A5010730357- Animal Behavior and Reproduction
- Avian ecology and behavior
- Bird parasitology and diseases
- Animal Nutrition and Physiology
- Species Distribution and Climate Change
- Hypothalamic control of reproductive hormones
- Physiological and biochemical adaptations
- Climate change and permafrost
- Circadian rhythm and melatonin
- Neuroendocrine regulation and behavior
- Effects of Environmental Stressors on Livestock
- Food Drying and Modeling
- Bat Biology and Ecology Studies
- Animal Vocal Communication and Behavior
- Reproductive Physiology in Livestock
- Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
- Climate variability and models
- Food composition and properties
- Arctic and Antarctic ice dynamics
- Rangeland and Wildlife Management
- Genetic diversity and population structure
- Wildlife Ecology and Conservation
- Thyroid Disorders and Treatments
- Pituitary Gland Disorders and Treatments
- Genomics and Phylogenetic Studies
University of South Alabama
2020-2025
University of California, Davis
2014-2024
Roslin Institute
2018-2021
University of Edinburgh
2018-2021
University of Glasgow
2019-2020
University of Aberdeen
2018
University of California System
2017
Google (United States)
2017
Kyushu University
2011-2015
Instituto Nacional de Pediatria
2012
Nest microclimate can have strong effects that carry over to later life-history stages. We experimentally cooled the nests of tree swallows ( Tachycineta bicolor ). Females incubating in reduced incubation time and allowed egg temperatures drop, leading extended periods. partially cross-fostered nestlings test carry-over cooling during on nestling innate constitutive immunity, assessed through bacteria killing ability (BKA) blood. Nestlings had been as eggs showed a lower kill than control...
ABSTRACT Orientation of nests can influence nest microclimate, particularly temperature. However, few investigators have examined orientation preference and microclimate simultaneously. We the possible correlation between entrance artificial boxes used by Tree Swallows (Tachycineta bicolor) internal temperature boxes. showed a for east- south-facing boxes, but only during first half breeding season (before 1 June). During second (after June), selected based on availability. found that were...
1. Life-history decisions are strongly affected by environmental conditions. In birds, incubation is energetically expensive and significantly ambient temperature. We reduced energetic constraints for female tree swallows (Tachycineta bicolor) experimentally heating nests during an average of 6.9 degrees C to test changes in behaviour. 2. Females heated boxes (hereafter 'heated females') increased time spent incubating maintained higher on-bout off-bout egg temperatures. This indicates that...
Investment in one life-history stage can have delayed effects on subsequent stages within a single reproductive bout. We experimentally heated tree swallow ( Tachycineta bicolor ) nests during incubation to test for parental and nestling conditions. Females incubating boxes maintained higher body condition fed nestlings at rates. cross-fostered found that young (4–7 days old) incubated had mass, regardless of treatment status their rearing parent. However, older which were by females mass...
Abstract Climate warming is affecting the Arctic in multiple ways, including via increased dominance of deciduous shrubs. Although many studies have focused on how this vegetation shift altering nutrient cycling and energy balance, few explicitly considered effects tundra fauna, such as millions migratory songbirds that breed northern regions every year. To understand increasing shrub may alter breeding songbird habitat, we quantified arthropod community characteristics both graminoid...
Seasonally breeding birds express variations of traits (phenotypic flexibility) throughout their life history stages that represent adaptations to environmental conditions. Changes body condition during migration have been well studied, whereas alterations skeletal and cardiac muscles, mass, fat scores yet be characterized the spring or fall migratory stages. Additionally, we examined flexible patterns muscle, score in migrant white-crowned sparrows (Zonotrichia leucophrys gambelii)...
Climate change is causing rapid shifts in temperature while also increasing the frequency, duration, and intensity of extreme weather. In northern hemisphere, spring 2013 was characterized as due to record high snow cover low temperatures. Studies that describe effects weather on phenology across taxa are limited morphological physiological responses remain poorly understood. Stress physiology, measured through baseline stress-induced concentrations cortisol or corticosterone, has often been...
Hematocrit is an easily measured parameter that can be used to assess changes in oxygen carrying capacity necessitated by fluctuations metabolic demands. Most hematocrit studies draw conclusions from occur over a small sampling interval without understanding of the variation exists across annual cycle. White-crowned sparrows provide excellent model system due existence resident subspecies (Zonotrichia leucophrys nuttalli) serves as natural control for migrant gambelii). Comparing these two...
Soundscape-level acoustic recordings revealed delay in arrival of songbird community to arctic breeding grounds.
Raising nestlings to fledging is energetically demanding for songbirds, requiring parents balance several major tradeoffs. Nestling growth rates are highly susceptible variation in environmental conditions and parental investment, variable environments with short breeding seasons such as the Arctic magnify these Arctic-nesting passerines provide a good model system which explore within between species regard timing of clutch initiation. Here we investigated interannual interspecies nestling...
Birds breeding at high latitudes can be faced with extreme weather events throughout the season. In response to environmental perturbations, vertebrates activate hypothalamic-pituitary-adrenal (HPA) axis and synthesize corticosterone, which promotes changes in behavior physiology help animal survive. The parental care hypothesis suggests that HPA activity should downregulated during stage of prevent nest abandonment. However, it is unknown what happens severe transition from pre-parental...
For wild free-living animals the availability of food resources can be greatly affected by environmental perturbations such as weather events. In response to perturbations, activate hypothalamic-pituitary-adrenal (HPA) axis adjust physiology and behavior. The literature asserts that during events intake declines leading changes in HPA activity, measured both baseline stress-induced glucocorticoid concentrations. Here we investigated how body condition, locomotor stress were varying lengths a...
A species' range can be thought of as a manifestation the ecological niche in space. Within niche, evolution has resulted traits that maximize fitness. Across millennia, natural oscillations temperature have caused shifts geographic location appropriate habitat and with corresponding changes ranges. Contemporary climate change human disturbance may lead to rapid expansion or contractions largely unknown consequences. Birds provide an excellent case study this phenomenon some taxa expanding...
To accommodate a migratory life history, migrants express greater number of physiological and behavioral stages per annum than residents are thus considered to have higher finite state diversity (FSD). investigate the mechanisms constraints associated with migration, direct comparison two subspecies white-crowned sparrow - migrant, Zonotrichia leucophrys gambelii, resident, Z. l. nuttalli were made under common garden conditions photoperiod housing, as birds progressed from winter through...
Individuals at the forefront of a range shift are likely to exhibit phenotypic traits that distinguish them from population breeding within historic range. Recent studies have examined morphological, physiological and behavioral phenotypes individuals edge their Several found differences in hypothalamic-pituitary-adrenal (HPA) axis activity response acute restraint stress limits. HPA activation leads elevations glucocorticoids regulate physiology behavior. Here we compare hormonal profiles...
1. Rapid warming has facilitated an increase in deciduous shrub cover arctic tundra. Because shrubs create a cooler microclimate during the growing season, could modulate effects of global on phenology and activity ectotherms, including arthropods. This possibility was explored here using two dominant arthropod groups (flies wolf spiders) Alaskan 2. We monitored arthropods with pitfall traps over five summers at four sites that differed abundance, used generalised additive mixed models...