Quantifying Dietary Breadth in Howlers

How Much Sampling Is Enough

Bibliographic Data

ID19387204
AuthorsAriadna Rangel‐negrín (0000-0003-3539-3652, Primate Behavioral Ecology Laboratory, Instituto de Neuro‐etología Universidad Veracruzana Xalapa Veracruz México), Ariadna Rangel Negrín (Universidad Veracruzana, corresponding author), Pedro A D Dias (0000-0002-2919-6479, Universidad Veracruzana, corresponding author)
Year2026
Volume88
Issue2
Pagese70126-e70126
Publication date2026-02-01
Open AccessYes
TypeARTICLE
VenueAmerican Journal of Primatology (JOURNAL)
Journal identifiersISSN: 0275-2565 • E-ISSN: 1098-2345
PublisherWiley (PUBLISHER • GB)
DOI10.1002/ajp.70126
PMID41674433
OpenAlexW7128693118
LanguageEN
Citations received1
References cited35

Accurate characterization of dietary breadth is fundamental to understanding animal ecology, yet comparative studies based on inconsistent sampling protocols have often confounded measurements of behavioral variation. We address a critical question: how much observation effort is required to adequately characterize dietary breadth in mantled howler monkeys ( Alouatta palliata )? Using a comprehensive ten‐year dataset, we applied multiple complementary accumulation curve approaches (abundance‐based, incidence‐based, and time‐based) to 56,540 feeding observations totaling 6828 observation hours across two groups. Sample coverage exceeded 0.99 for both groups, confirming near‐complete sampling. Species accumulation curves revealed that characterizing dietary breadth to near‐completion required approximately 5000–5200 observation hours. The first 1500–3000 h captured 85%–100% of dietary diversity, with accumulation rates declining dramatically (> 95%) beyond this threshold. Overall accumulation rates averaged 0.006–0.007 species per hour. Monthly incidence‐based approaches required 7–8 years of continuous sampling to reach asymptotic levels. Despite occupying neighboring habitats, groups differed substantially in observation hours required to reach equivalent species milestones, highlighting how foraging selectivity affects sampling requirements. Coverage‐based rarefaction enabled comparison at equivalent sampling completeness (0.999 coverage), revealing that Group 1 exhibited higher estimated richness (51.3 species) than Group 2 (36.2 species), though overlapping 95% confidence intervals precluded definitive conclusions about between‐group differences. Our results provide practical sampling benchmarks for this species and demonstrate methodological approaches applicable to primate dietary studies. We recommend that dietary studies routinely report accumulation curves and sample coverage statistics to enable assessment of sampling adequacy

Confidence interval · Foraging · Rarefaction (ecology) · Sample size determination · Sampling (signal processing) · Species richness · Primate Behavior and Ecology · Species Distribution and Climate Change · Wildlife Ecology and Conservation

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