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Record W2081700559 · doi:10.1139/cjz-78-9-1604

Energetics of free-ranging large herbivores: when should costs affect foraging behaviour?

2000· article· en· W2081700559 on OpenAlexvenueno aff
H. M. Armstrong, Antony Robertson

Bibliographic record

VenueCanadian Journal of Zoology · 2000
Typearticle
Languageen
FieldAgricultural and Biological Sciences
TopicRuminant Nutrition and Digestive Physiology
Canadian institutionsnot available
Fundersnot available
KeywordsForagingNet energyEnergy balanceHerbivoreOvisForageEnergeticsOptimal foraging theoryEnergy budgetBiologyEcologyGrazingAtmospheric sciencesForestryAnimal scienceGeographyPhysics

Abstract

fetched live from OpenAlex

Published relationships were used to build a mathematical model that predicts the daily net energy balance of free-ranging domestic sheep (Ovis aries L.) grazing in the U.K. hills. Net energy balance was predicted for a plausible range of environmental conditions. The behaviour of the model suggested the following predictions. Locomotion will be a relatively unimportant energetic cost. Ambient temperature and rainfall alone will rarely affect energy expenditure, whereas wind will greatly increase energetic costs in winter. These are further increased, but to a relatively small ex - tent, by any concurrent rainfall. Predictions of foraging behaviour based on maximisation of energy intake alone are likely to significantly overestimate dry matter intake from climatically exposed vegetation in winter. Where shelter is available, such models will also overestimate total intake in winter by not taking account of sheltering behaviour. This effect will be most pronounced when forage is of low digestibility or availability, wind speeds are high, or the level of coat insulation is low. Foraging models based instead on maximisation of net energy balance are likely to greatly improve predictions of the impact of large herbivores on vegetation and the mechanisms driving their population dynamics. Resume : Des donnees publiees ont servi a bâtir un modele mathematique permettant de predire le solde energetique quotidien net de moutons domestiques (Ovis aries L.) en liberte dans des pâturages sur des collines du Royaume Uni. Aucun solde energetique n'a pu etre estime dans une etendue realiste de conditions ecologiques. Le comportement du modele a permis de faire les predictions suivantes. La locomotion se fait a un cout energetique negligeable. La tempe- rature ambiante et les precipitations a elles seules affectent rarement la depense energetique, alors que le vent peut cau- ser une augmentation appreciable de la depense energetique en hiver, et l'effet du vent peut etre augmente encore davantage, quoique de facon limitee, par des precipitations. Les predictions au sujet du comportement de quete de nourriture, predictions basees sur l'optimisation de l'ingestion d'energie seulement, risquent de surestimer significative- ment l'ingestion de matiere seche a partir de la vegetation exposee aux conditions climatiques en hiver. La ou des refuges sont disponibles, de tels modeles peuvent egalement surestimer l'ingestion totale en hiver en ne tenant pas compte de l'utilisation des refuges. Cet effet est plus marque lorsque le brout est peu disponible ou de digestibilite faible, lorsque les vents sont forts ou lorsque les moutons n'ont qu'une mince couche d'isolant. Les modeles bases sur l'optimisation du solde energetique net donneront lieu a des predictions beaucoup plus justes au sujet de l'impact des grands herbivores sur la vegetation et sur les mecanismes qui gerent la dynamique de leurs populations. (Traduit par la Redaction) 1615

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.003
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.008
Threshold uncertainty score0.015

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.003
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0010.001
Open science0.0000.000
Research integrity0.0010.000
Insufficient payload (model declined to judge)0.0010.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.021
GPT teacher head0.231
Teacher spread0.211 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations7
Published2000
Admission routes1
Has abstractyes

Explore more

Same venueCanadian Journal of Zoology→Same topicRuminant Nutrition and Digestive Physiology→French-language works237,207→