190 MAINE AGRICULTURAL EXPERIMENT STATION. IQII. 



eggs; giving a percentage of 1.24 unrecorded eggs. We then 

 have for the ratio of efficiency of old nest to new : 



Old trap nest 4.01 



• = = 3-23 



New trap nest 1.24 



(2) The relative amount of unrecorded egg production is 

 not closely related to the total egg production. This is indi- 

 cated by the fact that the curves of unrecorded eggs by months 

 do not at all parallel the familiar curve of the seasonal or 

 monthly distribution of egg production.* The absolute num- 

 ber of unrecorded eggs tends to increase as the nest eggs in- 

 crease, and diminish as the latter diminishes. But there is no 

 indication whatever in the figures that proportioiiofcly more 

 eggs are unrecorded when the laying is heavy than when it is 

 light, and vice-versa. 



(3) There is plainly in the years 1908-09, and 1909-10 a 

 tendency for the unrecorded production to diminish relatively 

 as time elapses from the beginning of the laying year. That is 

 to say, the longer the same individual birds use the trap nests, 

 the smaller becomes the production of unrecorded eggs. This 

 suggests what is actually the fact, that there is an element of 

 learning in the operation of trap nests, looked at from the stand- 

 point of the bird. In a lot of several hundred pullets put into 

 the laying house in the fall there will always be a few who have 

 to be taugJit to use trapnests, or for that matter, any kind of a 

 nest. Usually such bircis learn fairly rapidly to lay in nests. 

 There are occasional lapses, but the number of these tends to 

 become smaller the longer the bird has used a nest. It is on 

 this account that the relative proportion of unrecorded eggs 

 tends to diminish during the course of the laying year. 



(4) The year 1910-11 seems to furnish a contradiction to 

 the statements made in (3). In that year the proportionate 

 number of unrecorded eggs was actually greater towards the 

 end of the laying year than at the beginning, though the 

 amount of the change was so small as not to be significant. 

 Practically the line is horizontal. It is not possible to state posi- 



*Cf. Pearl and Surface, U. S. Dept. Agr. Bur. An. Ind. Bui. no. 

 Part 11, p. 90. 



