Snakes Hang Out in Douglas-fir Forests Too

I’m back in Sonoma County, California doing some fieldwork. One last season, mostly to pass the reins to another PhD student. It got me thinking about my last trip out in 2014, so here is a tale from the field.

We were on the lookout for snakes. Western rattlesnakes to be more exact. Doing fieldwork in Sonoma County, California these are probably the biggest immediate danger, next to twisting an ankle or fracturing something in a fall. A bite is unlikely to be fatal if you stay calm and get to help in a reasonable amount of time, or so I’ve been told. Much worse is the possibility of contracting Lyme disease from a tick bite. Fortunately, in five seasons of fieldwork I had never had to find out. So there we were, well off of any trail except what deer or rabbits (or snakes!) might use, traversing a hillside with clump grass and mixed chaparral vegetation. That means often dense, impassable shrubs with stiff, sharp branches at face height. Okay, that’s not what the vegetation classification means, but we make up our own meanings while cursing our way through. Rattlesnake habitat. Looking carefully before placing a boot down while hanging on to the branches threatening to whack you in the face on a steep hillside, while it’s 75 degrees F (or 45 and rainy) is hard work. Usually we’re doing both over ~7 weeks. Our vigilance seemed to pay off as we finished our scramble by exiting into a shaded, cool, soft, open, needle-carpeted Douglas-fir forest. The terrain flattened out, the understory dissappeared, the ground softened, and the temperature cooled.

The three of us stopped to catch our breath, and I told the others we were close now as I scanned down the hillside looking for the solar radiation shield that marks the center of each of our 200 plots. I knew we were within about 100 meters, and could probably just see that far, but couldn’t spot the site. I turned back around to see how the heavy breathing was coming along for the others. Joe and Kerri are standing about three feet away from me and starting to breathe a little more evenly. Then I see Joe point at the ground and say, “Kerri” on one of his heavy exhales. I follow his pointing finger, and there right next to Kerri’s boot, and I don’t mean nearby, I mean right. next. to. is a ~12-inch rattlesnake, stretched out long so that her boot is probably around the middle of its body. Kerri doesn’t follow Joe’s pointing finger, when he says her name she looks over at him instead. Kerri is the one who taught me about keeping a calm, clear head in the field, by example and some crazy stories. In an even voice (I think), I say “Kerri, there’s a snake right next to your right boot.” She looks down, calmly looks around to make sure she isn’t stepping into more danger, and takes a good large step or two away. Danger averted.

Now, often if you’re getting near a rattlesnake it starts rattling. They don’t really want to get into it with something that is so much bigger than them. Wasted energy on something that can’t be a meal. But this one had been silent. Upon closer examination this appeared to be due to recently having a meal, i.e. it had a distinctive bulge along the otherwise slender body. We were lucky. Out of the usual danger area we had relaxed, and even moved a little farther from the edge of transition from chaparral to Doug-fir forest, and one of us almost stepped on a snake. That was damn close. We gathered ourselves up, after a few pictures to document our encounter, started to make our way down toward the plot. I had taken about four steps and froze. Directly ahead in my chosen path, maybe 15 or so feet away was another rattle snake, and this one was no baby. Easily an inch in diameter and probably about three feet long. It hadn’t made a sound either. So, not that way.


The snake that we inadvertently got way too close to

One other thing about Douglas-fir forests: the trees drop their lower limbs as they grow. In addition to the ground being covered in needles, it is littered with sticks. Interestingly, these sticks and twigs started looking a lot like snakes. It was the longest 100 meters I have ever walked, Kerri and Joe following my path (perils of being the leader), and all of us playing “stick-or-snake?” the entire time.


Kerri & Joe coming up the trail after finishing the plot


Politics Invading Science?

I was reading this article from ScienceInsider, growing more appalled and frustrated when I came across this statement quoted in the article that is just terribly obviously false:

“In his written statement to ScienceInsider, Smith said only that “there are many grants that no taxpayer would consider in the national interest, or worthy of how their hard-earned dollars should be spent

Now, many who are better versed in writing, science, politics, and any slew of other related areas have demonstrated with better clarity the nuance of this debacle, but I am going to share my own thoughts anyway. I am pretty sure the scientists who wrote the proposals for these grants, the scientists who reviewed them, and the scientists who ultimately approved funding for them felt that they were worthy of being funded by the national coffers. Also, they are probably all tax payers.

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Our frontier is climate change

UPDATE: This link to recent research showing a link between human CO2 emissions and the increased water vapor in the troposphere — possibly causing a positive feedback to greater warming.

Last week one of the scientific contributors to the recently published IPCC (Intergovernmental Panel on Climate Change) ipcc_ar55th Assessment Report, who is also an alumnus of NC State. In addition to the associated prestige, the speaker found that the force driving many of the contributors to spend countless hours working on this assessment is the hope that our global population will become sustainable. To me, this means providing avenues for equity not just in this generation, but for future generations. So, what would we have to do? Well, we can start by communicating the facts, so here are some things I learned and what I think they mean.

1. According to the analyses in 5th Assessment,  there is a 95% certainty that humans have been the dominant cause of observed warming since the mid-20th century. To me this is incredibly important, a little bit terrifying, and yet gives me hope. This means that the global human population is capable of affecting the earth systems to a degree never before seen or realized. It means that we hold some power to influence global cycles, and we can use this knowledge and our incredible ability to forecast, innovate, and adapt to sustain and prosper our existence.

2. One of the most, if not the most, important earth cycle we are affecting is the water cycle. Human bodies are made up of about 60% water. Water that is fit for consumption is the one thing we cannot live with out – something that is seldom given a second thought in the developed world. We just turn on the tap and out it comes. Yet, we have with great certainty (95%) increased the frequency and severity of drought or precipitation events in different areas of the globe (keeping in mind that no single event is attributable to human-induced changes).

3. The increase in carbon dioxide emissions caused by human’s activities were identified as one of the major influences on the rapid changes in earth’s systems. Furthermore, even if CO2 emissions were completely stopped, the inertia would continue to carry changes into the future. It is not as simple as a single consequence of increased CO2 concentrations in the atmosphere, such as warming temperatures, but also higher CO2 concentrations in the oceans causing acidification faster than species can adapt. This means that the livelihood of everyone who depends on the ocean is at increasing risk going into the future.

4. These are some indications that we will continue to exceed (mostly unidentified) resilience thresholds, where the systems we are influencing will no longer be able to self-correct. Populations of developing countries have thus far born the brunt of the consequences, with >95% of deaths related to natural disasters occurring in these locations (I do not know if this included earthquakes, or other things not related to climate/weather events).

So, with a 95% certainty that we can potentially have some control over the intensity and severity of future risks to much of the global population, why not try and do something to prevent and mitigate that risk? As a disease ecologist, it is clear to me that the cost of preventative action (e.g. vaccines) is substantially less than trying to manage the likely severe consequences (e.g. disease outbreak).