Forehead Patch Size Predicts the Outcome of Male–Male Competition in the Pied Flycatcher

Abstract

Males of many animal species express ornaments that affect their reproduction opportunities through male–male competition or female mate choice. Such ornaments can, for example, inform conspecifics about the fighting ability, condition or territory ownership of the bearer. Pied flycatcher (Ficedula hypoleuca) males have a conspicuous white forehead patch that varies greatly in size. We examined whether the white forehead patch is an intrasexually selected trait in a Finnish population. We artificially manipulated forehead patch size to represent two naturally occurring extremes and competed males against each other in the presence of a female. Males with a large forehead patch were more aggressive than males with a small patch, whereas the original patch size of the male had no influence on aggression. Neither manipulated nor original patch size influenced resource dominance (over female or nest box). These results indicate that forehead patch signals fighting ability of the bearer in the pied flycatcher. The next step is to find out what kind of costs may maintain the honesty of this signal.

Carry‐over effects of conditions at the wintering grounds on breeding plumage signals in a migratory bird: roles of phenotypic plasticity and selection

“…Nevertheless, we did find an age‐dependent effect on the expression of forehead patch size: patch sizes of young males were smaller than those of old males. As in this population males with a large forehead patch are more aggressive than males with a small patch (Järvistö et al ., ), a smaller patch of a young male might reduce serious attacks from old males.…”

“…Although high heritability has been reported for the forehead patch (Potti & Canal, ), heritability for the wing patch has not yet been studied. A large forehead patch has been shown to be preferred by female flycatchers in a Spanish population (Potti & Montalvo, ), and the size of the forehead patch predicted the outcome of male–male competition in a Finnish population (Järvistö et al ., ). Moreover, the size of the wing patch has been shown to be under intersexual selection in a Finnish population (Sirkiä & Laaksonen, ).…”

Information‐gathering as a response to manipulated signals in the eastern fence lizard, Sceloporus undulatus

“…There are many aspects to color patches that may be rich in information content. Signal size in pied flycatchers is positively associated with winning male contests (Järvistö et al., ), but in other taxa, color may play a more important, or similar role to size during agonistic male‐male encounters. For example, in wrasses (Braun, Michiels, Siebeck, & Sprenger, ), blue tits (Rémy, Grégoire, Perret, & Doutrelant, ) and scrub jays (Tringali & Bowman, ) the color of the signaling patches is important for mediating aggression or dominance status.…”

“…For example, experimental manipulations of color signals in pukekos (Dey et al, 2014) and white-crowned sparrows (Laubach et al, 2013) indicate that signaling patch size is positively associated with dominance status or aggression. Further, forehead patch size in pied flycatchers is positively associated with antioxidant capacity (Moreno et al, 2011) and winning male contests (Järvistö, Laaksonen, & Calhim, 2013). In addition to conveying information about body size and condition, colored patches may also lead to changes in the behavior of receiving animals that have long-term consequences to territorial competition and mate choice.…”

“…Recently, paint manipulation studies have offered fresh insight by emphasizing the impact of social interactions on the subsequent behavior of the signaler. For example, in birds, males with artificially decreased patches are less aggressive during social interactions (Järvistö et al, 2013), and the manipulation itself can lead to decreases in the size of the actual patch (e.g., Dey et al, 2014). In spiny-footed lizards, adult aggression was reduced toward juveniles with experimentally manipulated red coloration (Fresnillo, Belliure, & Cuervo, 2015).…”