Editing Razorbill (section)

=== Incubation and hatching ===
[[File:Alca torda MHNT Île Rouzic.jpg|thumb|upright|Egg]]
Females lay a single egg per year, usually from late April to May. The egg is an [[ovoid]]-pyramidal shape, creamy white to pale brown with has dark brown blotches. [[Avian incubation|Incubation]] starts generally 48 hours after laying the egg. Females and males take turns incubating the egg several times daily for a total of approximately 35 days before hatching occurs. Razorbill chicks are semi-[[precocial]].<ref name=Ralph/> During the first two days after hatching, the chick will spend the majority of its time under the parent's wing. There is always one parent at the nest site while the other goes to sea to collect food for the chick. The hatchling develops a complete sheath 10 days after hatching. After 17–23 days, the chick leaves the nest by jumping from a cliff, closely followed by the male parent, who will accompany the chick to sea. During this time, the male parent will dive more than the female parent.<ref>{{Cite journal|last1=Dunn|first1=Ruth E.|last2=Wanless|first2=Sarah|last3=Green|first3=Jonathan A.|last4=Harris|first4=Michael P.|last5=Daunt|first5=Francis|date=2019|title=Effects of body size, sex, parental care and moult strategies on auk diving behaviour outside the breeding season|journal=Journal of Avian Biology|language=en|volume=50|issue=7|doi=10.1111/jav.02012|s2cid=164436494|issn=1600-048X|doi-access=free}}</ref>