Seasonal Variation in Reproductive Output of House Sparrows: The Determination of Clutch Size

Ecology ◽  
1978 ◽  
Vol 59 (6) ◽  
pp. 1189-1199 ◽  
Author(s):  
Edward C. Murphy
Keyword(s):  
Seasonal Variation ◽  
Clutch Size ◽  
Reproductive Output ◽  
House Sparrows

Density‐dependent and seasonal variation in reproductive output and sporophyte production in the kelp, Ecklonia radiata

2021 ◽  
Author(s):  
Masayuki Tatsumi ◽  
Christopher J. T. Mabin ◽  
Cayne Layton ◽  
Victor Shelamoff ◽  
Matthew J. Cameron ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Reproductive Output ◽  
Ecklonia Radiata ◽  
Density Dependent ◽  
Sporophyte Production

Eggs, nests, and chicks

2020 ◽  
pp. 73-92
Author(s):  
Graham Scott
Keyword(s):  
Clutch Size ◽  
Shell Thickness ◽  
Anthropogenic Pollution ◽  
Genetic Determination ◽  
Trade Offs ◽  
Sexual Characteristics ◽  
Predator Risk ◽  
Egg Shell ◽  
And Function

This chapter considers the egg from its conception, through laying and incubation, to hatching; and chicks. It begins with the genetic determination of sex in birds, the resultant secondary sexual characteristics, and associated reproductive behaviours. The chapter then considers the structure and function of the egg. The evolution of clutch size and the trade-offs related to food availability and predator risk that birds make when optimizing clutch size are discussed. Egg shell colouration, camouflage, and mimicry are explored as are the impacts of urban living and of anthropogenic pollution upon egg shell thickness and strength. Nest building and the function of nests are described and incubation behaviours are discussed. Embryonic development is considered as are hatching and post-hatching behaviours.

scholarly journals Dynamical Constants and Reference Parameters for Mars

1980 ◽  
Vol 56 ◽  
pp. 325-328
Author(s):  
William H. Michael ◽  
George M. Kelly
Keyword(s):  
Seasonal Variation ◽  
Rotation Rate ◽  
Direct Determination ◽  
Time Span ◽  
Tracking Data ◽  
Doppler Tracking ◽  
Reference Parameters ◽  
Fundamental Reference ◽  
Precession Constant

AbstractDynamical constants and other fundamental reference parameters for Mars have been derived from analyses of Viking lander ranging and Doppler tracking data covering a time span of nearly four years. Precise values have been obtained for the coordinates of the spin axis and for the rotation rate, suggesting that these Viking-derived values are definitive and are suitable for adoption by the IAU. Preliminary results have been obtained for a small seasonal variation in the rotation rate, and progress has been made toward a direct determination of the precession constant.

Distribution of Miserotoxin in Varieties of Astragalus miser Dougl. ex Hook.

Weed Science ◽  
1969 ◽  
Vol 17 (2) ◽  
pp. 236-238 ◽  
Author(s):  
M. Coburn Williams ◽  
Frank A. Norris
Keyword(s):  
Seasonal Variation ◽  
Seed Dispersal ◽  
Quantitative Determination ◽  
Gallus Domesticus ◽  
The Other

A method was developed for quantitative determination of miserotoxin, a poison in timber milkvetch (Astragalus miser Dougl. ex Hook.). The presence and concentration of miserotoxin was determined in eight varieties of timber milkvetch. The seasonal variation in the concentration of the poison was followed in variety oblongifolius (Rydb.) Cron. Miserotoxin occurred primarily in the leaves with smaller amounts in the roots, flowers, and seeds. The poison level in leaves and stems decreased rapidly after seed dispersal. Miserotoxin was found in varieties oblongifolius (Rydb.) Cron., serotinus (Gray) Barneby, and hylophilus (Rydb.) Barneby, but was not found in varieties miser Dougl. ex Hook., tenuifolius (Nutt.) Barneby, crispatus (Jones) Cron., praeteritus Barneby, and decumbens (Nutt.) Cron. The three varieties containing miserotoxin were poisonous to 1-week-old chicks (Gallus domesticus, Arbor Acre 50 × Vantress hybrids); the other five varieties were not poisonous.

Papers read to the Society, June 20, 1901.

1901 ◽  
Vol 68 (442-450) ◽  
pp. 44-44
Keyword(s):  
Magnetic Field ◽  
Seasonal Variation ◽  
Solar Physics ◽  
Atmospheric Temperature ◽  
Electric Arc ◽  
Molecular Constants ◽  
Preliminary Note ◽  
Sea Temperature ◽  
Theory Of Evolution

I. “On the Mathematical Theory of Errors of Judgment, with Special Reference to the Personal Equation.” By Professor Karl Pearson, F. R. S. II. “Mathematical Contributions to the Theory of Evolution. X.—Supplement to a Memoir on Skew Variation.” By Professor Karl Pearson, F. R. S. III. “On the Application of Maxwell’s Curves to Three-colour Work, with Especial Reference to the Nature of the Inks to be employed, and to the Determination of the Suitable Light-filters.” By Dr. R. S. Clay. Communicated by Sir W. Abney, K.C.B., F. R. S. IV. “The Nature and Origin of the Poison of Lotus Arabicus .” By W. R. Dunstan, F. R. S., and T. A. Henry. V. “On the Structure and Affinities of Dipteris , with Notes on the Geological History of the Dipteridinse.” By A. C. Seward, F. R. S., and Miss E. Dale. VI. “Further Observations on Nova Persei. No. 3.” By Sir Norman Lockyer, K.C.B., F. R. S. VII. “Total Eclipse of the Sun, May 28, 1900: Account of the Observations made by the Solar Physics Observatory Eclipse Expedition and the Officers and Men of H.M.S. ‘Theseus,’ at Santa Pola, Spain.” By Sir Norman Lockyer, K.C.B., F. R. S. VIII. “The Mechanism of the Electric Arc ” By Mrs. H. Ayrton. Communicated by Professor Perry, F. R. S. IX. “The Yellow Colouring Matters accompanying Chlorophyll and their Spectroscopic Relations. Part 2.” By C. A. Schunck. Communicated by E. Schunck, F. R. S. X. “Magnetic Observations in Egypt, 1883-1901.” By Captain H. G. Lyons. Communicated by Professor Rucker, F. R. S. XI. “A Determination of the Value of the Earth’s Magnetic Field in International Units, and a Comparison of the Results with the Value given by the Kew Observatory Standard Instruments.” By W. Watson, F. R. S. XII. “Virulence of Desiccated Tubercular Sputum.” By H. Swithinbank. Communicated by Sir H. Crichton Browne, F. R. S. XIII. “The Effect of the Temperature of Liquid Air upon the Vitality and Virulence of the Bacillus tuberculosis .” By H. Swithinbank. Communicated by Sir H. Crichton Browne, F. R. S. XIV. “The Fermentation of Urea: a Contribution to the Study of the Chemistry of the Metabolism in Bacteria.” By Dr. W. E. Adeney. Communicated by Professor W. N. Hartley, F. R. S. XV. “On the Seasonal Variation of Atmospheric Temperature in the British Isles and its Relation to Wind-direction, with a Note on the Effect of Sea Temperature on the Seasonal Variation of Air Temperature.” By W. N. Shaw, F. R. S., and R. Waley Cohen. XVI. “On the Continuity of Effect of Light and Electric Radiation on Matter.” By Professor J. C. Bose. Communicated by Lord Rayleigh, F. R. S. XVII. “On the Similarities between Radiation and Mechanical Strains.” By Professor J. C. Bose. Communicated by Lord Rayleigh, F. R. S. XVIII. “On the Strain Theory of Photographic Action.” By J. C. Bose. Communicated by Lord Rayleigh, F. R. S. XIX. “The Anomalous Dispersion of Sodium Vapour.” By Professor R. W. Wood. Communicated by Professor C. V. Boys, F. R. S.. XX. “The Pharmacology of Pseudaconitine and Japaconitine considered in Relation to that of Aconitine.” By Professor J. T. Cash, F. R. S., and Professor W. R. Dunstan, F. R. S. XXI. “The Pharmacology of Pyraconitine and Methylbenzaconine considered in Relation to that of Aconitine. By Professor J. T. Cash, F. R. S., and Professor W. R. Dunstan, F. R. S. XXII. “On the Separation’of the Least Volatile Gases of Atmospheric Air, and their Spectra.” By Professor Liveing, F. R. S., and Professor Dewar, F. R. S. XXIII. “The Stability of a Spherical Nebula.” By J. H. Jeans. Communicated by Professor G. H. Darwin, F. R. S. XXIV. “On the Behaviour of Oxy-hæmoglobin, Carbonic Oxide Hæmoglobin, Methæmoglobin, and certain of their Derivatives, in the Magnetic Field, with a Preliminary Note on the Electrolysis of the Hæmoglobin Compounds.” By Professor Gamgee, F. R. S. XXV. “On the Resistance and Electromotive Forces of the Electric Arc.” By W. Duddell. Communicated by Professor Ayrton, F. R. S. XXVI. “On the Relation between the Electrical Resistances of Pure Metals and their Molecular Constants.” By W. Williams. Communicated by Professor Andrew Gray, F. R. S.

Effects of body mass on courtship, pairing, and reproduction in captive mallards

1989 ◽  
Vol 67 (2) ◽  
pp. 495-501 ◽  
Author(s):  
R. K. Pattenden ◽  
D. A. Boag
Keyword(s):  
Clutch Size ◽  
Body Mass ◽  
Reproductive Output ◽  
Breeding Biology ◽  
Laying Date ◽  
Body Reserves ◽  
Pair Bonds ◽  
Breeding Grounds ◽  
Delayed Initiation ◽  
Nutrient Reserves

The object of this study was to examine the influence of body mass, a measure of nutrient reserves, on the breeding biology of captive mallards. Low body mass delayed initiation of courtship and pairing, and decreased the number of permanent pair bonds formed. However, pairing date was not correlated with laying date. Low body mass during winter had a greater influence on laying date than low body mass during spring, but neither affected clutch size. This suggests that an individual arriving on the breeding grounds with low body reserves relative to others will have a lower reproductive output that year.

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