Nest design and breeding success in intraspecific investigations of non-cavity nesting avian species

Although more than 60 hypotheses predict associations between characteristics of nest architecture and at least one measure of breeding success, reproductive consequences of nest architecture remain quantitatively understudied. In addition, most detailed studies of animal constructions in natural conditions were conducted on species built inside human-made nest-boxes that facilitate monitoring. Here, we present the first review of methodologies and research findings in studies that examined the reproductive consequences of nest characteristics in wildlife species that build nests outside cavities, mainly focusing on nest-size components, animal-derived nest material, anthropogenic nest material, or fresh greenery (i.e., fresh vegetative materials placed in the nest). We found 84 published field studies that were conducted on 51 non-cavity nesting bird species from 10 different avian orders, mainly members of the Passeriformes (69%). We discuss why most investigations reported weak relationships between aspects of nest design and breeding success. We propose suggestions for future research on bird nests, and also highlight the importance of poorly studied research problems.