[R-sig-ME] glmm question

[Joaquín Aldabe]

Hello, this is Joaquín Aldabe from Uruguay. I´m trying to model shorebird
counts (Buff breasted Sandpiper, BBSA) with glmm (using lme4 package),
using continuous variables (grass height, field area, forest cover) and one
factor variable (presence/absence of other shorebird species: American
Golden Plover, AMGP). I sampled 19 fields during three years in December.
I´m interested in identifying predictors correlated with BBSA counts. I
used Year as a random effect as I´m not interested in Year as a fix effect
and because fields were counted three times (pseudoreplication).

The model doesn´t converge, and the output showed that the factorial
variable has not a significant effect. This is weird as in every field I
observed the Buff breasted Sandpiper I also observed the other
species. When I take AMGP out, the model runs ok.

This is the model I´m trying to run:

mysub3.3<-glmer(BBSA~Grass_height+Field_area+Field_enclosure_700m+Grass_height*Field_enclosure_700m+fAMGP+(1|fYear),family="poisson",
data=mysub3.2)

continuous variables were scaled.

I can send de data frame if somebody is interested.

Thanks in advanced for helping me on my master thesis.

Cheers,

Joaquín.

-- 
*Joaquín Aldabe*

*Grupo Biodiversidad, Ambiente y Sociedad*
Centro Universitario de la Región Este, Universidad de la República
Ruta 15 (y Ruta 9), Km 28.500, Departamento de Rocha

*Departamento de Conservación*
Aves Uruguay
BirdLife International
Canelones 1164, Montevideo

https://sites.google.com/site/joaquin.aldabe
<https://sites.google.com/site/perfilprofesionaljoaquinaldabe>

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