Table 1.
Comparing sexes for sensitivity/insensitivity to experimentally elevated T (+, treatment enhanced mean trait value, −, treatment reduced mean trait value)
| Trait | Males | Females | Source |
|---|---|---|---|
| Attractiveness | + | − | (Enstrom et al. 1997; Ketterson et al. 2005) |
| Song | + | n/aa | (Ketterson et al. 1992; n/a) |
| Incubate eggs | n/a | nddb | (n/a; Clotfelter et al. 2004) |
| Feed offspring | − | ndd | (Ketterson et al. 1992; Schoech et al. 1998; Clotfelter et al. 2004; O’Neal et al. 2008) |
| Defend offspring | − | − | (Cawthorn et al. 1998; O’Neal et al. 2008) |
| Immune function | − | − | (Casto et al. 2001; Zysling et al. 2006) |
| Corticosterone, CBGc | + | + | (Klukowski et al. 1997; Zysling et al. 2006) |
| Molt | − | − | (Nolan et al. 1992; Clotfelter et al. 2004) |
an/a, not applicable because trait is typically expressed in only one sex; T-treated females occasionally sang but frequency was not quantified; males do not incubate; bndd, no (statistically) detectable difference; cCBG, corticosteroid binding globulin.