Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Energy Budgets

Energy Budgets

Organisms must balance energy intake with the energy required for growth, maintenance and reproduction. These trade-offs result in a variety of survivorship and reproductive strategies, including semelparity and iteroparity. Semelparous species, like annual plants, have only one reproductive episode in their lifetimes and consequently have short lifespans. Iteroparous species, by contrast, have many reproductive events during their lifetimes but have relatively few offspring. These two...

Distribution and Dispersion

Distribution and Dispersion

To understand intra-specific interactions in populations, scientists measure the spatial arrangement of species individuals. This geographic arrangement is known as the species distribution or dispersion. Highly territorial species exhibit a uniform distribution pattern, in which individuals are spaced at relatively equal distances from one another. Species that are highly tied to particular resources, such as food or shelter, tend to concentrate around those resources, and thus exhibit a...

Ecological Niches

Ecological Niches

All organisms have a position within an ecosystem. The complete set of living and nonliving factors—including food resources, climate, and terrain—that define the position of a given organism are collectively referred to as the organism’s ecological niche.

What are Populations and Communities?

What are Populations and Communities?

Trophic Efficiency

Trophic Efficiency

Trophic level transfer efficiency (TLTE) is a measure of the total energy transfer from one trophic level to the next. Due to extensive energy loss as metabolic heat, an average of only 10% of the original energy obtained is passed on to the next level. This pattern of energy loss severely limits the possible number of trophic levels in a food chain.

Population Growth

Population Growth

Population size is dynamic, increasing with birth rates and immigration, and decreasing with death rates and emigration. In ideal conditions with unlimited resources, populations can increase exponentially, which plots as a J-shaped growth rate curve of population size against time. This type of curve is characteristic of newly-introduced invasive species, or populations that have suffered catastrophic declines and are rebounding.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Multifaceted Assessment of Amazonian Tree Diversity Reveals Pervasive Impacts of Human Modification.

Global change biology·2025

Same author

First Record of Mating Involving a Melanistic Jaguar (<i>Panthera onca</i>) in the Wild: Novel Behavioural Insights Into Colour Morphs and Captive-Wild Comparisons.

Ecology and evolution·2025

Same author

Nonlinear phenomena in mammalian vocal communication: an introduction and scoping review.

Philosophical transactions of the Royal Society of London. Series B, Biological sciences·2025

Same author

Functional composition of the Amazonian tree flora and forests.

Communications biology·2025

Same author

Winner-loser plant trait replacements in human-modified tropical forests.

Nature ecology & evolution·2024

Same author

The biogeography of the Amazonian tree flora.

Communications biology·2024

Search research articles

Related Experiment Video

Updated: May 8, 2026

Modeling the Size Spectrum for Macroinvertebrates and Fishes in Stream Ecosystems

Modeling the Size Spectrum for Macroinvertebrates and Fishes in Stream Ecosystems

Published on: July 30, 2019

Size-energy relationships in ecological communities.

Brent J Sewall¹, Amy L Freestone, Joseph E Hawes

¹Department of Biology, Temple University, Philadelphia, Pennsylvania, United States of America. bjsewall@temple.edu

|August 17, 2013

Summary

Body size does not affect energy use among foragers, supporting the energetic equivalence hypothesis. Direct energy measurements confirmed this, unlike indirect methods relying on size-density. This has implications for community ecology.

More Related Videos

Automatic Image Processing to Determine the Community Size Structure of Riverine Macroinvertebrates

Automatic Image Processing to Determine the Community Size Structure of Riverine Macroinvertebrates

Published on: January 13, 2023

JenaTron - An Experimental Approach to Study the Effects of Plant History and Soil History on Grassland Ecosystem Functioning

JenaTron - An Experimental Approach to Study the Effects of Plant History and Soil History on Grassland Ecosystem Functioning

Published on: March 21, 2025

Related Experiment Videos

Last Updated: May 8, 2026

Modeling the Size Spectrum for Macroinvertebrates and Fishes in Stream Ecosystems

Modeling the Size Spectrum for Macroinvertebrates and Fishes in Stream Ecosystems

Published on: July 30, 2019

Automatic Image Processing to Determine the Community Size Structure of Riverine Macroinvertebrates

Automatic Image Processing to Determine the Community Size Structure of Riverine Macroinvertebrates

Published on: January 13, 2023

JenaTron - An Experimental Approach to Study the Effects of Plant History and Soil History on Grassland Ecosystem Functioning

JenaTron - An Experimental Approach to Study the Effects of Plant History and Soil History on Grassland Ecosystem Functioning

Published on: March 21, 2025

Area of Science:

Community ecology
Macroecology
Metabolic theory

Background:

Size-energy hypotheses are central to ecological predictions but remain controversial.
Previous studies lacked direct energy use data and often confounded scaling relationships.
Ecological context and methodological assumptions influence size-energy relationship outcomes.

Purpose of the Study:

To directly test size-energy hypotheses using measured energy intake.
To compare direct energy measurements with indirect inference methods (size-density relationships).
To clarify the influence of ecological context and assumptions on size-energy relationships.

Main Methods:

Directly measured energy intake in a vertebrate frugivore guild in Madagascar.
Tested the energetic equivalence hypothesis and alternative size-energy hypotheses.
Compared results with those derived from conventional size-density relationships.

Main Results:

Direct energy intake measurements supported the energetic equivalence hypothesis.
Body size did not confer an advantage in energy competition among foragers.
Results were robust to different assumptions about energy regulation.
Indirect methods using size-density relationships yielded contrasting results.

Conclusions:

Direct energy measurement provides a more accurate assessment of size-energy relationships than indirect methods.
The energetic equivalence hypothesis is supported by direct energy intake data.
Findings have significant implications for predicting species interactions and community dynamics.