Academic literature on the topic 'Fledgling'

We compared factors affecting parental feeding rates in Western Bluebirds (Sialia mexicana) between the nestling and fledgling periods to evaluate intersexual variation in parental care. Parents did not adjust the frequency of feeding visits between modal (five young) and below-modal (four or less young) broods during the nestling period. The frequency of parental feeding visits also was not significantly affected by offspring age during the nestling period. Males and females exhibited no significant differences in provisioning offspring, although males maintained a constant level of care throughout the nestling period, whereas females increased feeding visits following the brooding period. During the fledgling period, offspring from below-modal broods were fed at higher rates with increasing age than offspring from modal broods. Broods remained together (siblings averaged 8 m apart) within 200 m of the nest box for a week after fledging. As fledglings became more mobile, they would pursue parents while parents were foraging; parental feeding rates thus tended to increase with fledgling age and distance moved from the nest. Offspring sex did not influence parental care during the fledgling period. Both adults fed fledglings, with males taking sole care of fledglings if females initiated a second clutch soon (7–10 days) after fledging of the first brood. Parental feeding rates increased by 60% during the fledgling period compared with the nestling period. No evidence for brood division during the fledgling period was found. Although brood division represents one way of reducing energetic costs attributable to feeding fledglings, Western Bluebirds exhibit an alternate behavior in which the energetics of raising a brood are shared equally between the parents throughout both the nestling and fledgling periods. This is further facilitated by a close association of young during the fledgling period that may reduce energetic costs related to locating and feeding young.

Rusty blackbird (Euphagus carolinus) populations have declined dramatically since the 1970s and the cause of decline is still unclear. As is the case for many passerines, most research on rusty blackbirds occurs during the nesting period. Nest success is relatively high in most of the rusty blackbird’s range, but survival during the post-fledging period, when fledgling songbirds are particularly vulnerable, has not been studied. We assessed fledgling and adult survivorship and nest success in northern New Hampshire from May to August in 2010 to 2012. We also assessed fledgling and adult post-fledging habitat selection and nest-site selection. The likelihood of rusty blackbirds nesting in a given area increased with an increasing proportion of softwood/mixed-wood sapling stands and decreasing distances to first to sixth order streams. Wetlands were not selected for nest sites, but both adults and fledglings selected wetlands for post-fledging habitat. Fledglings and adults selected similar habitat post-fledging, but fledglings were much more likely to be found in habitat with an increasing proportion of softwood/mixed-wood sapling stands and were more likely to be closer to streams than adults. No habitat variables selected during nesting or post-fledging influenced daily survival rates, which were relatively low for adults over the 60-day study periods (males 0.996, females 0.998). Fledgling survival rates (0.89) were much higher than reported for species of similar size.

Abstract Logistical and technological limitations have constrained the characterization of behavioural development in songbirds, particularly during the post-fledging period. Recently, advances in radio-telemetry technology — automated radio-telemetry systems (ARTS) capable of recording continuous, high-resolution spatial-temporal data on radio-tagged birds — have opened the door to more comprehensive examinations of fledgling behaviour. We examined development of activity rates (number of times a bird was determined to have moved per number of detections, per hour) in fledgling Dickcissels using ARTS established at two grassland sites in east-central Illinois, USA. Specifically, we described general patterns of fledgling activity rates and determined the age at which fledglings began exhibiting activity rates like adults. We found that juveniles decreased activity rates immediately following fledging, likely to avoid detection by snakes and other predators, but increased activity levels throughout the rest of the post-fledging period. Peak hours of fledgling activity occurred around 0700 and 1800 h for all ages, with consistently low activity rates at night. On average, fledglings began exhibiting adult-like activity rates approximately 22 days after fledging, around roughly the same time they stopped being fed by adults. While our study provides important insights into development of fledgling behaviour in the Dickcissel, it remains unclear how patterns of behavioural development vary within and among species.

We followed family groups of Hooded Warblers (Wilsonia citrina) from hatching through to fledgling independence to determine (i) the duration and extent of parental care of fledglings, (ii) the extent of brood division, and (iii) whether male parental effort in caring for nestlings predicts male effort in caring for fledglings. The 9-day nestling period of Hooded Warblers was followed by 4 – 6 weeks of further parental care of fledged young. Parental feeding rates increased from hatching to when the young fledged from the nest, and males fed nestlings significantly more than females did. At the fledgling stage feeding rates to fledglings were significantly higher than at the nestling stage, but there was no difference in feeding rates between the parents. Parents usually divided the brood of fledglings equally, so that each parent assumed full and exclusive care of a subset of the brood. However, many females (45%) initiated a second brood and the male assumed care of the entire first brood at the time when his mate began incubating. The proportion of feeding trips to nestlings made by the male was not predictive of his subsequent effort in the care of fledglings. Exclusion of the fledgling care period in studies of parental investment may give a biased picture of overall investment on the part of both male and female parents.

Background Fledglings of many mature forest-dependent Neotropical songbirds move from mature forest habitats into areas of thick vegetation such as regenerating clearcuts. The Cerulean Warbler (Setophaga cerulea), a Neotropical migratory songbird, is a species of conservation concern across its range and it is listed as endangered in Indiana. This species has declined faster than any other species of wood-warbler in North America. Most prior research on Cerulean Warblers has examined the breeding biology, but there are no data on habitat use by fledgling Cerulean Warblers. Our research aimed to determine where fledgling Cerulean Warblers dispersed after they left their nest, but before they migrated to their wintering grounds. Methods Since 2007, Cerulean Warbler breeding populations have been monitored in Yellowwood and Morgan–Monroe state forests in southern Indiana as part of a 100-year study called the Hardwood Ecosystem Experiment. To identify habitats used by fledgling Cerulean Warblers, we captured by hand or mist-nets, adult and juvenile Cerulean Warblers once young had fledged from a nest. We attached radio-transmitters to individuals and tracked each bird daily using radio-telemetry. Radio-telemetry data were collected from May to July 2015–2017, and microhabitat data on fledgling locations and random locations were collected during the same years in the month of July. Results Fledgling presence, when compared to random non-use sites, was positively correlated to presence of grapevines, greater vertical vegetation density, and greater ground and canopy cover. Fledgling presence was negatively correlated with white oak abundance, aspect, basal area, and the abundance of mature trees that Cerulean Warbler adults use for nesting. Conclusions Our study is the first to demonstrate that Cerulean Warbler fledglings occupy habitats that are characterized by specific habitat components. Fledgling sites were located in areas with high vegetation density, such as clusters of grapevine, which provided cover from predators. Identifying Cerulean Warbler habitats throughout the breeding season can better inform natural resource personnel on how to manage forests to meet the habitat needs of this rapidly declining migratory songbird.

Abstract When land managers incorporate the habitat needs of grassland birds into their planning, they typically rely on management recommendations based on habitat use by adults during nesting. Habitat requirements for other critical life stages are seldom known and may differ from those of nesting adults. Using radio-telemetry, we examined survival and habitat use by juvenile Dickcissels (Spiza americana) during the postfledging period. In 2003 and 2004, we monitored 60 fledgling Dickcissels for ≤30 days after they left the nest. Mortality rates were highest during the first week after leaving the nest, and only 33% of the fledglings survived the first four weeks after leaving the nest. Estimated mean survival times were 16.9 ± 1.6 days after birds left the nest. In both years, fledgling survival was positively associated with dense vertical and horizontal structure of forbs at nests. Survival tended to be positively associated with vertical grass density on adult territories and negatively associated with patchily distributed forbs on adult territories. Fledgling habitat use was restricted to areas where Dickcissels nested and adjacent fields. Habitats used included corn and soybean fields, grasslands, and wetlands. Our results suggest that the fledgling period is a critical stage for Dickcissels and that fledglings require habitat similar to habitat used for nesting. Supervivencia Durante el Período Posterior al Emplumamiento en Spiza americana: Implicancias para el Manejo de Hábitat y Conservación

Few data exist regarding survival of Ferruginous Hawks (Buteo regalis) during the fledgling period. Consequently, we estimated the survival rate of juvenile Ferruginous Hawks from fledging to dispersal from the breeding area in northern Montana in 1993 – 1994 using radiotelemetry. A 171-km2 study area contained 24 occupied breeding sites in both years (7.12 km2/pair). Mean productivity was 0.96 young fledged per occupied breeding site (SE = 0.19, n = 48) and 2.30 young fledged per successful nest (SE = 0.21, n = 20). The average fledging age was 43.3 days. The survival rate for 27 radio-marked fledglings was high during the 3 weeks after fledging (Ŝ = 0.86, SE = 0.02). No fledgling mortality occurred > 10 days after fledging. When fledgling mortality was considered, occupied breeding sites produced an average of 0.82 dispersing young (SE = 0.24) and successful nests produced an average of 1.96 dispersing young (SE = 0.18). Our data concur with smaller data sets from earlier studies, which suggested that postfledging mortality is low.

The mode of departure of Rhinoceros Auklet fledglings from their nest burrows has remained uncertain. Both walk-down and fly-down hypotheses have been proposed. Here we use the unique geography of Protection Island, Washington, to evaluate the fly-down hypothesis. Some fledglings raised on Protection Island do appear to walk to the water, but our results suggest that many of the island’s fledgling Rhinoceros Auklets fly to the sea.

SummaryKnowledge of species-specific spatial ecology is critical for applying appropriate management strategies to maximise conservation outcomes. We used radio-telemetry to describe spatial behaviour of the critically endangered, island-endemic Mariana Crow Corvus kubaryi. To determine whether management strategies should reflect life stage, we measured the home ranges and daily movements of 22 Mariana Crows. Fledgling mobility was low during the first 31 days post-fledging and effects of age (fledgling or sub-adult) and time (months post-fledging or post-dispersal) were often driven entirely by this period. After controlling for reduced fledgling mobility, cumulative home range size increased over time for both age classes and was, on average, more than twice the area for sub-adults than fledglings. Sub-adults also tended to make longer daily movements than fledglings. Non-cumulative, monthly home range areas did not increase over time but the average overlap in home range area between consecutive months was only 63%, suggesting large shifts in space use each month. These results highlight the dynamic nature of Mariana Crow home ranges and suggest that large-scale management efforts are critical for protecting both breeding and non-breeding individuals. The application of the traditional home range concept to Mariana Crows and other wide-ranging passerine birds may result in sub-optimal management strategies. Instead, we recommend that the spatial and temporal scale of conservation efforts be informed by species-specific spatial behaviour across all relevant life stages.

Abstract We quantified post-fledging pre-independence behavior and survival in Lark Buntings (Calamospiza melanocorys) using radio-telemetry. Brood division was recorded in six broods and was maintained throughout the observed fledgling care period. Chicks were capable of short flights (up to 25 m) by fledgling day 6 and longer flights (to 100 m) by fledgling day 13. During the first three weeks after fledging, juveniles moved as far as 800 m from nests. Nine of 23 (39%) monitored fledglings died within 15 days of fledging, primarily due to predation by raptors. Daily survival rates were 0.953 ± 0.019 for fledgling days 0–9, 0.955 ± 0.038 for fledgling days 10–20, and 0.953 ± 0.015 for fledgling days 0–20. The probability of surviving fledgling days 0–20 was 0.367. More quantification of juvenile survival is clearly needed to understand the role of post-fledging mortality in source-sink dynamics. Los Movimientos y Supervivencia de los Volantones de Calamospiza melanocorys Resumen. Cuantificamos la conducta y la supervivencia de volantones de Calamospiza melanocorys antes de independizarse de sus padres usando telemetría de radio. La división de la nidada se registró en seis nidadas y se mantuvo a través del período del cuidado de los volantones. Tras seis días de haber abandonado el nido, los polluelos eran capaces de realizar vuelos cortos (de hasta 25 m) y para el día trece ya realizaban vuelos más largos (a 100 m). Durante las primeras tres semanas después de salir del nido, los juveniles se movieron hasta 800 m de los nidos. Nueve de 23 (39%) volantones se murieron en los primeros 15 días fuera del nido, principalmente debido a depredación por aves rapaces. Las tasas diarias de supervivencia fueron de 0.953 ± 0.019 para los días 0 a 9, 0.955 ± 0.038 para los días 10 a 20, y 0.954 ± 0.015 para días 0 a 20. La probabilidad de sobrevivir entre los días 0 y 20 fue de 0.367. Se necesita más cuantificacion de la sobrevivencia en la etapa juvenil para entender el papel de la mortalidad tras la salida del nido en la dinámica de fuente-sumideros.

This study examines the prototypical female leader as constructed by Octavia Butler in her science fiction novels, Dawn and Fledgling. The premise of the study relates to the protagonists’ capacity to undergo arduous tasks in extraordinary circumstances so that they can ultimately lead their people into a revolutionized society. Overcoming enormous obstacles, including the rejection of the very people they must lead, proves that both protagonists, Lilith Ilypo, in Dawn, and Shori Matthews, in Fledgling, are the women of the future, created to lead human beings into a “brave new world.” The study further examines Butler’s portrayal of the “othemesses” that continue to plague societies, despite the societies’ “higher” evolution, and concludes that only through continuous compromise will the world become unified. Butler indicates that the onerous task of achieving this ultimate unification lies on the shoulders of women who will serve as, what I term, the future’s “female Adams.”

Mestrado em Ecologia Aplicada
During the last years tropical forest has been a target of intense study especially due to its recent big scale destruction. Although a lot still needs to be explored, we start realizing how negative can the impact of our actions be for the ecosystem. Subsequently, the living community have been developing strategies to overcome this problem avoiding bottlenecks or even extinctions. Cooperative breeding (CB) has been recently pointed out as one of those strategies. CB is a breeding system where more than two individuals raise one brood. In most of the cases, extra individuals are offspring that delay their dispersal and independent breeding what allows them to help their parents raising their siblings in the subsequent breeding season. Such behavior is believed to be due, per example, to the lack of mates or breeding territories (ecological constraints hypothesis), a consequence of habitat fragmentation and/or disturbance. From this point, CB is easily promoted by a higher reproductive success of group vs pairs or single individuals. Accordingly, during this thesis I explore the early post-fledging survival of a cooperative breeding passerine, namely the impact of individual/habitat quality in its survival probability during the dependence period of the chicks. Our study species is the Cabanis’s greenbul (Phyllastrephus cabanisi), a medium-sized, brownish passerine, classified within the Pycnonotidae family. It is found over part of Central Africa in countries such as Angola, Democratic Republic of the Congo, Mozambique and Kenya, inhabiting primary and secondary forests, as well as woodland of various types up to 2700m of altitude. Previous studies have concluded that PC is a facultative cooperative breeder. This study was conducted in Taita Hills (TH) at the Eastern Arc Mountains (EAM), a chain of mountains running from Southeast Kenya to the South of Tanzania. TH comprises an area of 430 ha and has been suffering intense deforestation reflecting 98% forest reduction over the last 200 years. Nowadays its forest is divided in fragments and our study was based in 5of those fragments. We access the post-fledging survival through radio-telemetry. The juvenile survey was done through the breeding females in which transmitters were placed with a leg-loop technique. Ptilochronology is consider to be the study of feather growth bars and has been used to study the nutritional state of a bird. This technique considers that the feather growth rate is positively proportional to the individual capability of ingesting food and to the food availability. This technique is therefore used to infer for individual/habitat quality. Survival was lowest during the first 5 days post-fledging representing 53.3%. During the next 15 days, risk of predation decreased with only 14.3% more deceased individuals. This represents a total of only 33% survived individuals in the end of the 50 days. Our results showed yet a significant positive relationship between flock size and post-fledging survival as well as between ptilochronology values and post-fledgling survival. In practice, these imply that on this population, as bigger the flock, as greater the post fledging survival and that good habitat quality or good BF quality, will lead to a higher juvenile survival rate. We believe that CB is therefore an adaptive behaviour to the lack of mates/breeding territory originated from the mass forest destruction and disturbance. Such results confirms the critical importance of habitat quality in the post-fledging survival and, for the first time, demonstrates how flock size influences the living probability of the juveniles and therefore how it impacts the (local) population dynamics of this species. In my opinion, future research should be focus in disentangle individual and habitat quality from each other and verify which relationship exist between them. Such study will allow us to understand which factor has a stronger influence in the post-fledging survival and therefore redirect our studies in that direction. In order to confirm the negative impact of human disturbance and forest fragmentation, it would be of major relevance to compare the reproductive strategies and reproductive success of populations living in intact forests and disturbed patches.
Ao longo dos últimos anos, a floresta tropical tem sido alvo de intenso estudo, especialmente devido à sua destruição em grande escala. Embora ainda haver muito ainda por explorar, já começamos a perceber quão negativo pode ser o impacto de nossas ações neste ecossistema. Por conseguinte, certas comunidades têm vindo a desenvolver estratégias para superar este problema evitando diminuição das populações ou até mesmo extinções locais. Reprodução cooperativa (RC) foi recentemente apontou como uma dessas estratégias. RC é um sistema reprodutivo em que dois ou mais indivíduos criam uma ninhada. A maioria dos indivíduos extras são crias de anteriores ninhadas que atrasam a sua dispersão e reprodução independente o que lhes permite ajudar os pais a criar os seus irmãos na época de reprodução subsequente. Acredita-se que tal comportamento possa ser devido, por exemplo, à falta de companheiros ou territórios de reprodução (hipótese das restrições ecológicas), uma consequência da fragmentação e / ou perturbação do habitat. A partir deste ponto, RC é facilmente promovida se o sucesso reprodutivo do grupo é maior que o de casais indivíduos isolados. Assim sendo, nesta tese explorei a sobrevivência das crias no período após saída do ninho de uma espécie de passeriforme com RC. Nomeadamente o impacto da qualidade do individuo/habitat na sua probabilidade de sobrevivência durante o período de dependência das crias. A espécie em causa é o Cabanis’s greenbul (Phyllastrephus cabanisi) (PC), um passeriforme acastanhado de médio porte, classificada dentro da família Pycnonotidae. Pode ser encontrada na África Central em países como Angola, República Democrática do Congo, Moçambique e Quénia, habitando vários tipos de florestas primárias e secundárias, até 2700m de altitude. Estudos anteriores concluíram que PC é um reprodutor cooperativo facultativo. Este estudo teve lugar em Taita Hills (TH) nas “East Arc Mountain” (EAM), uma cadeia de montanhas que vão de sudeste Quênia ao sul da Tanzânia. TH compreende uma área de 430 ha e devido à intensa desflorestação, 98% da floresta desapareceu nos últimos 200 anos. Hoje em dia a sua floresta está dividida em fragmentos sendo o nosso estudo baseado em 5 desses fragmentos. A sobrevivência das crias foi obtida por rádio-telemetria através das fêmeas reprodutoras (FR). Ptilocronologia é o estudo de barras crescimento das penas e tem sido utilizado para estudar o estado nutricional de uma ave. Esta técnica considera que a taxa de crescimento da pena é positivamente proporcional à capacidade individual de ingestão de alimentos e da disponibilidade alimentar. Esta técnica é utilizada para inferir, portanto, para a qualidade individual / habitat. A sobrevivência foi menor durante os primeiros 5 dias após saída do ninho, cerca de 53,3%. Durante os 15 dias seguintes, o risco de morte diminuiu para 14,3%. Isto representa um total de sobrevivência de apenas 33% no final dos 50 dias. Os nossos resultados mostraram ainda uma relação significativamente positiva entre o tamanho do grupo reprodutivo e a sobrevivência das crias, bem como entre os valores ptilocronologia e a probabilidade de sobrevivência das crias. Na prática, isto significa que quanto maior o grupo reprodutivo, maior a sobrevivência das crias e que quanto melhor for a qualidade do habitat ou de fêmea reprodutora, maior será a taxa de sobrevivência. Isto leva-nos a crer que a RC é um comportamento adaptativo no sentido de compensar pela falta de companheiros/território reprodutivo originado pela destruição da floresta e perturbação. Tais resultados confirmam a importância da qualidade do habitat na sobrevivência das crias, e ainda, pela primeira vez demonstra como o tamanho do grupo reprodutivo influencia a probabilidade de sobrevivência dos juvenis e consequentemente a dinâmica populacional desta espécie. Na minha opinião, futuros estudos devem tentar separar a qualidade do habitat e a qualidade do individuo bem como verificar que relação existe entre eles. Isto vai-nos ajudar a entender melhor que fator tem mais impacto na sobrevivência das crias e, portanto, redirecionar os nossos estudos nessa direção. A fim de confirmar o impacto negativo da perturbação humana e fragmentação da floresta, seria de grande relevância comparar as estratégias reprodutivas e o sucesso reprodutivo das populações que vivem nas florestas intactas VS floresta perturbada.

English
Ph.D.
This project argues that Octavia's Butler's construction of the black woman characters is unique within the pantheon of late eighties African-American writers primarily through Butler's celebration of black female physicality and the agency the black body provides. The project is divided into five sections beginning with an intensive examination of Butler's ur-character, Anyanwu. This character is vitally important in discussing Butler's canon because she embodies the attributes and thematic issues that run throughout the author's work, specifically, the author's argument that black woman are provided opportunity through their bodies. Chapter two addresses the way black women's femininity is judged: their sexual activity. In this chapter, I explore one facet of Octavia Butler's narrative examination of sexual co-option and her subsequent implied challenge to definitions of feminine morality through the character Lilith who appears throughout Butler's Xenogenesis trilogy. Specifically, I explore this subject using Harriet Jacobs' seminal autobiography and slave narrative, Incidents in the Life of a Slave Girl as the prism in which I historically focus the conversation. In chapter three, I move the discussion into an exploration of black motherhood. Much like the aforementioned challenge to femininity vis-à-vis sexual morality, Octavia Butler often challenges and interrogates the traditional definition of motherhood, specifically, the relationship between mother and daughter. I will focus on different aspects of that mother/daughter relationship in two series, the Patternist sequence, which includes, in chronological order, Wild Seed, Mind of my Mind and Patternmaster. Chapter four discusses Butler's final novel, Fledgling, and how the novel's protagonist, Shori not only fits into the matrix of Butler characters but represents the culmination of the privileging of black female physicality that I observe in the author's entire canon. Specifically, while earlier characters are shown to create opportunities and venues of agency through their bodies, in Shori, Butler posits a character whose existence is predicated on its blackness and discusses how that purposeful racial construction leads to freedom.
Temple University--Theses

Abstract This chapter is devoted specifically to count data for three reasons: (i) they are common in ecological studies (e.g. clutch sizes, numbers of fledglings from a nest, numbers of seeds per pod...); (ii) they are simple to collect and are therefore often the data collected by students (e.g. numbers of beetles in a pitfall trap, number of pollinator visits to flowers...); and (iii) they pose numerous issues that linear models with their normal error structure cannot deal with. Two studies will be examined with the response variable being counts, starting with one that nearly fits the ideals of a Poisson distribution well, the other less so. Example 1 deals with fledgling numbers in relation to clutch initiation date. The data are on the northern cardinal bird, Cardinalis cardinalis, and were collected to test the hypothesis that birds that start their clutches later may suffer higher pre-fledging offspring mortality. Example 2 focuses on pollinator flower visits in Passiflora speciosa in relation to flower size.

Abstract This chapter is devoted specifically to count data for three reasons: (i) they are common in ecological studies (e.g. clutch sizes, numbers of fledglings from a nest, numbers of seeds per pod...); (ii) they are simple to collect and are therefore often the data collected by students (e.g. numbers of beetles in a pitfall trap, number of pollinator visits to flowers...); and (iii) they pose numerous issues that linear models with their normal error structure cannot deal with. Two studies will be examined with the response variable being counts, starting with one that nearly fits the ideals of a Poisson distribution well, the other less so. Example 1 deals with fledgling numbers in relation to clutch initiation date. The data are on the northern cardinal bird, Cardinalis cardinalis, and were collected to test the hypothesis that birds that start their clutches later may suffer higher pre-fledging offspring mortality. Example 2 focuses on pollinator flower visits in Passiflora speciosa in relation to flower size.

Solving grand societal challenges such as equitable healthcare provision and climate change will require institutional entrepreneurs – people who can challenge prevailing regulations, behaviors, and ways of thinking. As the pinnacle of educational achievement, the doctoral degree should be the fire in which such fledgling institutional entrepreneurs are forged. Doctoral education has, however, been criticized as overspecialized and divorced from reality. We systematically review the doctoral education literature in our search for doctoral education programs that challenge institutional norms by bridging sectoral and disciplinary divides. We ask whether such programs can help to nurture institutionally entrepreneurial researchers. We find that students must manage ambiguous identities and wide networks but that such programs have the potential to equip them for both sense-making and sense-giving activities of institutional entrepreneurship.