Hi all.
I hope to run a basic robust design model for my capture-recapture data - 3 primary occasions (7 months apart), of 10 secondary occasions (daily). I am interested in determining survival, emigration and immigration probability between the primary occasions. I have run Huggins robust design models for three movement models: no movement, random movement, Markovian movement.
However, I am concerned by odd standard error estimates. I am aware that, given confounding factors, that odd estimates are to be somewhat expected. The standard errors range from 0 to 100+ - some examples are below.
Does anyone know why such large standard errors are estimated and whether this precludes the use of robust design for my data? My initial thought was a limitation due to only 3 primary occasions, but I have read empirical and theoretical papers that show 3 primary occasions suffice (although is the minimum to be used). I have read the manual and other relevant papers back to back and many times over in search of answers.
Any help would be MUCH appreciated. I have happy to provide the encounter histories if it would help.
Many thanks,
Lauren
Random movement model
Parameter Estimate Standard Error Lower Upper
-------------------------- -------------- -------------- -------------- --------------
1:S 0.9999999 0.3791123E-03 0.4543176E-301 1.0000000
2:S 0.3544058 152.27742 0.3053694E-308 1.0000000
3:Gamma'' 0.8593845 0.0540323 0.7178485 0.9362289
4:Gamma'' 0.5952970 173.88869 0.8182420E-308 1.0000000
No movement model
Parameter Estimate Standard Error Lower Upper
-------------------------- -------------- -------------- -------------- --------------
1:S 0.2865718 0.0727603 0.1666401 0.4465657
2:S 0.2328974 0.0602238 0.1355532 0.3702092
3:Gamma'' 0.0000000 0.0000000 0.0000000 0.0000000 Fixed
4:Gamma' 1.0000000 0.0000000 1.0000000 1.0000000 Fixed
Markovian movement model
Parameter Estimate Standard Error Lower Upper
-------------------------- -------------- -------------- -------------- --------------
1:S 0.6567963 0.0000000 0.6567963 0.6567963
2:S 0.6350457 0.0000000 0.6350457 0.6350457
3:Gamma'' 0.7859071 0.0000000 0.7859071 0.7859071
4:Gamma' 0.6012360 0.0000000 0.6012360 0.6012360