Female choice, parasite load and male ornamentation in wild turkeys

A tradeoff between immunocompetence and sexual ornamentation in domestic fowl

“…It is interesting to note that our study, in conjunction with the study of Leitner (43), provides experimental evidence for such feedback in birds, because testosterone levels responded to manipulation of immunocompetence. This finding is in agreement with the observation that testosterone and ornamentation decrease with increasing parasite load in domestic fowl and other species (48,(51)(52)(53)(54)(55)(56). Taken together, these observations suggest that testosterone in birds plays only some of the roles assumed in the original immunocompetence hypothesis, in the sense that it modulates the expression of sexual ornaments but in turn is modulated by immune function, rather than vice versa as originally assumed (7).…”

Morphology and Ornamentation in Male Magnificent Frigatebirds: Variation with Age Class and Mating Status

“…This differs from the general findings, for instance, in galliforms, where female mate preferences are based on the color and size expression of condition-associated and testosterone-mediated soft parts (Ligon et al 1990;Zuk et al 1990aZuk et al , 1990bHolder and Montgomerie 1993;Buchholtz 1995; Rintamä k ie ta l . 2000).…”

“…Skin ornaments are included in many displays and may play an important role in mate choice (Zuk et al 1990a(Zuk et al , 1995Spurrier et al 1991;Buchholtz 1995;Ligon and Zwartjes 1995;Rintamäki et al 2000). These ornaments reflect condition (Ligon et al 1990), parasite load (Zuk et al 1990b;Spurrier et al 1991), and testosterone levels (Stokkan 1979;Ligon et al 1990;Zuk et al 1995;Papeschi et Figure 2: Reflectance spectra, relative to a barium sulfate standard.…”

Mate preferences in female canaries (Serinus canaria) within a breeding season

“…Females with good or poor reproductive success faced two potential mates in a choice chamber: their previous mate and a male neighbor. Such a protocol was widely used to study mate preferences in previous studies (Collins 1994;Houtman and Falls 1994;Palokangas et al 1994;Swaddle and Cuthill 1994;Buchholz 1995;Mateos and Carranza 1995;White and Galef 1999;Jones et al 2001;Akins et al 2002).…”