Heterospecific female mimicry in Ficedula flycatchers.
Mimicry is a widespread phenomenon. Vertebrate visual mimicry often operates in an intraspecific sexual context, with some males resembling conspecific females. Pied flycatcher (Ficedula hypoleuca) dorsal plumage varies from the ancestral black to female-like brown. Experimental studies have shown that conspecific and heterospecific (collared flycatcher, F. albicollis) individuals of both sexes respond, at least initially, to brown individuals as if they were female. We quantified the perceptual and biochemical differences between brown feathers and found that brown pied flycatcher males are indistinguishable from heterospecific, but not from conspecific, females in both aspects. To our knowledge, this is the first evidence of a visual mimetic signalling system in a sexual context where the model is heterospecific to the mimic. By only mimicking heterospecific females, brown pied flycatcher males can establish territories next to the more dominant collared flycatcher in sympatry, suffer less aggression by darker conspecifics in allopatry and preserve within-species sexual recognition throughout the breeding range. A closer look at the evolutionary history and ecology of these two species illustrates how such a mimetic system can evolve. Although likely rare, this phenomenon might not be unique to Ficedula flycatchers.
Division of Ecology & Evolutionary Biology, Department of Biology & Environmental Sciences, University of Jyväskylä, Jyväskylä, Finland.|Department of Biology, University of Turku, Turku, Finland.
S
S
Calhim
Department of Zoology, Palacký University, Olomouc, Czech Republic.
P
P
Adamik
Department of Biology, University of Turku, Turku, Finland.
P
P
Järvistö
Department of Biology, University of Turku, Turku, Finland.
P
P
Leskinen
Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös University, Budapest, Hungary.
J
J
Török
Department of Chemistry, Fujita Health University School of Health Sciences, Toyoake, Japan.
K
K
Wakamatsu
Department of Biology, University of Turku, Turku, Finland.
T
T
Laaksonen
D000818:Animals; D005260:Female; D020308:Songbirds / Q000502:physiology*
melanin; sexual mimicry; structural colour; sympatric speciation; visual signals