Bright birds are cautious: seasonally conspicuous plumage prompts risk avoidance by male superb fairy-wrens

Abstract

Increased predation risk is considered a cost of having conspicuous colours, affecting the anti-predator behaviour of colourful animals. However, this is difficult to test, as individual factors often covary with colour and behaviour. We used alarm call playback and behavioural observations to assess whether individual birds adjust their response to risk according to their plumage colour. Male superb fairy-wrens () change from a dull brown to conspicuous blue plumage each year, allowing the behaviour of different coloured birds to be compared while controlling for within-individual effects. Because the timing of colour change varies among males, blue and brown birds can also be compared at the same time of year, controlling for seasonal effects on behaviour. While blue, fairy-wrens fled more often in response to alarm calls, and took longer to emerge from cover. Blue fairy-wrens also spent more time foraging in cover and being vigilant. Group members appeared to benefit from the presence of blue males, as they reduced their response to alarms, and allocated less time to sentinel behaviour when a blue male was close by. We suggest that fairy-wrens perceive themselves to be at a higher risk of predation while in conspicuous plumage and adjust their behaviour accordingly.

Reconciling ecogeographical rules: rainfall and temperature predict global colour variation in the largest bird radiation

“…), body and appendage size (Symonds & Tattersall ), or anti‐predator behaviour to compensate for imperfect camouflage (Mcqueen et al . ). It could be argued that some of these compensatory responses should be evident in males [e.g.…”

“…Furthermore, if patterns of covariation between climatic variables constrain the evolution of coloration that is optimally suited for the prevailing temperature or rainfall levels, alternative adaptations may evolve in compensation. These could include adaptations for thermoregulation such as insulation properties of fur or plumage (Briscoe et al 2015), physiology (Tattersall et al 2012), body and appendage size (Symonds & Tattersall 2010), or anti-predator behaviour to compensate for imperfect camouflage (Mcqueen et al 2017). It could be argued that some of these compensatory responses should be evident in males [e.g.…”

Revealing the colourful side of birds: spatial distribution of conspicuous plumage colours on the body of Australian birds

“…One straightforward overarching prediction that can already be made is that differences in conspicuousness between exposed and hidden body parts should be more marked for species exposed to higher predation risk, such as smaller species that inhabit open habitats (McQueen et al 2019). However, whether and how conspicuousness translates into higher predation risk across species can vary substantially (Götmark 1994, Götmark and Hohlfält 1995, Götmark 1997, Huhta et al 2003, Post and Götmark 2006, McQueen et al 2017, Cain et al 2019) and this may further obscure any general patterns.…”

Melanin‐based sexual dichromatism in the Western Palearctic avifauna implies darker males and lighter females

“…The chosen bird guide provides separate text descriptions and color illustrations when adult males and females present different phenotypes, including winter and summer plumages for species that change them seasonally. In this study, we only considered summer plumage (= breeding plumage) for the variable species, which is the time when color dichromatisms are more extensive and conspicuous (McQueen et al 2017). Comparative studies dealing with bird coloration and based on book plates are commonplace (Galván et al 2013, Dale et al 2015, as human vision provides a valid proxy for avian sexual dichromatism (Seddon et al 2010, Bergeron andFuller 2018).…”