The courtship and mating of this group of Blue-Throated Bee-Eaters (Merops viridis) have been posted earlier. This post by Micky Lim a.k.a. limmick documents nest excavation.
There were four pairs of bee-eaters and they started digging their nests in June 2009. The birds would fly directly onto the ground, dug the soft soil with their feet to slowly excavate the tunnels (left). As the depression deepened, they used their bills to dislodge the soil and feet to displace the loosened particles backwards. Each bout of digging took a few minutes before the birds flew off to rest. Excavation continued until the nests were ready. The discarded particles of soil were strewn around the nest entrances.
Each time the birds approached the nest entrance to start the digging, they would look around to check whether they were being watched before starting to dig.
A completed nest in cross-section probably looks like in the attached diagram below – about 1-2 feet below the surface (field) and about 3-5 feet long – ending in a chamber of sorts with probably a raised portion for the chicks to stay in.
This post is a cooperative effort between NaturePixels.org and BESG to bring the study of bird behaviour through photography to a wider audience.