Poop happens! Fecal matter is the natural biological excrement of the digestive process, but did you know that one of the most sought after specimen samples is actually an animal’s number two? Not only is scat important in tracking animals in the wild, it has been something that gets scientists to scratch their heads and come up with many ways to gain biological data. Fecal matter has been studied for various reasons such as diet analysis, hormone analysis, and even used as data in conservation studies. While it is considered gross, stinky, nasty, and disgusting, it is also considered stinking cool because it provides a wealth of information about an animal.
What can Scat tell us?
Scat, also known as droppings or dung, can tell us a lot about an animal. From observing scat, scientists can see physical evidence of what the animal eats and depending on the form, if an animal is healthy or sick. Scat is often used as indirect evidence that an animal is in a location. It can be used for conservation efforts such as identifying diet changes, change in prey consumption, and unfortunately even the rate of pollution. Animals can be found with all sorts of things from plastic to strings in their fecal matter if they are in a polluted area. Here is a link to a scat identification key if you ever wondered what kind of animal left those droppings? (http://icwdm.org/Inspection/Identification%20Key%20to%20Scatdferraro.htm).
Fecal Matter Provides Insight on Physiology
Scat can also give us insights to the physiology of an animal. Many zoos keep fecal samples from their animals for many reasons. Fecal matter can be examined for the phosphorus or nitrogen content. Animals help to spread these nutrients. No surprise that these are two nutrients found in fertilizer. They may use it in research to monitor the animal, or they may use it for certain tests to determine physiological answers such as if there are any parasites present, if there is a bacterial infection, determine the normal flora of the digestive tract, or what are the current hormone levels of a female in estrus. Poo can even determine if an animal is male of female based on hormone levels and other physiological markers.
Fecal samples have been crucial in hormone research and the data has been used in many breeding programs to determine when an animal is ready to mate. While hormones levels can be determined from blood, urine, and even hair, it is easily determined by analyzing fecal matter. The advantage is that scat is easily accessible in the wild or in human care. There is no harm or stress on the animal and all animals poop. The St. Louis Zoo’s endocrinology lab, for example, has tested nearly 42,000 stool samples in their 20 year history. They have tested samples from over 60 species at 150 different zoos. The Brookfield Zoo and the National Zoo are the only other two US zoos that accept outside samples (http://www.stltoday.com/news/local/education/st-louis-zoo-is-serious-about-poo/article_928f88c2-b477-5b03-8b05-b622ed7af82e.html). Most zoos only analyze samples form their own animals.
From these samples, researchers, keepers, and Veterinarians can test for progesterone levels, estrogen levels, testosterone levels, Luteinizing hormone, Gonadotropin, and more. It is important to collect fresh fecal matter because hormones degrade over time. Some of the tactics to identify whose poo is who’s include adding glitter to the animal’s food so that the desired sample will be sparkly poo. It’s not exactly a great smelling area of research, but keeping the fecal matter semi-frozen can reduce the pungent odor. Once in the lab, alcohol is added to the fecal sample to separate hormones from the poo.
Genetics and Poo
Not only is collection of fecal matter important in identification and understanding the physiology of an animal, it is also important when considering genetic diversity. DNA (the basic genetic material of all animals) can be found in excrement, dead skin, or hair, just to name a few. Scientists can create DNA barcodes for animals based on unique genome types or DNA fingerprints (https://uanews.arizona.edu/story/saving-wildlife-with-forensic-genetics). For example, Indian biologists from the Center for Cellular and Molecular Platforms, Center for Wildlife Studies,National Center for Biological Sciences, and Wildlife Conservation Society have developed a novel way to identify species, sex, and individuals from carnivore scats using a genetic approach. They can identify species and even individuals of tigers and leopards without even looking at the physical features of their scat (DOI 10.1007/s12686-014-0371-9). Using this data, scientists can make crucial decisions to move some animals with a high genetic diversity and translocate them to areas of low genetic diversity.
When All of the Poo is Gone
With extinction risk and the connectedness of nature, the loss of a large animal can have a detrimental effect. Extinction is very real and we are losing more and more species every year. Some of which we have never identified. Large animals are especially crucial as they are often not only an apex predator or herbivore, but also a keystone species. Large animals are especially important in the distribution of nutrients especially given the amount that they defecate. They help to fertilize vast areas of land and sea. Large free-ranging animals also move great distances to spread nutrients. There are less large free ranging animals than there once was on the planet. There are a lot of large free-roaming animals that have been fenced in such as cattle, which don’t move across the vast landscape to spread needed nutrients.
While this is more widely seen on land, there are large ocean animals that equally contribute to their ecosystems much in the same way as land animals. For instance, whale populations are declining, and their contribution to the spread of nutrients are subsequently far less than what they once were. Scientists estimate that whales contribute only 23% of the phosphorus that they once contributed (ttps://www.washingtonpost.com/news/speaking-of-science/wp/2015/10/26/as-large-animals-disappear-the-loss-of-their-poop-hurts-the-planet/). This is why it is important to restore animal populations before it is too late. Many people don’t think about nature in the true cycle form. Nature, while complex, can be simplified to a system of cycles and webs. The problem is that if you disrupt an array of the cycle or a web, it has effects up, down and all around so that many animals that don’t even directly interact with the missing link will feel the effects from the loss of that species. We need to understand the entire system in order to understand what needs to be done to fix it.
While poo seams gross to most people, to a scientist, it is an information gold mine. Not to mention that it is something the animal has left behind and it does not cause the animal any stress to collect. Over the years the use of fecal matter has become more and more important when studying biodiversity and developing plans to increase diversity in some populations. The information that fecal matter holds is important in monitoring hormone levels and measuring the loss of biodiversity. So the next time you think that poo is gross, remember the wealth of information that it can provide and the hope that it can provide to conservationist trying to save a species from the brink of extinction.