Quantifying sources of variability in infancy research using the infant-directed-speech preference

Psychological scientists have become increasingly concerned with issues related to methodology and replicability, and infancy researchers in particular face specific challenges related to replicability: For example, high-powered studies are difficult to conduct, testing conditions vary across labs, and different labs have access to different infant populations. Addressing these concerns, we report on a large-scale, multisite study aimed at (a) assessing the overall replicability of a single theoretically important phenomenon and (b) examining methodological, cultural, and developmental moderators. We focus on infants’ preference for infant-directed speech (IDS) over adult-directed speech (ADS). Stimuli of mothers speaking to their infants and to an adult in North American English were created using seminaturalistic laboratory-based audio recordings. Infants’ relative preference for IDS and ADS was assessed across 67 laboratories in North America, Europe, Australia, and Asia using the three common methods for measuring infants’ discrimination (head-turn preference, central fixation, and eye tracking). The overall meta-analytic effect size (Cohen’s d) was 0.35, 95% confidence interval = [0.29, 0.42], which was reliably above zero but smaller than the meta-analytic mean computed from previous literature (0.67). The IDS preference was significantly stronger in older children, in those children for whom the stimuli matched their native language and dialect, and in data from labs using the head-turn preference procedure. Together, these findings replicate the IDS preference but suggest that its magnitude is modulated by development, native-language experience, and testing procedure. (This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 798658.

2018 Research & Innovation Day Program

A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1005/thumbnail.jp

2017 Research & Innovation Day Program

A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1004/thumbnail.jp

Dietary flexibility of Wood Storks in response to human-induced rapid environmental change

Human-induced rapid environmental change (HIREC) has altered landscape processes and negatively impacted many species globally. Some of the most dramatic changes have been in wetlands where flows have been disrupted, and new wetlands have been created to retain runoff. In response to disrupted natural wetland conditions, Wood Stork (Mycteria americana) populations in South Florida have significantly declined over the past several decades. Despite the well-documented sensitivity of Wood Storks to natural wetland conditions, Wood Storks are often observed foraging in roadside created wetlands; however, the availability of prey in created wetlands is currently unknown. We sampled natural and created wetlands to determine aquatic fauna available for foraging Wood Storks. To determine prey use, we collected food boluses from Wood Storks in both natural wetland and urban landscapes. Historical studies found nonnative fish were absent in Wood Stork diet prior to the dominance of created wetlands in the landscape; however, we found nonnative fish frequently in both created wetlands and boluses. Furthermore, urban nesting Wood Storks consumed large-bodied prey species that were more characteristic of created wetlands whereas Wood Storks nesting in natural wetlands consumed large-bodied prey more characteristic of natural wetlands. Overall, Wood Storks consumed prey that were more similar to the fish community in created wetlands than those in natural wetlands. These dietary patterns suggest that Wood Storks have behavioral plasticity in both foraging habitat and prey use to cope with HIREC. Conservation efforts for species existing in both natural and urban habitats should consider the importance of novel prey and foraging habitats, as they may assist in sustaining populations in a rapidly changing world

Wading Bird Nestling Diet as a Measure of Food Availability in the Everglades

Lack’s Brood Reduction Hypothesis asserts that hatching asynchrony in most altricial birds is a reproductive strategy in which sibling competition for resources, such as food, works to reduce brood size in times of limited resources. Wading birds in the Florida Everglades are considered to be indicators of the overall ecosystem health and function, since their populations are limited by the amount of food available in the land-scape. As such, knowledge of food availability has great implications toward Everglades landscape management and wading bird population monitoring. To determine if wading birds were food limited during the 2013 nesting season, we collected and analyzed the mass of regurgitated boluses collected from little blue heron, snowy egret, tricolored heron, and wood stork nestlings. Our results suggest that food was not limited during the 2013 nesting season. We also discuss the importance of long-term studies in order to obtain data from both “good” and “bad” years in terms of prey availability, thus providing valuable information on Everglades ecosystem health and functioning for management and restoration efforts

Persistence and diversity of directional landscape connectivity improves biomass pulsing in simulations of expanding and contracting wetlands

In flood-pulsed ecosystems, hydrology and landscape structure mediate transfers of energy up the food chain by expanding and contracting in area, enabling spatial expansion and growth of fish populations during rising water levels, and subsequent concentration during the drying phase. Connectivity of flooded areas is dynamic as waters rise and fall, and is largely determined by landscape geomorphology and anisotropy. We developed a methodology for simulating fish dispersal and concentration on spatially-explicit, dynamic floodplain wetlands with pulsed food web dynamics, to evaluate how changes in connectivity through time contribute to the concentration of fish biomass that is essential for higher trophic levels. The model also tracks a connectivity index (DCI) over different compass directions to see if fish biomass dynamics can be related in a simple way to topographic pattern. We demonstrate the model for a seasonally flood-pulsed, oligotrophic system, the Everglades, where flow regimes have been greatly altered. Three dispersing populations of functional fish groups were simulated with empirically-based dispersal rules on two landscapes, and two twelve-year time series of managed water levels for those areas were applied. The topographies of the simulations represented intact and degraded ridge-and-slough landscapes (RSL). Simulation results showed large pulses of biomass concentration forming during the onset of the drying phase, when water levels were falling and fish began to converge into the sloughs. As water levels fell below the ridges, DCI declined over different directions, closing down dispersal lanes, and fish density spiked. Persistence of intermediate levels of connectivity on the intact RSL enabled persistent concentration events throughout the drying phase. The intact landscape also buffered effects of wet season population growth. Water level reversals on both landscapes negatively affected fish densities by depleting fish populations without allowing enough time for them to regenerate. Testable, spatiotemporal predictions of the timing, location, duration, and magnitude of fish concentration pulses were produced by the model, and can be applied to restoration planning