Efectos de la experiencia social temprana en las preferencias sexuales de la codorniz japonesa (coturnix japonica) / Effects of early social experiences on mating preferences of coturnix japonica

RESUMEN

Las teorías clásicas propuestas para explicar las preferencias sexuales han hecho énfasis en los determinantes genéticos; consideran que las preferencias de las hembras y los rasgos sexuales de los machos coevolucionan, porque los rasgos son un indicador confiable de "buenos genes" que favorecen la supervivencia de los hijos. Una hipótesis alternativa explica las preferencias sexuales mediante un mecanismo de aprendizaje; un ejemplo de este enfoque es el aprendizaje por impronta propuesto por Konrad Lorenz. El presente experimento se propuso evaluar los efectos de diferentes prácticas de crianza temprana sobre las preferencias de pareja. Para este propósito, se seleccionaron 35 pollitos de codorniz, de 15 días de nacidos, y se dividieron en cuatro grupos: (1) un grupo de 9 pollitos machos criados cada uno en compañía de una hembra adulta de tres meses;(2) un grupo de 9 pollitos hembras criadas cada una en compañía de un macho adulto de tres meses; (3) un grupo de 9 pollitos machos criados en jaulas individuales y sin contacto visual con otros de su especie, y (4) un grupo de 8 pollitos hembras criadas en jaulas individuales y sin contacto visual con otros de su especie. Estas condiciones se mantuvieron por tres meses, al cabo de los cuales cada uno de los animales fue sometido a una prueba de preferencia de pareja y se midió el tiempo que el animal dedicaba a observar a una pareja potencial (la pareja con la que se había criado y una pareja distinta) en ensayos de 10 minutos, durante 10 días. Los resultados muestran que el 50 por ciento de los 18 pollitos que conformaron los grupos de machos y hembras criados en pareja, presentaron diferencias significativas (23 por ciento a favor de la pareja de crianza y 27 por ciento a favor de una pareja distinta); y de los 17 pollitos que conformaron los grupos de crianza individualizada, sólo el 12 por ciento del grupo de machos mostró diferencias significativas en sus preferencias de pareja. Al ...

ABSTRACT

Current theories that attempt to explain mating preferences have placed particular emphasis on genetic determinants. They state that sexual preferences of females and sexual features of males evolve concurrently given the fact that male features are a reliable indicator of the presence of "good genes" which favor offspring survival. An alternative hypothesis explains mating preferences by means of a learning mechanism. An example of this approach is the theory of learning by imprinting proposed by Konrad Lorenz. This experiment aimed to evaluate the effects of different types of early breeding practices on later mating preferences. For this purpose, 35 quail chicks, 15 days old, were selected and split into four groups: (1) a group of 9 male chicks which were individually raised in the company of a mature three months old female; (2) a group of 9 female chicks which were individually raised in the company of a mature three months old male; (3) a group of 9 male chicks, which were raised alone in individual cages and without visual contact with other members of their species; and (4) a group of 8 female chicks which were raised alone in individual cages and without visual contact with others of their species. Subjects were exposed to these conditions for a period of three months. Later, each one of the animals underwent a mating preference test where the time that an animal spent observing a potential partner (the partner the chick had been raised with and a different partner) was measured during a 10minutes trial for10 days. Results show that 50 percent of the18 chicks that formed the groups of males and females raised in a pair fashion, presented significant differences in mating preferences (23 percent in favor of the breeding partner and 27 percent in favor of a different partner). But in the group of 17 chicks that were placed in the condition of individualized breeding, only 12 percent of the male chicks showed significant differences in their preference for a specific partner. When comparing the various rearing conditions by means of an ANOVA, significant differences were obtained between them: F (7, 663) = 2,072, P <0, 05. The results of this experiment suggest that rearing conditions have a differential effect on males and females in terms of mating preferences and seem to have a greater impact on females.