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Record W2098598342 · doi:10.2744/ccb-1055.1

Estimating Ages of Turtles from Growth Data

2014· article· en· W2098598342 on OpenAlexaff
Doug P. Armstrong, Ronald J. Brooks

Bibliographic record

VenueChelonian Conservation and Biology · 2014
Typearticle
Languageen
FieldEnvironmental Science
TopicTurtle Biology and Conservation
Canadian institutionsUniversity of Guelph
Fundersnot available
KeywordsBiologyEctothermTurtle (robot)CarapacePrediction intervalBayesian probabilityMark and recapturePopulationStatisticsEstimationGrowth modelPainted turtleBayesian inferenceEcologyDemographyMathematics

Abstract

fetched live from OpenAlex

Age estimation is important for management of turtle populations, but techniques such as growth ring counts or skeletochronology may be unreliable or impossible to perform. An alternative is to estimate age from growth models using Bayesian inference. However, individual variation in growth parameters needs to be incorporated into these models for them to generate realistic prediction intervals. For long-lived ectotherms such as chelonians, it is also important that models allow for changes in growth at sexual maturity, and that the growth models are combined with prior distributions reflecting realistic age structures. We describe how a hierarchical biphasic growth model fitted to a long-term data set of carapace length measurements for North American snapping turtles was combined with prior age distributions generated from survival estimates for the same population. The model was used to generate individual posterior age distributions for turtles captured on 2 or more occasions, and also for hypothetical turtles of any length that were measured only once. Posterior age distributions for hypothetical turtles were uncertain at any size due to individual variation in growth parameters, supporting the belief of many herpetologists that size is weakly related to age. Age estimates for adult turtles were also sensitive to the prior used. Using the most realistic prior, the 95% prediction intervals for large hypothetical turtles (38-cm male or 31-cm female) ranged from about 25 to 170 yrs with a median of about 70 yrs. Posterior age distributions for turtles first measured as juveniles (< 24 cm) were insensitive to the prior, and estimation precision was improved by individual growth information obtained from recaptures. For example, the 95% prediction interval for a hypothetical 10-cm turtle ranged from 2 to 14 yrs using the most realistic prior, whereas the ages of small (< 24 cm) turtles that were recaptured at least once could usually be estimated to within 1–3 yrs. Similar models could be applied to any data set where measurements and survival data are collected from a large sample of marked individuals, and could potentially be extended to incorporate data on other age indicators. This methodology allows us to produce age estimates that can be applied to management and advocacy of turtle populations while accounting for the inherent uncertainty involved.

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 distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.029
Threshold uncertainty score0.260

Codex and Gemma teacher scores by category

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

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 head0.043
GPT teacher head0.268
Teacher spread0.225 · 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 teacher head, 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

Citations22
Published2014
Admission routes1
Has abstractyes

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