Ignacio T. Moore's research while affiliated with Virginia Tech (Virginia Polytechnic Institute and State University) and other places

Publications (183)

Article
When hosts have a long coevolutionary history with their parasites, fitness costs of chronic infection have often been assumed to be negligible. Yet, experimental manipulation of infections sometimes reveals effects of parasites on their hosts, particularly during reproduction. Whether these effects translate into fitness costs remains unclear. Her...
Preprint
The neurogenomic mechanisms modulating cooperation are largely unknown, and previous work has been largely constrained to considering few genes in limited neurological space. Here we leverage transcriptomic and behavioral data on birds that perform cooperative courtship displays to better understand the mechanisms underlying cooperative behaviors....
Article
Full-text available
Background Wildlife conservation often focuses on establishing protected areas. However, these conservation zones are frequently established without adequate knowledge of the movement patterns of the species they are designed to protect. Understanding movement and foraging patterns of species in dynamic and diverse habitats can allow managers to de...
Preprint
Full-text available
Background Wildlife conservation often focuses on establishing protected areas, however, these conservation zones are frequently developed without adequate knowledge of the movement patterns of the species they are designed to protect. Understanding movement and foraging patterns of species in dynamic and diverse habitats can allow managers to deve...
Article
The neotropical manakins (family Pipridae) provide a great opportunity for integrative studies of sexual selection as nearly all of the 51 species are lek-breeding, an extreme form of polygyny, and highly sexually dimorphic both in appearance and behavior. Male courtship displays are often elaborate and include auditory cues, both vocal and mechani...
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Full-text available
Sexually transmitted microbes are hypothesized to influence the evolution of reproductive strategies. Though frequently discussed in this context, our understanding of the reproductive microbiome is quite nascent. Indeed, testing this hypothesis first requires establishing a baseline understanding of the temporal dynamics of the reproductive microb...
Article
Venom is an integral feeding trait in many animal species. Although venom often varies ontogenetically, little is known about the proximate physiological mediators of venom variation within individuals. The glucocorticoid hormone corticosterone can alter transcription and activation of proteins, including homologues of snake venom components such a...
Article
Full-text available
Invasive species can exert rapid depletion of resources after introduction and, in turn, affect their own population density. Additionally, management actions can have direct and indirect effects on demography. Physiological variables can predict demographic change but are often restricted to snapshots-in-time and delayed confirmation of changes in...
Article
Building on the predictions of state‐dependent life‐history theory, telomeres are hypothesized to either correlate with or function as an adaptive, proximate mediator of an individual's behaviour and life‐history strategy. To further understand the relationship between telomeres, behaviour and life‐history strategies, we measured male behaviour, te...
Article
Social networks can vary in their organization and dynamics, with implications for ecological and evolutionary processes. Understanding the mechanisms that drive social network dynamics requires integrating individual‐level biology with comparisons across multiple social networks. Testosterone is a key mediator of vertebrate social behavior and can...
Article
To maximize fitness, parents may trade-off time and energy between parental care and self-maintenance. In vertebrates, prolactin and corticosterone are two important hormones that regulate parental investment because they stimulate parental care and mobilize energy, respectively. Further, concentrations of both hormones change in response to distur...
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Full-text available
Host-associated microbial communities can influence the overall health of their animal hosts, and many factors, including behavior and physiology, can impact the formation of these complex communities. Bacteria within these communities can be transmitted socially between individuals via indirect (e.g., shared environments) or direct (e.g., physical...
Article
Steroid hormones regulate reproductive investment and play a critical role in coordinating reproductive responses to both short and long-term environmental change. Laboratory studies typically examine the mechanistic relationships among steroids and reproductive processes under controlled conditions and may fail to identify any seasonal patterns in...
Article
Full-text available
Many studies have identified the reproductive benefits of cooperative behaviors, yet few have identified the mechanisms that underlie these behaviors. Mechanistic studies can inform our understanding of why some individuals are more or less cooperative, as well as identify the physiological constraints imposed upon the evolution of reproductive tra...
Article
Behavioral tradeoffs occur when the expression of one behavior detracts from the expression of another. Understanding the proximate mediators of behavioral tradeoffs is important as these tradeoffs can act as potential constraints on evolutionary responses to selection. Here, we describe the tradeoff between cooperation and competition faced by spe...
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Full-text available
Water‐borne hormone measurement is a noninvasive method suitable for amphibians of all sizes that are otherwise difficult to sample. For this method, containment‐water is assayed for hormones released by the animal. Originally developed in fish, the method has expanded to amphibians, but requires additional species‐specific validations. We wanted t...
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Full-text available
The Cort-Fitness Hypothesis has generated much interest from investigators integrating field endocrinology with evolutionary biology, ecology, and conservation. The hypothesis was developed to test the assumption that if glucocorticoid levels increase with environmental challenges and fitness decreases with environmental challenges, then there shou...
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Full-text available
Stable cooperation requires plasticity whereby individuals are able to express competitive or cooperative behaviors depending on social context. To date, however, the physiological mechanisms that underlie behavioral variation in cooperative systems are poorly understood. We studied hormone-mediated behavior in the wire-tailed manakin (Pipra filica...
Preprint
Full-text available
Social networks can vary in their organization and dynamics, with implications for ecological and evolutionary processes. Understanding the mechanisms that drive social network dynamics requires integrating individual-level biology with comparisons across multiple social networks. Testosterone is a key mediator of vertebrate social behavior and can...
Article
Full-text available
Synopsis Reference to glucocorticoids as “stress hormones” has been growing in prevalence in the literature, including in comparative and environmental endocrinology. Although glucocorticoids are elevated in response to a variety of stressors in vertebrate animals, the primary functions of glucocorticoids are not responding to stressors and they ar...
Article
Metachrosis, or color change, in reptiles is used for thermoregulation, crypsis, and many other purposes. The mechanism and function of metachrosis remain unknown for many species, however, especially snakes. Anecdotal observations suggest that some snake species, including rattlesnakes, undergo varying degrees of color change when captured and con...
Article
According to the Challenge Hypothesis, social interactions, particularly among males, have a strong influence on circulating androgen levels. Specifically, males should respond to social challenges from conspecific males with a rapid increase in plasma androgen levels which support and stimulate further aggression. This basic tenet of the Challenge...
Article
For male vertebrates, androgens are considered physiological mediators of the trade-off between mating and parenting effort. About 30 years ago, the challenge hypothesis provided a conceptual framework to explain the variation in androgen levels among individuals and species, primarily as a function of male competition and parental care. Initially...
Article
Individual variation in parasite defences, such as resistance and tolerance, can underlie heterogeneity in fitness and could influence disease transmission dynamics. Glucocorticoid hormone concentrations often change in response to fluctuating environmental conditions and mediate changes in immune function, resource allocation and tissue repair. Th...
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Full-text available
The vertebrate basal forebrain and midbrain contain a set of interconnected nuclei that control social behavior. Conserved anatomical structures and functions of these nuclei have now been documented among fish, amphibians, reptiles, birds and mammals, and these brain regions have come to be known as the vertebrate social behavior network (SBN). Wh...
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Full-text available
The symbiotic microbial communities, or “microbiomes,” that reside on animals are dynamic, and can be affected by the behavior and physiology of the host. These communities provide many critical beneficial functions for their hosts, but they can also include potential pathogens. In birds, bacteria residing in the cloaca form a complex community, in...
Preprint
Full-text available
The Cort-Fitness hypothesis has generated much interest from investigators integrating field endocrinology with evolutionary biology, ecology, and conservation. The hypothesis was developed on the assumption that if glucocorticoid levels increase with environmental challenges and fitness decreases with environmental challenges, then there should be...
Article
Full-text available
Biparental care presents an interesting case of cooperation and conflict between unrelated individuals. Several models have been proposed to explain how parents should respond to changes in each other’s parental care to maximize their own fitness, predicting no change, partial compensation, or matching effort as a response. Here, we present an expe...
Article
Emergent diseases may result in population declines by inducing mortality directly or through sublethal effects on host reproduction. Snake fungal disease (SFD) is an emerging threat to biodiversity, but the sublethal impacts of disease on host fitness are poorly characterized. The cryptic nature of most snakes makes direct assessment of the fitnes...
Preprint
Full-text available
Stable social partnerships require physiological mechanisms that maintain a balance between competition and cooperation. Although the endocrine system is known to facilitate competitive behavior, we know very little about how steroid hormones affect cooperation and the stability of partnerships. Here, we examine how testosterone (T) modulates socia...
Preprint
Full-text available
The vertebrate basal forebrain and midbrain contain a set of interconnected nuclei that control social behavior. Conserved anatomical structures and functions of these nuclei have now been documented among fish, amphibians, reptiles, birds and mammals, and these brain regions have come to be known as the vertebrate social behavior network (SBN). Wh...
Article
Studies of birds have greatly advanced our understanding of how testosterone modulates complex phenotypes, specifically its role in mediating male reproductive and associated behaviors. Yet most of the foundational studies have been limited to northern latitude breeding species despite the fact that they represent only a small fraction of worldwide...
Article
Obtaining baseline hormone samples can be challenging because circulating hormone levels often change rapidly due to the acute stress of capture. Although field protocols are established for accurately sampling baseline glucocorticoid concentrations, fewer studies have examined how common sampling techniques affect androgens levels. Indeed, many st...
Article
The environment in which animals develop can have important consequences for their phenotype. In reptiles, incubation temperature is a critical aspect of the early developmental environment. Incubation temperature influences morphology, physiology, and behavior of non‐avian reptiles, however, little is known about how incubation temperature influen...
Article
Animal personality has been linked to individual variation in both stress physiology and social behaviors, but few studies have simultaneously examined covariation between personality traits, stress hormone levels, and behaviors in free-living animals. We investigated relationships between exploratory behavior (one aspect of animal personality), st...
Article
Estrogens are important regulators of reproductive physiology including sexual signal expression and vitellogenesis. For the regulation to occur, the hormone must bind and activate receptors in target tissues, and expression of the receptors can vary by sex and/or season. By simultaneously comparing circulating hormone levels with receptor expressi...
Article
Seasonal constraints on the timing and intensity of reproductive events shape observed variation in life history strategies across latitudes. Selection acts on the endocrine mechanisms that underlie reproductive investment. It is therefore important to examine the seasonal relationship between hormones and reproduction in geographically and phyloge...
Article
Full-text available
The level of parental investment in free-living offspring varies greatly within and among vertebrate taxa, and the mechanisms that mediate investment are likely targets of selection in the evolution of reproductive strategies. In mammalian and avian systems, individual investment is adjusted according to parental energetic status, and regulatory me...
Preprint
Full-text available
Biparental care presents an interesting case of cooperation and conflict between unrelated individuals. Several models have been proposed to explain how parents should respond to changes in each other’s parental care to maximize their own fitness, predicting no change, partial compensation, or matching effort as a response. Here, we present an expe...
Article
Full-text available
Snake fungal disease (SFD) is an emerging threat to snake populations intheUnited States.Fungalpathogens are oftenassociated with a physiological stress responsemediated by the hypothalamopituitary- adrenal axis (HPA), and afflicted individuals may incur steep coping costs. The severity of SFD can vary seasonally; however, little is knownregarding...
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Full-text available
1.Chronic, low-intensity parasite infections can reduce host fitness through negative impacts on reproduction and survival, even if they produce few overt symptoms. As a result, these parasites can influence the evolution of host morphology, behavior, and physiology. The physiological consequences of chronic infection can provide insight into the p...
Article
Glucocorticoid hormones allow individuals to rapidly adjust their physiology and behavior to meet the challenges of a variable environment. An individual’s baseline concentration of glucocorticoids can reflect shifts in life history stage and resource demands while mediating a suite of physiological and behavioral changes that include immune modula...
Article
The use of sexually selected characters in inter- and intra-sexual interactions has long been of interest to evolutionary biologists. Recently, a distinction between sexually selected traits as ornaments versus weapons has been advanced. We investigated the behaviour of an enigmatic lizard with a prominent sexually dimorphic trait in an effort to d...
Article
Female preference for local cultural traits has been proposed as a barrier to breeding among animal populations. As such, several studies have found correlations between male bird song dialects and population genetics over relatively large distances. To investigate if female choice for local dialects could act as a barrier to breeding between nearb...
Article
In the face of global change, free-ranging organisms are expected to experience more unpredictable stressors. An understanding of how organisms with different life history strategies will respond to such changes is an integral part of biodiversity conservation. Corticosterone (CORT) levels are often used as metrics to assess the population health o...
Article
Glucocorticoid hormones facilitate responses to environmental challenges by mediating diverse physiological and behavioral changes, including resource mobilization and altered reproductive effort. Elevated glucocorticoids might indicate that an individual is facing high levels of environmental challenges and thus, elevated concentrations might be a...
Article
Full-text available
Life-history theory predicts that optimal strategies of parental investment will depend on ecological and social factors, such as current brood value and offspring need. Parental care strategies are also likely to be mediated in part by the hypothalamic–pituitary–adrenal axis and glucocorticoid hormones. Here, we present an experiment in tree swall...
Article
Hydration is a critical element for many physiological processes in vertebrates. While it seems intuitive that drought is stressful to animals, studies examining drought are typically observational and do not explicitly assess how the hydration state of study subjects influences their physiology and behavior. We examined how hydration affects sever...
Article
The urban environment poses novel anthropogenic challenges to wildlife. Some species have been noted for changes in their behavior in response to humans and urban-associated activities. Understanding the anthropogenic factors which influence these behavioral changes would contribute significantly to avian conservation in an increasingly urbanized w...
Poster
Full-text available
Manakins of the family Pipridae are known for performing complex courtship displays at leks. These complex displays have evolved in association with strong reproductive skew, suggesting individual differences in courtship behavior exist. By measuring components of hormone regulatory networks, one may be able to elucidate the proximate mediators of...
Article
Full-text available
Elevation has been proposed as a dominant ecological variable shaping life history traits and subsequently their underlying hormonal mechanisms. In an earlier meta-analysis of tropical birds, elevation was positively related to testosterone levels. Furthermore, parasitism by avian haemosporidians should vary with elevation as environmental conditio...
Preprint
Full-text available
Life history theory predicts that optimal strategies of parental investment will depend on ecological and social factors such as current brood value and offspring need. Parental care strategies are also likely to be mediated in part by the hypothalamic-pituitary-adrenal (HPA) axis and glucocorticoid hormones. Here we present an experiment in tree s...
Article
Full-text available
Environmental temperature has profound effects on animal physiology, ecology, and evolution. Glucocorticoid (GC) hormones, through effects on phenotypic performance and life history, provide fundamental vertebrate physiological adaptations to environmental variation, yet we lack a comprehensive understanding of how temperature influences GC regulat...
Article
Translocation is an increasingly common conservation tool used to augment declining populations or to remove nuisance animals from areas of human conflict. Studies show that venomous snakes translocated long distances may wander and experience increased mortality. However, potential sub-lethal physiological effects on translocated snakes remain unk...
Article
Glucocorticoid stress hormones are important for energy mobilization as well as regulation of the immune system, and thus these hormones are particularly likely to both influence and respond to pathogen infection in vertebrates. In this study, we examined how the glucocorticoid stress response in house finches (Haemorhous mexicanus) interacts with...
Article
Synopsis All organisms must anticipate and balance energetic demands and available resources in order to maximize fitness. As hormones coordinate many interactions between an organism’s internal condition and the external environment, they may be key in mediating the allocation of resources to meet these demands. However, given that individuals dif...
Article
Begging calls provide a way for parents to gauge offspring state. Although temperature is known to affect call production, previous studies have not examined the influence of ambient temperature at the nest. We recorded ambient temperature and begging calls of 3 day-old tree swallows (Tachycineta bicolor). Our results indicate that typical daily te...
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Full-text available
1. Testosterone mediates several key aspects of male reproduction, but maintaining high testosterone levels can reduce long-term survival. One of the proposed pathways by which testosterone can influence survival is through increased risk of parasite infection. The hormone has the potential to affect the transmission of sexually transmitted infecti...
Article
Glucocorticoids can play a critical role in modulating life-history trade-offs. However, studying the effects of glucocorticoids on life-history often requires experimentally elevating plasma glucocorticoid concentrations for several weeks within normal physiological limits and without repeated handling of the animal. Recently, implants made of bee...
Article
Full-text available
Stress is ubiquitous in the life of animals and a key determinant of their well-being and fitness. By quantifying levels of feather corticosterone in growing feathers (CORTf), we measured integrated stress responses in a monogamous game bird, the red grouse Lagopus lagopus scoticus. We investigated the effects of parasites and social mate choice on...
Article
Sexually selected traits can signal an individual's ability to contribute offspring care. Differential allocation theory posits that when these same traits also influence brood value, it may be adaptive for partners to adjust care in response to their mates' traits. Evaluating the strength and direction of parental quality signalling and differenti...
Article
Full-text available
Studies of animal behavior often rely on human observation, which introduces a number of limitations on sampling. Recent developments in automated logging of behaviors make it possible to circumvent some of these problems. Once verified for efficacy and accuracy, these automated systems can be used to determine optimal sampling regimes for behavior...
Article
Urban animals often show differences in aggression relative to their rural counterparts, but the ultimate and proximate origins of these differences are poorly understood. Here, we compared urban and rural song sparrows (Melospiza melodia), a species for which higher levels of aggression in urban populations have previously been reported. First, we...
Preprint
Full-text available
Studies of animal behavior often rely on human observation, which introduces a number of limitations on sampling. Recent developments in automated logging of behaviors make it possible to circumvent some of these problems. Once verified for efficacy and accuracy, these automated systems can be used to determine optimal sampling regimes for behavior...
Preprint
Full-text available
Studies of animal behavior often rely on human observation, which introduces a number of limitations on sampling. Recent developments in automated logging of behaviors make it possible to circumvent some of these problems. Once verified for efficacy and accuracy, these automated systems can be used to determine optimal sampling regimes for behavior...
Article
Full-text available
Background Unpredictable and inclement weather is increasing in strength and frequency, challenging organisms to respond adaptively. One way in which animals respond to environmental challenges is through the secretion of glucocorticoid stress hormones. These hormones mobilize energy stores and suppress non-essential physiological and behavioral pr...
Preprint
Full-text available
Studies of animal behavior often rely on human observation, which introduces a number of limitations on sampling. Recent developments in automated logging of behaviors make it possible to circumvent some of these problems. Once verified for efficacy and accuracy, these automated systems can be used to determine optimal sampling regimes for behavior...
Preprint
Full-text available
Studies of animal behavior often rely on human observation, which introduces a number of limitations on sampling. Recent developments in automated logging of behaviors make it possible to circumvent some of these problems. Once verified for efficacy and accuracy, these automated systems can be used to determine optimal sampling regimes for behavior...
Article
Full-text available
In mid- to high-latitude songbirds, seasonal reproduction is stimulated by increasing day length accompanied by elevated plasma sex steroid levels, increased singing, and growth of the song control nuclei (SCN). Plasticity of the SCN and song behavior are primarily mediated by testosterone (T) and its metabolites in most species studied thus far. H...
Article
Full-text available
Playbacks of visual or audio stimuli to wild animals is a widely used experimental tool in behavioral ecology. In many cases, however, playback experiments are constrained by observer limitations such as the time observers can be present, or the accuracy of observation. These problems are particularly apparent when playbacks are triggered by specif...