Free stats help for MPhil student with glmmTMB on ecological data

General
1

Hi everyone,

I'm an MPhil student in ecology working on a thesis involving bird abundance data. I'm using the glmmTMB to fit zero-inflated negative binomial models, and I'm currently struggling with model validation and interpreting results.

Here's an example of one of my models:

model5a <- glmmTMB(
Count ~ Species + Temp + Wind +
(1 | Location) + (1 | Year),
family = nbinom2,
data = Mastersheetweb
)

  • The data are count-based and zero-inflated.
  • I suspect the model is overdispersed, but I’m not sure how to validate this properly.
  • I’d appreciate help with residual diagnostics and how to interpret the output meaningfully for my write-up.

In return, I’m happy to:

  • Provide a testimonial or acknowledgement in my thesis.
  • Offer data access (e.g., for teaching or examples).
  • Share feedback on your resources, or help edit ecological/academic writing in return.

If you’ve worked with glmmTMB, especially in applied ecology contexts, I’d be very grateful for your advice.

Please dm me if you'd be happy to help, thanks.

2

I am sure there are people who will be wiling to help from this group. However, you might also like to join the R mixed effects models special interest group. This group has some of the best and brightest in the world of mixed effects models (including those using glmmTMB) who are willing and helpful. There are also quite a lot of students like you who may be able to assist. The link is:

https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models

See you there, perhaps.
Stephen

3

Many thanks for your response, Stephen, I'll join it now.