8 BULLETIN 19 7, UNITED STATES NATIONAL MUSEUM 



(1938, vol. 1) has a note on a pair of white wagtails he saw in Kumania 

 facing one another with the tails of both birds almost perpendicularly 

 erected and appearing quite rigid, but unfortunately this somewhat 

 fragmentary observation was all that he could make, as he was passing 

 by in a boat. 



Nesting. — ^Where the white wagtail is a summer migrant the males 

 usually arrive in advance of the females. In Helgoland males have . 

 been passing for about three weeks before females begin to appear. 

 The nest is generally built in a recess or cavity of some sort or at least 

 in a more or less concealed position. It may be found in holes in walls 

 and other masonry or in rocks or cliffs, in steep banks, inside sheds or 

 outbuildings, under bridges, in hollow trees or among the roots of 

 trees, in wood stacks, among ivy, and so forth. Commonly it is well 

 above ground level, from a couple of feet or so to perhaps 9 or 10 feet, 

 but it may be merely under a clod in a plowed field or among marram 

 grass on sand dunes. Occasionally it is built in the nest of some other 

 bird, such as a song thrush, blackbird, or fieldfare. The bulk varies 

 a good deal according to the situation. It is made of dry grass, straws, 

 roots, fine twigs, dead leaves, and moss with cup lined with hair, 

 feathers, or bits of wool. It is built by the female only, with the 

 cock accompanying her. It is evident that the female is also mainly 

 concerned in the actual selection of the site, but C. and D. Nethersole- 

 Thompson (1943) state that the male of the pied wagtail also examines 

 possible sites and may "suggest" sites to the female, whicli she thor- 

 oughly tests. 



Eggs. — The ground color of the eggs is a slightly grayish or bluish 

 white, closely freckled with gray or brownish, Avith underlying pale- 

 gray markings often more or less distinct and sometimes with a few 

 hairlike dark-brown streaks. White eggs occur and an erythristic 

 variety has been recorded once. Jourdain ( 1938, vol, 1 ) gives the num- 

 ber as four or five to seven as a rule, rarely eight, and he gives the 

 following measurement of 100 eggs : Average, 20.4 by 15.1 ; maximum, 

 21.5 by 15 and 20 by 16.2; minimum 18 by 15 millimeters. The breed- 

 ing season is given by the same authority as from the end of April to 

 early in July, exceptionally later in central Europe, but in Iceland and 

 north Europe often not before June. Eggs may sometimes be found 

 in Iceland by the end of May. It may be recalled that the nest in 

 Greenland recorded by Chapman and already mentioned contained 

 egg-s on June 16, but is not known when they were laid. 



Young. — Incubation is performed chiefly by the female, though ac- 

 cording to Jourdain the male may take some share. The incubation 

 period is 12-14 days. Teschemaker (1913) observed that eggshells 

 were carried away from the nest by birds in captivity. 



Both parents feed the young. In the case of the pied wagtail the 

 feces of the nestlings are carried away by the parents, at least in the 



