How IMBCR population estimates can be used to support avian conservation:
The Integrated Monitoring in Bird Conservation Regions Program (IMBCR) annually collects breeding bird information in all or portions of 13 states. Each year, occupancy and density estimates are calculated at a variety of spatial scales. This information can be used in the following ways to inform avian conservation:
- Bird Population estimates can be compared in space and time. For example, stratum-level estimates can be compared to state and regional estimates to determine whether local populations are above or below estimates for the region;
- Population estimates can be used to make informed management decisions about where to focus conservation efforts. For example, strata with large populations can be targeted for protection and strata with low populations can be prioritized for conservation action; a threshold could be set to trigger a management action when populations reach a predetermined level;
- Population estimates of treatment areas can be compared to regional estimates to evaluate effectiveness of management actions. For example, if sagebrush areas are being treated to improve habitat for Greater Sage-grouse (GRSG) and estimates for sagebrush-obligate birds increase in these areas in relation to regional estimates where treatment is not occurring, the results would suggest that the GRSG management actions are also beneficial to other sagebrush-obligate bird species;
- Annual estimates of density and occupancy can be compared over time to determine if population changes are a result of population growth or decline and/or range expansion or contraction. For example, if population densities of a species declined over time, but the occupancy rates remained constant, then the population change was due to declines in local abundance. In contrast, if both density and occupancy rates of a species declined, then population change was due to range contraction;
- Occupancy rates can be multiplied by the land area in a region of interest to estimate the area occupied by a species. For example, if a stratum comprises 120,000 km2 and the occupancy estimate for Western Meadowlark is 0.57, managers can estimate that 68,400 km2 (120,000 km2 * 0.57) of habitat within that stratum is occupied by Western Meadowlarks.