Burrowing owls are unique among owls, preferring open habitats with sparse vegetation and living underground rather than in trees. Like many bird species, burrowing owl populations have been declining. Habitat loss and fragmentation are considered to be primary factors. The Front Range of Colorado has seen large amounts of human population growth and development, contributing to habitat loss for burrowing owls and other species. This project aimed to quantify burrowing owl habitat loss and fragmentation near Denver in Adams, Arapahoe, and Denver counties.
The primary data was land cover rasters from 1992 and 2019. Sufficient data covering prairie dog colony locations and sizes unfortunately could not be found. Grassland was combined with slope from DEMs to select areas of grassland with flat to gentle slope as burrowing owl habitat. Land cover classification changes were computed for the three counties between 1992 and 2019 to see what types of land cover change contributed the greatest amount of habitat loss. Fragmentation was analyzed by comparing changes in the number, average area, and distances between habitat patches.
Results show that potential burrowing owl habitat near Denver has significantly decreased. Net grassland loss between 1992 and 2019 was over 160,000 acres. The majority of grassland was lost to cultivated crops and development. The number of habitat patches increased and the average area of habitat patches decreased, indicating the occurrence of habitat fragmentation.