Pomarea dimidiata

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

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Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	AVES	PASSERIFORMES	MONARCHIDAE

Scientific Name:

Pomarea dimidiata

Species Authority:

(Hartlaub & Finsch, 1871)

Common Name/s:

English

–

Cook Islands Flycatcher, Kakerori, Rarotonga Flycatcher, Rarotonga Monarch

Assessment Information [top]

Red List Category & Criteria:

Endangered D ver 3.1

Year Published:

2008

Assessor/s:

BirdLife International

Reviewer/s:

Mahood, S., Butchart, S.

Contributor/s:

Robertson, H., Saul, E.

Justification:
Once among the rarest birds of the world, this species has been brought back from the brink of extinction. It is considered Endangered because it still has an extremely small population, a very small range, and remains threatened by chance events such as cyclones. The survival of the species is still dependent on a continuation of intensive conservation efforts, but if present trends continue, it will eventually require downlisting to Vulnerable.

History:

2006	–	Endangered
2004	–	Endangered
2000	–	Endangered
1996	–	Critically Endangered
1994	–	Critically Endangered

Geographic Range [top]

Range Description:	Pomarea dimidiata is endemic to Rarotonga, Cook Islands, where it is largely restricted to the Totokoitu, Turoa and western Avana Valleys. It was common until the middle of the 19th century, but thought to be extinct in the early 1900s⁴. A survey in 1983 located only 20 birds and two nests, and estimated a population of 35-50 birds^1,13. A recovery plan initiated in 1987 has improved breeding success and recruitment, and decreased mortality of adults, resulting in 177 birds in 1998, 196 in 1999, 222 in 2000, 255 in 2001, 289 in 2002, 308 in 2003 ¹⁷. In 2001, ten birds were translocated from Rarotonga and released on Atiu, 200 km north-east; similar numbers, consisting of one to two-year-old birds, were translocated in 2002 and in 2003¹⁵. Four fledglings were recorded on Atiu in autumn 2003¹⁰. By August 2004, at least 281 birds were found on Rarotonga, and 25 on Atiu, giving an overall estimated population of 306 individuals¹⁸. However, five cyclones passed through the southern Cook Islands in five weeks in summer 2005 and though direct mortality was less than expected, a very poor breeding season followed, and in August 2006 the population was estimated at 291 individuals; 255 on Rarotonga and 36 on Atiu¹⁶.
Countries:	Native: Cook Islands
Range Map:	Click here to open the map viewer and explore range.

Population [top]

Population:	Population estimated at 296-300+¹⁵ in August 2004, but subsequent series of devastating cyclones in early 2005 lead to a decline, especially on Rarotonga¹⁶. By spring 2007 the total population had begun to increase again, due to good recruitment on Atiu (where 30 birds were transferred in 2001-03) and a stable population on Rarotonga¹⁷.Although the actual figure may be slightly higher than this as more banded birds are recorded (H. Robertson in litt. 2007). However, the population is retained in the band 50-249 so as not to trigger a downlisting under D1 to Vulnerable.
Population Trend:	Unknown

Population:

Population estimated at 296-300+¹⁵ in August 2004, but subsequent series of devastating cyclones in early 2005 lead to a decline, especially on Rarotonga¹⁶. By spring 2007 the total population had begun to increase again, due to good recruitment on Atiu (where 30 birds were transferred in 2001-03) and a stable population on Rarotonga¹⁷.Although the actual figure may be slightly higher than this as more banded birds are recorded (H. Robertson in litt. 2007). However, the population is retained in the band 50-249 so as not to trigger a downlisting under D1 to Vulnerable.

Population Trend:

Unknown

Habitat and Ecology [top]

Habitat and Ecology:	It prefers steep-sided, wet, forested, small valleys sheltered from south-east trade winds in the headwaters of streams. It feeds mainly on small caterpillars, flies, beetles and bugs. Clutch-size is two. Usually only one brood is raised each year. ^2,6,7,8. Before intensive predator control began, annual adult mortality was 24.3% and life expectancy was 3.6-6.0 years for males and 2.4 years for females. Since intensive management, annual mortality has dropped significantly to 14.2% and life expectancy has increased to 7.6 years for males and 6.3 years for females¹⁷.
Systems:	Terrestrial

Habitat and Ecology:

It prefers steep-sided, wet, forested, small valleys sheltered from south-east trade winds in the headwaters of streams. It feeds mainly on small caterpillars, flies, beetles and bugs. Clutch-size is two. Usually only one brood is raised each year. ^2,6,7,8. Before intensive predator control began, annual adult mortality was 24.3% and life expectancy was 3.6-6.0 years for males and 2.4 years for females. Since intensive management, annual mortality has dropped significantly to 14.2% and life expectancy has increased to 7.6 years for males and 6.3 years for females¹⁷.

Systems:

Terrestrial

Threats [top]

Major Threat(s):	The species highly localised distribution leaves it vulnerable to cyclones, invasion of weeds and forest clearance. It continues to be threatened by black rat Rattus rattus and cats (Felis catus). Predation by Long-tailed Cuckoo Eudynamys taitensis, a winter migrant from New Zealand, remains a possibility. The introduction of avian diseases could have a major impact, as could invasion by new predators (e.g. snakes and mongooses)^4,5,8.

Major Threat(s):

The species highly localised distribution leaves it vulnerable to cyclones, invasion of weeds and forest clearance. It continues to be threatened by black rat Rattus rattus and cats (Felis catus). Predation by Long-tailed Cuckoo Eudynamys taitensis, a winter migrant from New Zealand, remains a possibility. The introduction of avian diseases could have a major impact, as could invasion by new predators (e.g. snakes and mongooses)^4,5,8.

Conservation Actions [top]

Conservation Actions:	Conservation Actions Underway The valleys where the species survives (called the Takitumu Conservation Area) are managed by three landowning families who are developing an ecologically and commercially sustainable ecotourism venture. Intensive rat control is carried out during the breeding season, including fortnightly poisoning^3,5. An insurance population has been established on Atiu and is breeding well in a variety of habitats^14,15,. Conservation Actions Proposed Continue monitoring the population. Continue rat control in designated areas. Win community support for occasional further translocations to Atiu to maintain genetic diversity in that population^4,9. Ensure new predators do not become established on Rarotonga. Monitor to ensure no predators become established on Atiu.

Conservation Actions:

Conservation Actions Underway
The valleys where the species survives (called the Takitumu Conservation Area) are managed by three landowning families who are developing an ecologically and commercially sustainable ecotourism venture. Intensive rat control is carried out during the breeding season, including fortnightly poisoning^3,5. An insurance population has been established on Atiu and is breeding well in a variety of habitats^14,15,.

Conservation Actions Proposed
Continue monitoring the population. Continue rat control in designated areas. Win community support for occasional further translocations to Atiu to maintain genetic diversity in that population^4,9. Ensure new predators do not become established on Rarotonga. Monitor to ensure no predators become established on Atiu.

Citation:	BirdLife International 2008. Pomarea dimidiata. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 26 May 2012.
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