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Filters: Tags: Mariana Islands (X) > partyWithName: U.S. Geological Survey (X)

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USGS high resolution orthorectified images from The National Map combine the image characteristics of an aerial photograph with the geometric qualities of a map. An orthoimage is a uniform-scale image where corrections have been made for feature displacement such as building tilt and for scale variations caused by terrain relief, sensor geometry, and camera tilt. A mathematical equation based on ground control points, sensor calibration information, and a digital elevation model is applied to each pixel to rectify the image to obtain the geometric qualities of a map. A digital orthoimage may be created from several photographs mosaicked to form the final image. The source imagery may be black-and-white, natural...
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This study examined the reproductive biology of the Mariana Swiftlet over five annual cycles on the island of O‘ahu in the Hawaiian Islands. This introduced population used a human-made tunnel for roosting and nesting, and was studied as a surrogate to negate interference with the endangered populations in the Mariana Islands. Active nests (N = 478) were observed in every month of the year. Data recorded included: nest visit dates, date nests were identified, number of visits to each nest; nest stage, nest fate, nest failure status, number of rat traps present, number of rats captures, daily rainfall, and nest ages.


    map background search result map search result map Nest success and predation data for Mariana swiftlets (Aerodramus bartschi), Hawai'i, USA, 2006-2010 Nest success and predation data for Mariana swiftlets (Aerodramus bartschi), Hawai'i, USA, 2006-2010