|Title||Variations in the incidence of hatching failure in the cedar waxwing and other species|
|Publication Type||Journal Article|
|Year of Publication||1973|
Unusually high incidences of hatching failure due to egg sterility and embryonic death in three songbird species may be related to the proximity of the nests to farms. The Cedar Waxwing suffered the greatest hatching failure with 24.2% of all eggs and 46.7% of eggs in orchards near farms not hatching due to sterility or developmental failure. Hatching failure is examined both by the total number of eggs failing to hatch and by the number of nests with various degrees of failure. If it occurred at all in a nest, hatching failure in most species tended to affect more than one egg. Statistical tests treating each egg as an independent event may therefore be invalid. Damage due to pesticides or other chemical agents may be the cause of the observed excessive hatching failure, but direct evidence is lacking. Other possible factors are mentioned and rejected. Hatching success in other studies is tabulated for comparative purposes. The paucity of work dealing with hatching failure in songbirds is stated and the need for such studies is noted.