White Tern

White Tern
Conservation status
Least Concern (IUCN 3.1)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Charadriiformes
Family:	Sternidae
Genus:	Gygis
Species:	G. alba
Binomial name
Gygis alba (Sparrman, 1786)

Mating White Terns at Midway Atoll

White Tern feeding a chick at Midway Atoll

The White Tern (Gygis alba) is a small seabird found across the tropical oceans of the world. It is sometimes known as the Fairy Tern although this name is potentially confusing as it is the common name of the Fairy Tern Sternula nereis. Other names for the species include Angel Tern and White Noddy.

Subspecies

The White Tern has 3-4 subspecies: the nominate race G. a. alba, G. a. leucopes, the Pacific White Tern (G. a. candida). Additionally, the Little White Tern (G. microrhyncha) was long and often is still included herein as a subspecies G. a. microrhyncha.[1]

Description

The White Tern is a small, all white tern with a long black bill, related to the noddies.^[2] It ranges widely across the Pacific and Indian Oceans, and also nests in some Atlantic islands. It nests on coral islands, usually on trees with thin branches but also on rocky ledges and on man-made structures. The White Tern feeds on small fish which it catches by plunge diving.

Behaviour

This small tern is famous for laying its egg on bare thin branches in a small fork or depression without a nest. This behaviour is unusual for terns, which generally nest on the ground, and even the related tree-nesting Black Noddy constructs a nest. It is thought that the reason for the absence of nests is the reduction in nest parasites, which in some colonial seabirds can cause the abandonment of an entire colony.^[3] In spite of these benefits there are costs associated with tree nesting, as the eggs and chicks are vulnerable to becoming dislodged by heavy winds. For this reason the White Tern is also quick to relay should they lose the egg. The newly hatched chicks have well developed feet to hang on to their precarious nesting site with. It is a long-lived bird, having been recorded living for 17 years.

Fairy or White Tern baby, Midway Island

Relationship with humans

The White Tern is not considered threatened as it is a widespread species with several large colonies around the world.

The White Tern, manu-o-Kū, was named Honolulu, Hawaiʻi's official bird on April 2, 2007.[2]

Chick near nest

References

1. ^ BirdLife International (2004). Gygis alba. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 11 May 2006. Database entry includes justification for why this species is of least concern.
2. ^ Niethammer, K. R., and L. B. Patrick-Castilaw. 1998. White Tern (Gygis alba). in The Birds of North America, No. 371 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA. doi:10.2173/bna.371
3. ^ Houston, D.C. (1978) "Why do fairy terns Gygis alba not build nests?" Ibis 121 (1): 102 - 104 doi:10.1111/j.1474-919X.1979.tb05023.x

External links

• White Tern videos, photos & sounds on the Internet Bird Collection