Editing Forster's tern (section)

===Mobbing===

Forster's tern exhibits very aggressive behavior when threatened by nest predators; if a nest is disturbed, the colony [[mobbing (animal behavior)|mobs]] the aggressor, diving towards it and issuing loud calls.<ref>Siglin RJ and Weller MW. 1963. Comparative nest defense behavior of four species of marsh birds. The Condor. 65(5): 432–437.</ref> Aggressiveness increases immediately prior to and during hatching of the chicks. Ducks and grebes nesting in the same area often benefit from the tern's aggressive behavior toward potential predators <ref name="McNicholl71" />

Yellow-headed blackbirds sharing nesting sites have been known to actively join tern mobs against predators.<ref name="McNicholl82" /> [[Western grebe]]s recognize the tern's alarm call; this can be interpreted as information [[parasitism]].<ref>{{cite journal|last1=Nuechterlein |first1=GL.|year= 1981|title='Information parasitism' in mixed colonies of western grebes and Forster's terns. |journal=Animal Behaviour|volume=29|issue=4|pages= 985–989|doi=10.1016/S0003-3472(81)80051-6 |s2cid=53152999 }}</ref>