A Mechanistic Examination of Interspecific Competition Between Wild and Domestic Herbivores

Large herbivores, such as mule deer and cattle have similar life histories and likely compete for resources. However, quantifying the extent to which these species compete and the specific resources they compete for has proved challenging. My research examines if cattle influence deer abundance and behavior due to competition for forage, competition for shade, and/or by affecting the predation risk of deer. Using a grid of autonomous trail cameras, I was able to determine if cattle abundance influences local deer abundance in relation to specific resources and habitat features. Using GPS data from collared deer, I was also able to examine if cattle density affects the probability that a deer was in a foraging, resting, or commuting state. I found evidence that cattle abundance reduces deer abundance in forage-rich areas, indicating that these species are likely competing for forage. Likewise, I found that cattle density increases the probability that a deer is foraging, and reduces the probability that a deer is commuting. Behavioral data is difficult to interpret, but this may suggest that deer must compensate for having less forage available due to competitors by spending more time foraging. However, it is also possible that cattle are merely an indicator of good habitat, so deer are more likely to forage in areas where cows are present. I did not find any compelling evidence of shade competition or predation risk effects between deer and cattle. My work demonstrates that it is important to examine many different data sources when trying to assess competition between large herbivores, and to not just assume what resources are driving competition. Additionally, my work demonstrated that forage competition occurs between mule deer and cattle, so managers should take this into account when balancing their goals for livestock, mule deer, and rangeland health

Annual Movement Patterns and Microhabitat Use of Two Anaxyrus Species in the Southeastern Coastal Plain

Amphibian populations have declined precipitously in recent decades, and effective management plans are needed to combat this ongoing decline. However, most amphibian management plans tend to be extremely generalized, and little research has explored species-specific responses of amphibians to microhabitat or climatic variables. Using a relatively novel tracking method, I examine the annual microhabitat and movement of two Anaxyrus species (A. americanus and A. fowleri), one of which has suffered population declines, for the purpose of informing management practices regarding these species. My study found large differences in microhabitat use between the two species. A. americanus primarily utilize microhabitats associated with forest, while A. fowleri utilize a variety of microhabitats, some of which are never used by A. americanus. Additionally, A. fowleri are more mobile and cover more distance on average than A. americanus, though both species tend to move greater distances at higher temperatures, higher cumulative 3-day rainfall, and earlier in the year. Overall, my results indicate the need for management practices that are tailored to conserve species-specific habitat requirements

Assessment of Psychosocial and Neonatal Risk Factors for Trajectories of Behavioral Dysregulation Among Young Children From 18 to 72 Months of Age

Importance Emotional and behavioral dysregulation during early childhood are associated with severe psychiatric, behavioral, and cognitive disorders through adulthood. Identifying the earliest antecedents of persisting emotional and behavioral dysregulation can inform risk detection practices and targeted interventions to promote adaptive developmental trajectories among at-risk children. Objective To characterize children’s emotional and behavioral regulation trajectories and examine risk factors associated with persisting dysregulation across early childhood. Design, Setting, and Participants This cohort study examined data from 20 United States cohorts participating in Environmental influences on Child Health Outcomes, which included 3934 mother-child pairs (singleton births) from 1990 to 2019. Statistical analysis was performed from January to August 2022. Exposures Standardized self-reports and medical data ascertained maternal, child, and environmental characteristics, including prenatal substance exposures, preterm birth, and multiple psychosocial adversities. Main Outcomes and Measures Child Behavior Checklist caregiver reports at 18 to 72 months of age, with Dysregulation Profile (CBCL-DP = sum of anxiety/depression, attention, and aggression). Results The sample included 3934 mother-child pairs studied at 18 to 72 months. Among the mothers, 718 (18.7%) were Hispanic, 275 (7.2%) were non-Hispanic Asian, 1220 (31.8%) were non-Hispanic Black, 1412 (36.9%) were non-Hispanic White; 3501 (89.7%) were at least 21 years of age at delivery. Among the children, 2093 (53.2%) were male, 1178 of 2143 with Psychosocial Adversity Index [PAI] data (55.0%) experienced multiple psychosocial adversities, 1148 (29.2%) were exposed prenatally to at least 1 psychoactive substance, and 3066 (80.2%) were term-born (≥37 weeks’ gestation). Growth mixture modeling characterized a 3-class CBCL-DP trajectory model: high and increasing (2.3% [n = 89]), borderline and stable (12.3% [n = 479]), and low and decreasing (85.6% [n = 3366]). Children in high and borderline dysregulation trajectories had more prevalent maternal psychological challenges (29.4%-50.0%). Multinomial logistic regression analyses indicated that children born preterm were more likely to be in the high dysregulation trajectory (adjusted odds ratio [aOR], 2.76; 95% CI, 2.08-3.65; P < .001) or borderline dysregulation trajectory (aOR, 1.36; 95% CI, 1.06-1.76; P = .02) vs low dysregulation trajectory. High vs low dysregulation trajectories were less prevalent for girls compared with boys (aOR, 0.60; 95% CI, 0.36-1.01; P = .05) and children with lower PAI (aOR, 1.94; 95% CI, 1.51-2.49; P < .001). Combined increases in PAI and prenatal substance exposures were associated with increased odds of high vs borderline dysregulation (aOR, 1.28; 95% CI, 1.08-1.53; P = .006) and decreased odds of low vs high dysregulation (aOR, 0.77; 95% CI, 0.64-0.92; P = .005). Conclusions and Relevance In this cohort study of behavioral dysregulation trajectories, associations were found with early risk factors. These findings may inform screening and diagnostic practices for addressing observed precursors of persisting dysregulation as they emerge among at-risk children

Host factors are associated with vaginal microbiome structure in pregnancy in the ECHO Cohort Consortium

Using pooled vaginal microbiota data from pregnancy cohorts (N = 683 participants) in the Environmental influences on Child Health Outcomes (ECHO) Program, we analyzed 16S rRNA gene amplicon sequences to identify clinical and demographic host factors that associate with vaginal microbiota structure in pregnancy both within and across diverse cohorts. Using PERMANOVA models, we assessed factors associated with vaginal community structure in pregnancy, examined whether host factors were conserved across populations, and tested the independent and combined effects of host factors on vaginal community state types (CSTs) using multinomial logistic regression models. Demographic and social factors explained a larger amount of variation in the vaginal microbiome in pregnancy than clinical factors. After adjustment, lower education, rather than self-identified race, remained a robust predictor of L. iners dominant (CST III) and diverse (CST IV) (OR = 8.44, 95% CI = 4.06–17.6 and OR = 4.18, 95% CI = 1.88–9.26, respectively). In random forest models, we identified specific taxonomic features of host factors, particularly urogenital pathogens associated with pregnancy complications (Aerococcus christensenii and Gardnerella spp.) among other facultative anaerobes and key markers of community instability (L. iners). Sociodemographic factors were robustly associated with vaginal microbiota structure in pregnancy and should be considered as sources of variation in human microbiome studies