Pairing patterns in monogamous birds are thought to be the consequence of mutual mate choice by males and females for characters linked to individual quality in the opposite sex. Although this may result in assortative pairing for a single character, there may be no simple match between male and female phenotype if the traits linked to individual quality are sex specific. For instance, in sever...

Missing data is a common problem for data quality. Most real datasets have missing data. This paper analyzes the missing data mechanisms and treatment rules. Popular and conventional missing data treatment methods are introduced and compared. Suitable environments for method are analyzed in experiments. Methods are classified into certain categories according to different characters.