Lack of fit after accounting for trap-dep in MS model

questions concerning analysis/theory using programs M-SURGE, E-SURGE and U-CARE

Lack of fit after accounting for trap-dep in MS model

Postby Teo Barracho » Tue May 08, 2018 5:15 pm

Hello,

I'm fitting multistate models with 3 reproductive states (non breeder, failed breeder and successful breeder) to 13 years of data on a seabird (2004-2017, with 2014 missing).

Testing for Goodness-of-fit with U-Care, I don't find any problem of memory (WBWA non-significant) nor transience (3G.SR and 3G.Sm non-significants) in the data. Concerning trap-dependence however, I find immediate trap-happiness (M.ITEC significant but M.LTEC non significant). This is not so surprising because the birds are monitored from a tower which is also one of their only nesting places on this island.
If I'm correct, one of the ways to treat trap-dependence is to split the capture histories and then to use a model with a time-since-marking structure on p. So that's what I did. However, when I look at the residual plot of this model [ Phi(state*sex*t) p(state*sex*t / state*sex*t) Psi(state*sex*t) ] on MARK, I still find a strong structure (see picture). This makes me think that there is still an excessive lack of fit.

[img][IMG]https://nsa39.casimages.com/img/2018/05/08/180508112024513990.png[/img][/img]

Do you think it is really the case and would it thus be irrelevant to start model comparisons from this model ? If this is the case, do you have an idea of how I could solve the situation ?

An interesting feature of my data is that trap-dependence only starts to be significant after some point (year 2011), so maybe there is a better way to account for trap-dependence when the phenomenon is not constant over resighting occasions.

Many thanks in advance,

Teo
Teo Barracho
 
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Re: Lack of fit after accounting for trap-dep in MS model

Postby Guillaume Souchay » Mon May 14, 2018 6:35 am

Hi Teo,

If you have any trap-dependence, it could be relevant to read how to treat it with the paper of Pradel and Sanz-Aguilar : Pradel, R. & Sanz-Aguilar, A.2012 .Modeling trap-awareness and related phenomena in capture-recapture studies. PLoS One, 7 : e32666
you can find if for free at http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0032666

it is often better to treat it directly in the states.

Regarding your study, are you sure of the states of each individual? if not, you may consider using multievent models.

Cheers,
Guillaume
Guillaume Souchay
 
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Re: Lack of fit after accounting for trap-dep in MS model

Postby Teo Barracho » Mon May 14, 2018 10:18 am

Hi Guillaume,

Thanks for your reply ! I take note that you recomend the multi-state approach to treat trap-dependence and I'll definitely use it.

Actually, I had already read this paper you recommend, but I decided to use the traditional method (the one of Pradel 1993) because I found it easier to implement. Moreover, I could see in Pradel and Sanz-Aguilar (2012) that they obtained the exact same results for both traditional and multi-state methods.

Just by curiosity, do you always observe "satisfying" residuals plots after accounting for trap-dependence (when of course it's the only deviation from JMV that you find in your (multi-state) data) ?

Concerning uncertainty on state assignment, I feel quite confident that the states are observed with very few error. Although I've never been on this field personally, people who went there assured me that it was exceptionally rare to observe banded birds nesting elsewhere than in the place from where they're monitored.

Thanks again for replying,

Cheers,

Teo.
Teo Barracho
 
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