Importance of androgens in male territorial acquisition in the lizard Anolis sagrei: an experimental test

The importance of androgens in the ability of male lizards to acquire a territory was tested by determining whether male brown anoles, Anolis sagrei, treated with the anti-androgen, cyproterone acetate (CA), were less successful in acquiring a ‘high-quality’ habitat patch in an outside enclosure than placebo-treated males of similar size. The habitat patch had a tree for perching, ornamental plants and twigs for refuge, and three females for mating partners. Reproductively active males were treated for 21 days with either CA (0· 1 mg/day) or placebo, both delivered from subcutaneously placed pellets. On day 21, a CA-treated male and a placebo-treated male were placed into the enclosure (6·0 m 2). Two hours later, the behaviour and location of the males were monitored for a 30-min period. In tests of 20 pairs, significantly fewer CA-treated males headbob displayed to their male pair-mate, showed the static display modifier of crest erection, and courted females than placebo-treated males. In addition, CA-treated males spent significantly less time in the high-quality habitat patch and less time perched on the tree than did placebo-treated males; they also had significantly less time of exclusive use of these areas. Males treated with CA also perched lower in the habitat than did placebo-treated males. These results suggest that androgens may play an important role in the ability of male A. sagrei and perhaps other lizards to acquire a territory.