Methods for demography studies on the Cle Elum Study Area
- Two levels of survey effort:
- General Study Area
- Return to historic owl territories each year
- Determine territory occupancy
- Multiple (3) visits to each territory
- Band new adults and all juveniles
- Determine reproduction
- Density Study Area
- General study area survey plus:
- Attempt a total population count by surveying the complete area 3 times/year
Status and trends in demography of northern spotted owls, 1985-2003.
Wildlife Monographs: 163
- Consisted of data from 14 study areas (including 8 NWFP monitoring areas)
- Indicated Spotted Owl populations, on average, declined by a rate of 3.7% per year 1987-2003
- Populations were declining on 9 of 13 study areas, 1 study area had insufficient data to derive estimates
- 5 of the 8 monitoring areas showed population declines. Average decline 2.4 %/year
- Cle Elum population growth rate - 6.2% per year
- 2009 Meta-analysis draft in preparation, to be released late summer, 2009