Ndege huyu analala akiwa anaruka

Ndege aitwaye frigatebird anaweza kuruka kwa siku nyingi. Anaruka juu ya bahari kuu. Hawezi kutua juu ya maji. Basi analala lini?

A frigatebird can fly for many days. It flies over the open sea. It cannot land on the water. So when does it sleep?

Wanasayansi wanaweka mashine ndogo kwenye ndege hao. Ndege wanaruka hadi siku kumi. Wanalala wakiwa wanaruka. Nusu ya ubongo inalala. Jicho moja linabaki wazi.

Scientists put small machines on the birds. The birds fly for up to ten days. They sleep while they fly. Half the brain sleeps. One eye stays open.

Hii inashangaza. Baharini, ndege wanalala dakika arobaini tu kwa siku. Nchi kavu, wanalala zaidi ya saa kumi na mbili. Wanapumzika sana wakiwa nyumbani.

This is surprising. At sea, birds sleep only forty minutes a day. On land, they sleep more than twelve hours. They rest a lot at home.