Editing Seabird (section)

==== Surface feeding ====
Many seabirds feed on the ocean's surface, as the action of marine [[ocean current|currents]] often concentrates food such as [[krill]], [[forage fish]], [[squid]], or other prey items within reach of a dipped head.

[[File:Wilson's storm petrel.jpg|thumb|left|[[Wilson's storm petrel]]s pattering on the water's surface]]

Surface feeding itself can be broken up into two different approaches, surface feeding while [[bird flight|flying]] (for example as practiced by [[gadfly petrel]]s, [[frigatebird]]s, and [[storm petrel]]s), and surface feeding while swimming (examples of which are practiced by [[gull]]s, [[fulmar]]s, many of the [[shearwater]]s and gadfly petrels). Surface feeders in flight include some of the most acrobatic of seabirds, which either snatch morsels from the water (as do frigatebirds and some terns), or "walk", pattering and hovering on the water's surface, as some of the storm petrels do.<ref>{{cite journal|author=Withers, P. C. |year=1979|title=Aerodynamics and hydrodynamics of the 'hovering' flight of Wilson's storm petrel |journal=Journal of Experimental Biology |volume=80|pages= 83–91 |doi=10.1242/jeb.80.1.83|url=http://jeb.biologists.org/cgi/reprint/80/1/83|doi-access=free}}</ref> Many of these do not ever land in the water, and some, such as the frigatebirds, have difficulty getting airborne again should they do so.<ref>Metz, V. G. and Schreiber, E. A. (2002). Great Frigatebird (''Fregata minor''). In ''The Birds of North America'', No. '''681''' (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA</ref> Another seabird family that does not land while feeding is the [[Skimmer (bird)|skimmer]], which has a unique fishing method: flying along the surface with the lower mandible in the water—this shuts automatically when the bill touches something in the water. The skimmer's bill reflects its unusual lifestyle, with the lower mandible uniquely being longer than the upper one.<ref name = "HBW">{{Citation | first = R. L. | last = Zusi |editor-first = Josep | editor-last = del Hoyo | editor2-first = Andrew | editor2-last = Elliott | editor3-last = Sargatal | editor3-first = Jordi | contribution = Family Rynchopidae (Skimmers) | title = [[Handbook of the Birds of the World]]. Volume 3, Hoatzin to Auks | year = 1996 | pages = 668–675 | place = Barcelona | publisher = Lynx Edicions | isbn = 84-87334-20-2 }}</ref>

Surface feeders that swim often have unique bills as well, adapted for their specific prey. [[Prion (bird)|Prions]] have special bills with filters called [[lamella (zoology)|lamellae]] to filter out [[plankton]] from mouthfuls of water,<ref name="Brooke">Brooke, M. (2004). ''Albatrosses and Petrels Across the World''. Oxford University Press, Oxford, UK {{ISBN|0-19-850125-0}}</ref> and many albatrosses and petrels have hooked bills to snatch fast-moving prey. On the other hand, most gulls are versatile and opportunistic feeders who will eat a wide variety of prey, both at sea and on land.<ref name="Davenport">{{cite book |last1=Davenport|first1=John|last2=D. Black|first2=Kenn|last3=Burnell|first3=Gavin|last4=Cross|first4=Tom|last5=Culloty|first5=Sarah|last6=Ekaratne|first6=Suki|last7=Furness|first7=Bob|last8=Mulcahy |first8=Maire|last9=Thetmeyer|first9=Helmut|date=2009|title=Aquaculture: The Ecological Issues|publisher=John Wiley & Sons|page=68|isbn=978-1444311259|url=https://books.google.com/books?id=304yeBTnjpYC&pg=PA68}}</ref>