Northern Spotted Owl Changes in Suitable Habitat, 1993-2022

These data track changes in Northern spotted owl habitat suitability from 1993-2022. The primary purpose of this ongoing monitoring is to track changes in habitat that could be used by NSO over the time frame of the Northwest Forest Plan (NWFP). Data to date reflect changes over the first 30 years of the NWFP. The modeled output covers the entire range of northern spotted owls, Washington, Oregon, and northern California. It has been clipped to the Northern California region. This data layer indicates:

  • Forest capable lands that were not suitable habitat in 1993 and still are not
  • Forest capable lands that were not suitable habitat in 1993 but are now
  • Forest capable lands that were suitable habitat in 1993 but have been lost to disturbance (e.g. fire)
  • Forest capable lands that were suitable habitat in 1993 and still are

This subspecies is found in the Northern California Region.

Data and Resources

Additional Info

Field Value
Version Version 5.0
Last Updated March 28, 2025, 08:36 (UTC)
Created March 7, 2025, 07:52 (UTC)
categorical_values {"0": 2886861, "1": 569156, "12": 688749, "11": 283854}
category /Biodiversity Conservation/Focal Species/Birds
collection_name California Landscape Metrics
creation_method The authors followed methods for habitat modeling and estimating density of occupied territories that were developed by Glenn et al. (2017), who reported high predictability based on independent data. The authors relied upon the modeling technique, MaxEnt to to model the suitability of habitat. MaxEnt uses a machine learning process and a suite of potential response functions to estimate the most uniform distribution (maximum entropy) of the "average" environmental conditions at known species locations compared to what is available across the modeled area (background) (Phillips et al. 2006). The modeling process does not require an a priori specification of a set of models, but instead fits training data (presence locations of owl pairs) to environmental covariates using various combinations of response functions (features) such as linear, quadratic, product, hinge, and threshold structures. The authors modeled relative habitat suitability using known owl pair nest and roost locations to train and test the model which was based on vegetation, topographic, and climate data (see Glenn et al. 2017 for modeling data sources, methods, and results). Each habitat suitability model performed well in predicting known territorial owl pair locations. The model was well-calibrated in all regions with higher densities of owls in areas with higher relative habitat suitability. 90% of the independent test locations were on or within 100 m of mapped suitable spotted owl habitat. 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 categorical null values = not forest capable. 0 = not habitat in 1993 and still not. 1 = not habitat in 1993 but is in 2022 11 = has been habitat since 1993 but lost (fires, etc). 12 = habitat in 1993 and still habitat in 2022.
data_vintage 2022
date_updated August 2024
element Focal Species
encoding utf8
file_name NorCal_NSO_SuitHabChange_19932022_202310_T3_v5
format GeoTiff
harvest_object_id 7890ba72-5777-4ef4-b456-2491b516fa94
harvest_source_id a2637971-af12-457f-ae4a-831d2202a539
harvest_source_title WIFIRE Commons
maximum_value 12.0
metric_definition_and_relevance These data track changes in Northern spotted owl habitat suitability from 1993-2022. The primary purpose of this ongoing monitoring is to track changes in habitat that could be used by NSO over the time frame of the Northwest Forest Plan (NWFP). Data to date reflect changes over the first 30 years of the NWFP. The modeled output covers the entire range of northern spotted owls, Washington, Oregon, and northern California. It has been clipped to the Northern California region. This data layer indicates: * Forest capable lands that were not suitable habitat in 1993 and still are not * Forest capable lands that were not suitable habitat in 1993 but are now * Forest capable lands that were suitable habitat in 1993 but have been lost to disturbance (e.g. fire) * Forest capable lands that were suitable habitat in 1993 and still are This subspecies is found in the Northern California Region.
minimum_value 0.0
pillar Biodiversity Conservation
spatial {"type": "Polygon", "coordinates": [[[-124.5094747456173, 37.98514797729529], [-121.17548901211018, 37.98514797729529], [-121.17548901211018, 42.11042124918754], [-124.5094747456173, 42.11042124918754], [-124.5094747456173, 37.98514797729529]]]}
sub_element Birds
tier 3