Gerygone modesta

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	ACANTHIZIDAE

Scientific Name:

Gerygone modesta

Species Authority:

Pelzeln, 1860

Common Name/s:

English

–

Norfolk Gerygone, Norfolk Island Gerygone

Assessment Information [top]

Red List Category & Criteria:

Near Threatened ver 3.1

Year Published:

2012

Assessor/s:

BirdLife International

Reviewer/s:

Butchart, S. & Taylor, J.

Contributor/s:

Christian, M., Holdaway, R. & Ward, R.

Justification:
This species has been downlisted to Near Threatened because although it has a very small range and population on a single island, its population is estimated to be stable or increasing and it has not been significantly affected by introduced predators, including rats, and therefore there is not thought to be any plausible threat likely to lead to very rapid future declines. If such a plausible future threat were to be identified it would warrant classification as Vulnerable, and any evidence of declines would likely lead to its reclassification in a higher threat category.

History:

2008	–	Vulnerable
2004	–	Vulnerable
2000	–	Vulnerable
1996	–	Vulnerable
1994	–	Vulnerable

Geographic Range [top]

Range Description:	Gerygone modesta is endemic to Norfolk Island (to Australia). It is widespread and abundant on the island, and is thought to number c.10,000 individuals (Garnett et al. 2011). The population is probably stable (R. Ward, M. Christian and R. Holdaway in litt. 2007, Garnett et al. 2011).
Countries:	Native: Norfolk Island
Range Map:	Click here to open the map viewer and explore range.

Population [top]

Population:	The population within Norfolk Island National Park is estimated at at least 3,800 pairs (G. Dutson pers. obs.), with many more hundreds outside the park. The total population is therefore estimated at c.10,000 mature individuals (Garnett et al. 2011).
Population Trend:	Stable

Habitat and Ecology [top]

Habitat and Ecology:	It is found only in remnant areas of tree or shrub growth on the island, such as rainforest, thicket, gardens and white oak pasture, and is common in weedy forest dominated by the exotic red guava Psidium cattleianum and African olive Olea africana but at a density about half that in native forest (G. Dutson pers. obs.). It is scattered and much less common in patchy forest and scrub away from the National Park (G. Dutson pers. obs.).
Systems:	Terrestrial

Habitat and Ecology:

It is found only in remnant areas of tree or shrub growth on the island, such as rainforest, thicket, gardens and white oak pasture, and is common in weedy forest dominated by the exotic red guava Psidium cattleianum and African olive Olea africana but at a density about half that in native forest (G. Dutson pers. obs.). It is scattered and much less common in patchy forest and scrub away from the National Park (G. Dutson pers. obs.).

Systems:

Terrestrial

Threats [top]

Major Threat(s):	Although clearing for timber, cultivation, pasture and ongoing development (R. Ward, M. Christian and R. Holdaway in litt. 2007) has removed some habitat, there are no apparent serious threats that are likely to affect the viability of the population in the foreseeable future, but its restriction to such a small area could make it susceptible to catastrophe such as newly-introduced predators or disease. The population may be affected by the clearing of hedges and vacant land for the development of domestic and commercial buildings (R. Ward, M. Christian and R. Holdaway in litt. 2007). It coexists with the introduced black rat Rattus rattus and cats, and its behaviour and the positioning of its domed nests reduces the probability of predation (Garnett and Crowley 2000).

Major Threat(s):

Although clearing for timber, cultivation, pasture and ongoing development (R. Ward, M. Christian and R. Holdaway in litt. 2007) has removed some habitat, there are no apparent serious threats that are likely to affect the viability of the population in the foreseeable future, but its restriction to such a small area could make it susceptible to catastrophe such as newly-introduced predators or disease. The population may be affected by the clearing of hedges and vacant land for the development of domestic and commercial buildings (R. Ward, M. Christian and R. Holdaway in litt. 2007). It coexists with the introduced black rat Rattus rattus and cats, and its behaviour and the positioning of its domed nests reduces the probability of predation (Garnett and Crowley 2000).

Conservation Actions [top]

Conservation Actions:	Conservation Actions Underway Norfolk Island National Park was declared in 1986, and encompasses the main remaining stands of native forest on the island. Although the control of mammalian predators takes place within the Norfolk Island National Park, in 2006, it was noted that the control of rats was budget-constrained and limited in its effectiveness (S. Garnett in litt. 2006). There is an ongoing programme to control exotic shrubs within native forest in the National Park (Garnett et al. 2011). The Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks 2010) recommends a set of recovery measures required to reduce or remove threats to native species on the island. Conservation Actions Proposed Monitor the population through the analysis of birdwatchers' records. Install predator-proof fencing around the national park and other important habitat and remove introduced predators from within these areas (R. Ward, M. Christian and R. Holdaway in litt. 2007). The elimination of mammalian predators from the island or at least significant sections of it, with measures to prevent their reintroduction (Director of National Parks 2010), may benefit the species, despite them not being a serious threat.

Conservation Actions:

Conservation Actions Underway
Norfolk Island National Park was declared in 1986, and encompasses the main remaining stands of native forest on the island. Although the control of mammalian predators takes place within the Norfolk Island National Park, in 2006, it was noted that the control of rats was budget-constrained and limited in its effectiveness (S. Garnett in litt. 2006). There is an ongoing programme to control exotic shrubs within native forest in the National Park (Garnett et al. 2011). The Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks 2010) recommends a set of recovery measures required to reduce or remove threats to native species on the island.

Conservation Actions Proposed
Monitor the population through the analysis of birdwatchers' records. Install predator-proof fencing around the national park and other important habitat and remove introduced predators from within these areas (R. Ward, M. Christian and R. Holdaway in litt. 2007). The elimination of mammalian predators from the island or at least significant sections of it, with measures to prevent their reintroduction (Director of National Parks 2010), may benefit the species, despite them not being a serious threat.

Citation:	BirdLife International 2012. Gerygone modesta. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 22 May 2013.
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