Fresh Meat
9
posts
0
likes
I have nothing to say.
|
Post by victorgrant on Feb 1, 2018 6:10:50 GMT -6
Hello! I'm using two-species models to study species interaction. I have 73 sampling points, that have been surveyed 3 times. One of the species is very abundant but the other is declining. I have built 16 models testing different scenarios, with 2 detection covariates and two occupancy covariates. I've been having two issues. Firstly, two of the models don't converge (message: Numerical convergence may not have been reached. Parameter estimates converged to approximately 5.44 significant digits.). And a few others, although they don't show this message, the beta coefficient for the psiBa parameter is huge. Does anyone know why this happens and what I should do? Secondly, in models using covariates, PRESENCE output shows occupancy and detection estimates for each site. Is there any way of obtaining a single, average estimate of each parameter, for each model? Either using PRESENCE or by-hand? Also about PRESENCE, I have a doubt regarding the output file. When using two-species models, you have to enter presence/absence data for the two species in the same columns. From what I read, the program assumes the first 73 data for species A and the other 73 for species B. But in the output I have estimates for 146 sites. Is this normal or have I done something wrong when entering the data? Thanks I didn't find the right solution from the internet. References: www.phidot.org/forum/viewtopic.php?f=11&t=3491SaaS Promotion
|
|