HOME RANGES AND SATELLITE TACTICS OF MALE GREEN SWORDTAILS (XIPHOPHORUS-HELLERI) IN NATURE

Dominance relationships were studied between marked or otherwise indiv idually recognizable male green swordtails in a creek at Lake Catemaco and in a tributary of the Rio Atoyac (Veracruz, Mexico). The Atoyac p opulation is unique because of a high degree of polymorphism, includin g both macromelanophore spotting and a micromelanophore tailspot patte rn. During the dry season males living in the same area maintained a l inear social hierarchy for periods of many days. The subordinate males settled down either in the same home ranges or in home ranges largely overlapping with that of dominant males. Although dominant males unti ringly chased the subordinate males away, they returned persistently a nd achieved the status of non-tolerated satellites. Females were less stationary and presumably passed through many male home ranges during their feeding activities. The data clearly demonstrate that green swor dtails live in complex social systems in which male-male competition a nd probably also female mate choice are likely to be essential factors for individual reproductive success. (C) 1998 Elsevier Science B.V. A ll rights reserved.