scholarly journals Size-dependent reproductive output of female bagworms (Lepidoptera: Psychidae): Implications for inter-generational variations of population density.

2002 ◽  
Vol 37 (3) ◽  
pp. 357-364 ◽  
Author(s):  
Marc Rhainds ◽  
Cheng Tuck Ho
Keyword(s):  
Population Density ◽  
Reproductive Output ◽  
Size Dependent ◽  
Generational Variations

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.

scholarly journals Rapid Anthropocene realignment of allometric scaling rules

2020 ◽  
Author(s):  
Luca Santini ◽  
Nick J.B. Isaac
Keyword(s):  
Global Change ◽  
Population Density ◽  
Allometric Scaling ◽  
Negative Relationship ◽  
Change Scenario ◽  
Anthropogenic Pressures ◽  
Size Dependent ◽  
Energetic Constraints ◽  
The Relationship

AbstractThe negative relationship between body size and population density (SDR) in mammals is often interpreted as resulting from energetic constraints. In a global change scenario, however, this relationship might be expected to change, given the size-dependent nature of anthropogenic pressures and vulnerability to extinction. Here we test whether the SDR in mammals has changed over the last 50 years. We show that the relationship has shifted down and became shallower, corresponding to a decline in population density of 32-72%, for the largest and smallest mammals, respectively. However, the SDRs become steeper in some groups (e.g. carnivores) and shallower in others (e.g. herbivores). The Anthropocene reorganization of biotic systems is apparent in macroecological relationships that were previously believed to be immutable, reinforcing the notion that biodiversity pattens are contingent upon conditions at the time of investigation. We call for an increased attention on the role of global change on macroecological inferences.

Size-dependent reproductive output in agricultural weeds

1991 ◽  
Vol 69 (3) ◽  
pp. 442-446 ◽  
Author(s):  
B. K. Thompson ◽  
J. Weiner ◽  
S. I. Warwick
Keyword(s):  
Reproductive Output ◽  
Datura Stramonium ◽  
Abutilon Theophrasti ◽  
Sorghum Halepense ◽  
Panicum Miliaceum ◽  
Threshold Size ◽  
Size Dependent ◽  
Linear Relationships ◽  
Apparent Relationship ◽  
Agricultural Weeds

Data on reproductive and vegetative weights of individuals from five species of agricultural weeds (Apera spica-venti L., Datura stramonium L., Abutilon theophrasti Medic., Sorghum halepense (L.) Pers., and Panicum miliaceum L.) were used to test Weiner's (1988) model of linear size-dependent reproductive output in plants. In general, the populations showed strong evidence (P < 0.001) of linear relationships between reproductive and vegetative weight. Linearity was most pronounced in cases where size differences were primarily due to competition. Generally, the linear relationships were consistent from population to population within a species. Many of the populations also showed positive x-intercepts, indicating a threshold size for reproduction. However, there were a number of populations with no apparent relationship between reproductive and vegetative weight, with departures from linearity, or with positive y-intercepts (negative x-intercepts). Key words: reproductive weight, vegetative weight, agricultural weeds, size-dependent reproduction.

On the Analysis of Size-Dependent Reproductive Output in Plants

1992 ◽  
Vol 6 (3) ◽  
pp. 308 ◽  
Author(s):  
P. G. L. Klinkhamer ◽  
E. Meelis ◽  
T. J. de Jong ◽  
J. Weiner
Keyword(s):  
Reproductive Output ◽  
Size Dependent

Differences in energy partition between crowded and uncrowded individual barnacles (Balanus glandula Darwin)

1977 ◽  
Vol 55 (4) ◽  
pp. 643-647 ◽  
Author(s):  
R. S. S. Wu ◽  
C. D. Levings ◽  
D. J. Randall
Keyword(s):  
Population Density ◽  
Reproductive Output ◽  
Population Regulation ◽  
The Other ◽  
Body Tissue ◽  
Balanus Glandula ◽  
Energy Partition ◽  
Adequate Amount ◽  
Other Hand ◽  
Feeding Area

The egg: body tissue ratio and shell: tissue ratio, when expressed in terms of energy, may serve as a good indication of the energy partition of individual barnacles. When comparing these two ratios between crowded and uncrowded individual barnacles, a decrease in degree of crowding was associated with: (1) an increase in the egg: body tissue ratio and (2) a decrease in shell: tissue ratio of the individuals. This appears to suggest a difference in energy partition in the barnacles with different degrees of crowding. Uncrowded individuals, which acquire an adequate amount of energy, could channel more energy into egg output and hence produce more progeny. On the other hand, crowded individuals acquire a limited amount of energy and apparently use a larger proportion of their assimilated energy in (1) building body tissue rather than egg and (2) building a taller shell so as to increase the general feeding area of the population. The reduction in reproductive output when population density is high (and vice versa) could be an important mechanism in population regulation of the species.

Effect of Population Density and Female Body Size on Number and Size of Offspring in a Species with Size-Dependent Contests over Resources

Ethology ◽  
2010 ◽  
Vol 116 (2) ◽  
pp. 120-128 ◽  
Author(s):  
Claudia M. Rauter ◽  
Michael J. Mcguire ◽  
Melissa M. Gwartney ◽  
Jason E. Space
Keyword(s):  
Body Size ◽  
Population Density ◽  
Female Body ◽  
Size Dependent ◽  
Female Body Size
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