Geographic Range
Polynesian storm petrels are found throughout much of the tropical Pacific, from Vanuatu
in the west to Sala y Gomez in the east. Not much is known about their distribution
and behavior outside of the breeding season, but they are thought to remain near their
breeding islands, possibly concentrating in the region of the equatorial current (between
10 degrees north and south).
- Biogeographic Regions
- pacific ocean
Habitat
Polynesian storm petrels are found in tropical oceanic waters and on small coral or
volcanic islands where they breed. They dig burrows on nesting islands, either among
vegetation or in rock crevices. They may forage mainly in the waters near islands
where they breed, but little is known of their habits. Other sources suggest they
are mainly pelagic, except when breeding.
- Habitat Regions
- tropical
- saltwater or marine
Physical Description
Polynesian storm petrels are about 24 to 26 cm in length and exhibit a wide range
of color variation. Color morphs range from light to dark and the frequency of morphs
varies geographically. Some populations have only light morphs, some only dark, and
some have various morphs. They are large petrels, with broad, rounded wings and forked
tails. The wings do not have marked curvature of the leading or trailing edges, which
is distinctive in this species. The most common plumage pattern is with a brown to
black dorsal parts, from the head to the tail, with a white rump band and bar dorsally
across the wings. The throat is white, with a brown chest band and the breast and
belly are white. The darkest morphs are uniformly sooty-brown, being similar in appearance
to Tristram's storm petrels (
Oceanodroma tristrami
) but larger. Intermediate morphs have light flecking on their dark plumage. Polynesian
storm petrels have a distinctive way of taking flight: they kick off from the ocean,
glide for about 30 seconds, and then kick off again before finally lifting off. Wings
are from 175 to 219 mm, bills are from 14.5 to 19 mm, the tail is from 83 to 122.5
mm, and mass is from 56 to 86 g. They have narrow webs on their feet. There are no
described subspecies and no sexual dimorphism is reported, although geographic and
sexual variation in body measurements is possible.
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
Reproduction
Little is known about mating in Polynesian storm petrels.
Little is known about breeding in Polynesian storm petrels. They nest in colonies
on islands throughout their range. Nests are in burrows under vegetation or in rocky
crevices. Nests are occasionally burrowed into sandy soil, but these are fragile and
prone to collapse. Egg-laying seems to occur throughout the year, with some concentration
of egg-laying from August to December on Kiritimati and July to September in the Marquesas.
On islands closer to the equator, breeding seems to occur throughout the year, but
on islands further south, breeding may be seasonal. Females lay a single egg. Time
to incubation is estimated at about 50 days and time to fledging at about 60 days.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- year-round breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- oviparous
Polynesian storm petrel males and females both protect and feed their young to independence.
However, little is known of the details of parental investment. Young are protected
in nest burrows until they fledge.
- Parental Investment
- altricial
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- male
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- male
- female
-
protecting
- male
- female
-
provisioning
Lifespan/Longevity
Lifespan in Polynesian storm petrels is not known.
Behavior
Little is known about the life history of Polynesian storm petrels. They breed in
colonial nesting colonies on coral or volcanic islands. Most individuals arrive at
breeding colonies at night but some arrive during the day as well. This indicates
that they may forage mainly during the day and return to burrows at night to rest.
They are thought to be sedentary, mainly staying in the area of their breeding colony,
but little is known of their movements.
Home Range
Home range sizes in Polynesian storm petrels are not known.
Communication and Perception
Polynesian storm petrels produce soft "grr" calls, but the context of these calls
has not been well-documented.
- Communication Channels
- acoustic
Food Habits
Little is known about the diet of Polynesian storm petrels. Like other
storm petrels
, they probably eat a variety of fish, cephalopods, and crustaceans. They forage mainly
while in flight, grabbing prey from the surface or making brief, shallow dives.
- Primary Diet
-
carnivore
- piscivore
- eats non-insect arthropods
- molluscivore
- Animal Foods
- fish
- mollusks
- aquatic crustaceans
Predation
Polynesian storm petrels have been extensively preyed on at breeding colonies by non-native
mammalian predators, including domestic cats (
Felis catus
), ship rats (
g.Rattus rattus
), and house mice (
Mus musculus
), all of which take eggs, hatchlings, and fledglings. Native predators have not been
reported, but are likely to include gulls and skuas. Polynesian storm petrels seem
to visit breeding colonies mainly at night, indicating that they try to avoid avian
predators by minimizing their exposure.
Ecosystem Roles
Polynesian storm petrels are predators of fish, cephalopods, and crustaceans in the areas they live. Otherwise, almost nothing is known of their ecosystem role. They are rare, so their impacts are probably small at the ecosystem level throughout most of their range.
Economic Importance for Humans: Positive
Polynesian storm petrels are important, although rare, members of native, tropical Pacific environments. They may attract ecotourism interest.
Economic Importance for Humans: Negative
There are no adverse effects of Polynesian storm petrels on humans.
Conservation Status
Polynesian storm petrels are considered vulnerable by the IUCN because of the local
extinction of many breeding populations throughout their range in the last 50 years.
These localized extinctions are primarily the result of decimation by introduced predators
on their breeding islands. However, surveys have not been comprehensive and healthy
breeding populations may still exist. Populations are estimated at a maximum of 10,000
individuals, but may be smaller. Polynesian storm petrel populations have become extinct
in the Cook Islands, Tahiti, Henderson Island, and possibly Fiji. Breeding populations
number only in the 10's in New Caledonia, the smaller Society Islands, Samoa, and
the Australs and Marquesas Islands. Larger populations are supported on the Line Islands,
Phoenix Islands, Gambiers Islands, and Sala y Gomez. Cat and rat eradication programs
on some islands have had mixed success and are considered essential to the long-term
survival of this species. Reintroduction efforts at Jarvis Island National Wildlife
Refuge (near Kiritimati) have had limited success.
Other Comments
Nesofregetta fuliginosa
is also known by the common names white-throated storm petrels and Samoan storm petrels.
This species was previously recognized as
Procellaria fuliginosa
.
Additional Links
Contributors
Tanya Dewey (author), Animal Diversity Web.
- Pacific Ocean
-
body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- saltwater or marine
-
mainly lives in oceans, seas, or other bodies of salt water.
- pelagic
-
An aquatic biome consisting of the open ocean, far from land, does not include sea bottom (benthic zone).
- coastal
-
the nearshore aquatic habitats near a coast, or shoreline.
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- seasonal breeding
-
breeding is confined to a particular season
- year-round breeding
-
breeding takes place throughout the year
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- altricial
-
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- social
-
associates with others of its species; forms social groups.
- acoustic
-
uses sound to communicate
- carnivore
-
an animal that mainly eats meat
- piscivore
-
an animal that mainly eats fish
- molluscivore
-
eats mollusks, members of Phylum Mollusca
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
References
BirdLife International, 2009. "Species factsheet: Nesofregetta fuliginosa" (On-line). BirdLife International. Accessed July 20, 2009 at http://www.birdlife.org/datazone/search/species_search.html?action=SpcHTMDetails.asp&sid=3975&m=0 .
Brooke, M. 2004. Albatrosses and petrels across the world . Oxford: Oxford University Press.
del Hoyo, J., A. Elliott, J. Sargatal. 1992. Handbook of the Birds of the World, Volume I . Barcelona: Lynx Edicions.