A method for detecting undervalued resources with application to breeding birds

Anthropogenic changes to ecosystems can decouple habitat selection and quality, a phenomenon well illustrated by ecological traps in which individuals mistakenly prefer low-quality habitats. Less recognized is the possibility that individuals might fail to select high-quality habitat because of the absence of some appropriate cue. This incorrect assessment of resource quality can lead to relatively high-quality resources being undervalued, whereby they support fewer individuals than optimal. We developed a habitat selection model to predict the expected patterns in patch-level density, fitness, and individual quality derived from either accurate assessment of habitat quality or from undervaluing of habitat patches (i.e., quality is not correctly assessed). Unlike previous habitat selection models, we explicitly and simultaneously incorporated variation in both individual and habitat quality into our estimates of realized fitness. Although multiple mechanisms can reduce patch-average density, fitness, and individual quality in less preferred patches, only undervaluation results in the occupation of higher-quality territories by similar-quality individuals in less preferred vs. preferred patches. We then looked for evidence of undervaluation in our seven-year data set of Acadian Flycatchers (Empidonax virescens) occupying forests in urbanizing landscapes in Ohio, USA. We suspected that forests within more urban landscapes may be undervalued in our study system because (1) urban forests typically support lower densities of Neotropical migratory birds than rural forests and (2) anthropogenic disturbance and habitat alterations are likely to result in mismatches between cues typically used in habitat selection and actual habitat quality. In contrast to our predictions, field data suggest that urban forests are not undervalued. Our work not only expands upon previous habitat selection models by considering undervaluation, but also demonstrates how predictions derived from our model can be tested using a long-term empirical data set

Nest survival in year-round breeding tropical red-capped larks <i>Calandrella cinerea </i>increases with higher nest abundance but decreases with higher invertebrate availability and rainfall

Nest survival is critical to breeding in birds and plays an important role in life-history evolution and population dynamics. Studies evaluating the proximate factors involved in explaining nest survival and the resulting temporal patterns are biased in favor of temperate regions. Yet, such studies are especially pertinent to the tropics, where nest predation rates are typically high and environmental conditions often allow for year-round breeding. To tease apart the effects of calendar month and year, population-level breeding activity and environmental conditions, we studied nest survival over a 64-month period in equatorial, year-round breeding red-capped larks Calandrella cinerea in Kenya. We show that daily nest survival rates varied with time, but not in a predictable seasonal fashion among months or consistently among years. We found negative influences of flying invertebrate biomass and rain on nest survival and higher survival of nests when nests were more abundant, which suggests that nest predation resulted from incidental predation. Although an increase in nest predation is often attributed to an increase in nest predators, we suggest that in our study, it may be caused by altered predator activity resulting from increased activity of the primary prey, invertebrates, rather than activity of the red-capped larks. Our results emphasize the need to conduct more studies in Afro-tropical regions because proximate mechanisms explaining nest predation can be different in the unpredictable and highly variable environments of the tropics compared with the relatively predictable seasonal changes found in temperate regions. Such studies will aid in better understanding of the environmental influences on life-history variation and population dynamics in birds

Reproductive phenology of the Acadian flycatcher (Empidonax virescens), a Neotropical migratory bird species, across an urban to rural gradient in central Ohio, USA

FAES and Human Ecology: 1st Place (The Ohio State University Edward F. Hayes Graduate Research Forum)The tendency for birds to reproduce earlier in the season has been observed in urban compared to rural populations, but these observations are limited primarily to species that spend all or most of the year in North America (i.e., resident or short-distance migrants). However, the factors that influence the reproductive timing of resident and short-distance migrants are unlikely to have the same influence on Neotropical migrants, a group of birds requiring conservation action due to long-term population declines. To understand the relationship between urbanization and reproductive phenology or timing of a Neotropical migratory bird species I (1) described the pattern of reproductive phenology in Neotropical migratory bird species across an urban to rural gradient, (2) assessed the reproductive consequences of varied breeding phenology, and (3) evaluated the extent to which alternative factors might explain differences in reproductive phenology. Data were collected between 2001 and 2007 on 35 different forests spanning an urban to rural gradient in central Ohio, USA. I used Acadian flycatchers (Empidonax virescens) as a model species. Birds were captured, marked, measured, released, and monitored throughout the breeding seasons. The general pattern of breeding phenology was opposite that found in most resident and short-distance migrant birds. Birds arrived later, initiated clutches later, and finished nesting earlier than birds breeding in more urban forests. The combination of delayed clutch initiation and earlier completion of nesting activity resulted in an abbreviated nesting season associated with urbanization. Ultimately, this attenuated nesting season reduced the number of nests attempted and young produced by urban-breeding birds and shifted the timing of fledging, with the first fledglings being produced relatively later in the breeding season. The underlying causes of the phenological differences are less clear. One possibility supported by my data is that urban forests were disproportionately settled by small females, which initiated their first clutches later in the nesting season than larger females. This study provides the first evidence that urbanization is associated with attenuated nesting seasons for Neotropical migratory birds and that this shift in breeding phenology may have reproductive consequences.A five-year embargo was granted for this item

A Qualitative Case Study on Professionals’ Prevention and Intervention Strategies for Gendered Interpersonal Adolescent Violence Among Adolescents in Haiti

This dissertation is a collective case study that developed an understanding about the knowledge professionals and community agency personnel in Haiti have about gendered adolescent interpersonal violence (GAIV). The study also explored the strategies and interventions utilized by professionals who work with adolescents, in response to GAIV. The researcher gathered data about the participating professionals’ knowledge of GAIV, their interventions and approaches with adolescents, and the ways in which Haitian culture shaped the ways in which they intervened. Five professionals, including a physician, a nurse, a social worker, a former school vice principal and a teacher were interviewed over Skype and completed three electronic, reflective journals. This presentation will discuss methodological issues associated with international research and reflect on the researchers experiences conducting Skype interviews and using electronic journals