Whitehead returned to Corsica in May 1884 to collect additional specimens and discovered that the species was sexually dimorphic in colour; the bird he had shot the previous year had been a male bird.
Whitehead tornou a Córsega en 1884 para recoller máis espécimes e descubriu que a especie era sexualmente dimórfica en coloración; a ave que cazara o ano anterior era un macho.