scholarly journals Clutch Size in the Eastern Kingbird: Factors Affecting Nestling Survival

The Auk ◽  
1983 ◽  
Vol 100 (2) ◽  
pp. 326-334 ◽  
Author(s):  
Michael T. Murphy
Keyword(s):  
Clutch Size ◽  
Brood Size ◽  
Weather Conditions ◽  
Ambient Air ◽  
Factors Affecting ◽  
Temperature And Precipitation ◽  
Trade Offs ◽  
Nestling Survival ◽  
Eastern Kingbird ◽  
Induced Changes

Abstract Observational and experimental procedures were used to evaluate the potential importance of brood size and weather on the evolution of clutch size in the Eastern Kingbird. Modal clutch size was three eggs, yet broods of four were most productive. Nestling size varied inversely with brood size, so that "nestling quality" was lower in broods of four than in broods of three. Asymptotic weight of nestlings in broods of three was directly and significantly correlated with ambient air temperature, followed by hatch order. Because larger broods were being fed during a period of relatively cool and wet weather, the effects of brood size were probably confounded by weather-induced changes in food availability, suggesting that the ability to produce surviving young successfully from large broods is dependent upon weather conditions during the nestling period. These observations match patterns seen in other aerial foragers and indicate that unpredictable changes in temperature and precipitation dramatically affect the ability of the adults to feed young. A high variance in fledging success from the largest broods is indicated and probably selects for a reduced number of offspring in the Eastern Kingbird. Trade-offs in reproductive effort and parental survival do not appear to be required to explain patterns of clutch size in the Eastern Kingbird or, probably, other aerial foragers.

The costs of reproduction in tree swallows (Tachycineta bicolor)

1991 ◽  
Vol 69 (10) ◽  
pp. 2540-2547 ◽  
Author(s):  
Nathaniel T. Wheelwright ◽  
Joanna Leary ◽  
Caragh Fitzgerald
Keyword(s):  
Life History ◽  
Clutch Size ◽  
Brood Size ◽  
Life History Theory ◽  
Tachycineta Bicolor ◽  
Laying Date ◽  
Tree Swallows ◽  
Costs Of Reproduction ◽  
Return Rates ◽  
Trade Offs

We investigated the effect of brood size on nestling growth and survival, parental survival, and future fecundity in tree swallows (Tachycineta bicolor) over a 4-year period (1987–1990) in an effort to understand whether reproductive trade-offs limit clutch size in birds. In addition to examining naturally varying brood sizes in a population on Kent Island, New Brunswick, Canada, we experimentally modified brood sizes, increasing or decreasing the reproductive burdens of females by two offspring. Unlike previous studies, broods of the same females were enlarged or reduced in up to 3 successive years in a search for evidence of cumulative costs of reproduction that might go undetected by a single brood manipulation. Neither observation nor experiment supported the existence of a trade-off between offspring quality and quantity, in contrast with the predictions of life-history theory. Nestling wing length, mass, and tarsus length were unrelated to brood size. Although differences between means were in the direction predicted, few differences were statistically significant, despite large sample sizes. Nestlings from small broods were no more likely to return as breeding adults than nestlings from large broods, but return rates of both groups were very low. Parental return rates were also independent of brood size, and there was no evidence of a negative effect of brood size on future fecundity (laying date, clutch size). Reproductive success, nestling size, and survival did not differ between treatments for females whose broods were manipulated in successive years. Within the range of brood sizes observed in this study, the life-history costs of feeding one or two additional nestlings in tree swallows appear to be slight and cannot explain observed clutch sizes. Costs not measured in this study, such as the production of eggs or postfledging parental care, may be more important in limiting clutch size in birds.

Variation in incubation length and hatching asynchrony in Eastern Kingbirds: Weather eclipses female effects

The Auk ◽  
2021 ◽  
Author(s):  
Samantha M Gillette ◽  
Amanda L Klehr ◽  
Michael T Murphy
Keyword(s):  
New York ◽  
Clutch Size ◽  
Egg Laying ◽  
Hatching Asynchrony ◽  
Ambient Temperatures ◽  
Temperature And Precipitation ◽  
Incubation Periods ◽  
Tyrannus Tyrannus ◽  
Eastern Kingbird ◽  
Small Clutch

Abstract Incubation length and hatching asynchrony are integral elements of the evolved reproductive strategies of birds. We examined intra- and interpopulation variation in both traits for Eastern Kingbird (Tyrannus tyrannus) populations from New York (NY), Kansas (KS), and Oregon (OR) and found that both incubation length and hatching asynchrony were not repeatable among females, after controlling for a repeatable trait, clutch size. Instead, incubation length and clutch size were influenced by ambient temperature and precipitation. Incubation length exhibited the same median (15 days) and range (13–17 days) at all sites. Model selection results indicated that incubation periods for the smallest and largest clutches were longer in NY than KS when rain was frequent throughout incubation, in replacement nests, and likely when ambient temperatures were low during egg-laying. Full hatching usually required 2 days (but up to 3), with synchronous hatching associated with small clutch sizes, short incubation periods, frequent rain during the egg-laying period, and low ambient temperatures during the first half of incubation. Nestling starvation was uncommon (5–9% of nestlings monitored) and not associated with greater hatching asynchrony. These results indicate that while clutch size, a repeatable female trait, contributed to variation in incubation length and hatching asynchrony in Eastern Kingbirds, weather was a greater source of variation, especially for incubation length.

A tes

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
IJE Manager
Keyword(s):  
Energy Supply ◽  
Fossil Fuels ◽  
Geographical Location ◽  
Weather Conditions ◽  
Past Century ◽  
Solar Pv ◽  
Pv Systems ◽  
Trade Offs ◽  
A Site ◽  
Selection Methodology

In the past century, fossil fuels have dominated energy supply in Indonesia. However, concerns over emissions are likely to change the future energy supply. As people become more conscious of environmental issues, alternatives for energy are sought to reduce the environmental impacts. These include renewable energy (RE) sources such as solar photovoltaic (PV) systems. However, most RE sources like solar PV are not available continuously since they depend on weather conditions, in addition to geographical location. Bali has a stable and long sunny day with 12 hours of daylight throughout the year and an average insolation of 5.3 kWh/m2 per day. This study looks at the potential for on-grid solar PV to decarbonize energy in Bali. A site selection methodology using GIS is applied to measure solar PV potential. Firstly, the study investigates the boundaries related to environmental acceptability and economic objectives for land use in Bali. Secondly, the potential of solar energy is estimated by defining the suitable areas, given the technical assumptions of solar PV. Finally, the study extends the analysis to calculate the reduction in emissions when the calculated potential is installed. Some technical factors, such as tilting solar, and intermittency throughout the day, are outside the scope of this study. Based on this model, Bali has an annual electricity potential for 32-53 TWh from solar PV using amorphous thin-film silicon as the cheapest option. This potential amount to three times the electricity supply for the island in 2024 which is estimated at 10 TWh. Bali has an excessive potential to support its own electricity demand with renewables, however, some limitations exist with some trade-offs to realize the idea. These results aim to build a developmental vision of solar PV systems in Bali based on available land and the region’s irradiation.

Robust Environmental Sensing Using UAVs

2021 ◽  
Vol 2 (4) ◽  
pp. 1-20
Author(s):  
Ahmed Boubrima ◽  
Edward W. Knightly
Keyword(s):  
Air Pollution ◽  
Gas Sensors ◽  
High Performance ◽  
Weather Conditions ◽  
Ambient Air ◽  
Mission Planning ◽  
Pollution Monitoring ◽  
Compound Pollution ◽  
Planning Algorithm

In this article, we first investigate the quality of aerial air pollution measurements and characterize the main error sources of drone-mounted gas sensors. To that end, we build ASTRO+, an aerial-ground pollution monitoring platform, and use it to collect a comprehensive dataset of both aerial and reference air pollution measurements. We show that the dynamic airflow caused by drones affects temperature and humidity levels of the ambient air, which then affect the measurement quality of gas sensors. Then, in the second part of this article, we leverage the effects of weather conditions on pollution measurements’ quality in order to design an unmanned aerial vehicle mission planning algorithm that adapts the trajectory of the drones while taking into account the quality of aerial measurements. We evaluate our mission planning approach based on a Volatile Organic Compound pollution dataset and show a high-performance improvement that is maintained even when pollution dynamics are high.

Weather conditions, brood size and hatching order affect Common SwiftApus apusnestlings’ survival and growth

Bird Study ◽  
2014 ◽  
Vol 62 (1) ◽  
pp. 64-77 ◽  
Author(s):  
Beatrice Sicurella ◽  
Mario Caffi ◽  
Manuela Caprioli ◽  
Diego Rubolini ◽  
Nicola Saino ◽  
...  
Keyword(s):  
Brood Size ◽  
Weather Conditions ◽  
Hatching Order ◽  
Survival And Growth

Light Effects on Food

1990 ◽  
Vol 53 (5) ◽  
pp. 430-440 ◽  
Author(s):  
MIRAY BEKBÖLET
Keyword(s):  
Dairy Products ◽  
Light Exposure ◽  
Meat Products ◽  
Fats And Oils ◽  
Food Groups ◽  
Visual Appearance ◽  
Factors Affecting ◽  
Off Flavors ◽  
Interval Type ◽  
Induced Changes

Current research studies carried out on light-induced changes in dairy products, fats and oils, and meat products are reviewed. General factors affecting thus formed off-flavors in these food groups are the intensity of light, exposure interval, type of packaging, and some specific nutritive constituents. In dairy products, riboflavin degradation, losses of vitamin A and C are the major effects, whereas in fats and oils the effective constituents are ß-carotene, tocopherols, the undesirable flavors being related mainly to photosensitized oxidation. In case of meat products, the visual appearance seems to be the most important effect due to the formation of oxidized pigment metmyoglobin from oxymyoglobin upon light exposure. The effects of packaging materials and types on photooxidation are also being discussed for each of the above three food commodity groups.

Factors Affecting Clutch Size in the Teiid Lizards Cnemidophorus tigris gracilis and C. t. septentrionalis

1992 ◽  
Vol 26 (4) ◽  
pp. 443 ◽  
Author(s):  
Harry L. Taylor ◽  
Christopher R. Cooley ◽  
Rose Ann Aguilar ◽  
Carmeliza J. Obana
Keyword(s):  
Clutch Size ◽  
Factors Affecting

scholarly journals How fast should social restrictions be eased  in England as COVID-19 vaccinations are rolled out?

2021 ◽  
Author(s):  
David Miles ◽  
Adrian Heald ◽  
Mike Stedman
Keyword(s):  
Healthcare Services ◽  
Key Factors ◽  
Healthcare Provision ◽  
Factors Affecting ◽  
Education Outcomes ◽  
Trade Offs ◽  
Standards Of Living ◽  
Life Years ◽  
The Uk ◽  
The Impact

Vaccination against the COVID-19 virus began in December 2020 in the UK and is now running at 5% population/week. High Levels of social restrictions were implemented for the third time in January 2021 to control the second wave and resulting increases in hospitalisations and deaths. Easing those restrictions must balance multiple challenging priorities, weighing the risk of more deaths and hospitalisations against damage done to mental health, incomes and standards of living, education outcomes and provision of non-Covid-19 healthcare. Weekly and monthly officially published values in 2020/21 were used to estimate the impact of seasonality and social restrictions on the spread of COVID-19 by age group, on the economy and healthcare services. These factors were combined with the estimated impact of vaccinations and immunity from past infections into a model that retrospectively reflected the actual numbers of reported deaths closely both in 2020 and early 2021. It was applied prospectively to the next 6 months to evaluate the impact of different speeds of easing social restrictions. The results show vaccinations are significantly reducing the number of hospitalisations and deaths. The central estimate is that relative to a rapid easing, the avoided loss of 57,000 life years from a strategy of relatively slow easing over the next 4 months comes at a cost in terms of GDP reduction of around £0.4 million/life-year loss avoided. This is over 10 times higher than the usual limit the NHS uses for spending against Quality Adjusted Life Years (QALYs) saved. Alternative assumptions for key factors affecting give significantly different trade-offs between costs and benefits of different speeds of easing. Disruption of non-Covid-19 Healthcare provision also increases in times of higher levels of social restrictions. In most cases, the results favour a somewhat faster easing of restrictions in England than current policy implies.

scholarly journals Promising varieties of spring glumaceous oat of the mowing and grain-mowing directions, adapted to the natural and climatic conditions of the Volga-Vyatka region

2021 ◽  
Vol 36 ◽  
pp. 01003
Author(s):  
Elena Vologzhanina ◽  
Galina Batalova
Keyword(s):  
Weather Conditions ◽  
Climatic Conditions ◽  
High Yield ◽  
Positive Dependence ◽  
Green Mass ◽  
North East ◽  
The North ◽  
Temperature And Precipitation ◽  
Green Mass Yield ◽  
Favorable Conditions

The results of the study of 12 varieties and promising lines of glumaceous oat in the competitive variety testing of the FASC of the North-East (Kirov region) in the period from 2018 to 2020 are presented. The purpose of the research is to assess the productivity, ecological plasticity and stability of the genotypes of glumaceous oat for feed and universal use in the conditions of the Volga-Vyatka region. The dependences of grain yield and dry matter harvesting on the state of agro-climatic resources (HTC), temperature and precipitation are established. The contrasting weather conditions during the years of research allowed to conduct the most complete assessment of the studied genotypes. The most favorable conditions for the formation of a high yield of green mass of oat were formed in 2020 (Ij=3.76), grain - in 2019 (Ij=1.35). The average degree of positive dependence of green mass yield on the height of oat plants was revealed (r=0.51). The variety of the high-intensity type of the universal direction Medved, promising lines of the mowing direction (178h13 and 245h14) are distinguished.

scholarly journals Vertical Distribution of Arthropod Assemblages and the Effects of Weather Conditions on Arthropod Rain in a Temperate Conifer Forest

2021 ◽  
Vol 4 ◽  
Author(s):  
Tomohiro Yoshida ◽  
Yasunori Kusunoki ◽  
Yuya Fukano ◽  
Naoki Hijii
Keyword(s):  
Vertical Distribution ◽  
Weather Conditions ◽  
Vertical Stratification ◽  
Food Sources ◽  
Conifer Forest ◽  
Additional Food ◽  
Temperature And Precipitation ◽  
Taxonomic Groups ◽  
Forest Arthropods ◽  
Pan Traps

Vertical stratification of forests results in the occurrence of different arthropod assemblages between the vertical layers. Fallen arthropods from the canopy layers (i.e., “arthropod rain”) are additional food sources for predators thriving on the forest floor (FF). However, the abundances of arthropods are strongly affected by weather conditions and vertical stratification. Therefore, in this study, we investigated the vertical distribution of arthropod assemblages and effects of temperature and precipitation on the arthropod rain in a temperate conifer (Cryptomeria japonica) forest. Arthropods were collected by water-pan traps and trunk-sticky traps in the upper canopy (UC; 16 m), lower canopy (10 m), and FF (0.5 m). Among the fallen arthropods collected by water-pan traps, wandering detritivores, and herbivores were more abundant ranging from the FF to the UC, whereas the abundance of wandering predators (mainly spiders) was similar in the upper and lower canopies. However, detritivores, herbivores, and predators showed the highest abundance in the UC among the flying arthropods. Wandering arthropods moved upward from the FF toward the tree trunks more frequently than downward, indicating the importance of arthropod immigration from the ground to arboreal habitats. Temperature and precipitation had different effects on fallen and moving arthropods among different taxonomic groups. Flying arthropods were affected only by temperature, while wandering detritivores and herbivores were affected by precipitation and temperature. Thus, the abundance of wandering and flying arthropods differed among the vertical layers of a temperate conifer forest; additionally, arthropod rain was closely associated with weather conditions.

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