Multiple paternity in polyandrous barn owls (Tyto alba)

Area of Science:

• Behavioral Ecology
• Avian Reproduction
• Molecular Genetics

Background:

• Polyandrous species exhibit females mating with multiple males across successive clutches.
• Female barn owls (Tyto alba) frequently desert first broods to produce a second annual brood with a new male.

Purpose of the Study:

• To investigate if copulation during the first brood influences male paternity in a subsequent, second brood.
• To determine if female desertion and mating with a second male impacts paternity certainty.

Main Methods:

• Molecular paternity analyses were employed to identify sires of nestlings.
• Comparison of extra-pair paternity rates in broods of deserting versus non-deserting females.

Main Results:

• Eight percent of second broods from deserting females contained extra-pair young sired by the first male.
• No extra-pair young were found in first or second broods of non-deserting females.
• Extra-pair young in second broods were exclusively sired by the male from the first annual brood.

Conclusions:

• Female desertion may drive male counter-strategies to enhance paternity and individual fitness.
• Females might seek genetic benefits by mating with the higher-quality initial male.