Editing Procellariiformes (section)

====Navigation====

Many species in the order travel long distances over open water but return to the same nest site each year, raising the question of how they navigate so accurately.<ref name=Lockley>{{cite book |last=Lockley |first=Ronald M. |title=Animal Navigation |year=1967 |publisher=Pan Books| pages=114–117}}</ref> The Welsh naturalist [[Ronald Lockley]] carried out early research into [[animal navigation]] with the [[Manx shearwater]]s that nested on the island of [[Skokholm]]. In release experiments, a Manx shearwater flew from [[Boston]] to Skokholm, a distance of {{convert|3000|mi|km|abbr=off}} in 12{{frac|1|2}} days.<ref name=Lockley/><ref name=BirdsBritManx>Cocker, 2005. pp. 21–24</ref>
Lockley showed that when released "under a clear sky" with sun or stars visible, the shearwaters  oriented themselves and then "flew off in a direct line for Skokholm", making the journey so rapidly that they must have flown almost in a straight line. But if the sky was overcast at the time of release, the shearwaters flew around in circles "as if lost" and returned slowly or not at all, implying that they navigated using astronomical cues.<ref name=Lockley/>

Researchers have also begun investigating olfaction's role in procellariiform navigation. In a study where Cory's shearwaters were rendered anosmic with zinc sulphate, a compound which kills the surface layer of the olfactory epithelium, and released hundreds of kilometers away from their home colony at night, control birds found their way to their home nests before night was over, whereas anosmic birds did not home until the next day.<ref>{{Cite journal|last1=Dell'Ariccia|first1=G.|last2=Bonadonna|first2=F.|date=2013-04-15|title=Back home at night or out until morning? Nycthemeral variations in homing of anosmic Cory's shearwaters in a diurnal colony|journal=Journal of Experimental Biology|language=en|volume=216|issue=8|pages=1430–1433|doi=10.1242/jeb.082826|pmid=23307801|issn=0022-0949|doi-access=free}}</ref> A similar study that released Cory's shearwaters 800&nbsp;km from their home nests, testing both magnetic and olfactory disturbances’ effects on navigation, found that anosmic birds took longer to home than magnetically disturbed or control birds.<ref>{{Cite journal|last1=Gagliardo|first1=A.|last2=Bried|first2=J.|last3=Lambardi|first3=P.|last4=Luschi|first4=P.|last5=Wikelski|first5=M.|last6=Bonadonna|first6=F.|date=2013-08-01|title=Oceanic navigation in Cory's shearwaters: evidence for a crucial role of olfactory cues for homing after displacement|journal=Journal of Experimental Biology|language=en|volume=216|issue=15|pages=2798–2805|doi=10.1242/jeb.085738|pmid=23842626|issn=0022-0949|doi-access=free|hdl=11568/208687|hdl-access=free}}</ref>