EBT Ecology/ Population Dynamics

[Tccarolina]

I read every article I can find on eastern box turtle populations, their decline, and the issues they face. Their natural history fascinates me. But one thing that stands out but doesn't seem to show up in the literature is the differences in climate north to south that they face in the wild, and its affect on their long-term survival.
Much of the research documenting steady declines seems to be in northern states; Maryland, Pennsylvania, Ohio, etc. But it seems they are far more numerous in the Georgia and the Carolinas.
It seems that they are much easier to find, and they are more numerous in the southern part of their range. Is this true? What I read on the internet is that people encounter box turtles much more frequently in Georgia, the Carolinas, etc, then up north. Also, collection still occurs in these states, and many of the individuals offered for sale are quite beautiful, suggesting the collectors are able to pick and choose the wild turtles they are selling.
It makes sense that survival would be easier in Georgia or South Carolina than in Pennsylvania or Ohio. A turtle reaches adulthood several years sooner, has shorter, much less harsh winters, tends to produce more clutches, and likely is better able to replenish body weight after a nesting season due to the longer growing season. It seems that a longer growing season would allow for more mating opportunities for a thinned population than would occur further north.
On the other hand, denser southern populations might be more frequently hit by disease, and southern populations might be harder hit by drought and hot spells (last August!).
Every time I hear about how removal of a couple adults from a local population might lead to a slow irreversable decline, I wonder if this is primarily true for northern populations. I wonder if the local wipeout in the Ohio river valley centuries ago would have occurred if the same pressure had happened in Georgia. And, would repatriation be more successful in the south than it is in Pennsylvania or Long Island.?

Or am I completely wrong? Are populations declining just as fast in the south as they are in northern states? Is anyone doing research on EBT's in the southern part of their range?

I'm not insinuating that collection might be sustainable or should continue in the southern part of their range; just that they seem to thrive better there.

Steve

 

[Saloli]

The populations in the area of New York and neighboring areas represent the northern limits of their range. The populations in Maryland and Virginia represent the appoximate middle of the north -south distribution of the species when you disregard the Mexican subspecies. They are very slow to reproduce generally 10+ years when they reach sexual on set. They are declining everywhere. There have been several studies done, unfortunately they are not available to the general public because they are published in professional magazines and such. As far as the climates in different states, they can't be grouped by state. I live in Middle Riverwhich, for example, is climactic zone 7 whereas just to the west of Baltimore City is zone 6. So generaly speeking if a turtle is from a population in say zone 7 the winter in zone 6 maybe outside of it's tolerance; though zone 5 would deffinitly be too cold. The same in reverse the summer may be too warm for a turtle from zone 5 if they are taken to zone 7. The question about repatriation generally speeking unless the turtles are from the immidiate area (few dozen meters) they will try to go back to their home. Though if taking about babies raised in captivity from the same population they may have a better chance at setting up a home range within the area they are released. Though if that was done they would have to be screened for parasites, viruses and such to prevent exposing the remaining population.

 

[Tccarolina]

That makes sense. . . I don't doubt they are declining generally everywhere. I would assume the urban centers and highly populated areas of southern states have declines similar to that of northern states. But what about the rural areas, and mountainous areas of the Appalachians? My guess would be that a large stretch of untouched woods in SW Pennsylvania has a box turtle population that is declining faster than an equivalent untouched acreage in western North Carolina, simply because the climate is more conducive to sustaining and rebuilding the population. Southern turtles reach maturity faster, are at less risk of winter kill, and can produce more offspring per year, simply because the climate is better.

 

[terryo]

Southern turtles reach maturity faster, are at less risk of winter kill, and can produce more offspring per year, simply because the climate is better.

I definitely would agree with this. Here in NY early in the am you can usually find a few Eastern's. I have never seen a high color one here, as the one's that are selling on the classified ads, or the ones that people post pictures of from Southern states. Most here are yellow in color, although I've seen some orange ones. I've never come across a high red in color. I love the black with high red on the face and legs....still searching for one of those. In forty years of living here, I've never seen a juvenal or hatchling in the woods here, although I've been searching.

 

[Saloli]

HeY Terryo look in the marshes edges of ponds fern clumps near water, the hatchlings spend a lot of time in the water until they take on the adult shape which is about their first season.