Wednesday, May 17, 2017

The Cotton Fields in the Sky ---Guest Post---

Catch up with Part I and II.

    A standard methodology for assessing Gopher Tortoise abundance across landscapes is to perform “line-transect distance sampling” (or LTDS). Using this methodology, a crew of three people walks in standardized, straight lines across a specified area and searches for tortoise burrows within a set distance to the transect. This methodology works well because tortoise burrows are very visible, with the large mound of sand in front of the burrow (called an apron) and the unique D shape of the burrow entrance. Once a burrow is found, the crew must determine whether the burrow is occupied (if there is a tortoise in the burrow), unoccupied but active (the burrow seems active with footprints, shell marks, etc., but no one is home) or inactive (it is clearly a tortoise burrow, but a tortoise hasn’t been in the burrow recently). To determine this status, we have a digital camera that is connected to a large hose with a scope on the end. The scope can be run all the way to the end of the burrow (think Roto Rooter), thereby enabling us to peer all the way into the back of the burrow (which may be more than 20 feet long).

    Most tortoise biologists have walked countless miles through some of the most beautiful as well as some of the most dreaded, thorny, buggy habitats this side of the Mississippi. During these extensive transect walks, a range of conversations are had, from what we will eat for lunch to the ultimate fate of gopher tortoise populations. I think we are usually optimistic about the latter conversation point. However, even the greatest optimism can give way to pessimism when we walk long distances and never encounter a single tortoise. Over the past couple of years, out of reluctance to accept that a tortoise could ever actually die, we jokingly would declare if we couldn’t find occupied tortoise burrows, that the animals must be out foraging in “the cotton fields in the sky.” Of course, an Elysian reference simply allows us to avoid the inescapable fact that the recent past has been Hell for tortoise populations. But the optimism is not lost.

    While my time has been relatively short in Alabama (just over five years), I think there are many reasons to be optimistic about the future for conservation in this state, and the southeast as a whole. And this is not optimism as seen through rose colored glasses, but is rooted in demonstrable, objective progress. The conclusion to this blog post is going to be an outline of but a few positive movements for conservation, and why, although we have certainly lost much of biodiversity to the cotton fields in the sky, we have reasons to be genuinely optimistic for the future.

    As I wrote in Part I of this series, gopher tortoise population stability is dependent upon adult tortoises surviving for decades, and remaining reproductively viable throughout this long lifespan. Because of this dependence on adult survival, even if adults are no longer being killed, we would still expect to see a lag in populations recovering from past exploitation. To put it another way- tortoise populations (and landscapes in general) do not immediately recover from past mistakes. When it comes to landscapes (and of course tortoises), slow and steady may just win the race. I think that much of the present absence of tortoises from many sites reflects this lag in response and to a lesser extent reflects current threats to adult survival.

Many practices of the past that imposed these significant sources of adult mortality have either been completely eliminated, or nearly completely eliminated. As I have already described, human predation of adult tortoises was common through much of the twentieth century, and this has generally ended. A result of legal protection and the abundance of readily available and cheap food sources, human tortoise consumption is nearly nonexistent today. So thanks, McDonalds.

    An additional detrimental practice to tortoise populations, the gassing of burrows to collect rattlesnakes, has been outlawed in Alabama (more here from the blog on tortoise gas) and across the southeast. This destructive practice was common across the region, and it certainly accounted for significant losses to adult tortoise populations. While this practice is not likely eliminated, it has certainly been reduced over the past decade, and will continue to die out.

    My optimism in not only rooted in the snuffing out of many detrimental practices. In fact, significant gains have also been made to restore and conserve high-quality habitats for biological conservation. Numerous governmental and non-governmental organizations currently operate to restore and protect longleaf pine ecosystems and the flora and fauna inhabiting these systems.

The Natural Resources Conservation Service (NRCS, a branch of the US Department of Agriculture) had a $10.6 million dollar initiative in 2016 to restore and manage Longleaf Pine forests across the historical range in the southeast (click here for details and how you can be involved). This program began in 2010 and has been successful at partnering federal funding with private landowners to incentivize and support longleaf pine conservation measures. Since 2010, the NRCS, together with non-governmental organizations such as the Longleaf Alliance and The Nature Conservancy, have grown Longleaf Pine forests in the southeast from 3 million acres to more than 4 million acres. There is great reason to believe this number will continue to grow.

    In the state of Alabama, great progress has been made by the Alabama Department of Conservation and Natural Resources to secure large blocks of land for conservation, with an ultimate goal of restoring and managing longleaf pine ecosystems (checkout Alabama’s growing WMA additions). I have had the opportunity to sample gopher tortoises on some of these state-owned lands, and there are great reasons to be optimistic. Some of these sites have in-tact longleaf pine sand ridges, including gopher tortoises and diverse, native plant and animal communities associated with this imperiled ecosystem. Additionally, the US Forest Service has been pro actively restoring and managing Longleaf Pine ecosystems across major tracts of land in the southeast.

    It has been suggested that conservation is one of the most depressing fields in which a biologist can choose to work; a good day in conservation is either bringing back what was lost, or preventing the loss of something not yet lost. While these facts may be true, I disagree that the field is depressing. I believe we are at an inflection point in time. We are at a point in which we have acknowledged the unsustainable mistakes of the past and turned to practices that sustain biodiversity into the future. Because of this unique time, conservation is more exciting than ever. We have the present opportunity to see positive change happening all around. And this change is more than merely “feel good” aesthetic change. It is change rooted in saving what we know to be good, not only for ourselves, but for future generations.

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