On the relationship between baseline corticosterone levels and annual survival of the thorn-tailed rayadito

AbstractThe production of high quality secondary sexual traits can be constrained by trade-offs in the allocation of energy and nutrients with other metabolic activities, and is mediated by physiological processes. In birds, the factors influencing male plumage quality have been well studied; however, factors affecting female plumage quality are poorly understood. Furthermore, it remains uncertain which physiological traits mediate the relationship between body condition and ornaments. In this three-year study of after-second-year female tree swallows (Tachycineta bicolor), we investigated (1) the relationship between baseline corticosterone near the end of the brood-rearing period (CORTBR) and feather colour characteristics (hue, saturation, brightness) the following year, and (2) the relationship between baseline corticosterone measured during incubation (CORTI) and brood rearing (CORTBR), and feather colour in the same year. To control for reproductive effort, we included reproductive parameters as covariates in all analyses. In this first study between CORT and the plumage colour characteristics of a species bearing iridescent feathers, we did not find any relationship between CORTBRand the colour of subsequently-produced feathers, nor did we find any relationship between CORTIand the colour of feathers displayed during that breeding season. If CORT levels at the end of breeding carry over to influence the immediately subsequent moult period as we expect, our results generally indicate that structural plumage quality may not be as sensitive to circulating CORT levels compared to carotenoid-based colouration. Future studies, particularly those employing experimental manipulations of CORT during moult in species with iridescent traits, are necessary to fully determine the role glucocorticoids play in mediating the quality of secondary sexual characteristics.

Download Full-text

Hormonal correlates of individual quality in a long-lived bird: a test of the ‘corticosterone–fitness hypothesis’

Biology Letters ◽

10.1098/rsbl.2010.0376 ◽

2010 ◽

Vol 6 (6) ◽

pp. 846-849 ◽

Cited By ~ 93

Author(s):

Frédéric Angelier ◽

John C. Wingfield ◽

Henri Weimerskirch ◽

Olivier Chastel

Keyword(s):

Breeding Season ◽

Environmental Conditions ◽

Stress Hormones ◽

Poor Quality ◽

Individual Quality ◽

Baseline Corticosterone ◽

Energetic Constraints ◽

The Relationship

Measuring individual quality in vertebrates is difficult. Focusing on allostasis mechanisms may be useful because they are functionally involved in the ability of an individual to survive and reproduce in its environment. Thus, a rise in stress hormones levels (corticosterone) occurs when an organism has to cope with challenging environmental conditions. This has recently led to the proposal of the ‘cort–fitness hypothesis’, which suggests that elevated baseline corticosterone levels should be found in individuals of poor quality that have difficulty coping with their environment. We tested this hypothesis by comparing an integrative measure of individual quality to baseline corticosterone in black-browed albatrosses ( Thalassarche melanophrys ). We found that individual baseline corticosterone levels were related to individual quality and highly repeatable from one breeding season to the next. Importantly, this relationship was found in males, but not in females. Therefore, we suggest that the relationship between quality and baseline corticosterone levels may depend on the environmental and energetic constraints that individuals have to cope with.

Download Full-text

The Relationship between Body Mass and Annual Survival in American Black Ducks

Ornis Scandinavica ◽

10.2307/3676871 ◽

1989 ◽

Vol 20 (2) ◽

pp. 81 ◽

Cited By ~ 13

Author(s):

David G. Krementz ◽

James E. Hines ◽

Pat O. Corr ◽

Ray B. Owen

Keyword(s):

Body Mass ◽

Annual Survival ◽

American Black ◽

The Relationship

Download Full-text

The relationship between social dominance, subcutaneous fat, and annual survival in wintering white-throated sparrows (Zonotrichia albicollis)

Behavioral Ecology and Sociobiology ◽

10.1007/bf00172087 ◽

1990 ◽

Vol 26 (3) ◽

Cited By ~ 48

Author(s):

W.H. Piper ◽

R.H. Wiley

Keyword(s):

Social Dominance ◽

Subcutaneous Fat ◽

Zonotrichia Albicollis ◽

Annual Survival ◽

The Relationship

Download Full-text

Interstellar gas in the central region of the Galaxy

Symposium - International Astronomical Union ◽

10.1017/s0074180900101032 ◽

1967 ◽

Vol 31 ◽

pp. 239-251 ◽

Cited By ~ 3

Author(s):

F. J. Kerr

Keyword(s):

Central Region ◽

Galactic Plane ◽

Neutral Hydrogen ◽

Continuum Emission ◽

Galactic Centre ◽

Interstellar Gas ◽

Hydrogen Recombination ◽

The Galaxy ◽

Centre Region ◽

The Relationship

A review is given of information on the galactic-centre region obtained from recent observations of the 21-cm line from neutral hydrogen, the 18-cm group of OH lines, a hydrogen recombination line at 6 cm wavelength, and the continuum emission from ionized hydrogen.Both inward and outward motions are important in this region, in addition to rotation. Several types of observation indicate the presence of material in features inclined to the galactic plane. The relationship between the H and OH concentrations is not yet clear, but a rough picture of the central region can be proposed.

Download Full-text

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽

10.1017/s0094837300025707 ◽

1980 ◽

Vol 6 (02) ◽

pp. 146-160 ◽

Cited By ~ 29

Author(s):

William A. Oliver

Keyword(s):

Critical Points ◽

Scleractinian Corals ◽

Convincing Evidence ◽

Early Triassic ◽

Rugose Corals ◽

History Of ◽

The Subject ◽

Relationship Of ◽

The Relationship ◽

Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Download Full-text

Choosing a Markov blanket

Behavioral and Brain Sciences ◽

10.1017/s0140525x19002632 ◽

2020 ◽

Vol 43 ◽

Author(s):

Thomas Parr

Keyword(s):

Markov Blanket ◽

Target Article ◽

The Relationship

Abstract This commentary focuses upon the relationship between two themes in the target article: the ways in which a Markov blanket may be defined and the role of precision and salience in mediating the interactions between what is internal and external to a system. These each rest upon the different perspectives we might take while “choosing” a Markov blanket.

Download Full-text

Tinkering with cognitive gadgets: Cultural evolutionary psychology meets active inference

Behavioral and Brain Sciences ◽

10.1017/s0140525x19001018 ◽

2019 ◽

Vol 42 ◽

Author(s):

Paul Benjamin Badcock ◽

Axel Constant ◽

Maxwell James Désormeau Ramstead

Keyword(s):

Evolutionary Psychology ◽

Research Program ◽

Active Inference ◽

Innovative Research ◽

Cognitive Faculties ◽

Cultural Evolutionary ◽

The Relationship

Abstract Cognitive Gadgets offers a new, convincing perspective on the origins of our distinctive cognitive faculties, coupled with a clear, innovative research program. Although we broadly endorse Heyes’ ideas, we raise some concerns about her characterisation of evolutionary psychology and the relationship between biology and culture, before discussing the potential fruits of examining cognitive gadgets through the lens of active inference.

Download Full-text

Radiation Damage, Contrast and Statistics in High Resolution Biological Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100068291 ◽

1970 ◽

Vol 28 ◽

pp. 260-261

Author(s):

Robert M. Glaeser

Keyword(s):

High Resolution ◽

Particle Flux ◽

Unit Area ◽

Signal To Noise ◽

Resolution Image ◽

High Resolution Image ◽

Pass Through ◽

Counting Statistics ◽

The Relationship ◽

Picture Element

It is well known that a large flux of electrons must pass through a specimen in order to obtain a high resolution image while a smaller particle flux is satisfactory for a low resolution image. The minimum particle flux that is required depends upon the contrast in the image and the signal-to-noise (S/N) ratio at which the data are considered acceptable. For a given S/N associated with statistical fluxtuations, the relationship between contrast and “counting statistics” is s131_eqn1, where C = contrast; r2 is the area of a picture element corresponding to the resolution, r; N is the number of electrons incident per unit area of the specimen; f is the fraction of electrons that contribute to formation of the image, relative to the total number of electrons incident upon the object.

Download Full-text