NT
Yap Monarch Metabolus godeffroyi



Justification

Justification of Red List category
This species has a moderately small range, being restricted to four very small islands. The population is currently considered stable; however, the accidental introduction of predators such as brown tree-snake Boiga irregularis could plausibly cause the species to become VU or EN within a very short time period. It is therefore assessed as Near Threatened.

Population justification
Within its small range it is considered common and widespread (Clement 2020). Engbring et al. (1990) published a population estimate of 26,961 individuals, roughly equating to 18,000 mature individuals and placed here in the range 10,000-30,000. Although there is no more recent population estimate or trend assessment, they remain among the most commonly encountered avian species on Yap (Robertson and Robertson 2016).

Trend justification
Most species surveyed on Yap in 2004 appeared to be less abundant than in Engbring et al.'s (1990) surveys (Robertson and Robertson 2016). The reasons for this are uncertain but could be attributed to Typhoon Sudall (2004), difference in survey methods or changes in habitat availability (Robertson and Robertson 2016). However, there has been no recent trend assessment and the species is thought to be common and tolerates a wide range of habitats. Remote sensing data indicate no ongoing forest loss in the three generations to 2021 (data from Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein). Currently the population is suspected to be stable in the absence of any recent evidence for any declines or substantial threats.

Distribution and population

This species endemic to the islands of Yap, Federated States of Micronesia, occurring on Yap, Gagil-Tomil, Rumung (presumably) and Maap, where it is widespread.

Ecology

It inhabits virtually all forest types including mangroves and secondary growth (Engbring et al. 1990). Common along line transects in mangroves, savannah and forest (Robertson and Robertson 2016).

Threats

It is unlikely to be affected by habitat degradation as it is able to utilise the scrubby vegetation which often invades forest-cleared sites. However, given its small range, it is at risk from the accidental introduction of alien species, especially brown tree snake Boiga irregularis which has caused the extirpation and extinction of birds on nearby Guam (Engbring et al. 1990).

Conservation actions

Conservation Actions Underway
None are known.

Conservation Actions Proposed
Regular population monitoring to determine trends and understand population dynamics (Robertson and Robertson 2016). Ensure B. irregularis does not become established on any of the Yap islands.

Acknowledgements

Text account compilers
Vine, J., Shutes, S., Derhé, M., O'Brien, A., Mahood, S.


Recommended citation
BirdLife International (2024) Species factsheet: Yap Monarch Metabolus godeffroyi. Downloaded from https://datazone.birdlife.org/species/factsheet/yap-monarch-metabolus-godeffroyi on 06/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 06/12/2024.