Marbled Murrelet Suitable Nesting Habitat

This data layer has been developed by an interagency team of scientists from the US Forest Service, US Fish and Wildlife Service, and Oregon State University. It was published in "Status and Trend of Nesting Habitat for the Marbled Murrelet Under the Northwest Forest Plan, 1993 to 2017" in 2021. It is part of the work to monitor the effectiveness of the Northwest Forest Plan. The data represent relative habitat suitability of habitat for marbled murrelet range in California for 2017; categorized as lower, moderate, and higher probability of nesting habitat, with probability gradients in each class. This species is only found in the Northern and Central California Regions.

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Field Value
Last Updated February 28, 2025, 07:37 (UTC)
Created February 28, 2025, 07:37 (UTC)
category /Biodiversity Conservation/Focal Species/Birds
collection_name California Landscape Metrics
creation_method Using Maxent species distribution models, the authors modeled the amount and distribution of probable nesting habitat in the murrelet's range in 2017. Probability scores from Maxent provide information on the relative suitability of habitat. While thresholds were necessary in this report for estimating acres of habitat in different categories (e.g., comparing acres in 1993 to 2017), Maxent probability scores provide a complete, probabilistic map of habitat suitability. Note: Imagery was obtained in late summer (July to September) rather than at the change in the calendar year (December to January). Thus, some 2017 fires were excluded from the analysis, such as the Chetco Bar Fire, which occurred in late summer in 2017. Within the higher probability nesting habitat, the authors estimated the amount of contiguous habitat (core) versus the amount of habitat bounding core habitat (edge) and habitat scattered in small forest fragments (scatter). The authors considered this "core habitat" as the best habitat. Their models indicate that there were 1.51 million acre of higher probability nesting habitat over all lands in the murrelet's range in Washington, Oregon, and California 1 year prior to the start of the Northwest Forest Plan (NWFP) in 1993. Of this, 0.14 million acres were identified as core habitat, which are defined as intact patches of higher probability nesting habitat >5.56 acre in size. The authors estimated a net loss of about 1.4 percent in higher probability nesting habitat across the NWFP area and 1.8 percent in core habitat from 1993 to 2017. Their analysis estimates that in 2017 there were 3,175,539 acres of lower probability nesting habitat, 35,939 acres of moderate probability nesting habitat, and 38,564 of higher probability habitat in California. The CLPM team combined the Low (0.003 - 0.38), Moderate (0.381 - 0.645) and High (0.646 - 1) suitability rasters into one raster. The modeled output covers the entire range of Northern Spotted Owls: Washington, Oregon, and northern California within the Northwest Forest Plan (NWFP) boundary.
data_units relative suitability ranging from 0 1.0
data_vintage 09/2017
element Focal Species
encoding utf8
file_name MarbledMurreletNestingHab_201709_202401_T2_v5
format GeoTiff
harvest_object_id 5b23e33f-7d72-4e30-9b14-1768e94fbcc4
harvest_source_id a2637971-af12-457f-ae4a-831d2202a539
harvest_source_title WIFIRE Commons
maximum_value 1.0
metric_definition_and_relevance This data layer has been developed by an interagency team of scientists from the US Forest Service, US Fish and Wildlife Service, and Oregon State University. It was published in "Status and Trend of Nesting Habitat for the Marbled Murrelet Under the Northwest Forest Plan, 1993 to 2017" in 2021. It is part of the work to monitor the effectiveness of the Northwest Forest Plan. The data represent relative habitat suitability of habitat for marbled murrelet range in California for 2017; categorized as lower, moderate, and higher probability of nesting habitat, with probability gradients in each class. This species is only found in the Northern and Central California Regions.
minimum_value 0.0
pillar Biodiversity Conservation
spatial {"type": "Polygon", "coordinates": [[[-124.83685850424546, 37.53832319212637], [-121.17525654377484, 37.53832319212637], [-121.17525654377484, 42.16119598551989], [-124.83685850424546, 42.16119598551989], [-124.83685850424546, 37.53832319212637]]]}
sub_element Birds
tier 2