Red-cockaded Woodpecker Home Range 41 



the crown, limb, and pine cone. Trees and locations were classed as 

 living or dead. 



Although observations were made of all family members, only data 

 for the adult male and female of each group were analyzed because 

 other birds were not present throughout the study. The 5-minute 

 observation bout was used as the unit of analysis because observations 

 made at 15-second intervals were not independent (Repasky 1984). 

 Substrates were divided into mutually exclusive pairs for analysis, 

 including pine and non-pine substrates, living and dead pines, trunk and 

 non-trunk surfaces of live pines, trunk-within-crown and trunk-below- 

 crown of live pines, and dead limb and other components of non-trunk 

 areas of live pines. The proportion of foraging time spent upon one 

 category of each pair was calculated for each bout. Least squares means 

 (SAS Institute 1982b) from analyses of variance were used to estimate 

 substrate use because of differences between time periods and between 

 sexes in substrate use and sample size. Calculations were by weighted 

 least squares regression to satisfy the assumption of homogeneity of 

 variance (Neter and Wasserman 1974). 



Foraging behaviors were analyzed in a manner similar to that used 

 for substrates. The proportion of foraging time spent in each behavior 

 was calculated for each observation bout. Least squares means were 

 estimated using weighted least squares ANOVAs. 



The independence of foraging behavior and substrate was tested 

 with a 2-way chi-square contingency table. A pool of presumably 

 independent observations was created by randomly selecting one 

 observation from each substrate in each 5-minute observation bout. All 

 observations from the month and individual with the least number of 

 observations were used in the test with equal numbers of randomly 

 chosen observations for other months and individuals. In this analysis, 

 substrates were pooled to hardwoods, dead pine surfaces, non-trunk 

 surfaces of living pines, live pine trunk within the crown, and live pine 

 trunk below the crown. 



Overlap between the foraging niches of the adults of each group 

 was calculated monthly as a from Levins (1968). Calculations were 

 based on the proportions of total foraging time spent on the substrates. 

 These were calculated from the least squares means obtained from the 

 analyses described above. For example, the proportion of foraging time 

 spent on dead limbs of living pines was calculated as the proportion of 

 foraging time spent on pines times the proportion of pine foraging time 

 spent on living pines times the proportion of live-pine foraging time 

 spent on non-trunk areas times the proportion of non-trunk foraging 

 time spent on dead limbs. Categories used in the calculations were dead 

 pines, live limbs on live pines, dead limbs on live pines, pine cones, 



