Mar., 1919 THE MARITAL TIE IN BIRDS 79 
is an impartial mixture of sexes and of generations, in which the social tie dom- 
inates the other two, if these other two exist at all at the time. Are they really 
present? Will the flock coagulate in the spring and give out the same marital 
combinations that existed during the previous breeding season? Is not parent 
just as liable to mate with its own offspring as with a member of its own gen- 
eration? 
Consider the case of our non-social birds, such as the Shrikes and the 
Mockingbird. The asexual winter bird sees only a competitor in every other 
one of his own species who invades the particular territory which he has pre- 
émpted as his own. These birds are, with us here in the south, more or less 
localized as to individuals; hence it doubtless often happens that, through pro- 
pinquity, the same combination of individuals may recur in successive years. 
But does this involve a marital constance? I doubt it. 
Take again in the case of the migratory species. There is a separate mi- 
gration of the sexes in many of them. By the end of August most of the male 
Hooded Orioles have gone from the neighborhood of Los Angeles. There are 
still plenty of females and young of the year. The same might be said of the 
Black-headed Grosbeak and of a number of other species. The ‘‘men folk’’ 
have gone off on a regular stag party (or Elk’s excursion) to the tropics. Wiil 
their ‘*women folk’’ follow after with the children and hunt up their neglect- 
ful lords? May they not even winter in separate intra-tropical states, spend 
ing the asexual part of their yearly cycle wholly unconscious of each other’s 
being? On the return migration, the same separate movement may be ob- 
served. The vagrancy impulse seems to attack the males first and they push 
northward in great pioneer armies of males. I have seen a flock of male gros- 
beaks flying like a flock of blackbirds and entirely unleavened by feminine 
presence. They were just arriving from the south. Did their last season’s 
wives follow later and claim, each, her recalcitrant spouse? 
Then there are cases of abject desertion on the part of the male. Such is 
true of the Anna Hummingbird. I have found many nests of this species, in 
various stages of progress of the nest or of its content, but never yet have I 
seen the marital tie survive the early stages of nest building. The female com- 
pletes the nest, incubates the. eggs, and rears the young without assistance from 
the male. Mrs. Hummingbird is the original golf widow, with a husband some- 
where at the club, but she is not sure where (nor probably does she care). 
Perhaps we should not offer here as evidence the great variety of courting 
antics in which birds indulge, from the classic flight of the retiring woodcock 
to the dancing tournaments of the grouse. Are they merely for stimulus and 
not for selection of the mate? If birds mated for life would we see these court- 
ing activities so commonly? They would be needed only by the young and by 
the bereaved. 
The theorist, however, feels it proper to ask the question: Are there noi 
biologic reasons why a seasonal readjustment of the marital relation would 
prove advantageous to the race? If a protracted effort is required each season 
before a mate is obtained, the less virile bird will go unmated. Would not the 
result average better for the maintainance of tone in the race? Whatever else 
may be claimed for the principle of sexual selection, it seems to be more or less 
vital to racial vigor. Seasonal recurrence of the selective process would then 
be classed as a sort of protective adaptation in a class of animals showing 
abundant specialization in other respects. 
