FACIAL RECOGNITION: INTRASPECIFIC VARIATION AND DEVELOPMENT OF SPECIALIZATION IN POLISTES FUSCATUS, A MODEL SYSTEM

Specialized face learning, the ability to learn and remember faces better than other visual stimuli, occurs across a wide range of social animal taxa. However, the ontogeny of specialized face learning, specifically whether it develops due to innate, learned, or a combination of innate and learned factors, remains debated in the literature. Empirical data on face specialization has supported all three hypotheses, yet conflicting methodologies and data interpretations complicate our understanding of the ontogeny of face specialization. In this study, we use Polistes fuscatus (paper wasp), a system with intraspecific variation in developmental environment (innate) and experience (learned), to test the ontogeny of specialized face learning. Our results support the combination hypothesis for the development of specialized face learning, with both innate and learned factors needed to fully explain intraspecific variation in face specialization. Wasps with better early nutritional environment (gynes) learned to discriminate faces more accurately than wasps with poorer nutrition during early development (workers), perhaps due to innate variation in neural structures. Furthermore, older wasps (foundresses) learned faces faster than other stimuli, while younger wasps (gynes) showed no difference in rate of learning between stimuli. We posit that older wasps have greater specialization for learning faces than younger wasps due to higher levels of facial exposure throughout life. Controlled manipulations of early development and adult experience will be useful to provide a more detailed analysis of the ontogeny of specialized face learning. Our results, which suggest that the combined effects of learned and innate factors are necessary to explain the ontogeny of specialized face learning, may be generalizable to all social animals. In many signaling systems, intraspecific variation in recognition abilities is based on developmental stage, experience, or caste. However, the occurrence of intraspecific variation in recognition has not been thoroughly examined in species with individual recognition. For example, previous work has shown that individual recognition is an important aspect of the social life of Polistes fuscatus (paper wasp) nest founding queens, as individual recognition stabilizes dominance interactions and reduces aggression. Yet, to date the potential for individual recognition among P. fuscatus workers has been largely ignored. Here, we explore whether there is intraspecific variation in individual recognition by testing P. fuscatus worker recognition abilities in a series of staged contests. The results indicate that P. fuscatus workers are capable of individual recognition: focal workers paired with previously encountered partners experienced significantly less aggression and more nonaggressive bodily contact than focal workers paired with unknown social partners. Therefore, this study finds no evidence of intraspecific variation in individual recognition across castes of P. fuscatus. We propose two potential explanations for individual recognition among workers: 1) worker individual recognition may be favored because it provides social benefits to workers, or 2) worker individual recognition may be a byproduct of selection for individual recognition in foundresses. Individual recognition is often considered a cognitively challenging form of recognition, so future studies that compare the sophistication of recognition across castes will be useful to assess whether there are more subtle differences in cognitive abilities or recognition behavior between P. fuscatus nestfounding queens and workers.Master of Science (MS)Ecology and Evolutionary Biology Traditional Masters ProgramUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/98097/1/Injaian MS Thesis FINAL (1).pd

TRES Settlement 2016_FigShare.xlsx

This data is from a breeding population of tree swallows, nesting in nest boxes in Davis, CA. Data from adults and nestlings was recorded during the 2016 breeding season. <div><br></div><div>Measurements were taken from bird exposed to traffic noise playbacks and control conditions. </div><div><br></div><div>There are 2 sheets in the Excel file. The first sheet contains the data and the second sheet contains the descriptions of each column. </div

Aircraft events correspond with vocal behavior in a passerine

Abstract Airports can affect birds by hindering acoustic communication. Here, we investigated the impacts of aircraft events on vocal behavior in wood thrush (Hylocichla mustelina) breeding one mile from an airport in Ithaca, NY, USA. We identified the number of wood thrush songs between 0500 and 0800 h at various distances from the airport and on days with various morning flight schedules. We also analyzed the number of sites from which birds sang during the peak of aircraft events (proxy of number of wood thrush). We found that birds sang more from 0600 to 0640 h when there were aircraft events during this period. This increased vocal behavior is likely explained by increased song output per individual wood thrush, rather than more wood thrush vocalizing. Increased song rate may negatively affect wood thrush fitness through increased energetic demands and/or time tradeoffs with other important behaviors, such as foraging. Identifying the noise thresholds associated with fitness costs (if any) and how different behavioral strategies (i.e. changing the pattern of vocalizations) may allow individuals to evade these costs would be useful for establishing conservation policy in breeding habitats used by passerines, such as the wood thrush

Data from: Effects of experimental anthropogenic noise on avian settlement patterns and reproductive success

The acoustic footprints of factories, roadways, etc. reach far beyond their physical infrastructure because high amplitude, low frequency noise can propagate many kilometers. Previous studies found that noise exposure decreases habitat quality and reproductive success for some species. However, few studies have linked the reduction in perceived habitat quality due to noise exposure to effects on avian settlement patterns and reproductive success. Here, we experimentally investigate the impacts of noise pollution during settlement on adult settlement patterns and subsequent reproductive success in tree swallows (Tachycineta bicolor). We found that tree swallow adults preferentially settled in quieter nest boxes (a 1 dBA increase delayed settlement date by 1.4 and 3.5 days for males and females, respectively). Egg-laying date (a proxy of female quality) also increased by 3.8 days for every 1 dBA increase in noise. These results suggest that lower quality tree swallows settled in noise, however more research is needed to confirm this result, as we did not measure adult quality directly. Our results also suggest a negative relationship between noise exposure during settlement and reproductive success, which cannot be explained by differences in adult quality alone. When controlling for egg-laying date, females that settled in noise-exposed nests laid 0.58 fewer eggs than controls. Finally, maternal noise exposure, but not egg-laying date, was negatively related to nestling body condition. These results are concerning, as they highlight multiple pathways through which traffic noise may result in negative impacts at the local, population level for free-living birds

Dryad_TRES Settlement 2016

Data collected from a tree swallow population in Davis, CA during the 2016 breeding season. Explanations of variables provided on sheet 2

Baseline and stress-induced corticosterone levels across birds and reptiles do not reflect urbanization levels

Rates of human-induced environmental change continue increasing with human population size, potentially altering animal physiology and negatively affecting wildlife. Researchers often use glucocorticoid concentrations (hormones that can be associated with stressors) to gauge the impact of anthropogenic factors (e.g. urbanization, noise and light pollution). Yet, no general relationships between human-induced environmental change and glucocorticoids have emerged. Given the number of recent studies reporting baseline and stress-induced corticosterone (the primary glucocorticoid in birds and reptiles) concentrations worldwide, it is now possible to conduct large-scale comparative analyses to test for general associations between disturbance and baseline and stress-induced corticosterone across species. Additionally, we can control for factors that may influence context, such as life history stage, environmental conditions and urban adaptability of a species. Here, we take a phylogenetically informed approach and use data from HormoneBase to test if baseline and stress-induced corticosterone are valid indicators of exposure to human footprint index, human population density, anthropogenic noise and artificial light at night in birds and reptiles. Our results show a negative relationship between anthropogenic noise and baseline corticosterone for birds characterized as urban avoiders. While our results potentially indicate that urban avoiders are more sensitive to noise than other species, overall our study suggests that the relationship between human-induced environmental change and corticosterone varies across species and contexts; we found no general relationship between human impacts and baseline and stress-induced corticosterone in birds, nor baseline corticosterone in reptiles. Therefore, it should not be assumed that high or low levels of exposure to human-induced environmental change are associated with high or low corticosterone levels, respectively, or that closely related species, or even individuals, will respond similarly. Moving forward, measuring alternative physiological traits alongside reproductive success, health and survival may provide context to better understand the potential negative effects of human-induced environmental change.publishe

Baseline and Stress-induced Corticosterone Levels Across Birds and Reptiles do not Reflect Urbanization Levels

Rates of human-induced environmental change continue increasing with human population size, potentially altering animal physiology and negatively affecting wildlife. Researchers often use glucocorticoid concentrations (hormones that can be associated with stressors) to gauge the impact of anthropogenic factors (e.g. urbanization, noise and light pollution). Yet, no general relationships between human-induced environmental change and glucocorticoids have emerged. Given the number of recent studies reporting baseline and stress-induced corticosterone (the primary glucocorticoid in birds and reptiles) concentrations worldwide, it is now possible to conduct large-scale comparative analyses to test for general associations between disturbance and baseline and stress-induced corticosterone across species. Additionally, we can control for factors that may influence context, such as life history stage, environmental conditions and urban adaptability of a species. Here, we take a phylogenetically informed approach and use data from HormoneBase to test if baseline and stress-induced corticosterone are valid indicators of exposure to human footprint index, human population density, anthropogenic noise and artificial light at night in birds and reptiles. Our results show a negative relationship between anthropogenic noise and baseline corticosterone for birds characterized as urban avoiders. While our results potentially indicate that urban avoiders are more sensitive to noise than other species, overall our study suggests that the relationship between human-induced environmental change and corticosterone varies across species and contexts; we found no general relationship between human impacts and baseline and stress-induced corticosterone in birds, nor baseline corticosterone in reptiles. Therefore, it should not be assumed that high or low levels of exposure to human-induced environmental change are associated with high or low corticosterone levels, respectively, or that closely related species, or even individuals, will respond similarly. Moving forward, measuring alternative physiological traits alongside reproductive success, health and survival may provide context to better understand the potential negative effects of human-induced environmental change

Baseline and stress-induced corticosterone levels across birds and reptiles do not reflect urbanization levels

Rates of human-induced environmental change continue increasing with human population size, potentially altering animal physiology and negatively affecting wildlife. Researchers often use glucocorticoid concentrations (hormones that can be associated with stressors) to gauge the impact of anthropogenic factors (e.g. urbanization, noise and light pollution). Yet, no general relationships between human-induced environmental change and glucocorticoids have emerged. Given the number of recent studies reporting baseline and stress-induced corticosterone (the primary glucocorticoid in birds and reptiles) concentrations worldwide, it is now possible to conduct large-scale comparative analyses to test for general associations between disturbance and baseline and stress-induced corticosterone across species. Additionally, we can control for factors that may influence context, such as life history stage, environmental conditions and urban adaptability of a species. Here, we take a phylogenetically informed approach and use data from HormoneBase to test if baseline and stress-induced corticosterone are valid indicators of exposure to human footprint index, human population density, anthropogenic noise and artificial light at night in birds and reptiles. Our results show a negative relationship between anthropogenic noise and baseline corticosterone for birds characterized as urban avoiders. While our results potentially indicate that urban avoiders are more sensitive to noise than other species, overall our study suggests that the relationship between human-induced environmental change and corticosterone varies across species and contexts; we found no general relationship between human impacts and baseline and stress-induced corticosterone in birds, nor baseline corticosterone in reptiles. Therefore, it should not be assumed that high or low levels of exposure to human-induced environmental change are associated with high or low corticosterone levels, respectively, or that closely related species, or even individuals, will respond similarly. Moving forward, measuring alternative physiological traits alongside reproductive success, health and survival may provide context to better understand the potential negative effects of human-induced environmental change

Baseline and Stress-induced Corticosterone Levels Across Birds and Reptiles do not Reflect Urbanization Levels

Rates of human-induced environmental change continue increasing with human population size, potentially altering animal physiology and negatively affecting wildlife. Researchers often use glucocorticoid concentrations (hormones that can be associated with stressors) to gauge the impact of anthropogenic factors (e.g. urbanization, noise and light pollution). Yet, no general relationships between human-induced environmental change and glucocorticoids have emerged. Given the number of recent studies reporting baseline and stress-induced corticosterone (the primary glucocorticoid in birds and reptiles) concentrations worldwide, it is now possible to conduct large-scale comparative analyses to test for general associations between disturbance and baseline and stress-induced corticosterone across species. Additionally, we can control for factors that may influence context, such as life history stage, environmental conditions and urban adaptability of a species. Here, we take a phylogenetically informed approach and use data from HormoneBase to test if baseline and stress-induced corticosterone are valid indicators of exposure to human footprint index, human population density, anthropogenic noise and artificial light at night in birds and reptiles. Our results show a negative relationship between anthropogenic noise and baseline corticosterone for birds characterized as urban avoiders. While our results potentially indicate that urban avoiders are more sensitive to noise than other species, overall our study suggests that the relationship between human-induced environmental change and corticosterone varies across species and contexts; we found no general relationship between human impacts and baseline and stress-induced corticosterone in birds, nor baseline corticosterone in reptiles. Therefore, it should not be assumed that high or low levels of exposure to human-induced environmental change are associated with high or low corticosterone levels, respectively, or that closely related species, or even individuals, will respond similarly. Moving forward, measuring alternative physiological traits alongside reproductive success, health and survival may provide context to better understand the potential negative effects of human-induced environmental change