Saturday: 16 June 2012
This first half of June has been very cool, with temperatures peaking in the lower 80s most days. We had three inches of rain last week. It’s been quite a turn around since our very warm, dry spring.
Though there may be a reduction in turtle activity over the last two or three weeks, it might not be as much as I was estimating earlier in the week.
I ran across this two for one presentation on Thursday.
The male on top isn’t having much success. The female has closed up completely, and if you look carefully at the male’s right rear leg, you’ll see that it’s been caught in her shell. Oops!
He can’t actually climb down, not without ending up on his back. Not only that, but since he can’t get his leg out, he also can’t withdraw into his own shell. What a mess! What part of “no” do you think he didn’t understand?
Those were two new turtles, never before seen, and there has been an influx of new turtles into the initial study area over the last few weeks. You can see it in the rise of population numbers from the last week of May onwards:
That’s a plot, by the way, of the estimated population size based on two ways of handling mark and recapture data. The numbers along the x-axis are just the turtle encounter numbers (I’ve encounted 42 turtles so far this season).
The population size estimate fluctuated wildly for the first 15 encounters, or so, and then it stabilized at around 40 turtles at the end of April. At the end of May, the population estimate started to rise again, and I think this is a real result. Of the seven study area turtles I’ve seen since May 29, four have been new and all have been female (the other three have been seen before, this year). No males until Thursday, and this one doesn’t count since he’s in the new study area and can’t be included in the population size estimates until next year.
So I’m thinking that there might be migrations of mainly females into (and perhaps) out of our study area. Given the time of year it might be due to a search for nesting sites. If this is so, then I’d expect that in a few days or weeks I’ll stop seeing new females, and may not be seeing any of the last four again as they do their thing and then leave.
(This might be the first of two well defined migrations of box turtles during the active season. You might recall that last October I saw something similar, a sudden increase in the number of turtles I’d never seen before. At that time I speculated that turtles searching for hibernacula might be returning to old favorite locations that they don’t inhabit during most of the active season. I’ll certain be watching for that again this year.)
Though there may be a reduction in turtle activity over the last two or three weeks, it might not be as much as I was estimating earlier in the week.
I ran across this two for one presentation on Thursday.
The male on top isn’t having much success. The female has closed up completely, and if you look carefully at the male’s right rear leg, you’ll see that it’s been caught in her shell. Oops!
He can’t actually climb down, not without ending up on his back. Not only that, but since he can’t get his leg out, he also can’t withdraw into his own shell. What a mess! What part of “no” do you think he didn’t understand?
Those were two new turtles, never before seen, and there has been an influx of new turtles into the initial study area over the last few weeks. You can see it in the rise of population numbers from the last week of May onwards:
That’s a plot, by the way, of the estimated population size based on two ways of handling mark and recapture data. The numbers along the x-axis are just the turtle encounter numbers (I’ve encounted 42 turtles so far this season).
The population size estimate fluctuated wildly for the first 15 encounters, or so, and then it stabilized at around 40 turtles at the end of April. At the end of May, the population estimate started to rise again, and I think this is a real result. Of the seven study area turtles I’ve seen since May 29, four have been new and all have been female (the other three have been seen before, this year). No males until Thursday, and this one doesn’t count since he’s in the new study area and can’t be included in the population size estimates until next year.
So I’m thinking that there might be migrations of mainly females into (and perhaps) out of our study area. Given the time of year it might be due to a search for nesting sites. If this is so, then I’d expect that in a few days or weeks I’ll stop seeing new females, and may not be seeing any of the last four again as they do their thing and then leave.
(This might be the first of two well defined migrations of box turtles during the active season. You might recall that last October I saw something similar, a sudden increase in the number of turtles I’d never seen before. At that time I speculated that turtles searching for hibernacula might be returning to old favorite locations that they don’t inhabit during most of the active season. I’ll certain be watching for that again this year.)
