Here is a question i hope someone may have some insights for me.
I am in the process of starting up a long-term project that involves
rodent demography. I switched from a grid-based to web-based after
reading Parmenter et al 2003 (Ecol Mono.). Now, I am wondering about
estimating demographic parameters (e.g, surviorship).
The current design is as follows:
1. Web-based design (10 traps at 10m spacing with 12 radial lines, with
4 traps at the center of the web = 124 traps total). I have been running
the grids for 5 consective nights, marking each individual animal.
2. The grids are being sampled between 3-5 times a year.
Can I use MARK (e.g, CJS, Prandel) to estimate demographic parameters
with this web-based design, or would that violate any assumptions (i.e.,
each marked animal has the equal probablility of being recaptured)?
THE BIG QUESTION BEING: If i am interested in demographic parameters
(particularly in a comparative sense between certain grids), as well as
density - is it better to use a grid-based or web-based design?
any insights would be excellent. thanks!
C. Josh Donlan
Department of Ecology and Evolutionary Biology
Ithaca, New York 14853-2701
"Nearly any dedicated curator would take a bullet for the last
impregnated dodo" S.J. Gould