EXPERIENCE, NEIGHBHORHOODS, AND HABITATS: BREEDING DISPERSAL OF MALE BLACK-CAPPED VIREOS (VIREO ATRICAPILLA)

Abstract

1. Mechanisms driving breeding dispersal are complex and potentially interactive. These mechanisms are of general interest because dispersal strongly links individual fitness to population dynamics. We examine the relative importance of personal information, neighborhood effects, and structural habitat characteristics in determining an individual’s propensity for breeding dispersal. 2. To document dispersal events in 2017 and 2018, we individually marked and radio tagged male black-capped vireos in Southwestern Oklahoma. We used a classification tree analysis to explore ten potential factors that individuals used as information to evaluate for emigration. We used the correlation between arrival date and habitat structure to determine habitat preference. 3. Older and younger age classes that reproduced successfully did not disperse, but younger age class individuals that failed to reproduce were more likely to disperse than older individuals. Dispersal events among young males were significantly related to the proportion of their neighbors that successfully reproduced. More individuals dispersed from neighborhoods of fewer, less successful neighbors. Male black-capped vireos did not disperse due to the vegetation structure of their habitat, though there was a trend for young males to be located in habitats with structure less preferred by older males. 4. Breeding dispersal propensity among black-capped vireos, like many other avian species, depended mostly on their personal breeding experience, but also on reproductive information gleaned from their neighbors. In this Oklahoma population, black-capped vireos of different ages were spatially segregated into habitats of differing structure, which may further influence neighborhood quality and the degree to which age group participates in breeding dispersal. 5. Our results indicate localized, neighborhood effects are important to breeding dispersal, which has implications for the genesis of new populations or a population to become stabilized within a metapopulation. The creation of preferred habitat will be needed to produce rates of nest success that support healthy metapopulation dynamics. These preferred habitats are needed to balance potential high rates of breeding dispersal out of habitats with low neighborhood quality for this species. Future studies focused on the spatio-temporal aspects of breeding dispersal would be valuable. Especially useful would be studies of search behaviors of dispersing individuals and processes involved in selecting new habitat after leaving their initial territory. In general, further study is needed on interactions of multiple dispersal cues and how spatial structuring influences the evaluation of these cues by potential dispersers.