Ke. Bruce et Wg. White, AGONISTIC RELATIONSHIPS AND SEXUAL-BEHAVIOR PATTERNS IN MALE GUPPIES,POECILIA-RETICULATA, Animal behaviour, 50, 1995, pp. 1009-1021
Two experiments were conducted to assess the influence of agonistic re
lationships among male guppies on their sexual and aggressive behaviou
r under different social conditions. In experiment 1, each male of sma
ll mixed-sex groups of guppies was systematically removed and reintrod
uced to the group. Only during the alpha male reintroduction were ther
e any changes in the sexual behaviour of the remaining males; the fema
le-preferred sigmoid display of the beta males was depressed. During r
eintroductions, the alpha male was responsible for most aggression dir
ected towards the reintroduced male. Females also responded aggressive
ly towards the reintroduced males, particularly the alpha male. In exp
eriment 2, an unfamiliar male was introduced to each established mixed
-sex group. Again, rank-related behaviour was evident; most aggression
directed towards the unfamiliar male was performed by the alpha male.
The unfamiliar male also performed fewer sigmoid displays than did th
e alpha male. Thus, agonistic relationships among males may be respons
ible for suppression of sexual behaviour by subordinate and non-reside
nt males and should be considered as a factor in sexual selection proc
esses in guppies. (C) 1995 The Association for the Study of Animal Beh
aviour