The coverboards have all been placed, the t-posts are in the ground and cameras mounted, the traps are ready to be baited, 10-20 years ago half of the sites being monitored were restored with native perennial grasses…. we built it, but will they come?
Short answer: In droves.
April of 2014 was our first season of sampling across a wide range of vertebrate species at paired restored and control grasslands at four locations across the Central Valley of California. If you haven’t read the initial post about this project, it might be a good place to start. It is called: Wildlife Use of Native Perennial and Exotic Annual Grasslands: A Comparative Study.
We started by monitoring coverboards for reptiles, amphibians, and rodents; live trapping for rodents (mostly mice, with the occasional vole); and camera traps for both rodents (cameras face down towards non-toxic bait block attractants) and larger species (cameras upright about 2′ off the ground).
This first season we caught 768 rodents (496 unique individuals) in total in our live traps, which is a LOT considering we had 2,464 trap nights. That’s a capture rate of > 30%! At some locations, we had a capture rate of > 90%.
There were more rodents at control sites than restored sites within EACH of three locations. We were not able to continue trapping past Day One the fourth location in Esparto because ~ one hundred cattle were fenced into one of the sampling sites, and they kept knocking the traps on their sides – traps don’t work so well when they are sideways! Well – you live and you learn. Next time, we will communicate better with the land owners to ensure livestock are not present in the sampling sites for at least several weeks prior.
Coverboards were monitored at ALL locations, however, as cattle were not put into the fourth location until the end of the sampling month. That was pretty lucky because we found dozens of snakes, rodents and lizards utilizing coverboards, and even some Western toads (as well as some really large insects and spiders – watch your fingers!)!
Patterns of coverboard use mirrored live trapping results: rodents and snakes utilized coverboards at higher rates at the control sites than at the restored sites. It will be interesting to see if these patterns remain consistent in future sampling seasons.