In birds, which of these is the most widespread species of the genus 'Upupa'?

The Eurasian hoopoe ('Upupa epops') is the most widespread species of the genus 'Upupa', native to Europe, Asia and the northern half of Africa.

Nine subspecies of Eurasian hoopoe are recognised. They vary mostly in size and the depth of colour in the plumage.

The Eurasian hoopoe is a medium-sized bird, 25–32 cm (9.8–12.6 in) long, with a 44–48 cm (17–19 in) wingspan. It weighs 46–89 g (1.6–3.1 oz). The species is highly distinctive, with a long, thin tapering bill that is black with a fawn base. The strengthened musculature of the head allows the bill to be opened when probing inside the soil.