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From the rituals demonstrated with masks and nature-inspired costumes to epitomise supernatural beings to a church-based dramatization in the Early Middle Ages focusing solely on commemoration of Christ with a theatrical rite on Easter, or even to Shakespeare, where characters in disguise fill the scene at a time when Elizabethan notion of visceral force was replaced by intrigue, theatre has always been the shadow of a changing society. What, in fact, goes under a change is not the notion of theatre per se, but the idea of relating to people from all walks of life. In this sense, theatre, which has a structuring power that has managed to infiltrate deeply within the society, has sustained its existence in parallel with the developing and shifting social dynamics. For theatre, change is bound to happen if one retains his/her permanency. Theatre, which is in a continuous motion, allows interaction between the audience and the actor. Though the dimension of this interaction is multifaceted, one of the most broadly known is indubitably the reflection of Freud's concept of psychoanalysis on the characters of the play, which is based on the view that certain situations that take place in human consciousness and especially in the subconscious have a great role in their daily lives. Simon Stephens, who reflects this change and interaction to his works by going beyond the traditional understanding of theatre and by including the post-dramatic elements with music and abundant visuality, stands out as one of the important playwrights of contemporary British theatre in recent years. The play Bluebird (1998), which he wrote on a level reminiscent of the cinema scene, presents sections from the lives of postmodern individuals who are struggling to hold on to life in the grip of the developing and globalizing world, which Stephens himself personally experienced and observed. The author tries to reflect the psychological disorders of today's individuals and Freud's subconscious concept to the audience with his play Bluebird. This study deals with the characters in Stephens' Bluebird within the context of Sigmund Freud's personality theories.

Background Accurate nestling age is valuable for studies on nesting strategies, productivity, and impacts on reproductive success. Most aging guides consist of descriptions and photographs that are time consuming to read and subjective to interpret. The Western Bluebird (Sialia mexicana) is a secondary cavity-nesting passerine that nests in coniferous and open deciduous forests. Nest box programs for cavity-nesting species have provided suitable nesting locations and opportunities for data collection on nestling growth and development. Methods We developed models for predicting the age of Western Bluebird nestlings from morphometric measurements using model training and validation. These were developed for mass, tarsus, and two different culmen measurements. Results Our models were accurate to within less than a day, and each model worked best for a specific age range. The mass and tarsus models can be used to estimate the ages of Western Bluebird nestlings 0–10 days old and were accurate to within 0.5 days for mass and 0.7 days for tarsus. The culmen models can be used to estimate ages of nestlings 0–15 days old and were also accurate to within less than a day. The daily mean, minimum, and maximum values of each morphometric measurement are provided and can be used in the field for accurate nestling age estimations in real time. Conclusions The model training and validation procedures used here demonstrate that this method can create aging models that are highly accurate. The methods can be applied to any passerine species provided sufficient nestling morphometric data are available.

Anthropogenic noise is a ubiquitous feature of the American landscape, and is a known stressor for many bird species, leading to negative effects in behavior, physiology, reproduction, and ultimately fitness. While a number of studies have examined how anthropogenic noise affects avian fitness, there are few that simultaneously examine how anthropogenic noise impacts the relationship between parental care behavior and nestling fitness. We conducted Brownian noise playbacks for 6 h a day during the nesting cycle on Eastern Bluebird (Sialia sialis) nest boxes to investigate if experimentally elevated noise affected parental care behavior, nestling body conditions, and nestling stress indices. We documented nest attendance by adult females using radio frequency identification (RFID), and we assessed nestling stress by measuring baseline corticosterone levels and telomere lengths. Based on the RFID data collected during individual brood cycles, adult bluebirds exposed to noise had significantly higher feeding rates earlier in the brood cycle than adults in the control group, but reduced feeding rates later in the cycle. Nestlings exposed to noise had higher body conditions than the control nestlings at 11 days of age, but conditions equalized between treatments by day 14. We found no differences in nestling baseline corticosterone levels or nestling telomere lengths between the two treatment groups. Our results revealed that noise altered adult behavior, which corresponded with altered nestling body condition. However, the absence of indicators of longer-term effects of noise on offspring suggests adult behavior may have been a short-term response.

In this article the main point is in comparing of two ways to work with anasynchronous code in Node.js. Because Node.js is native asynchronous this problem is very important. In high load applications which are built on Node.js server every second is important. So, very long time there are many discussions between different programmers: what we should to use? Going through every version of Node.js we will compare and calculate which way has more advantages in speed. All results will be displayed in understandable graphics and tables.Ref. 3, pic. 7, tabl. 4

Background Changes in wild animal gut microbiotas may influence host health and fitness. While many studies have shown correlations between gut microbiota structure and external factors, few studies demonstrate causal links between environmental variables and microbiota shifts. Here, we use a fully factorial experiment to test the effects of elevated ambient temperature and natural nest parasitism by nest flies (Protocalliphora sialia) on the gut microbiotas of two species of wild birds, the eastern bluebird (Sialia sialis) and the tree swallow (Tachycineta bicolor). Results We find that bacterial communities from the nestlings of each host species show idiosyncratic responses to both heat and parasitism, with gut microbiotas of eastern bluebirds more disrupted by heat and parasitism than those of tree swallows. Thus, we find that eastern bluebirds are unable to maintain stable associations with their gut bacteria in the face of both elevated temperature and parasitism. In contrast, tree swallow gut microbiotas are not significantly impacted by either heat or nest parasitism. Conclusions Our results suggest that excess heat (e.g., as a result of climate change) may destabilize natural host-parasite-microbiota systems, with the potential to affect host fitness and survival in the Anthropocene.

O_LIHosts have developed or evolved defense strategies, including tolerance and resistance, to reduce damage caused by parasites. Environmental factors, such as elevated temperature, can influence the effectiveness of these different host defenses but also can directly affect parasite fitness. Therefore, the net effect of elevated temperature on host-parasite relationships are determined by its direct effects on the host and the parasite. Furthermore, because host species can defend themselves differently against their parasites, the net effect of temperature might differ across each hosts interaction with the same parasite. C_LIO_LIFew studies have determined the net effects of temperature on both host defenses and parasites in a multi-host system. To address this gap, we experimentally manipulated temperature and parasite presence in the nests of two host species who defend themselves differently to the same parasitic nest fly (Protocalliphora sialia). Specifically, we conducted a factorial experiment by increasing temperature (or not) and removing all parasitic nest flies (or not) in the nests of tolerant eastern bluebirds (Sialia sialis) and resistant tree swallows (Tachycineta bicolor). We then quantified parasite load in nests and measured nestling body size metrics, blood loss, and survival. C_LIO_LIIf temperature predominately affected parasite fitness, then elevated temperature would cause similar directional effects on parasite abundance across species. If temperature has different effects on hosts, then parasite abundance would differ in response to elevated temperature across host species. C_LIO_LIIn contrast to previous years, we found that bluebird nests had half as many parasites as compared to swallow nests. Elevated temperature affected parasite abundance differently in each host species. Swallows from heated nests had fewer parasites compared to non-heated nests, suggesting that they were more resistant to the parasites. Interestingly, swallows from heated nests were also more tolerant to the effects of parasites than controls. In contrast, bluebirds from heated nests had more parasites and lower body mass compared to controls, suggesting that they lost tolerance, and resistance, to the parasites. C_LIO_LIOur results suggest that a changing climate could have complex net effects on host-parasite interactions, including on host defenses, with implications for host health and parasite survival. C_LI

Long‐term data on host and parasite fitness are important for predicting how host–parasite interactions will be altered in an era of global change. Here, we use data collected from 1997 to 2013 to explore effects of changing environmental conditions on bird–blowfly interactions in northern New Mexico. The objectives of this study were to examine what climate variables influence blowfly prevalence and intensity and to determine whether blowflies and climate variables affect bird fledging success. We examined how temperature, precipitation, and drought affect two parasitic blowflies and their hosts, Western Bluebirds (Sialia mexicana) and Ash‐throated Flycatchers (Myiarchus cinerascens). We found that blowfly prevalence did not change over time. Blowfly intensity increased over time in bluebird nests, but not in flycatcher nests. More blowflies result in slightly higher fledging success in bluebirds, but not flycatchers. There was a significant interaction between blowflies and precipitation on bluebird fledging success. For flycatchers, there was a significant interaction between blowflies and temperature and between blowflies and drought severity on fledging success. Given that the southwest is projected to be hotter and have more frequent and prolonged droughts, we predict that flycatchers may be negatively impacted by blowflies if these trends continue. Future work should focus on investigating the role of both blowflies and climate on fledging success. Climate patterns may negatively impact host fitness through altered parasite pressure.

Volunteers support wildlife conservation, but engagement is often limited and short-term. This article examined the demographics, commitment, retention, and turnover among volunteer managers of blu...

The allocation of prey within broods of altricial nestlings may be the result of parents targeting certain offspring preferentially and/or the result of intrabrood competition related to features of nestlings such as body size. We investigated two mechanisms that could influence allocation of food within broods of Mountain Bluebirds (Sialia currucoides) by filming the size and type of prey that parents fed nestlings. According to the gape size constraint hypothesis, the inability of small nestlings to physically swallow large prey items might place junior brood members at a higher risk of starvation than older siblings if parents do not bring enough small items. Consistent with this idea, the frequency of ‘testing’, placing an item in the gape of a nestling but then withdrawing it, was positively correlated with prey size. The junior nestling of a brood was fed less often when parents brought larger prey items, and nestlings were tested more in the early nestling stage (0–4 days old) when their gapes were smaller than at older stages. Parents of many cavity-nesting species may feed the brood from the nest entrance and the resulting scramble competition among brood members to access the entrance hole also potentially increases the mortality of the least competitive (smallest) nestlings. Although the frequency of feeding from the entrance hole was prevalent during the late nestling stage (≥ 12 days old), feeding from the entrance was not associated with mortality rate in bluebird broods and the mortality of junior nestlings was not linked to the testing of prey. The results confirm that a mechanism of gape size constraint does direct large prey away from junior nestlings, but apparently small-sized prey items were abundant enough during our study so that this did not result in increased mortality of nestlings.

Understanding complex natural systems requires approaches with minimal statistical limitations and biases. Previously, however, the fields of behaviour, ecology and evolution generally have been restricted to evaluating differences between statistical distributions. This framework can be very powerful. Unfortunately, it has also created a bias in these, and many other, fields towards publications focusing only on phenomena for which there are statistically significant differences. However, there is a wide range of questions that would benefit from reversing the existing paradigm and testing, instead, for equivalence. We have adapted the two one-sided test (TOST), also known as equivalence testing, from pharmaceutical science to be applicable to behavioural and ecological studies. We created a repeated measures analysis that allows researchers to statistically examine similarities between distributions. We compared song structure in male and female eastern bluebirds, Sialia sialis, as a case study for this method. We failed to find significant differences between male and female songs via a more traditional test, repeated measures ANOVA. Therefore, no definitive conclusion could be drawn about the similarities or differences in song structure. However, our repeated measures equivalence test showed that, based on five standard measures of song variation, male and female eastern bluebirds sing statistically equivalent songs. Our study highlights the presence of complex female song in a temperate songbird species. Additionally, we provide a new statistical test useful for expanding the statistical toolbox to assess new behavioural and ecological questions, and to help counteract publication bias in our fields.

This chapter discusses Heartman’s Heart Breakers, “Feels Good”, “Let Me Play with It”, sexual metaphor, stringband, female musicians, Bluebird Records, and Eli Oberstein

This chapter discusses Riverside Ramblers, “Wondering”, Hackberry Ramblers, stringband, Louisiana Cajun music, and Bluebird Records

This chapter discusses Three Tobacco Tags, “V-8 Blues”, “Courtin”, white blues, rural humor, and Bluebird Records

We assessed features characterizing the most attractive nest sites for Sialia sialis (Eastern Bluebird) in an urban setting, hypothesizing that noise and availability of open grass would significantly influence nest-box occupancy. In 2019, we monitored 72 nest boxes on the University of Florida campus and compared features of occupied and unoccupied boxes. Predictor variables included ambient noise, box orientation, percent grass (within 150 m), human activity, visibility from box, and distances to nearest high perch, road, occupied building, and grassy area (larger than 1 ha). The occupancy was significantly higher for boxes located where percent grass within 150 m was greatest and also where noise was lower. We conclude that conservation of viable populations of Eastern Bluebirds is compatible with integrated urban-greenspace planning. Further work is needed, however, to mitigate negative effects of noise on reproductive output.

Hosts of brood parasitic Brown-headed Cowbirds (Molothrus ater) have acquired a suite of behavioral responses against them, including egg rejection and nest defense. Several cavity-nesting species have been shown to exhibit egg rejection, including the Mountain Bluebird (Sialia currucoides). Previous work reported egg rejection rates as low as 20%, under the assumption that they may instead be relying heavily on aggressive interactions to defend their nests from parasitism. In the present study, we evaluated the egg rejection and aggression behaviors of a population of Mountain Bluebirds in western Montana. Results indicate a higher rate of rejection than previously documented, with model cowbird eggs rejected in over 40% of trials (n = 37), compared with 5% rejection of mimetic eggs. In contrast, we found little aggressive response by Mountain Bluebirds toward both an adult cowbird model and a nonthreatening American Goldfinch (Carduelis tristis) model. Aggression patterns were consistent between sexes, with the most common behaviors including sitting and watching from within 5 m and flying past the models (n = 21). Hovering above the model was observed on a few occasions, and physical contact by bluebirds happened on only 3 occasions toward the goldfinch model. In summary, Mountain Bluebirds in western Montana showed relatively high rates of cowbird egg rejection but little aggressive response toward adult heterospecific nest intruders.

Our understanding of the proximate and ultimate mechanisms shaping competitive reproductive phenotypes primarily stems from research on male-male competition for mates, even though competition is widespread in both sexes. We evaluate the hypothesis that the restricted nature of a resource required for reproduction, i.e. nest site, is a key variable driving territorial competition and testosterone secretion in female and male birds. Obligate secondary cavity-nesting has evolved repeatedly across avian lineages, providing a useful comparative context to explore how competition over limited nest cavities shapes aggression and its underlying mechanisms across species. Although evidence from one or another cavity-nesting species suggests that territorial aggression is adaptive in both females and males, this has not yet been tested in a comparative framework. We predicted that cavity-nesting generates more robust territorial aggression, in comparison to close relatives with less restrictive nesting strategies. Our focal species were two obligate secondary cavity-nesting species and two related species with more flexible nesting strategies in the same avian family: tree swallow (Tachycineta bicolor) vs. barn swallow (Hirundo rustica); Eastern bluebird (Sialia sialis) vs. American robin (Turdus migratorius). We assayed conspecific aggression using simulated territorial intrusion and found that cavity-nesting species displayed greater territorial aggression than their close relatives. This pattern held for both females and males. Because territorial aggression is often associated with elevated testosterone, we also hypothesized that cavity-nesting species would exhibit higher testosterone levels in circulation. However, cavity-nesting species did not have higher testosterone in circulation for either sex, despite some correlative evidence that testosterone is associated with higher rates of physical attack in female tree swallows. Our focus on a context that is relevant to both sexes - competition over essential breeding resources - provides a useful framework for co-consideration of proximate and ultimate drivers of reproductive competition in females and males.

Brood parasitism results in substantial costs to hosts, yet not all species eject foreign eggs. Because the costs of mistakenly ejecting one's own eggs are high, selection may favor ejection behavior only if it is unlikely a host will incorrectly eject her own eggs. Eastern Bluebirds (Sialia sialis) are currently subject to relatively low levels of interspecific brood parasitism but still sometimes eject parasitic eggs. Therefore, we tested which visual cues they use to eject foreign eggs with the prediction that only the most dissimilar eggs would be ejected, reducing the likelihood of a female making a mistake. House Sparrows (Passer domesticus), which occasionally parasitize bluebirds, lay eggs that have an off-white ground color with brown speckling. Therefore, to test which colors or patterns allow for discrimination of parasitic eggs, we generated 3-dimensional (3D)-printed model House Sparrow eggs and painted them entirely off-white, entirely brown, half off-white and half brown, or off-white with brown speckling. We then sequentially placed these 4 different model eggs in the nests of Eastern Bluebirds, with each nest receiving all treatments over the course of 4 days. After watching females enter and leave the nest box just one time after placement of the model egg, we found that speckled eggs were ejected half the time (7 of 14 nests), while no other treatment was ejected more than 3 times. Thus, Eastern Bluebird females eject eggs based primarily on color patterning (i.e. a speckled pattern) rather than coloration per se, and that they can do so quickly, as the average female had removed the model egg within 6 min of entering the nest. Because Eastern Bluebirds do not lay speckled eggs, but some brood parasites do (e.g., House Sparrows, Brown-headed Cowbirds [Molothrus ater]), selection may specifically favor ejection of eggs with a speckled pattern, not just eggs that have within-egg color contrasts.Lay SummarySome birds (brood parasites) lay their eggs in another bird's (host's) nest; if the parasite is successful, the host ends up doing a lot of extra work raising the parasite's young.We painted model eggs to test how Eastern Bluebirds (Sialia sialis), which lay blue eggs, figure out which eggs are theirs and which ones were laid by brood parasites.Eastern Bluebirds rarely get rid of white, brown, or half-white/half-brown model eggs. However, they frequently eject model eggs that are white with brown spots; thus it is the spotting—and not the colors—that indicates to Eastern Bluebirds which eggs are not theirs.

Sensory pollutants such as anthropogenic noise and night lighting now expose much of the world to evolutionarily novel sound and night lighting conditions. An emerging body of literature has reported a variety of deleterious effects caused by these stimuli, spanning behavioral, physiological, population, and community-level responses. However, the combined influence of noise and light has received almost no attention despite the co-occurrence of these stimuli in many landscapes. Here we evaluated the singular and combined effects of these stimuli on Western Bluebird (Sialia mexicana) reproductive success using a field-based manipulation. Nests exposed to noise and light together experienced less predation than control and light-exposed nests, and noise-exposed nests experienced less predation than control nests, yet overall nest success was only higher in noise-exposed nests compared to light-exposed nests. Although exposure to light decreased nestling body condition and evidence was mixed for the singular effects of noise or light on nestling size, those nestlings exposed to noise and light together were smaller across several metrics than nestlings in control nests. Our results support previous research on the singular effects of either stimuli, including potential benefits, such as reduced nest predation with noise exposure. However, our results also suggest that noise and light together can negatively affect some aspects of reproduction more strongly than either sensory pollutant alone. This finding is especially important given that these stimuli tend to covary and are projected to increase dramatically in the next several decades.LAY SUMMARYNoise and light pollution often occur together, but their combined influence on wildlife is poorly understood.We manipulated traffic noise and artificial night lighting exposure at Western Bluebird nests.Relative to control nests, those exposed to noise experienced lower nest predation and produced more fledglings whereas chicks in nests exposed to light took longer to fledge and had lower body condition.Nests exposed to noise and light together produced smaller nestlings than control nests and, for some body measurements, those exposed to either noise or light alone.

Optimizing breeding phenology, an important aspect of fitness, is complex for migratory species as they must make key timing decisions early, and remotely, from breeding sites. We examined the role of weather (locally and cross-seasonally), cavity availability, and competitive exclusion in determining among-year variation in breeding phenology over 17 yr for 2 migratory, cavity-nesting birds: Mountain Bluebirds (Sialia currucoides; n = 462 nests) and Tree Swallows (Tachycineta bicolor; n = 572) using natural tree cavities in British Columbia, Canada. We assessed weather effects within the winter and migratory range and at our study sites. We quantified competition as the proportion of cavities occupied by European Starlings (Sturnus vulgaris) (for both species) and Mountain Bluebirds (for Tree Swallow only) in each year. For 229 bluebird and 177 swallow nests with known fates, we tested whether late years resulted in reduced productivity. Although the effects were small, heavy rainfall and strong diurnal westerly winds during migration were associated with breeding delays for Mountain Bluebirds. However, cavity availability (earlier breeding with increases) had a 5–8 × greater effect on timing than migratory conditions. There was no evidence that starling competition delayed bluebirds. In Tree Swallows, greater local daily rainfall was associated with delayed breeding, as was starling abundance (the effect of starlings was 1.4 × smaller than that of rainfall). Neither bluebird abundance nor cavity availability changed swallow phenology. Neither species showed reduced productivity in late breeding years. In both species, individuals that bred late relative to conspecifics within-year had smaller clutches and greater probability of nest failure. We conclude that breeding ground conditions, particularly cavity limitation and local rainfall (for swallows), are important drivers of breeding phenology for our focal species, but that the productivity cost of late years, at least for Tree Swallows, is minimal.

Cooperation between parents in species with biparental care can reduce sexual conflict and increase reproductive success. If parents cooperate in a conditional way – that is, alternate feeding visits to offspring – this should equalize parental investment and may improve nestling growth. Environmental variation, including competition for limited resources, may influence the need for, and benefits of, parental cooperation. We measured the benefits of partner coordination in offspring provisioning behavior among eastern bluebird partners (Sialia sialis) in which the strength of interspecific density varied spatially. Tree swallows (Tachycineta bicolor) are a recent (

Diagnosis of socio-environmental effects due to noise in cocoa processing of the CAORO corporation at Río Negro site Autores: Yuri Patricio Espinoza Aguilar yespinoza@utmachala.edu.ec Alex Dumany Luna Florin adluna@utmachala.edu.ec Maria Belén Buele Calderón mbbuele_est@utmachala.edu.ec Filiación: Universidad Técnica de Machala Km.5 1/2 Via Machala Pasaje 2983362 - 2983365 - 2983363 - 2983364 utmachala@utmachala.edu.ec Resumen En el sector Río Negro perteneciente a la parroquia La Victoria del cantón Santa Rosa, la corporación CAORO (Corporación Agroexportadora El Oro) ha venido desarrollando la actividad de la compra de cacao donde se realiza la fermentación y secado del mismo para la comercialización a nivel nacional y posterior exportación, esta actividad presenta impactos sociales y ambientales los cuales se darán a conocer en la presente investigación. Entre los impactos sociales se encontró que los trabajadores están expuestos por un periodo de tiempo extenso al ruido con decibeles que superan los límites permisibles establecidos en el Texto Unificado de Legislación Secundaria Medio Ambiental, lo que a futuro le puede causar un riesgo a la salud como nerviosismo y sordera. En los impactos ambientales se observó que el ruido afecta a las aves terrestres como Furnarius cinnamomeus, Dives warszewiczi, Ara chloroptera, Eastern bluebird, Columba livia, Turdus merula, del sector causando que se perturben en la búsqueda de alimentos por estar siempre alerta a los depredadores, también algunas aves modificaban su comportamiento natural al trinar en este entorno ruidoso. Las vibraciones generadas por la maquinaria utilizada tienen efectos adversos en la salud del trabajador que habita en la corporación, causando espondilitis, calcificación de discos e incluso menor habilidad manual. En la fauna las vibraciones causan daños mecánicos al aparato digestivo y sistemas respiratorios, además desorientación puesto que cada animal tiene una vibración específica de energía que los ayuda a comunicarse entre sí.

Avian nesting behavior has been correlated with environmental variables and many birds appear to be breeding earlier in response to warming spring temperatures. A primary concern associated with changes in nesting phenology is the potential for ecological asynchrony, whereby avian lifecycle events become out of sync with food resources, potentially leading to avian population declines and decreased opportunities for some birds to suppress pests in agroecosystems. Studies assessing changes in nesting phenology have been conducted at multiple scales and, in many cases, regional assessments allow researchers to pinpoint particular climate variables that impact first egg dates. The objective of this study is to assess the impacts of temperature, precipitation, and growing degree-days (GDD) on first egg dates of Eastern Bluebirds (Sialia sialis) and Tree Swallows (Tachycineta bicolor) across a latitudinal gradient in Ohio. In total we assessed 6535 nesting records submitted through the Cornell Lab of Ornithology's NestWatch Project from 2000-2015. Eastern Bluebirds and Tree Swallows generally nested earlier in areas of lower latitude, although bluebirds in southwest Ohio nested later than birds in central Ohio. Eastern Bluebird first egg dates were earlier in warmer spring (P < 0.001) and both Eastern Bluebird and Tree Swallow first egg dates were later in wetter springs (P < 0.001). Spring temperature did not impact the first egg dates of Tree Swallows (P = 0.89). Tree Swallows first egg dates coincided with greater GDD accumulations than first egg dates of Eastern Bluebirds, and both overlapped key control windows for common insect pests in Ohio. Given climate change predictions in this region in the next century, our results suggest temperature-related first-egg-date advancements may be moderated by nesting delays associated with increased precipitation. Our results also demonstrate a mechanism for using GDD to identify overlaps between the nesting dates of birds and important pest emergence windows in Ohio, which could inform efforts to biologically suppress insect pests.

Habitat type can dramatically affect wildlife by influencing availability of resources (such as food) or behavior, which in turn can impact reproductive output. Human-dominated areas with short grass, such as golf courses, can provide habitat for wildlife but may have reduced arthropod abundance, which can lower habitat quality for birds. We investigated food availability, foraging behavior, and reproductive success of Eastern Bluebirds (Sialia sialis) nesting in areas with relatively short grass (primarily golf courses) and in nearby fields with taller grass (natural areas) in Wisconsin, USA. We found that areas with shorter grass had significantly lower arthropod biomass. When foraging, bluebirds made more successful prey captures at sites with short grass, but individual foraging success did not influence fledging success or number of broods. Overall, no differences were found between areas with short grass and tall grass in terms of the number of eggs laid or young fledged. The results of thi...

Los Alamos National Laboratory (LANL) was established in 1943 as part of the Manhattan Project to build nuclear weapons, and currently operates as a national research laboratory. As part of an ongoing assessment of site-related ecological risk at LANL, western bluebird (Sialia mexicana) and ash-throated flycatcher (Myiarchus cinerascens) eggs were collected from 1997 to 2012 and analyzed for 18 inorganic elements. Concentrations of many inorganic elements in eggs were below reporting limits. Between species comparisons revealed that western bluebird eggs had higher levels of barium while ash-throated flycatcher eggs had higher levels of mercury. No statistically significant differences were observed in concentrations of inorganic elements in western bluebird eggs collected from the study area (which consists of areas within the current and historic LANL boundary) and from a non-industrial reference site; nor were any statistically significant differences observed between two canyons of interest, known to have received effluents and storm water runoff from LANL facilities, and the non-industrial reference site. Inorganic element levels detected in western bluebirds were typically within the range measured in eggs of other passerine in the published literature. These data suggest that concentrations of inorganic elements in passerine eggs collected from the study area appear to be at levels causing negligible risks to local bird populations.

Simple Summary Environmental changes such as climate change have affected wildlife species behavior and geographic ranges globally. We analyzed nesting data of western bluebirds to determine whether the link between geographic range shifts of a western bluebird population in New Mexico, USA is due to individual adaptations or changes occurring at a larger scale. We looked at location data of marked and recaptured nestlings and adults that nested within our study area. We found that individual choices have no impact on the geographic range shift being observed in this population, suggesting that population-level processes, such as emigration and immigration, may be the main cause of these shifts. Abstract Geographic ranges of plants and animals are shifting due to environmental change. While some species are shifting towards the poles and upslope in elevation, the processes leading to these patterns are not well known. We analyzed 22 years of western bluebird (Sialia mexicana) data from a large nest box network in northern New Mexico at elevations between 1860 m and 2750 m. This population has shifted to higher elevations over time, but whether this is due to changes in nesting behavior and preference for higher elevation within the population or driven by immigration is unclear. We banded adults and nestlings from nest boxes and examined nesting location and elevation for individual birds captured two or more times. Most recaptured birds nested at the same nest boxes in subsequent years, and the number of birds that moved upslope did not significantly differ from the number that moved downslope. Fledglings moved greater distances and elevations than adults, but these movements were not upslope specific. Female fledglings showed greater changes in elevation and distance compared to male fledglings, but again, movements were not consistently upslope. The upslope shift in this population may be due to birds immigrating into the population and not from changes in individual nesting behavior.