parental imprinting (either paternal or mater- imprinting on, or learning, various characteristics of nal). However, mate-choice learning may also be preva- an adult model, whether the model is their mother, fa- lent in species that lack parental care, yet still have sig- ther, or another nonparental adult. Subsequently, these nificant exposure to other conspecifics. For example, learned characteristics are incorporated into the indi- female wolf spiders are known to choose to mate with vidual’s mate-choice criteria, and mating partners with mature males of a phenotype with which they had expe- similar characteristics are preferred. However, experi- rience as a subadult. This type of imprinting is referred ence with conspecific adults may not always lead to a to as “oblique imprinting”—imprinting on a nonpa- preference for individuals resembling a model. Some- rental adult. In another example of oblique imprinting, times, early experience may simply increase choosiness. damselfly males alter their preference of female morphs Such effects of early experience have been documented based upon prior experience – males raised in the ab- in various animal taxa. For example, in both field crick- sence of females show no preference, while those raised ets and