Editing Tropicbird (section)

==Behaviour and ecology==
Tropicbirds frequently catch their prey by hovering and then plunge-diving, typically only into the surface-layer of the waters.  They eat mostly fish, especially [[flying fish]], and occasionally squid.<ref name=EoB>{{cite book |editor=Forshaw, Joseph|author= Schreiber, E.A.|year=1991|title=Encyclopaedia of Animals: Birds|publisher= Merehurst Press|location=London|pages= 63|isbn= 978-1-85391-186-6}}</ref>  Tropicbirds tend to avoid multi-species feeding flocks, unlike the [[frigatebirds]], which have similar diets.

[[File:White-tailed tropicbird (Phaethon lepturus).jpg|thumb|right|White-tailed tropicbird nesting on the ground on [[Cousin Island]]]]
Tropicbirds are usually solitary or in pairs away from breeding colonies. There they engage in spectacular courtship displays.  For several minutes, groups of 2–20 birds simultaneously and repeatedly fly around one another in large, vertical circles, while swinging the tail streamers from side to side.  If the female likes the presentation, she will mate with the male in his prospective nest-site.  Occasionally, disputes will occur between males trying to protect their mates and nesting areas.

Tropicbirds generally nest in holes or crevices on the bare ground.  The female lays one white egg, spotted brown, and incubates for 40–46 days.  The incubation is performed by both parents, but mostly the female, while the male brings food to feed the female.  The chick hatches with grey down.  It will stay alone in the nest while both parents search for food, and they will feed the chick twice every three days until fledging, about 12–13 weeks after hatching.  The young are not able to fly initially; they will float on the ocean for several days to lose weight before flight.

Tropicbird chicks have slower growth than nearshore birds, and they tend to accumulate fat deposits while young.  That, along with one-egg clutches, appears to be an adaptation to a pelagic lifestyle where food is often gathered in large amounts, but may be hard to find.