This week I am collecting the herp cover boards we set out over a month ago. We have completed our sand skink assessment and it is now time to remove the boards. Unlike when I was checking them, now I am not raking the soil underneath. Nevertheless, I am seeing far more critters now than when doing the actual survey, and I think it is due to mainly to the weather.
It has become much wetter now that summer afternoon thunderstorms are everyday, several-times-a-day events. This has created conditions under the boards moister than during the spring survey, which in turn has apparently selected for mesic ground dwellers based on my observations.
I also suspect that the longer the cover boards stay out, the more herps they attract. First, the herps have to find the boards, and secondly the boards have to settle in and volatilize off some of their glue chemicals.
Another factor seems to be that particle boards absorb more rain water than plywood, swelling up and remaining cooler. Herps, therefore, do not need to burrow down to escape the summer heat, so they stay on top of the sand where I can easily see them. Therefore, even though I do not like particle board, that's what I am taking back to plant all over the woods of a friend.
Numbers of anole lizards (Anolis carolinensis and sagrei), scrub lizards (Sceloporus woodi) and roaches (3 species) are down, so I suspect the moister conditions select against them. On the other hand, since numbers of snakes are up, perhaps they are just getting eaten?
Yesterday I caught a juvenile coachwhip (Masticophis flagellum) and a milk snake (Lampropelits triangulum). I thought that was a pretty good day but then today I caught another three juvenile coachwhips and four milk snakes! When was the last time you caught four milk snakes in a day? Perhaps this is a common occurrence in the herpetological world?
Ordinarily I would not catch the snakes, but today I was afraid they would be snagged by a hawk if I left them out in the open, so I grabbed each of them and tossed them into cover where hawks could not easily see them. I am also seeing daily maybe three dozen southern toads (Bufo terrestris), a few narrowmouth toads (Gastrophryne carolinensis), and plenty of six-lined racerunners (Cnemidophorus sexlineatus). Saw a skink today that was probably a five-lined skink (Eumeces inexpectatus).
Spiders have increased hugely in number under the boards. They are underneath nearly every board. There is a woolly black web spinner that I think is a scrub specialized species, which I want to look up but not tonight. The second commonest spider is the black widow (Lactrodesmus sp.). I have undoubtedly seen more black widows yesterday or (not and) today than I have seen over the rest of my life! And they all ran away from me, thanky.
In case you are wondering, I checked appx 400 boards daily during the spring and am removing appx 500 boards daily now. If you cipher out the math it might seem that the rate of observations is low. Remember, however, that the habitat has a carrying capacity, and therefore it is possible that a greater density of boards would produce few or no more herps.