What Shape Is the Relationship between Body Size and Population Density?

Oikos ◽  
1993 ◽  
Vol 66 (2) ◽  
pp. 353 ◽  
Author(s):  
David J. Currie
Keyword(s):  
Body Size ◽  
Population Density ◽  
The Relationship

scholarly journals Is the relationship between population density and body size consistent across independent studies? A meta-analytical approach

2001 ◽  
Vol 61 (1) ◽  
pp. 1-6 ◽  
Author(s):  
L. M. BINI ◽  
A. S. G COELHO ◽  
J. A. F. DINIZ-FILHO
Keyword(s):  
Body Size ◽  
Population Density ◽  
Regression Model ◽  
Phylogenetic Relationships ◽  
Analytical Approach ◽  
Analytical Procedure ◽  
Significant Heterogeneity ◽  
Sampling Variation ◽  
Homogeneity Hypothesis ◽  
The Relationship

The Energetic Equivalence Rule (EER) is a controversial issue in ecology. This rule states that the amount of energy that each species uses per unit of area is independent of its body size. Here, we perform a meta-analytical procedure to combine and compare the slopes of population density and body size relationships across independent studies of mammals and birds. We then compared a distribution of 50,000 bootstrap combined slopes with the expected slope (b = -0.75) under the EER. The combined slopes obtained for mammals and birds separately were -0.755 and -0.321, respectively. The homogeneity hypothesis (i. e. within studies the slopes differ by no more than would be expected due sampling variation) was rejected in both cases. So, EER cannot be supported since the use of an exponent of -0.75 is, in fact, an oversimplification. Significant heterogeneity of slopes within each group (mammals and birds) is an indicator of inferential problems related with variation in body size, spatial scale, the regression model adopted and phylogenetic relationships among species. So, we consider that questions regarding the estimation and validity of slopes is the next challenge of density-body size relationship studies.

The Relationship between Population Density and Body Size: The Role of Extinction and Mobility

Oikos ◽  
1995 ◽  
Vol 73 (2) ◽  
pp. 225 ◽  
Author(s):  
Bo Ebenman ◽  
Anders Hendenström ◽  
Uno Wennergren ◽  
Börje Ekstam ◽  
Jan Landin ◽  
...  
Keyword(s):  
Body Size ◽  
Population Density ◽  
The Relationship

Leg Strength Is Related to Endurance Run Performance in Children and Adolescents with Mental Retardation

2000 ◽  
Vol 12 (3) ◽  
pp. 324-333 ◽  
Author(s):  
Bo Fernhall ◽  
Kenneth H. Pitetti
Keyword(s):  
Mental Retardation ◽  
Body Size ◽  
Children And Adolescents ◽  
Aerobic Capacity ◽  
Significant Influence ◽  
Moderate Mental Retardation ◽  
Leg Strength ◽  
And Gender ◽  
The Relationship ◽  
Shuttle Run

This study evaluated the relationship between leg strength and endurance run performance, independent of aerobic capacity (V̇O2peak), body size, and gender, in children and adolescents with mild or moderate mental retardation. Twenty-six individuals (15 boys and 11 girls) volunteered and underwent tests of V̇O2peak, isokinetic leg strength, and endurance run performance (600-yard ran/walk and 20-m shuttle run). Results showed that leg strength was significantly related to both types of run performance; however, when controlling for V̇O2peak, body size, and gender, leg strength was a more significant contributor to the 600-yard run/walk than to 20-m shuttle run performance. Gender did not influence these relationships. These data suggest that leg strength has a significant influence on endurance run performance in children and adolescents with mild or moderate mental retardation.

scholarly journals Intraspecific Variation in Maximum Ingested Food Size and Body Mass in Varecia rubra and Propithecus coquereli

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Adam Hartstone-Rose ◽  
Jonathan M. G. Perry
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Individual Variation ◽  
Size Variation ◽  
Maximum Size ◽  
Least Squares Regression ◽  
Scaling Relationship ◽  
Varecia Rubra ◽  
Food Size ◽  
The Relationship

In a recent study, we quantified the scaling of ingested food size (Vb )—the maximum size at which an animal consistently ingests food whole—and found that Vb scaled isometrically between species of captive strepsirrhines. The current study examines the relationship between Vb and body size within species with a focus on the frugivorous Varecia rubra and the folivorous Propithecus coquereli. We found no overlap in Vb between the species (all V. rubra ingested larger pieces of food relative to those eaten by P. coquereli), and least-squares regression of Vb and three different measures of body mass showed no scaling relationship within each species. We believe that this lack of relationship results from the relatively narrow intraspecific body size variation and seemingly patternless individual variation in Vb within species and take this study as further evidence that general scaling questions are best examined interspecifically rather than intraspecifically.

An ecological explanation for hyperallometric scaling of reproduction

2021 ◽  
Author(s):  
Tomos Potter ◽  
Anja Felmy
Keyword(s):  
Body Size ◽  
Reproductive Output ◽  
Resource Competition ◽  
Natural Populations ◽  
Scaling Exponent ◽  
Wild Populations ◽  
Wet Season ◽  
Size Dependent ◽  
In The Wild ◽  
The Relationship

AbstractIn wild populations, large individuals have disproportionately higher reproductive output than smaller individuals. We suggest an ecological explanation for this observation: asymmetry within populations in rates of resource assimilation, where greater assimilation causes both increased reproduction and body size. We assessed how the relationship between size and reproduction differs between wild and lab-reared Trinidadian guppies. We show that (i) reproduction increased disproportionately with body size in the wild but not in the lab, where effects of resource competition were eliminated; (ii) in the wild, the scaling exponent was greatest during the wet season, when resource competition is strongest; and (iii) detection of hyperallometric scaling of reproduction is inevitable if individual differences in assimilation are ignored. We propose that variation among individuals in assimilation – caused by size-dependent resource competition, niche expansion, and chance – can explain patterns of hyperallometric scaling of reproduction in natural populations.

Letters to the Editor

PEDIATRICS ◽  
1963 ◽  
Vol 31 (6) ◽  
pp. 1058-1059
Author(s):  
WILLIAM A. SILVERMAN
Keyword(s):  
Population Density ◽  
Nosocomial Infections ◽  
Specific Recommendation ◽  
Letters To The Editor ◽  
Airborne Infection ◽  
The Relationship

I was saddened to read that Doctor Harvie thinks the Committee on Fetus and Newborn has contributed to creeping authoritarianism by making a specific recommendation after evaluating evidence concerning the relationship between "spacing out" and airborne infection in hospital nurseries. Moreover I think he has misinterpreted the Committee's recommendations if he believes that they have advised nurseries to place sole reliance on reducing population density in order to minimize the risk of nosocomial infections. As Doctor Harvie comments, different modes of spread may be involved in the various types of infection that can be acquired in a newborn nursery.

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