LIMITED TRAPNESTING 19 



For predicting summer clutch size, trapnesting on the first two days of each 

 month probabh' is the most satisfactory, with trapnesting one week each month 

 and August trapnesting of about equal value. Trapnesting in October at the 

 beginning of the year or from first egg to January 1 cannot be used to predict 

 summer intensity. 



Fall Clutch Size 



Various types of limited trapnesting may be tested for predicting possible 

 fall clutch size during September and October. The importance of heavy fall 

 production has been fully emphasized by many students of the problem. 



All five of the methods used in this study were employed to determine their 

 value for estimating fall clutch size, with results given in Tables 16 and 17. No 

 correlation was shown for October and only very slight correlation for produc- 

 tion to January 1 ; therefore no regression tables are given for these two measures. 



Of the types of limited trapnesting studied, records for the first week of each 

 month are the most accurate for predicting fall intensity. Trapnesting two days 

 of each month is also useful, and August records at the close of the first laying 

 year have considerable value. October records at the beginning of the year 

 and complete trapnest records from first egg to January 1 have no value for 

 predicting fall clutch size. 



Table 16. — The Value of Limited Trapnesting for Estimating 

 Fall Clutch Size. 



