The available evidence indicated that net emigration of 

 yearling females occurred at the lowest and highest female 

 densities observed during the study, but not at intermediate 

 densities. Considering the small samples of marked yearlings, 

 it was possible that dispersal occurred but was not detected 

 during years of moderate to relatively high female density. 

 However, because female population estimates generally were 

 closely consistent with numbers of yearling females recruited, 

 any emigration that occurred during those years had to have 

 been balanced by immigration. 



The observed pattern of emigration among yearling females 

 was similar to the pre-saturation and saturation dispersal 

 proposed by Lidicker (1978). It was not consistent with the 

 "social fence" hypothesis proposed by Hestbeck (1982) in that 

 it did not explain the net emigration at high population 

 density. This inconsistency may be explained by the habitat 

 and social behavior of deer on our study area. The southern, 

 southeastern, and southwestern portions of the area were 

 bounded by blocks of very marginal or non-deer habitat, across 

 which yearlings could disperse and not encounter aggressive 

 "neighboring" deer until they were a significant distance from 

 their natal range. Also, variation in size of social groups 

 apparently depended more on fawn survival than on deer 

 density, and dispersal did not necessarily consist of movement 

 to just the nearest available, open habitat. At both low and 

 high densities, dispersers moved long distances within a day 

 or two, by-passing interaction with close neighbors. 



Saturation dispersal (Lidicker 1985), occurs at densities 

 at or above "carrying capacity"; pre-saturation dispersal 

 occurs before "carrying capacity" has been reached. Reasons 

 advanced for pre-saturation dispersal include genetic 

 selection and availability of unfilled habitat. Although it 

 is possible that "habitat fill" was the motivating factor 

 behind dispersal of yearling females at high densities, 

 previous social experience could also explain their dispersal 

 at both low and high densities. Occupation of vacant habitat 

 should not occur at 100% efficiency up to the point of habitat 

 fill. Thus, during all years, at least some animals should 

 not find habitat suitable to establish home ranges until they 

 have passed the study area boundaries. If habitat fill was 

 the only factor motivating emigration at high densities, it 

 would follow that at least some, and probably an increasing 

 amount of emigration would occur as density increased 

 (Lidicker 1978). Similar to Gaines and McClenaghan (1980), we 

 did not find that emigration increased proportionally with 

 density. However, it is possible that more intrapopulation 

 dispersal or small shifts in home range occurred with 

 increasing density. 



309 



