Forensic ANTHROPOLOGY: Crime Scene Investigations
For this project we were assigned one of 3 different crime scenes in partners and had to solve the crime. Colleen made up these crime scene scenarios to be as realistic as possible. Crime scene 1 dealt with a man shot in his home. The case originally looked like a suicide as there were alcohol bottles and things surrounding the victim. Through blood spatter analysis, toxicology and DNA processing, it was determined that the man's wife and stepson murdered him because he was, among other things, abusive. Crime scene 2 involved skeletal remains found near a hiking trail. The remains belonged to teenager Nathan Herron, who'd been missing for around 5 years. The suspects involved were his Mother's current boyfriend, and a man named John Hannah who was in jail at the time the body was discovered. Hannah was supposedly mental, but had been overheard bragging to another inmate that he killed Nathan. Through DNA processing it was determined that neither of the two suspects killed Nathan, and the case was declared a cold case. Crime scene 3 was about a man found outside Animas who had been run over accidentally and the couple left the man there, unsure of what to do. I was assigned crime scene 2, and worked with my partner, JJ.
I enjoyed this project. It was a lot of fun learning to think like investigators and solve crimes. I've always been fascinated with forensic anthropology. I'm addicted to a show called Bones about a forensic anthropologist and FBI agent who solve crimes using some of the same techniques we learned how to use. I learned all about DNA processing, fingerprint fuming, using skeletal remains to determine height and gender, entomology and learning how to use insects to determine time of death, and blood typing. I was really frustrated that our case was a cold case. I really wanted to know who solved Nathan Herron and was really angry when I found out that since we had no more leads there was nothing else we could do. I hated that our case couldn't be solved.
Evidence Logs
Community connection
For my community connection my Mom and I did a fundraiser walk for cystic fibrosis. Cystic fibrosis is a genetic disease that is passed down only when both parents are carriers for the trait. It cause thick mucus to form in the lungs and the pancreas. The walk was from Santa Rita park to the Harley Davidson area on the river trail. Afterwards pizza and drinks were provided. My friend Ian, also in biology, did the walk with me. It was really fun and good to be helping a cause.
Fetal Pig Dissection
We spent 2 weeks on dissection in biology. We had the choice to dissect a shark, cat, or fetal pig. I chose to do the fetal pig. My pig was female and she was within a few days of being born when her mother was killed for meat. The piglets were likely discovered after she had been killed. Instead of wasting them the pigs were at least sold to science to use educationally for dissection (I know, still sad). I worked with my friend JJ on the pig. We learned the respiratory system, digestive system, urogenital system, reproductive system, and circulatory system, and we also studied the basics of the brain. The first few days were the hardest, but after that it got easier to take it down from the top of the refrigerator and cut the pig open. My partner and I actually decided to dissect an eyeball, which was probably the most fascinating part. At the end of dissection we videoed finals going through everything and using proper terms.
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Monkey and chimp Meal planning
For this project we created recipes for monkeys and chimps based on special diet restrictions. There's a monkey and chimp facility that tries to provide different meals for the chimps each day to provide enrichment. After creating our recipes we sent them to the facility and many of them will actually be used. There were restrictions on fat, carbohydrates, sugar and other things like the amount they could eat.
durango nature studies habitat assessment paper
Project Reflection
The project was to write a technical paper about Durango Nature Studies. They have a native population of leopard frogs that are being threatened by the invasive bullfrog population. We took a fieldtrip to DNS and spent half an hour "catching" leopard frogs, then did other habitat assessments including veg plot surveys. To ID the frogs when a frog was cought the first group tagged them with pink day, and the next day the second group counted how many frogs were tagged and how many were untagged. We used excel to make charts and tables of the data of water quality, veg plot data, macro invertebrates, and frog populations. Then we researched both frogs to include the info in out technical writing papers. The papers have a results section, executive summary section, species overview section, and a discussion and recommendations section.
I think my paper is okay, but it could be better. I didn't use a lot of my class time wisely so was a little rushed to finish it in time. I like my suggesstion of using tadpole traps to get better population estimates because I feel like it's unique. I've never used technical and objective writing before so that provided a challenge for me. It was interesting to me that we've never seen bullfrogs in several years of data collection. |
Challenge Extension
One of the challenge extension options was to create propaganda about the frogs. Colleen forgot to tell my class period what the requirements were until the day it was due and everyone was dropping out so she let us work in partners and gave my partner and I an extension. The challenge extension requirements were to create a sticker, a poster, and a brochure. My partner did the brochure.
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Habitat Assessment Paper
Executive Summary
The Durango Nature Studies has 140 acres of land dedicated to preserving a wildlife ecosystem. It was established in 1994, and is home to a variety of different habitats and species of wildlife. Throughout the year, the Durango Nature Studies is host to outdoor workshops, school field trips, a bluegrass festival, Earth Day celebrations, summer camps for kids, and rafting trips. Because so many people are affected positively by the Nature Studies center, it is important to keep the ecosystem in good condition with balance and diversity.
Located on the property is a pond that is home to a native leopard frog (Rana pipiens) population. Bullfrogs (Rana catesbeiana) were spotted on the property a few years ago, causing concern. Bullfrogs are an invasive species that is very aggressive. If left alone the Bullfrogs will compete out the native population of leopard frogs for food, eradicating the species from the property. It is crucial to eradicate the bullfrog population, so as to maintain the health of the leopard frog population.
The students of Animas high conducted several surveys on the property to determine the population of both species of frogs. The surveys conducted include water quality tests in both the river and pond, inventory of the local plants located on the property, and a visual count of the amphibians observed. These tests will allow the students to predict the population of the amphibians, and determine that the Durango Nature Studies has a healthy habitat.
The Durango Nature Studies has an annual budget of $139,529 to use for the maintenance of the ecosystem. The 10th grade biology students from Animas High School have been conducting annual fieldwork to accurately assess the ecosystem health and to make recommendations for future management.
Species Overview
Bullfrog: Rana catesbeiana
Bullfrogs, or Rana catesbeiana are an invasive species of frog. Bullfrogs are a large species of frog that range from 10-18 cm. They are native in Eastern Northern America, but have spread to over 40 countries and 4 continents. They eat anything they can fit in their mouths, including reptiles, birds, rodents, and invertebrates.
Bullfrogs hibernate in winter, but typically don’t live in places with cold winters. They breed between April and May, and the females can lay up to 2,000 eggs. During mating season the males are territorial. Bullfrogs threaten numerous species and are carriers for a deadly fungus. (Spitzen, 2010).
Leopard frog: Rana pipiens
The Northern Leopard Frog, Rana pipiens, is a vulnerable or threatened species. The geographic range is Northern and Western North America. Leopard frogs are threatened by bullfrogs, carnivorous fish, and habitat loss (Patton 2001). Leopard frogs are fairly small, at between 5 and 12 cm in length. Adults eat small invertebrates (Northern 2013).
They can be found in habitats containing slow moving or still water (Northern 2013). During the winter they hibernate at the bottom of a pond, semi-buried in mud (How Do 1997). The breeding season for leopard frogs is March to June, and the females can lay 3,000 to 6,000 eggs (Colleen’s notes) (Shiels 1999). Leopard frogs are known as “indicator species,” because they reflect the condition of their environment.
Results
The data collected shows the results of the water chemistry tests conducted of the pond and river at the Durango Nature Studies. The nitrate levels in both the pond and the river were lower than 4 ppm, meaning that the pond and river are unpolluted in regards to nitrates. The pH levels of the pond and river were between 8 and 9 which qualifies as alkaline. The phosphate levels of the pond were 5 ppm, while the river was at 4 ppm. This is considered to be a high measure of phosphates. The dissolved oxygen levels of the pond were 7.5 mg/L, which is normal and the river was inconclusive due to heavy rainfall over the days prior to the conducted tests. Both the river and the pond tested positive for coliform. The population of bullfrogs is unknown due to none being found. A total of 47 people hours were spent searching for the frogs, and the estimated population of leopard frogs is 6 frogs.
During the tests conducted in 2013, a total of 35 macro-invertebrates were found. The biodiversity of the pond was 1.273 and the biodiversity of the river was 1.414. A survey of 8 different veg plots was conducted, and the average biodiversity was 1.143. The biodiversities of both the macro-invertebrates and veg plots shows that the ecosystem at DNS has adequate diversity.
Discussion and Recommendations
Diversity is crucial to creating a stable environment and ecosystem that can adequately support a range of plants and animals. The more diversity there is within a system, the more stable and ultimately sustainable that system is. The Shannon-Weiner Diversity Index was used to quantify diversity on the DNS property based on macro-invertebrate and plant data. Based on the Shannon-Weiner index calculated it can be determined that the DNS property has adequate diversity and can be considered sustainable.
The absence of stoneflies indicates that the water quality of the pond and river is moderate. This was determined because stoneflies have the lowest tolerance for pollution, so their absence suggests that the water has moderate pollution.
The source of the elevated phosphates found in the pond and river is the farms upriver. Elevated levels of phosphates can be caused by manor from farms traveling downriver. When the phosphate level is high, it causes plant growth to increase, which in turn causes the amounts of decaying plant matter to increase. This causes the population of animals that eat decaying plant matter to increase, and then everything will die, and the system will start over. Elevated phosphate levels will cause an increase in plant growth and create algal blooms. Algal blooms cause a decrease in oxygen levels, which can negatively affect an ecosystem.
Bullfrogs are nocturnal hunters, so searching for them in the day could be the reason we’ve never caught one. A more effective way to capture bullfrogs may be to set numerous traps and leave the traps overnight, then return to check the traps again the next day. Possible traps that could be set are Pitfall traps and funnel traps, however these are not the best solutions because both traps involve amphibians trapped in a container. The problem with this is that leopard frogs could be trapped with bullfrogs, resulting in the death of several leopard frogs, instead of protecting them.
One possible suggestion is to make a funnel trap with a small enough opening that only tadpoles can fit in. Bullfrog tadpoles won’t eat the leopard frog tadpoles so this idea eliminates the issue of bullfrogs eating leopard frogs. The difference between bullfrog tadpoles and leopard frog tadpoles are that bullfrog tadpoles are much larger; bullfrog tadpoles are olive to grayish olive in color, with faint black specks (Hallock 2009) (Rorabaugh 2008), while leopard frog tadpoles are dark brown to gray in color (Cossel 1997) (Ross 2010). There are many different types of funnel traps, and different ways to make them. The simplest is to use plastic bottles. After cutting off the top of the water bottle, flip it so that the end is inside the other half of the bottle, creating a funnel. Each student can easily and quickly make their own trap. The traps should be baited and left overnight in water that just submerges the trap for the second group to collect the next day. Bullfrog tadpoles can be counted and killed, while the leopard frog tadpoles can be released back into the pond. The benefit of using a trap like this is that simultaneously leopard frog tadpole populations can be monitored providing an estimate of how many tadpoles survive to adults.
The population of leopard frogs can be better monitored by collecting population estimates of both the tadpoles, and adult leopard frogs. This would provide the info of how many leopard frogs survive, and give an estimate of the bullfrogs impact on the population of leopard frogs. It would also be more effective to spread out the classes going to the DNS center to avoid disrupting the natural schedule of the frogs and to increase the likelihood that frogs will be caught.
To preserve the leopard frog populations at DNS, modifications can be made. One modification is to attempt to reduce the pollutants in the water by filtering them out, and to try and prevent further pollution of the pond. Another recommendation is to eradicate bullfrogs, both by killing all tadpoles found and any adult bullfrogs caught on the property. A suggestion is to involve human interference and start a leopard frog breeding program, but this is strongly advised to be used only as a last resort due to the negative impact disruption could have on the ecosystem. The best solution would be if nature could smooth things out without the disruption of human contact.
The visual encounter surveys provided the estimate of 6 frogs, but the mark-recapture data calculated 20 frogs. The mark-recapture data estimate was generated using numbers and an equation, causing it to seem more reliable, and therefore the method that should be referenced.