298 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1949 
While actually rising in the air the half-open wings are worked with a very 
quick shivering motion, and the feet are also moved up and down very rapidly, 
beating the air. 
The bird springs straight up in the air, sometimes for a few inches and sometimes 
to the height of two or more feet, and then drops. 
The whole of the plumage is much puffed out throughout the performance, 
which is repeated five or six times, with a short interval for rest. 
The game would appear to be somewhat fatiguing, as the bird rarely makes 
more than five or six jumps at a time without a short rest . . . They very often 
assume their curious jumping attitude some little distance before they arrive at 
their playground. . . 
Besides the data quoted above it may be added that apparently 
but one male may make use of one dancing area, and that often at the 
end of the jumping dance it appears to try to burrow into the shallow 
recesses of the central tuft of grasses (as though there were nests 
there). 
Jackson’s whydah shows the courtship behavior pattern developed 
to a greater degree of display and ostensible rivalry between males, 
and to a greater specialized areal usage (courtship, or dancing, ground 
as contrasted with nesting site or even breeding territory) than others 
of its relatives, but the difference seems to be more one of degree than 
of kind. As typified by its habits, this section of the terrestrial Plo- 
ceinae may be said to be characterized by elaboration of courtship 
behavior from individual displays near the nest to a complex display 
at a dancing ground, and by what seems to be monogamy. (More 
detailed information is needed on this point, however. In the case of 
the black whydah, Coliuspasser concolor, and of the red-collared why- 
dah, Coliuspasser ardens, there are observational data supporting a 
monogamous state; in the long-tailed wydah, Coliuspasser procne, 
similar but less extensive data suggest polygamy.) Recently V. D. 
van Someren (1945, pp. 131-141) has concluded that Jackson’s why- 
dah is polygamous, but his own presentation of the case is not too pos- 
itive. Thus, he writes that— 
. polygamy appears to be general, and seems to arise because of the imper- 
fect correlation between the maturation of the males and females. Some males 
mature early, others late, and the early males may cease dancing and start moult- 
ing while later males are just beginning to assume breeding plumage and dance. 
This irregular maturation of the males may be spread over several months, while 
by contrast, the females mature almost simultaneously, and all nests are found 
at the same stage of building or incubation within a few days. Since the sex- 
ratio of the mixed flock is almost 50:50, late maturing males are thus able to 
mate with several females, because the mature females probably now outnumber 
the mature males. Males may commence dancing some four months before the 
first nest is found, but these early males are probably unsuccessful at mating be- 
cause of the unready state of the females. Males may start dancing while still 
in non-breeding plumage, but the behaviour pattern of these immature males is 
undeveloped in several respects. 
