SOiME PROBLEMS WITH EVERYDAY' BIRDS 



719 



the eggs for a short time when the " female " was in searcli 

 of food. The second " male " continued to help feed the 

 young and often came when hoth of the other birds 

 were present, the first " male " usually leaving upon his 

 arrival but sometimes merely Ijacking uj) and permit- 

 ting him to feed. 



Thirteen days later all four eggs in the second nest 

 hatched and the other young were almost ready to leave, 

 crowding over on to the second nest until the " female " 

 had difficulty in getting upon it to brood the newly hatched 

 young. The next day the " male's " young f^ew to the 

 ground, while the " female " continued to brood until the 

 middle of the afternoon. She did not, however, feed them 

 and before evening deserted them to help feed the fledg- 

 lings with the result that the next day all were dead. 



Now what is the explanation of the double nest? 

 What were the relations of the three birds and why did 

 the " female '" desert her young? The greatest difficulty 

 arises because the sexes of the different birds could not 

 be determined accurately. The two brightly colored birds 

 have been called " males," but it is known that mature 



A ■■DUMMY" NEST 



This was built and is owned by tlie long-billed marsh wren. These wrens are 

 architectural plutocrats because they build several nests in which they never 

 live. Why they do it has never been satisfactorily explained. 



females may be as bright as males and one or the other 

 might have been a female. We have, therefore, two 

 alternatives. 



Assuming that both of the bright birds were males, 

 we would have a case of polyandry, but it is difficult to 

 understand how two males could live amicably together, 

 or why the second male should help the first in the care 

 of the young. It is too far removed from bird or animal 

 nature as we know it. When polyandry does occur, there 

 is usually no spirit of cooperation between the different 

 males. It is much easier to think of one of the bright 



l)irds being a female and the case as one of polygamy. 

 It is known that polygamy does occur among birds, but 

 nevertheless, it is difficult to explain why two females 

 should nest so close together. It is unfortunate that the 

 birds were not observed when selecting the site, so that 

 it might be known whether both worked together, or 

 whether the duller, more immature l)ird came later and 

 mereh' annexed herself. This sort of iiolygamy occurs 

 with the red-winged blackbirds when the later-migrating, 

 immature females, which ha\e difficulty finding mates, 

 submit to the driving of a male already mated and are 

 content to settle somewhere within the area defended by 

 him, usually within five or ten feet of the nest of his first 

 mate. It might be well to explain here that mating with 

 most birds consists of the acceptance by the female of 



A BELIEVER IN MORMONISM 



Here is a house wren that had two mates at the same time and fathered four 

 broods of young and seemed to be proud of it. 



tlie nesting area selected by the male and the power of 

 the male to keep other males out of this area. It is fur- 

 thermore known that most birds return each spring to 

 their former nesting sites and that the females reaccept 

 their former mates provided they are still able to drive 

 off all other males. Now it is possible that both of these 

 female robins may previously have nested for one brood 

 or another on this porch and, coming back together thfs 

 spring, may both have accepted the one male capable of 

 driving away all others. 



A reason for the desertion of her newly hatched young 

 by the second female lies in the fact that a bird's instinct 

 to feed and protect fledglings is much more powerful than 

 its instinct to care for newly hatched young, a fact that 

 bird photographers must always bear in mind, especially 

 when working with wary, sensitive birds in which the 



