Multi Method with Covariates

[scash]

Hi,

I'm using the single-season, multi-method extension in PRESENCE to compare 4 different survey methods to identify the most efficient technique for detecting each of 9 species of frog. When I've attempted to include detection covariates such as air temperature or rainfall I receive an error message that advises me to check the data file or the design matrix. I've entered the covariate data in the same manner as the detection data (so it should correspond) and set up the design matrix as for other types of analyses. Nichols et al. (2008) makes no mention of environmental covariates of detection and they stick to models looking at the effect of time and method on detection. Is it possible to include environmental covariates for detection probability so that I may compare how these covariates affect detection by the different methods? Or must this be done individually? If it is possible using the multi method extension, does anyone have insight into what I may be doing wrong?

Thank You,
Scott

[darryl]

Hi Scott,
It should all work. Can you fit simple multi-method models with no covariates? What a standard single-season models with covariates for your data set (don't worry if it doesn't make any sense, it's just to check there's nothing funny with your data file)? If these both work, then it could be some other problem with the code, but if you have problems with these, then there's likely something wrong with your data set.
Cheers
Darryl

[scash]

Thanks Darryl,

Yes, I can fit simple multi-method models with no covariates and I've just run a single season model with covariates for the data set and it worked as well, so perhaps something with the code as you say?

Cheers,
Scott

[darryl]

Are you running the latest version of PRESENCE? You can check under the Tools menu

[scash]

I was using version 4.3, then updated to 4.4 but covariates are still not working

[jhines]

Hi,

Sorry for jumping in late, but were you able to find out why your model with covariates didn't work? If not, I'd be happy to diagnose the problem if you send me the latest zipfile in your project folder.

Jim