Editing Razorbill (section)

==Description==
[[File:Razorbill (Alca torda) pair.jpg|thumb|Courting on [[Skomer Island]]]]
The razorbill has a white belly and a black head, neck, back, and feet during the 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 the non-breeding season, the throat and face behind the eye become white, and the white line on the face and bill becomes less prominent.<ref name=LPZRazorbill/> The bill is black, deep and laterally compressed, with a blunt end. It has several vertical grooves or furrows near the curved tip, one of them adorned with a white, broken vertical line. The bill is thinner and the grooves are less marked during the non-breeding season. It is a large and thick-set bird for an [[alcid]], and its mean weight ranges from {{cvt|505|to|890|g|oz|frac=4}}.<ref name=Conder/> The female and male adults are very much alike, having only small differences such as wing length. It is 37–39&nbsp;cm in body length, the wing length of adult males ranges from {{cvt|201|–|216|mm|in|frac=16}} while that of females ranges from {{cvt|201|to|213|mm|in|frac=16}}.<ref name=Gaston/> During incubation, 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 distinctly long tail which is not common for an auk. In-flight, the feet do not protrude beyond the tail.

Their mating system is female-enforced monogamy; the razorbill pairs for life. It nests in open or hidden crevices among cliffs and boulders. It is a [[Bird colony|colonial]] breeder and only comes to land to breed. The annual survival rate of the razorbill is between 89 and 95%.<ref name=NRC/> Though the razorbill's average lifespan is roughly 13 years, a bird ringed in the UK in 1967 survived for at least 41 years—a record for the species.<ref name=McCarthy/>