FEMALE SEXUAL-RESPONSE TO CONDITION-DEPENDENT ORNAMENTS IN THE GUPPY, POECILIA-RETICULATA

The relationship between male ornamentation, display rate, vigour and female sexual response was investigated in the guppy. Male ornamentation was quantified as the area and number of orange, black and structural colour spots and was calculated using the complexity of a male's colour pattern relative to others in the sample. Male constitution (an individual's physical makeup, comprised of inherited qualities altered by environment) was measured as (1) an individual's prolonged swimming ability, indicating vigour or endurance, and (2) as a calculated condition-factor, indicating general health. Male display rate and attractiveness were determined in a female-response experiment. Male display rate, ornament complexity, and area of orange were correlated with sustained swimming performance, and to a lesser extent, with the condition factor, suggesting that male ornamentation and display rates are condition dependent in guppies. Females responded to males that had significantly higher display rates, more complex ornamentation containing more carotenoid pigments, and higher sustained swimming speeds. The results are interpreted in the framework of the Fisherian and 'good genes' models of female choice. © 1993 The Association for the Study of Animal Behaviour. All rights reserved.