Midway Atoll National Wildlife Refuge
Pacific Region
 

Birds of Midway Atoll

Brown Noddy / Anous stolidus pileatus

photo of brown noddy and chick

Description

Medium size, dark, brown bird. Adults have ashy-white forehead and crown sharply demarcated from black lores, merging evenly into gray nape. Long, narrow, wedged-shaped tail. Bill is black and stouter than the black noddy. Legs/feet dark brown. Weigh twice as much as black noddies. Young noddies have a more restricted white cap on forehead than adults. Length: 40-45 cm (16-18 in); wingspan: 79-86 cm (31-34 in); Average life span: 25 years.

Brown Noddy
Photo credit: Robert Shallenberger
  

Midway Population

In 1984, about 1,000 pairs nested on Sand and Eastern Island. The brown noddy breeds in tropical waters of Atlantic, Indian, and Pacific Oceans.

Vocalization

Low-pitched guttural calls. Vocalizes at nest and in flight.

Feeding Habits

Primarily feed by plunge diving. Feed offshore over schools of large predatory fish that drive small fry to surface. Feeds mainly on small fish (i.e., goatfish, flying fish) and squid. Often feeds in mixed species flocks.

Breeding

Limited information is available on age at first breeding, but it ranges from 3-6 years. Mates display characteristic "nodding" to one another. Courtship feeding is performed by the female begging from the male. The male may courtship feed the female several times a day. "Fish flights" occur, in which one bird transfers a fish to its partner.

A single egg is laid in a nest built on the ground or in a tree. On Midway, they have adapted to nesting in ironwood trees (Casuarina equisetfolia), naupaka (Scaevola sericea), and on the ground. Fidelity to nest site is high.

Incubation length ranges between 33-36 days. Both parents incubate. Incubation shift lengths varies between geographical locations. Within the Hawaiian Islands lengths range between 14-30 hour shifts. Fledging occurs between 40-56 days after hatching (Kure Atoll). Chicks reach adult weight in 18 days. Most chicks outweigh parents in six weeks. Chicks are capable of short flights before reaching full wing development, and will flee if alarmed. Post-fledging feeding continues for several weeks.
Last updated: March 22, 2010