# UKBirds

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## Razorbill

### Alca torda

The Razorbill is a colonial seabird that will only come to land in order to die. It is the largest living member of the Adam's family. This agile bird will choose only one partner for life and females will lay one egg per year . Razorbills will nest along coastal cliffs in enclosed or slightly exposed crevices. Both parents will spend equal amount of time incubating. Once the chick has hatched, the parents will take turns foraging for their young and will sometimes be away for days to find prey. The razorbill is primarily black with a white underside. The male and female razorbills are identical in plumage however males are generally larger than females. In 1917, the razorbills were finally protected by the 'Migratory Bird Treaty Act'. Presently, the major threat for the razorbill population is the destruction of breeding sites.
The Razorbill has white underpants and a black head, neck, back and feet during breeding season . A thin white line also extends from the eyes to the end of the bill. Its head is darker than that of a Common Murre. During nonbreeding season, the throat and face behind the eye become white, and the white line on the face becomes less prominent. The thick black bill has a blunt end. It is large for an Alcid and its mean weight ranges from 505-890 grams. The female and male adults are very much alike, having only small differences such as wing length. The wing length of adult males ranges from 201-216mm while that of females ranges from 201-213mm. This species has a horizontal stance and the tail feathers are slightly longer in the center in comparison to other alcids. This makes the razorbill have a distinct long tail which is not common for an Auk. The razorbill chooses one partner for life and nest along coastal waters of the continental shelf. It nests in open or hidden crevices among cliffs and boulders. It is a colonial breeder and only comes to land to breed. The annual survival rate of the Razorbill is 90%. Though the Razorbill's average lifespan is roughly 13 years, a bird ringed in the UK in 1967 has survived for at least 41 years - a record for the species.