TY - JOUR
T1 - Male-male competition and the sword in male swordtails, Xiphophorus helleri
AU - Benson, Kari E.
AU - Basolo, Alexandra L.
N1 - Funding Information:
We gratefully acknowledge J. Anderson, A. Aspbury, K. Delaney, A. Kamil, S. Louda, D. Leger, B. Trainor, W. E. Wagner and two anonymous referees for insightful comments on earlier revisions of this manuscript. We also thank the Fisheries Ministry of Belize for collection permits. Support for this research was provided by Sigma Xi and the Nebraska Behavioral Biology Group (to K.B.), and by the National Science Foundation (to A.L.B.: IBN 95-0509211, IBN 96-29318, IBN 01-12656; to A.L.B. and K.B.: IBN 97-01258).
PY - 2006/1
Y1 - 2006/1
N2 - Male green swordtails, Xiphophorus helleri, express a secondary sexual trait, the sword, which is favoured by female mate choice. However, the role of the sword as a signal in male-male competition has received little attention. We studied the effect of both male body size and sword length on the outcome of male-male competition. Although body size and natural sword length were positively correlated, only body size had a significant effect on competitive success. To examine the independent effect of sword length on competitive success, males were matched for body size and natural swords were replaced with plastic caudal attachments simulating swords. The attachments were of equal size but were painted to approximate swords of different lengths. When matched for body size, males with longer apparent swords won significantly more contests than males with shorter apparent swords. These data suggest that, controlling for body size, longer-sworded males experience greater competitive success. Thus, in green swordtails, it appears that both male-male competition and female choice may have played a role in the evolution of longer swords.
AB - Male green swordtails, Xiphophorus helleri, express a secondary sexual trait, the sword, which is favoured by female mate choice. However, the role of the sword as a signal in male-male competition has received little attention. We studied the effect of both male body size and sword length on the outcome of male-male competition. Although body size and natural sword length were positively correlated, only body size had a significant effect on competitive success. To examine the independent effect of sword length on competitive success, males were matched for body size and natural swords were replaced with plastic caudal attachments simulating swords. The attachments were of equal size but were painted to approximate swords of different lengths. When matched for body size, males with longer apparent swords won significantly more contests than males with shorter apparent swords. These data suggest that, controlling for body size, longer-sworded males experience greater competitive success. Thus, in green swordtails, it appears that both male-male competition and female choice may have played a role in the evolution of longer swords.
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U2 - 10.1016/j.anbehav.2005.05.004
DO - 10.1016/j.anbehav.2005.05.004
M3 - Article
AN - SCOPUS:29444457343
SN - 0003-3472
VL - 71
SP - 129
EP - 134
JO - Animal Behaviour
JF - Animal Behaviour
IS - 1
ER -