Wilson's Snipe, #176, Data, and Placobdella ornata video

#176

Sunday the total number of turtles in the Dairy Drainage grew to sixteen with the capture of number one hundred and seventy-six, a large female. She was free of leeches but missing a toenail. This very dour turtle had a few remains of a crayfish in her stomach and was otherwise unremarkable.

The most remarkable event is that I began doing some quantitative analysis of my data. One of the interesting things to do is look at numbers from different perspectives. For example, when I compare the total number of samples on a month-by-month basis, it appears that July is remarkable. However, if I factor in the total number of days I trap compared to the results I get then May is remarkably higher in success. Specifically, I get more turtles and a larger variety of stomach food resources in their stomachs in this month. Further, even though I am part way through August and the total number of samples is low, my results match those of June and July.

Interestingly, I often think I am less interested in numbers when compared to colleagues who are doing theoretical research, but that is clearly not the case. I am surprised how automatically I began playing with the data and creating charts when I wanted an answer about my trapping success rate. Even more shocking is the fact I automatically gather data and create table as I work - without even thinking about it. I suspect this is the sign of a true analytical person - my friends and family will not be shocked.

The above display of the data shows that in May I get more stomach content samples with less effort. Further,  regardless of the amount of trapping effort I put forth the results are largely proportional between the other months. For example, in June and July I have set out traps more often compared to my work in August that is still ongoing. However, the success rate stays the same. To see the total trapping effort by month see the table below.

In this table it looks like the month of July is most productive because I have more samples and August is less productive. However, the previous table is a more accurate way to display the data. It is an example of one of the most confounding things about doing research - how to accurately display the data. As you can see here, I am showing the data in both forms rather than "cherry picking" the results that please me. It is more honest to display all the data and assess if my conclusions seem reasonable. 

Above is a preliminary summary of food items I found in stomach content samples. Note that there are two non-food items, thereby making the title inaccurate. Plant and substrate material (soil and gravel) are listed as by-catch; meaning they were caught while the turtle was in the process of capturing prey.

Placobdella ornata - the turtle leech

Next, as promised a video of Placobdella ornata the freshwater turtle leech and a close up of number one-seventy five’s rear leg where it was holding on. These simple elegant creatures fascinate me.

Number 175!

A self-portrait of the bicycling biologist ready to take #175 home.

AFTER FOUR DAYS AND NINE HOURS OF BICYCLE RIDING I FINALLY CAUGHT A TURTLE!

This male Western pond turtle is sleeping quietly just before I administer the reversal medication status post gastric lavage. As you can see the turtles a quite relaxed and not aware of the procedure. Ten minutes later it was wide awake and twenty minutes later he was ambulating.

Here he is twenty minutes later moving his foot (left) and smiling.

The cool thing is that this is another turtle that I have not caught before and that means there are 13 turtles in this drainage ditch that is about 100 meters long. So, it should be easy to catch them, or so it seems. After spending three hours with my radio telemetry unit I found out they are living in the dense bulrushes where the crayfish and Odonate naiads are feeding. 

After this year's work of examining the ecosystem for food resources I can identify discrete  body parts and determine what they ate. The picture below shows what I face when I am examining stomach contents. Two years ago it was baffling, last year somewhat confusing, but now it is an interesting forensics like exploration. 

Odonate tissue near the end of
the digestion process.

Certainly this kind of work is not for everybody. However, I am fortunate that body fluids and parts do not bother me. It allows me to do this kind of work and also helped me earn my way through university doing nursing, ER, and Trauma Center work. 

One interesting thing in the photograph below is that I find pieces of the bank soil and vegetation their food resources cling to. Many researchers in the past mistakenly thought the Western pond turtles eat these items. I know this is the substrate the prey live on and that turtles take a big bite and get the prey and anything nearby. Often scientists like everybody else are myopic and their focus it too narrow and this leads to mistakes. 

The light brown is part of a plant and the darker material is soil from the bank that is ingested.

That's it for now. Tomorrow a cool video of a leech and more.

A MONTH OF SUSTAINABLE RESEARCH

Today is the first day of my last month of research. Since I ride my bike and rarely use an automobile, I decided to take a better approach to my fieldwork in an urban setting. It would be easy to climb into my automobile and drive to my study site BUT I am making the choice to ride my bike. I have little patience with folks who talk about sustainable living but go no further AND make excuses for not doing so.

If you think about it, I get much needed exercise and save fuel – nothing is better! Most of all, it demonstrates I follow words with deeds.

And, yes it took three and one-half hours and I was hot and sweaty. Nonetheless, as you can see, I was smiling and having fun as usual!

Cheers,

Nicole

DUCKLING WOOD DUCKS, OTTERS, AND A WEEK OFF

Sometimes they do their own thing

 at other times we do things together

and every now and then ... it's the same but different?

SAMPLING FOR AVAILABLE FOOD RESOURCES

Even though Western pond turtles forage in the water, the aquatic ecosystem has strong links to the adjacent terrestrial ecosystem. Further, it is common for a terrestrial insect to land in or near the water and when a turtle sees it, they eat it. Therefore, I am sampling both habitats, as you can see from my previous posts that include pictures of terrestrial insects (i.e., beetles and grasshoppers). I use brush net sweeps along the bushes and bankside vegetation to sample the terrestrial ecosystem. In the aquatic ecosystem, I use a D-net to pull samples from the emergent vegetation and the substrate (creek bottom landscape). To do this I jab the net into the sample area and then with a twisting and jabbing motion I stir the area up and then withdraw the sample. My other tool is activity-traps that I fashion from plastic soft and juice drink bottles. I put a small amount of bait, usually sardines, inside of them to attract carnivores and scavengers, which largely encompasses the feeding habits of all the organisms living there. It seems that nobody turns down a free meal!

The direct impact on my research is that I can readily identify organisms or parts of them I find in the stomach contents of Western pond turtles. In addition, it gives me peripheral information such as the variety of available food resources and its seasonality. In the future, I want to examine in grater detail, because it is helpful when measuring the effects of human activity on these ecosystems.

YIKES, THE OTTERS ARE BACK!

The "calling cards" or scats left behind by otters are useful tool for me and let other predators in the area know they are present. 

Otter feces rich in crayfish parts.

Generally, North American river otters (Lontra canadensis) seem to be largely absent from Santa Rosa Creek. Occasionally I see an occasional scat (feces), but rarely encounter them until near the end of July. When they move into the area to feed on crayfish, they are competing with Western pond turtles for the same food resource. The larger, faster mammal out competes the turtles for the most available food resource.

In addition, they also attempt to remove the punctured cans of sardines I put in turtle traps as bait. They dislodge the traps from their moorings, sinking them, making it possible to drown any turtle that is inside. To prevent this kind of incident I set out activity traps to discover if they are present during mid-July along the areas of Santa Rosa Creek I plan to work. These baited traps, filled with sardines, attract the otters and they drag them from place to place while trying to remove the sardines.

On July 20, 2012, I thought I heard otters foraging in the bulrushes, found scats (feces), and crayfish parts along the section of the bank I was planning to work. Because of this, I set out two traps to confirm my suspicions. The next day, I found them buried deep inside the emergent vegetation and bulrushes instead of being along the edge, a clear sign that otters are present. My final confirmation was hearing an otter yipping at me, as if to warn me off, as I approached the area to retrieve the traps.

In addition, they were working along a nearby bike trail I use for access to other sites. Hence, I took a week off, examined and compiled my data, and took some time to rest and gather my thoughts. Therefore, I did not add to the blog last week.

OVERVIEW AND METHODS

Early in May there were ten crossing the water

Hidden in plain view are two, maybe three - see if you can find them.

Yep, it's going to be duckling Wood Ducks for the next few days!

OVERVIEW

If you recall, I am developing a model for my research methods because of reading a wide variety of research and critiques of the methods for doing a diet and feeding ecology study. However, I did not discuss the reason for doing the research, its rationale. Throughout much of its range in Southern California and in Washington State the Western pond turtle is largely extinct. Much of this happened as land development, especially urbanization, spread throughout those regions. It is unlikely but possible this is a coincidence. Today the Western pond turtle Washington State gives it total legal protection and has partial protection in both California and Oregon. Because of disagreements in the scientific community and lack of evidence U.S. Fish and Wildlife are unwilling to give it endangered status. This is largely because there is no scientific information on its population size outside of areas where they are essentially missing. In fact, one agency decried the fact there is so little information that it makes it impossible to make an informed decision. Therefore, I chose to do research that avoids the major criticisms of diet and feeding ecology examinations, uncover some of the effects that may help explain their disappearance because of land development, and provide information for policy makers.

Consequently, I am examining the diet of Western pond turtles during the season they most actively feed, May through August. Further, I use activity traps to determine what food resources are available when I trap turtles. Consequently, many of my previous posts depict the various organisms they eat. Finally, I am choosing to tangentially investigate (e.g., as an aside) ways to inform citizens about my research (i.e., this blog). In addition, to see if my methods may be helpful to them, I am communicating by email or in person with city and county agencies making policies that affect the Western pond turtles living in the waterway. My goal in the future is to do similar research and spend more time examining the ecosystem in ways that may foster citizen awareness and policymaker decision making that promotes sustainable use of these resources.

THEN METHODS

After the overview and rationale for a research project, the next most important aspect is the methods I am using. Since my previous posts show some of the results of using activity traps, I will explain I make and use them. Then I will move on to trapping turtles, radio telemetry, and other processes such as gastric lavage and anesthesia.

Further, since this forum informal I will also cover other topics. For example, my current examination of the possible negative effects of RoundUp and its cousin pesticides I am doing for a colleague.

CHEMICALS, THE ECOSYSTEM, AND YOU

The following article excerpts reveal some of the possible negative effects of the pesticide, sometimes because of the interactions between various ingredients in it. The following is an overview that was published on the topic. Later I will publish excerpts from journal articles including the one reported in this article. 

Roundup Revelation: Weed Killer Adjuvants May Boost Toxicity (Bonn, 2005)

                 

 “Although the glyphosate-based herbicide RoundUp is generally thought to be less toxic to the ecosystem than other pesticides, concerns about its effects on human reproduction persist. In a study in Ontario, Canada, exposure of male farmers to glyphosate-based herbicides was associated with an increase in miscarriage and premature birth in farm families. Seeking an explanation for these pregnancy-related problems, researchers at France's Universite de Caen investigated the effects of the full Roundup formulation and glyphosate alone on cultured human placental cells The herbicide, they found, killed the cells at concentrations far below those used in agricultural practice.”

·      “Surprisingly, they also found that Roundup was at least twice as toxic as glyphosate alone. Virtually all previous testing of Roundup for long-term health damage has been done on glyphosate rather than on the full herbicide formulation, of which glyphosate makes up only around 40%. The remainder consists of inactive ingredients including adjuvants, chemicals that are added to improve the performance of the active ingredient. Roundup's main adjuvant is the surfactant polyethoxylated tallowamine, which helps glyphosate penetrate plant cells.”

·      “Polyethoxylated tallowamine is just being investigated but indications are that it has some remarkable toxic effects. Check out pub med and there is a hint. This kind of investigation should be done by any reputable scientist before using this chemical AND this points to the problems with the current system regarding the release of a chemical for use on food crops.”

·      “No one is sure how Roundup interferes with reproduction, so the team also tested whether it, like other pesticides, would disrupt the activity of aromatase (an enzyme that regulates estrogen synthesis) in placental cells. Aromatase activity was measured after 1 hour and 18 hours. The study showed that the effect of Roundup on cell viability increased with time and was obtained with concentrations of the formulation 10 times lower than those recommended for agricultural use. Roundup also disrupted aromatase activity at concentrations 100 times lower than those used in agriculture. The researchers suspect that the adjuvants used in Roundup enhance the bioavailability and/or bioaccumulation of glyphosate. How these findings translate into activity of Roundup in the human body is hard to say. The French researchers point out that serum proteins can bind to chemicals and reduce their availability and therefore their toxicity to cells. Nevertheless, the authors conclude that the demonstrated toxicity of Roundup, even at concentrations below those in agricultural use, could contribute to some reproduction problems.”

BIBLIOGRAPHY

Bonn, D. (2005). Roundup Revelation: Weed Killer Adjuvants May Boost Toxicity. Environmental Health Perspectives, 113(61), A404.

RoundUp herbicide, ducks and geese

RoundUp the herbicide that alters genes

A friend called me earlier today and needed me to collaborate on a comment he is going to make on a U.S. Navy environmental impact report. Specifically, they want to use RoundUp to knock down trees near the power lines in his community. Our local water agency here does not want to use it because of some problems that have come to light about it. In fact, I have been preparing some information for them on the topic - to support their unwillingness to use it. Even though we allow its use on food crops! 

You can Google it and find some things out but is largely non-technical.

 For example:

“Medical reports link exposure to glyphosate herbicides with short-term symptoms including blurred vision, skin problems, heart palpitations, and nausea. Studies have also found associations with increased risk of miscarriages, premature birth, non-Hodgkin’s lymphoma, and diabetes. Formulations in which glyphosate is combined with other ingredients can be more acutely toxic than glyphosate alone (6, pgs. 5-8). Monsanto, a major manufacturer of glyphosate-based herbicides, was challenged by the Attorney General of New York State for making safety claims similar to those now being repeated by the U.S. State Department. In an out-of-court settlement in 1996, Monsanto agreed to stop advertising the product as "safe, non-toxic, harmless or free from risk”.

“New York State's Attorney General has sued Monsanto for claiming that RoundUp is "safe" and "environmentally friendly."  This suit ended in a settlement with Monsanto in which Monsanto agreed to cease and desist from using these terms in advertising RoundUp in the state of New York.  Monsanto, while not admitting any wrongdoing, paid the state of New York $250,000 in settlement of this suit.  When Monsanto violated the first settlement agreement by advertising within New York that RoundUp is "safe," a second agreement was negotiated.”

I took this mural like photograph at a nearby urban lake when the Canada Geese (Branta canadensis) were sitting on their nests. They are so large bodied because they are herbivores and this is common for plant eaters because they need to eat a lot of food to get the nutrition they need. For some folks the by product of this diet (feces) is a problem when it is in their parks. However, the other waterfowl that would normally be there move out, largely because of human and pet activity in the water. Therefore, it is easy for me to be understanding and appreciate their presence.

So, I have two good reasons to be investigating RoundUp. Thus far, the claims that it is not safe because it modifies DNA and inhibits cell function and interferes with reproduction are true. I cannot post these peer-reviewed articles BUT you can email me and I will send the peer-reviewed information to you. One in particular is interesting because it is challenged and the author does an effective job of refuting the allegations. 

It is somewhat disheartening to discover that scientists who uncover these kinds of problems do not speak out. However, it is not surprising since few if any scientists are willing to study ethics. In fact, I am attending a two-year long seminar at U.C. Berkeley and one presenter, a bioethicist, was given the task of discussing this with cell and molecular biologists by the National Science Foundation - they refused to participate. 

THE LONG-JAWED ORB WEAVER

Sometimes ... nature speaks to me and I listen.

   And I make something ...

   more out of it - just for me.

THE EVOLUTION OF A PROJECT

... and the beauty of some non-natives  

Yesterday, I mentioned differential digestion rate and hinted that it is important. Now it is time to find out how considering it and other pieces of information shaped my methods.

Specifically, when I was first developing a proposal about doing a diet study I read a number of papers and many weighed and measured the volume of the items in the animal’s stomach. Also using these values, they made comparisons using age, size, and gender. It was easy to embrace the idea of doing this because allows me to report on my research results using quantitative methods. 

In addition to reading papers on turtle diets, I read ones done by ichthyologists (fish biologists) and ornithologists (bird biologists). Both groups have a long history of doing diet studies. One point they both discuss is that it is impractical to attempt to determine what percentage of the diet is a particular food resource or kind of food resources. This is because each food item has a different rate of digestion (differential digestion rate). In addition, turtles eat whenever food is available rather than on a schedule. Further, preserving the contents of the stomach in any preservative alters the weight and mass of some items but not others. For example, ethanol alcohol (a common preservative) dissolves fats, thereby reducing the mass of fats.

The only way I can reasonably discuss what foods make up their diet on a percentage basis is to lock them in cage (i.e., a zoo) and present them with a wide variety of food choices and measure what they eat each day. Of course, the minute you put an animal in an artificial setting its exercise and diet change.

Therefore, all I can do is portray what they were eating before capturing them. The next time I will tell will begin to explain what I am doing to add robustness to the research.

"Many weeds and ornamental plants have been here so long that the soil and the organisms in it are an ideal habitat for them. Because of this, many native plants cannot successfully live in these soils. In fact, many of the remaining native animals rely on these non-native plants. This is sometimes vexing for urban ecologists."