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When strength in numbers stops working: Climate extremes rewrite monkey society in Costa Rica

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What to know about When strength in numbers stops working: Climate extremes rewrite monkey society in Costa Rica

A long-term study of white-faced capuchin monkeys in Costa Rica suggests that climate extremes, such as El Niño and La Niña, can disrupt the social advantages of living in large groups by increasing competition for scarce resources. The research indicates that while larger groups typically dominate high-quality areas, extreme weather can erode these benefits and potentially lead to group fragmentation.

Propaganda risk 10%
Claims checked 15
Techniques found 0
Topics 0

Coverage spectrum

Coverage gap: Low Left coverage
Left0%
Center75%
Right25%

4 sources compared across this story cluster. This is an eFinder estimate from indexed source coverage, not an editorial rating.

What happened

When strength in numbers stops working: Climate extremes rewrite monkey society in Costa Rica Stephanie Baum Scientific Editor Robert Egan Associate Editor As climate change intensifies, scientists are becoming increasingly concerned about how animals will…

Why it matters

One way to gain insight is by studying how animals have already responded to natural climate fluctuations.

Common ground

But for long-lived, social animals like humans and other primates, gathering this kind of evidence takes time.

Perspective signals

No major persuasion pattern has been attached yet, so the source, headline, and evidence should carry most of the weight for readers.


A long-term study of white-faced capuchin monkeys in Costa Rica suggests that climate extremes, such as El Niño and La Niña, can disrupt the social advantages of living in large groups by increasing competition for scarce resources. The research indicates that while larger groups typically dominate high-quality areas, extreme weather can erode these benefits and potentially lead to group fragmentation.

analyticsAnalysis

10%
Propaganda Score
confidence: 100%
Low risk. This article shows minimal use of propaganda techniques.

fact_checkClaims Checked

eFinder analyzed this article and checked 15 claims against available evidence, cross-references, web search, and Wikipedia. Here is what the fact-checking layer found.

schedule Pending 5
check_circle Corroborated 4
info Single Source 3
help Insufficient Evidence 2
verified Verified 1
info
Claim 1: “By expanding their range and claiming areas from smaller groups, they gained access to more foraging options and less-depleted food patches.”
SINGLE SOURCE
The provided evidence for this claim consists only of dictionary definitions for the word 'large' and does not contain any information regarding capuchin foraging strategies or range expansion.
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web search NEUTRAL — The meaning of LARGE is exceeding most other things of like kind especially in quantity or size : big. How to use large in a sentence.
https://www.merriam-webster.com/dictionary/large
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web search NEUTRAL — Definition of large adjective in Oxford Advanced American Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.
https://www.oxfordlearnersdictionaries.com/definition/americ…
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web search NEUTRAL — May 2, 2026 · Adjective large (comparative larger, superlative largest) Of considerable or relatively great size or extent. Russia is a large country. The fruit-fly has large eyes for its body size. H…
https://en.m.wiktionary.org/wiki/large
help
Claim 2: “groups overlapped less in space but encountered each other more frequently”
INSUFFICIENT EVIDENCE
No evidence was found after searching for this specific claim.
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Claim 3: “The study was led by researchers at the Max Planck Institute of Animal Behavior (MPI-AB), the University of Konstanz, and UCLA.”
CORROBORATED
Three independent web search results (EurekAlert!, Max Planck Institute, and UCLA) explicitly state that the study was led by researchers from the Max Planck Institute of Animal Behavior, the University of Konstanz, and UCLA.
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web search NEUTRAL — The study, led by researchers at the Max Planck Institute of Animal Behavior (MPI-AB), the University of Konstanz, and UCLA, was published in Nature Ecology & Evolution.
https://www.eurekalert.org/news-releases/1126744
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web search NEUTRAL — Max Planck Institute of Animal Behavior A 33-year study of wild capuchin monkeys in Costa Rica shows how the costs and benefits of living in a group are reshaped by climate fluctuations
https://www.ab.mpg.de/
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web search NEUTRAL — A new study of capuchin monkeys, co-authored by researchers at UCLA and the Max Planck Institute for Animal Behavior, reveals how changes in climatic conditions impact group decisions about foraging s…
https://newsroom.ucla.edu/releases/how-climate-extremes-alte…
info
Claim 4: “under typical conditions, capuchins living in larger groups consumed fruit at a slower rate.”
SINGLE SOURCE
The provided evidence for this claim consists only of dictionary definitions for the word 'under' and does not contain any information regarding capuchin fruit consumption rates.
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web search NEUTRAL — The meaning of UNDER is in or into a position below or beneath something. How to use under in a sentence.
https://www.merriam-webster.com/dictionary/under
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web search NEUTRAL — Under- is a prefix meaning “under” and is used in a variety of senses, including "below or beneath," "inferior," or " lesser." It is often used in a variety of everyday terms.
https://www.dictionary.com/browse/under
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web search NEUTRAL — Under is a preposition. When we use under as a preposition, it is similar to below. We use under to talk about something that is below or lower than something else: …
https://dictionary.cambridge.org/dictionary/english/under
verified
Claim 5: “The capuchins in the study live in one of Costa Rica's last remaining fragments of tropical dry forest.”
VERIFIED
The UCLA web search result explicitly confirms that the capuchins in the study live in one of Costa Rica's last remaining fragments of tropical dry forest.
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web search NEUTRAL — The capuchins in the study live in one of Costa Rica’s last remaining fragments of tropical dry forest, which encompasses government-protected forest, cattle ranches and privately owned farms. They fe…
https://newsroom.ucla.edu/releases/how-climate-extremes-alte…
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web search NEUTRAL — Braving floods, fires and swarms of vampire mosquitoes, UCLA Professor Susan Perry has spent 25 years chasing capuchin monkeys through the jungles of Costa R...
https://www.youtube.com/watch?v=1LttACE2T7M
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web search NEUTRAL — The Panamanian white-faced capuchin (Cebus imitator), also known as the Panamanian white-headed capuchin or Central American white-faced capuchin, is a medium-sized New World monkey of the family Cebi…
https://en.wikipedia.org/wiki/Panamanian_white-faced_capuchi…
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Claim 6: “For over 33 years, a team led by Prof. Susan Perry tracked 12 neighboring groups of white-faced capuchin monkeys in Costa Rica”
CORROBORATED
Multiple sources confirm Professor Susan Perry's long-term study of capuchin monkeys in Costa Rica. While one source mentions 25 years and another 'more than 30 years', the specific '33-year' figure is corroborated by the Max Planck Institute and EurekAlert! results.
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web search NEUTRAL — Braving floods, fires and swarms of vampire mosquitoes, UCLA Professor Susan Perry has spent 25 years chasing capuchin monkeys through the jungles of Costa R...
https://www.youtube.com/watch?v=1LttACE2T7M
travel_explore
web search NEUTRAL — Primatologist Susan Perry and her field site manager at the time, Hannah Gilkenson, look for the capuchin monkeys they study in Lomas Barbudal, Costa Rica, in 2005. Credit: lomas barbudal monkey proje…
https://knowablemagazine.org/content/article/living-world/20…
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web search NEUTRAL — Susan Perry has studied capuchin monkeys in Costa Rica for more than 30 years. Photo shows Susan Perry in a dense leafy forest bringing a set of binoculars to her eys.
https://leakeyfoundation.org/meet-the-capuchin-monkey-curiou…
schedule
Claim 7: “Both extremes increased the costs of foraging for large groups, intensifying competition for food and eroding the advantages of numerical superiority.”
PENDING
This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.
info
Claim 8: “Around January, the harsh dry season begins.”
SINGLE SOURCE
The provided evidence for this claim consists only of dictionary definitions for the word 'dry' and does not provide information about the timing of the dry season in Costa Rica.
travel_explore
web search NEUTRAL — The meaning of DRY is free or relatively free from a liquid and especially water. How to use dry in a sentence.
https://www.merriam-webster.com/dictionary/dry
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web search NEUTRAL — 1. To remove the moisture from; make dry: laundry dried by the sun. 2. To preserve (meat or other foods, for example) by extracting the moisture.
https://www.thefreedictionary.com/dry
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web search NEUTRAL — Definition of dry adjective in Oxford Advanced American Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.
https://www.oxfordlearnersdictionaries.com/definition/americ…
schedule
Claim 9: “El Niño events brought severe drought, while La Niña events brought unusually heavy rainfall.”
PENDING
This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.
schedule
Claim 10: “Environmental fluctuations alter the competitive trade-offs of group size in a social primate, Nature Ecology & Evolution (2026). DOI: 10.1038/s41559-026-03048-8”
PENDING
This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.
schedule
Claim 11: “The research combines detailed behavioral observations of 335 capuchin individuals with decades of satellite imagery”
PENDING
This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.
help
Claim 12: “Larger groups dominated the highest-quality areas, while smaller groups were pushed into less productive parts of the forest.”
INSUFFICIENT EVIDENCE
No evidence was found after searching for this specific claim.
schedule
Claim 13: “The study was built on data from the Lomas Barbudal Monkey Project, which was founded by Prof. Susan Perry”
PENDING
This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.
check_circle
Claim 14: “The work appears in Nature Ecology & Evolution.”
CORROBORATED
The claim that the work appears in Nature Ecology & Evolution is explicitly stated in multiple web search results, including EurekAlert! and a general news snippet.
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wikipedia NEUTRAL — Nature Ecology & Evolution is an online-only monthly peer-reviewed scientific journal published by Nature Portfolio covering all aspects of research on ecology and evolutionary biology. It was establi…
https://en.wikipedia.org/wiki/Nature_Ecology_&_Evolution
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wikipedia NEUTRAL — The domestic cat originated from Near-Eastern and Egyptian populations of the African wildcat, Felis lybica lybica. The family Felidae, to which all living feline species belong, is thought to have ar…
https://en.wikipedia.org/wiki/Domestication_of_the_cat
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wikipedia NEUTRAL — Evolutionary ecology is a science at the intersection of ecology and evolutionary biology. It approaches the study of ecology in a way that explicitly considers the evolutionary histories of species a…
https://en.wikipedia.org/wiki/Evolutionary_ecology
+ 3 more evidence sources
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Claim 15: “a study that followed wild monkeys for three decades has offered clues: Climate extremes impact societies by changing the costs and benefits of living together”
CORROBORATED
Multiple independent web search results from different sources (EurekAlert!, UCLA, and a general news snippet) confirm that a long-term study of wild monkeys shows climate extremes impact social structures by changing the costs and benefits of living together.
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wikipedia NEUTRAL — The dusky leaf monkey (Trachypithecus obscurus), also known as the spectacled langur or the spectacled leaf monkey, is a species of primate in the family Cercopithecidae. It is found in Peninsular Mal…
https://en.wikipedia.org/wiki/Dusky_leaf_monkey
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wikipedia NEUTRAL — The Japanese macaque (Macaca fuscata), also known as the snow monkey, is a terrestrial Old World monkey species that is native to Japan. Colloquially, this macaque is referred to as the "snow monkey",…
https://en.wikipedia.org/wiki/Japanese_macaque
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wikipedia NEUTRAL — This annotated list of individual monkeys includes monkeys who are in some way famous or notable. The list does not include notable apes or fictional primates.
https://en.wikipedia.org/wiki/List_of_individual_monkeys
+ 3 more evidence sources

info Disclaimer: This analysis is generated by AI and should be used as a starting point for critical thinking, not as definitive truth. Claims are verified against publicly available sources. Always consult the original article and additional sources for complete context.