Testing the Likeable, Therefore Abundant Hypothesis: Bird Species Likeability by Urban Residents Varies Significantly with Species Traits

The urbanization of landscapes filters bird communities to favor particular species traits, driven in part by the changes that homeowners make to the amount and quality of habitat in yards. We suggest that an ultimate driver of these proximate mechanisms underlying bird community change with respect to urbanization is the likeability of species traits by urban residents. We hypothesize that bird species likeability, modulated by species traits, influences the degree to which homeowners alter the availability and quality of habitat on their properties and thereby affects species population sizes in urbanized landscapes. We refer to this new hypothesis as the Likeable, therefore Abundant Hypothesis. The Likeable, therefore Abundant Hypothesis predicts that (1) bird species likeability varies with species morphological and behavioral traits, (2) homeowners use trait-based likeability as a motivator to modify habitat availability and quality on their properties, and (3) residential habitat availability and quality influences species populations at landscape scales. We tested the first prediction of the Likeable, therefore Abundant Hypothesis using a survey of 298 undergraduate students at the University of North Carolina at Charlotte who were asked to rank their preferences for 85 forest generalist and edge/open country songbird species grouped according to 10 morphological and behavioral traits. Survey respondents preferred very small, primarily blue or black species that are insectivorous, aerial or bark foragers, residents, and culturally unimportant. On the other hand, respondents disliked large or very large, primarily yellow or orange species that forage on the ground and/or forage by flycatching, are migratory, and are culturally important. If the Likeable, therefore Abundant Hypothesis is true, natural resource managers and planners could capitalize on the high likeability of species that are nevertheless negatively affected by urbanization to convince homeowners and residents to actively manage their properties for species conservation.