Bird of the Week

The White Tern (Gygis alba) nests in tropical and subtropical coastal regions worldwide. This species is well known for laying a single egg placed precociously in a tree, on a rock, or even on buildings1. The White Tern does not build a tree nest like the related Black Noddy (Anous minutus), or a ground nest like the Sooty Tern (Sterna fuscata). The variability in nesting strategies is possibly my favorite aspect of this group (subfamily Sterninae).

The lack of a nest may seem like a haphazard way to hatch an egg, but the White Tern has adaptations that make this a fitting strategy. For example the White Tern takes a relatively short amount of time after each failed egg before it lays another allowing it to lay multiple eggs in quick succession1. Having no nest also removes the risk of brood parasites. The White Tern reduces it's molting time, which increases the length of the nesting season, by replacing it's feathers in waves1.




Photos by Forest and Kim Starr

For more information visit:
http://bna.birds.cornell.edu/bna/species/371/articles/introduction
http://www.hear.org/starr/birds/images/species/?q=gygis+alba
http://www.state.hi.us/dlnr/dofaw/cwcs/files/NAAT%20final%20CWCS/Chapters/Terrestrial%20Fact%20Sheets/Seabirds/White%20fairy%20tern%20NAAT%20final%20!.pdf

1. Niethammer, Kenneth R. and Laura B. Patrick. 1998. White Tern (Gygis alba), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/371 doi:10.2173/bna.371

All taxonomy from itis.gov