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Sam Ellis

@samellisq.bsky.social

Lecturer at the University of Exeter. Interested in general but especially in life history evolution and social behaviour.

1,034 Followers  |  122 Following  |  14 Posts  |  Joined: 24.04.2024  |  2.1484

Latest posts by samellisq.bsky.social on Bluesky


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New (competition funded) PhD opportunity with me,
@iaciac.bsky.social and @dralgernon.bsky.social
www.findaphd.com/phds/project...
Higher-order networks and animal communication. Suited to someone keen on network science theory/computational modeling and keen to adapt this to ecology & evolution.

09.02.2026 14:41 โ€” ๐Ÿ‘ 32    ๐Ÿ” 41    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 2
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A typology of rules for knowledge exchange in higher-order interactions Author summary Learning from each other is important to humans and other animals as it provides safe or quick ways to gather information about the world around you. Because of this โ€˜social learningโ€™, ...

A new paper in @plos.org Complex Systems from my time at @nimbios.bsky.social with Nina Fefferman.
We set out some ways of classifying rules for social learning and knowledge exchange in higher-order networks.
doi.org/10.1371/jour...

26.01.2026 17:24 โ€” ๐Ÿ‘ 10    ๐Ÿ” 2    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
A white beluga surfacing in greenish-brown waters. Overlaid is the title of a new review published in Behavioral Ecology and Sociobiology: Beluga Societies: the social and cultural lives of an enigmatic odontocete.

A white beluga surfacing in greenish-brown waters. Overlaid is the title of a new review published in Behavioral Ecology and Sociobiology: Beluga Societies: the social and cultural lives of an enigmatic odontocete.

Our new review of beluga sociality and culture just dropped at Behavioral Ecology and Sociobiology! Some of our key conclusions summarized ๐Ÿงต
doi.org/10.1007/s002...
@marine-valeria.bsky.social @dmennill.bsky.social @raincoast.org

21.01.2026 20:04 โ€” ๐Ÿ‘ 78    ๐Ÿ” 38    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 5
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Charli Grimes discusses the social ontogeny of resident killer whales, exploring how lifelong social bonds form and change from early life through maturity. ๐Ÿ‹๐Ÿค #UKIRSC26

16.01.2026 11:06 โ€” ๐Ÿ‘ 9    ๐Ÿ” 3    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 1
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We are hiring โ€“ postdoc position exploring how kinship shapes social ageing in killer whales. Collaboration with @samellisq.bsky.social @drwhale.bsky.social and Prof Rufus Johnstone (Cambridge) starts 1st April 2026 and ends 31st March 2029. Apps close 2nd Feb. www.jobs.ac.uk/job/DPZ788/p...

13.01.2026 14:42 โ€” ๐Ÿ‘ 54    ๐Ÿ” 58    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 2
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Fully funded #PhD studentships, start Sept 2026:
1. Weaponry and aggression in wild fiddler crabs, with me, Safi Darden, Martin How tinyurl.com/weaponsPhD
2. The emotional basis of behaviour, with me, Danny Williamson, Andy Higginson tinyurl.com/emotionsPhD
#AnimalBehaviour @crab-exeter.bsky.social

03.12.2025 15:38 โ€” ๐Ÿ‘ 16    ๐Ÿ” 26    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 1
Cover image with sleeping baboon

Cover image with sleeping baboon

Our paper is published today in Current Biology and is featured on the cover!

We report a neat, and somewhat counter-intuitive, finding: higher-ranking baboons get less and more interrupted night-time rest.

06.01.2026 09:39 โ€” ๐Ÿ‘ 58    ๐Ÿ” 21    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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Late-reporting, but last year some of our CRABbers headed up to Edinburgh to present their posters at the @asab.org Winter meeting. Well done all! @libbychaps.bsky.social @charli-ocean.bsky.social and @ Manuela Carona R

05.01.2026 10:02 โ€” ๐Ÿ‘ 15    ๐Ÿ” 6    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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Festive Season in CRAB, which we celebrate with a quiz and by rediscovering the password to the CRAB Bluesky account.

10.12.2025 16:50 โ€” ๐Ÿ‘ 6    ๐Ÿ” 4    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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Meat transfer patterns reflect the multi-level social system of Guinea baboons Wildlife behavior; Biological sciences; Zoology; Evolutionary biology

New paper out in iScience. We found the pattern of Guinea baboon meat transfers follows the shape of their nested multi-level society. Transfers of meat are more tolerant at the lower levels of the society and are more likely to occur along stronger social relationships. www.cell.com/iscience/ful...

31.10.2025 13:36 โ€” ๐Ÿ‘ 13    ๐Ÿ” 5    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
Dwarf mongoose

Dwarf mongoose

Rhesus macaques grooming

Rhesus macaques grooming

Meerkat

Meerkat

โ“ Want to join us?
๐Ÿ“ข Fully funded #PhD for UK-domiciled Black heritage candidates
๐Ÿต Biological market monitoring & manipulation in social animals #mongooses #macaques #fieldwork

๐Ÿ‘ฅ With me, #LaurenBrent & #PatrickKennedy
๐ŸŽ“ @bristolbiosci.bsky.social

โ„น๏ธ www.findaphd.com/phds/project...

๐Ÿ™Share widely

16.10.2025 07:45 โ€” ๐Ÿ‘ 29    ๐Ÿ” 40    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 1
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MSc by Res opportunity - developing behavioural indicators to inform killer whale conservation with
@exeter.ac.uk @whaleresearch.bsky.social @seadocsociety.bsky.social

People from underrepresented groups in marine science encouraged to apply.

Deadline 19Dec

www.exeter.ac.uk/study/fundin...

22.10.2025 10:44 โ€” ๐Ÿ‘ 29    ๐Ÿ” 21    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 3
The Adaptive Relationships Framework illustrating how broad socioecological pressures shape the social solutions animals use to meet these challenges, and how these lead to social strategies and emergent structures that help them gain access to those solutions.

The Adaptive Relationships Framework illustrating how broad socioecological pressures shape the social solutions animals use to meet these challenges, and how these lead to social strategies and emergent structures that help them gain access to those solutions.

Social relationships are powerful predictors of fitness across social animals. But *why*?

In our new @cp-trendsecolevo.bsky.social paper, we outline testable predictions for why relationship quality and quantity adaptively vary across socio-ecological contexts.

tinyurl.com/55dnkeh7

16.10.2025 07:07 โ€” ๐Ÿ‘ 100    ๐Ÿ” 53    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 3
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We are hiring - PDRA position exploring how information access shapes social dynamics in killer whales. Collaboration with @samellisq.bsky.social @drwhale.bsky.social Prof Dan Franks (York) start 1st Nov (or ASAP) end 31st Oct 2028. Apps close on 19th Oct.

www.jobs.ac.uk/job/DOT336/p...

23.09.2025 18:29 โ€” ๐Ÿ‘ 32    ๐Ÿ” 44    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 5
Models as Prediction Machines: How to Convert Confusing Coefficients into Clear Quantities

Abstract
Psychological researchers usually make sense of regression models by interpreting coefficient estimates directly. This works well enough for simple linear models, but is more challenging for more complex models with, for example, categorical variables, interactions, non-linearities, and hierarchical structures. Here, we introduce an alternative approach to making sense of statistical models. The central idea is to abstract away from the mechanics of estimation, and to treat models as โ€œcounterfactual prediction machines,โ€ which are subsequently queried to estimate quantities and conduct tests that matter substantively. This workflow is model-agnostic; it can be applied in a consistent fashion to draw causal or descriptive inference from a wide range of models. We illustrate how to implement this workflow with the marginaleffects package, which supports over 100 different classes of models in R and Python, and present two worked examples. These examples show how the workflow can be applied across designs (e.g., observational study, randomized experiment) to answer different research questions (e.g., associations, causal effects, effect heterogeneity) while facing various challenges (e.g., controlling for confounders in a flexible manner, modelling ordinal outcomes, and interpreting non-linear models).

Models as Prediction Machines: How to Convert Confusing Coefficients into Clear Quantities Abstract Psychological researchers usually make sense of regression models by interpreting coefficient estimates directly. This works well enough for simple linear models, but is more challenging for more complex models with, for example, categorical variables, interactions, non-linearities, and hierarchical structures. Here, we introduce an alternative approach to making sense of statistical models. The central idea is to abstract away from the mechanics of estimation, and to treat models as โ€œcounterfactual prediction machines,โ€ which are subsequently queried to estimate quantities and conduct tests that matter substantively. This workflow is model-agnostic; it can be applied in a consistent fashion to draw causal or descriptive inference from a wide range of models. We illustrate how to implement this workflow with the marginaleffects package, which supports over 100 different classes of models in R and Python, and present two worked examples. These examples show how the workflow can be applied across designs (e.g., observational study, randomized experiment) to answer different research questions (e.g., associations, causal effects, effect heterogeneity) while facing various challenges (e.g., controlling for confounders in a flexible manner, modelling ordinal outcomes, and interpreting non-linear models).

Figure illustrating model predictions. On the X-axis the predictor, annual gross income in Euro. On the Y-axis the outcome, predicted life satisfaction. A solid line marks the curve of predictions on which individual data points are marked as model-implied outcomes at incomes of interest. Comparing two such predictions gives us a comparison. We can also fit a tangent to the line of predictions, which illustrates the slope at any given point of the curve.

Figure illustrating model predictions. On the X-axis the predictor, annual gross income in Euro. On the Y-axis the outcome, predicted life satisfaction. A solid line marks the curve of predictions on which individual data points are marked as model-implied outcomes at incomes of interest. Comparing two such predictions gives us a comparison. We can also fit a tangent to the line of predictions, which illustrates the slope at any given point of the curve.

A figure illustrating various ways to include age as a predictor in a model. On the x-axis age (predictor), on the y-axis the outcome (model-implied importance of friends, including confidence intervals).

Illustrated are 
1. age as a categorical predictor, resultings in the predictions bouncing around a lot with wide confidence intervals
2. age as a linear predictor, which forces a straight line through the data points that has a very tight confidence band and
3. age splines, which lies somewhere in between as it smoothly follows the data but has more uncertainty than the straight line.

A figure illustrating various ways to include age as a predictor in a model. On the x-axis age (predictor), on the y-axis the outcome (model-implied importance of friends, including confidence intervals). Illustrated are 1. age as a categorical predictor, resultings in the predictions bouncing around a lot with wide confidence intervals 2. age as a linear predictor, which forces a straight line through the data points that has a very tight confidence band and 3. age splines, which lies somewhere in between as it smoothly follows the data but has more uncertainty than the straight line.

Ever stared at a table of regression coefficients & wondered what you're doing with your life?

Very excited to share this gentle introduction to another way of making sense of statistical models (w @vincentab.bsky.social)
Preprint: doi.org/10.31234/osf...
Website: j-rohrer.github.io/marginal-psy...

25.08.2025 11:49 โ€” ๐Ÿ‘ 1007    ๐Ÿ” 288    ๐Ÿ’ฌ 47    ๐Ÿ“Œ 22

Pleasure and honour to have the opportunity to discuss some of the work we have been doing on over the last few years.

Thanks to @behaviour2025.bsky.social for the invite (and great conference), @asab.org for the funding and everyone who turned up to listen at 9am on day 5.

29.08.2025 10:25 โ€” ๐Ÿ‘ 6    ๐Ÿ” 1    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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Animal Behaviour from Exeter and Bristol, plus some of our alumni, went to @behaviour2025.bsky.social in Kolkata and had mountains of rice. @crab-exeter.bsky.social @bristolbiosci.bsky.social @uniexecec.bsky.social

27.08.2025 17:15 โ€” ๐Ÿ‘ 27    ๐Ÿ” 5    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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It was a real pleasure to have accidently been involved in Joe Wilde's (not here) paper published last week: doi.org/10.1098/rspb...

It has terrifying Bayesian Hidden Markov Models, important insights about dynamic sexual signalling, and a robot crab called "Wavey Dave"- what's not to love?

20.08.2025 08:53 โ€” ๐Ÿ‘ 4    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

BEHAVIOR IS THE WAY

07.08.2025 17:16 โ€” ๐Ÿ‘ 25    ๐Ÿ” 9    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
Five misunderstandings in animal social network analysis

๐Ÿ’๐Ÿ•ธ๏ธ New preprint! Confused about how to model animal social networks?

ASNA can be confusingโ€”but also full of opportunity. We break down 5 common misunderstandings in animal social network analysis and share solutions from behavioural ecology, anthro, stats, & network science. Hope it helps!

A ๐Ÿงต

04.08.2025 16:21 โ€” ๐Ÿ‘ 47    ๐Ÿ” 23    ๐Ÿ’ฌ 2    ๐Ÿ“Œ 3

I learned a lot working on this new paper with this group of network scientists, sociologists, anthropologists and behavioural ecologists. We're hoping it helps anyone who feels (understandably!) lost in the animal social networks weeds.

06.08.2025 14:39 โ€” ๐Ÿ‘ 26    ๐Ÿ” 8    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Loved listening to this discussion, and so pleased our research on the gorillas monitored by @savinggorillas.bsky.social, led by the fantastic Vic Martignac is resonating with so many!

06.08.2025 11:01 โ€” ๐Ÿ‘ 5    ๐Ÿ” 3    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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โ€ชCome join us at the @asab.org Winter Conference 2025: how sensory info affects behaviour.

15th & 16th Dec, abstracts due end Aug. More info and registration asabwinter.github.io/2025

Co-hosted with @jtroscianko.bsky.social and Innes Cuthill

29.07.2025 16:50 โ€” ๐Ÿ‘ 24    ๐Ÿ” 11    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
Comic. [two people in labcoats look at body pierced with blade draped over bench] PERSON 1: We found him lying uncomformably on the lab bench. I wonder if the iron-rich intrusion in his back is related. PERSON 2 with ponytail: It could be clastic. Maybe a rift opened in his body, and the intrusive material later fell into the hole. [caption] The Geology Department Investigates Their First Murder

Comic. [two people in labcoats look at body pierced with blade draped over bench] PERSON 1: We found him lying uncomformably on the lab bench. I wonder if the iron-rich intrusion in his back is related. PERSON 2 with ponytail: It could be clastic. Maybe a rift opened in his body, and the intrusive material later fell into the hole. [caption] The Geology Department Investigates Their First Murder

Geology Murder

xkcd.com/3112/

09.07.2025 01:19 โ€” ๐Ÿ‘ 5771    ๐Ÿ” 874    ๐Ÿ’ฌ 50    ๐Ÿ“Œ 38
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Our #study finds that #male #dominance isn't the norm among #primates, and starts to unravel what shapes flexibility in intersexual power

paper (OA) https://www.pnas.org/doi/10.1073/pnas.2500405122

press release https://www.mpg.de/24986976/0630-evan-beyond-the-alpha-male-150495-x?c=2249

08.07.2025 13:55 โ€” ๐Ÿ‘ 75    ๐Ÿ” 50    ๐Ÿ’ฌ 3    ๐Ÿ“Œ 2
5-panel comic. (1) [teacher with long hair next to whiteboard] TEACHER: Iโ€™m supposed to give you the tools to do good science. (2) [teacher addressing students] But what *are* those tools? Methodology is hard and there are so many ways to get incorrect results. What is the magic ingredient that makes for good science? (3) TEACHER: To figure it out, I ran a regression with all the factors people say are important: [embedded list in sub-panel, cut off at end] Outcome variable: correct scientific results. Predictors: collaboration; skepticism of othersโ€™ claims; questioning your own beliefs; trying to falsify hypotheses; checking citations; statistical rigor; blinded analysis; financial disclosure; open data (4) TEACHER: The regression says two ingredients are the most crucial: 1) genuine curiosity about the answer to a question, and 2) ammonium hydroxide. (5) STUDENT: Wait, why did *ammonia* score so high? How did it even get on the list? LONG HAIR: ...And now youโ€™re doing good science!

5-panel comic. (1) [teacher with long hair next to whiteboard] TEACHER: Iโ€™m supposed to give you the tools to do good science. (2) [teacher addressing students] But what *are* those tools? Methodology is hard and there are so many ways to get incorrect results. What is the magic ingredient that makes for good science? (3) TEACHER: To figure it out, I ran a regression with all the factors people say are important: [embedded list in sub-panel, cut off at end] Outcome variable: correct scientific results. Predictors: collaboration; skepticism of othersโ€™ claims; questioning your own beliefs; trying to falsify hypotheses; checking citations; statistical rigor; blinded analysis; financial disclosure; open data (4) TEACHER: The regression says two ingredients are the most crucial: 1) genuine curiosity about the answer to a question, and 2) ammonium hydroxide. (5) STUDENT: Wait, why did *ammonia* score so high? How did it even get on the list? LONG HAIR: ...And now youโ€™re doing good science!

Good Science

xkcd.com/3101/

12.06.2025 20:28 โ€” ๐Ÿ‘ 3522    ๐Ÿ” 628    ๐Ÿ’ฌ 24    ๐Ÿ“Œ 33

๐ŸšจAnyone want a job?๐Ÿšจ
We have two #postdocs up for grabs! ๐Ÿงช
- cell developmental biology/#evodevo/#neuroevodevo
- bioinformatics and molecular biology
Both working on brain evolution in Heliconiini butterflies
Details below! Please repost ๐Ÿ™ 1/n

04.06.2025 09:51 โ€” ๐Ÿ‘ 67    ๐Ÿ” 96    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 7

Thanks to the editors and reviewers for their support, comments and forbearance over the years (!, I might have underestimated how my first couple of years of teaching would impact my time to respond to reviewers...)

06.06.2025 10:14 โ€” ๐Ÿ‘ 2    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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Using this method we were able to estimate the lifespans of 32 Female and 33 Male species of toothed whale. Data and methods in these R packages:

github.com/samellisq/ma...
github.com/samellisq/ma...

06.06.2025 10:14 โ€” ๐Ÿ‘ 2    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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In the paper we develop Bayesian methods to infer the underlying mortality function of toothed whales from age-structured data, while carrying through potential sources of error into the final estimates.

06.06.2025 10:14 โ€” ๐Ÿ‘ 2    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

@samellisq is following 20 prominent accounts