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10 recordsLinked to original sources
USGS1999

Status of the Mariana Crow population on Rota, Mariana Islands

We conducted a survey of the endangered Mariana Crow ( Corvus kubaryi ) population on Rota, Commonwealth of the Northern Mariana Islands, in October-November 1995 to provide current information on numbers and distribution of this species. To allow direct comparisons with a previous survey, we resurveyed transects established in 1982 using the same field methods and used identical analysis methods for both surveys. Several areas on Rota that lack suitable habitat and have few if any resident crows were excluded from our 6,315-ha study area. Our reanalysis of 1982 survey data for our study area gave an estimated population size of 1,348 crows (95% CI = 1,136–1,564), compared to a 1995 estimate of 592 crows (95% CI = 474–720). Mean number of crows detected per sampling station decreased 57% from 1.06 ± 0.09 SE in 1982 to 0.46 ± 0.05 in 1995. The apparent 56% decrease in population size may be a result of habitat loss from development and typhoons, as well as persecution, but other factors contributing to the decline cannot be identified until more is known about the ecology and demography of the Mariana Crow population.

Rota↗
USGS1999

Forest bird and fruit bat populations on Sarigan, Mariana Islands

We conducted the first quantitative surveys of forest bird and bat populations on the uninhabited island of Sarigan, Commonwealth of the Northern Mariana Islands. Severe habitat degradation has occurred on Sarigan because of overgrazing by introduced goats and pigs. Planting of coconut palms ( Cocos nucifera ) for copra production has also eliminated much of the island’s native forest. We recorded five species of forest birds on Sarigan: Micronesian Honeyeater ( Myzomela rubratra ), Micronesian Megapode ( Megapodius laperouse laperouse ), Micronesian Starling ( Aplonis opaca ), Collared Kingfisher ( Halcyon chloris ), and White-throated Ground Dove ( Gallicolumba xanthonura ). Estimated population sizes (95% confidence interval) in 1997 were 1,821 (1,617–2,026) for Micronesian Honeyeater, 677 (545–810) for Micronesian Megapode, 497 (319–675) for Micronesian Starling, 107 (82–131) for Collared Kingfisher, and 170 (101–238) for Mariana Fruit Bat ( Pteropus mariannus ).

Sarigan↗
USGS2000

Population status of the Tinian Monarch ( Monarcha takatsukasae ) on Tinian, Commonwealth of the Northern Mariana Islands

We conducted surveys to evaluate the current population status of the Tinian Monarch ( Monarcha takatsukasae ), an insectivorous forest bird restricted to the island of Tinian, Commonwealth of the Northern Mariana Islands. In 1996, we recounted transects surveyed in 1982 and used the same analysis procedure to compare 1982 and 1996 population estimates. The 1996 population estimate was 55,721 ± 3,846 SE (48,345–63,495 95% CI), which is 57% higher than our estimate of 35,846 ± 2,211 SE (31,668–40,337 95% CI) for 1982. Vegetation density, measured by canopy cover and lateral visibility at each station, has also increased since 1982. Our data suggest that the Tinian Monarch population has increased possibly due to increased habitat availability, but remains at risk both from an accidental introduction of brown tree snakes ( Boiga irregularis ) to the island and stochastic processes.

Tinian↗
USGS2018

Human induced trauma and directed take inhibits sea turtle recovery in the Commonwealth of the Northern Mariana Islands

Sea turtle conservation is often hindered by the lack of reliable information on population status and threats due to sampling difficulties of these highly migratory reptiles that live in remote and data-poor locations. This paper summarizes more than a decade of stranding recoveries (live and dead turtles) on the islands of Saipan and Tinian, Commonwealth of the Northern Mariana Islands (CNMI), to obtain baseline information on the primary threats to sea turtles in the CNMI. Gross external examination and necropsy of dead turtles was used to infer primary cause of stranding of 89 sea turtles (92.1% green ( Chelonia mydas ), 5.6% hawksbill ( Eretmochelys imbricata ), 1.1% olive ridley ( Lepidochelys olivacea ), and 1% unknown). Of these stranding recoveries, 80.9% were juveniles, 15.7% were adults, and 3.4% were unknown. Trauma related to illegal human take was the primary cause of stranding and accounted for 79% of CNMI sea turtle injuries and mortalities. The remaining 21% of strandings were attributed to (in rank order): marine debris entanglement, shark bite, boat strike, emaciation, and infectious disease. This study provides the first comprehensive characterization of cause-specific sea turtle injury and mortality in CNMI, described within the unique socio-cultural and historical dynamics of the region. Culturally-relevant suggestions for management are provided that may help address the primary threat to CNMI sea turtles.

Commonwealth of the Northern Mariana Islands, Guam↗
USGS2024

A review of the ecology and conservation biology of Sali (Micronesian Starling, Aplonis opaca guami) on Guam

The accidental introduction of the Brown Treesnake (BTS, Boiga irregularis ) to Guam following World War II led to the extinction, extirpation, or severe decline of most of Guam’s native avifauna. One forest bird species that managed to persist is the cavity-nesting Såli (Micronesian Starling, Aplonis opaca guami ), a once-ubiquitous native omnivore whose current Guam distribution is restricted primarily to urbanized areas in the northern half of the island, with a second much smaller population on Cocos Island off southern Guam. Såli on Guam breed year-round and are habitat generalists with large home ranges. Besides arthropods and small vertebrates, they consume fruit from a wide range of native and introduced plant species and are key seed dispersers within the local ecosystem. Såli on Guam suffer extremely high post-fledging mortality due to predation by BTS and cats, leading to a population age structure strongly skewed towards adult birds. Other threats include habitat loss and degradation, extreme weather events, and sea level rise. Key management activities aimed at restoring this species include predator control, while non-native ungulate removal and vegetation management may be undertaken to support broader ecological recovery. This species account on Såli provides a review of the literature on this species, synthesizing information on habitat use, life history, and demographics to provide a biological foundation for future recovery efforts.

Micronesica↗