Biology

Computer science

Generalist and specialist species

Gene

Trait

Biodiversity

Urbanization

Biochemistry

Brood

Habitat

Phenotypic trait

Ecology

Programming language

Life history

Reproduction

Avian clutch size

Life history theory

Phenotype

Land

Urbanization poses a major threat to biodiversity worldwide. We focused on birds as a well-studied taxon of interest, in order to review literature on traits that influence responses to urbanization. We review 226 papers that were published between 1979 and 2020, and aggregate information on five major groups of traits that have been widely studied: ecological traits, life history, physiology, behavior and genetic traits. Some robust findings on trait changes in individual species as well as bird communities emerge. A lack of specific food and shelter resources has led to the urban bird community being dominated by generalist species, while specialist species show decline. Urbanized birds differ in the behavioral traits, showing an increase in song frequency and amplitude, and bolder behavior, as compared to rural populations of the same species. Differential food resources and predatory pressure results in changes in life history traits, including prolonged breeding duration, and increases in clutch and broo...

Which Traits Influence Bird Survival in the City? A Review