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conspecific colony (whether becoming fertile there or not) and 
founding her own colony in one of the following springs either 
solitarily or by budding or colony fission. Whereas independent 
colony foundation by young Myrafant queens has frequently been 
observed, females of Leptothorax s. str. have only occasionally been 
found to hibernate solitarily. Buschinger (1968a) collected 13 incip- 
ient colonies, consisting of queen and brood only, in a total of 754 
nests of L. acervorum , and 2 in 319 colonies of L. muscorum. Incip- 
ient colonies are rare in L. spec. A and B, too, far too rare to explain 
the abundance of mature colonies. Observations made in August 
1988 on Mt. Seymour near Vancouver, however, indicate that there 
is a certain percentage of gynomorphic Leptothorax females which 
do not immediately return to conspecific colonies after mating. A 
similar behavior was observed in gynomorphic females of Lepto- 
thorax spec. A. in laboratory experiments. The rarity of incipient 
colonies in spring might perhaps be due to a low survival rate of 
solitarily hibernating females or to a return of females into 
conspecific colonies in late fall. 
In L. spec. A queen polymorphism, together with differences in 
mating behavior, may have led to alternative dispersal strategies. 
Intermorphs mate in the immediate neighborhood of their colonies 
and are easily accepted back after mating, hence the high percentage 
of nests with supernumerary intermorphs in the field. Gynomorphic 
females, on the other hand, show some flight activity before starting 
sexual calling behavior, and might not be able to find their way 
home. In constrast to L. acervorum, where allozyme data suggest 
that foreign females perhaps are tolerated in other colonies (Douwes 
et al., 1987), in Leptothorax spec. A workers show aggression 
toward foreign young inseminated females, and eventually kill 
them. After hibernation in conspecific nests, females of Leptothorax 
s. str. might found colonies either solitarily, as was assumed for 
L. muscorum (Buschinger and Winter, 1978), or by budding. 
In polygynous species, colony fission might increase the kinship 
in the daughter colonies compared to that in the mother colony by 
giving the workers the chance to arrange in different matrilines 
(Crozier, 1981), and indeed the segregation of workers into sorori- 
ties has been observed in the honey bee (Getz et al., 1982). In func- 
tionally monogynous species, however, the overall level relatedness 
might decrease by budding, similar to the relations in colony fission 
