Miller and Ralph 



Chapter 20 



Inland Habitat Relationships in California 



Kilometers From Coast 10 20 30 40 50 60 



Pacific Ocean 



10 km 



Figure 3 Distribution of Marbled Murrelet survey stations in northern California. Stations are 

 located on private and public lands and surveys were conducted one or more seasons from 1 988 to 

 1 994. Open circles represent one survey station or a group of stations in one isolated stand. In areas 

 with high concentrations of stations, open circles appear filled in or shaded. 



non-forested or harvested habitat. If groups of trees were 

 less than 160 meters apart they were considered one stand. 

 Stands that met all of the following criteria were 

 included in the group of potential survey sites: old-growth 

 or residual stands with dominant and codominant trees that 

 comprised at least 20 percent canopy cover; size between 2 

 ha and 400 ha; distance from coast less than 40 km (25 

 miles); dominant vegetation type of coast redwood (Sequoia 

 sempervirens) or Douglas-fir (Pseudotsuga menziesii) at 



elevations of less than 1,000 m; and safely accessible by 

 road or well-defined trail. 



Analyses 



Standardization for Seasonal Variation 



Various factors may influence the numbers of detections 

 of murrelets at inland locations, including environmental 

 conditions, time of year (O'Donnell and Naslund, this 



208 



USDA Forest Service Gen. Tech. Rep. PSW-152. 1995. 



