Riparian Zone Retreat and population studies Vince Anto Honors Biology II Honors Period 1
Niche of the Bobcat (Lynx Rufus)
Bobcats are found throughout the United States, they inhabit forests, brush land, semi desert areas, and mountainous regions. They generally live in des, such as a small caves or hollow logs.
Bobcats are strict carnivores, they generally prey on small game, for example rabbits, birds, squirrels, and mice; but they also attack deer, lambs, and poultry.
Bob are nocturnal generally hunting at dusk or night; they stalk there prey and pounce, )with a leap that can cover over 10 feet) attempting to bite the vertebrae in the neck to kill their prey.
Factors which Affect Birth Rate of Bobcats
Bobcats normally mate in the spring; females begin to reproduce after they are one year old, while males mate after they are two.
Bobcats generally reproduce once per year.
The bobcats gestation period is 60-70 days.
The size of the bobcats litter ranges from 1-6, the average little contains 3 or 4 kittens.
Female bobcats nurse their young for two months. After the two months the mother brings food to the kittens and teaches them how to hunt. Male bobcats do not care for their offspring.
Bobcats usually reproduce near two years of age, they stop reproducing when they are around 6 or 7 years old.
Factors Which Affect the Death Rate of Bobcats
Bobcats are carnivores and are involved in predator-play relationships with small game. For example the bobcat, predator, captures and kills rabbits, the prey.
Bobcats live around 12 years in the wild, but in captivity they can live up to 32 years.
Bobcats can be plague by many parasites, for example; mange mites which feed off the skin and cause inflammation, lice which feed off blood, and tape worms and round worms which live in the intestine and nurture themselves from the bobcats food.
Overpopulation, when population exceeds the carry capacity of an ecosystem, causes lack of resources, in this case prey, for the bobcat population. When the population can not be supported due to lack of food bobcats perish until the ecosystem can support their population.
Food Chain of a Bobcat Producer Autotroph Primary Consumer Herbivore Secondary Consumer Carnivore Tertiary Consumer Omnivore
Food web of the Bobcat Herbivore Omnivore Producer Carnivore Herbivore Producer Herbivore Herbivore Herbivore Carnivore
Population Sampling Techniques
Ecologist use population sampling techniques that involve tagging a certain number of organisms and then recapturing a certain number of the organisms some time later. Then the number of tagged organisms is compared to the number caught that are unmarked, and the proportion is used to estimate the total population size.
Mark-recapture techniques are often used to determine the population of bobcats.
Stream Quality Data & Analysis
This graph represents a stream of pristine quality.
The number of organisms in each class is used to determine stream quality. Large numbers of Class I organisms suggest that the water is very good quality because those organisms cannot tolerate pollution. However, large numbers of Class III organisms, which are tolerant of pollution, indicate poor water quality. Class II organisms can live in a wide range of water quality so they can not be used to clearly illustrate the quality of the stream.
The good stream quality would be beneficial to bobcats. It would increase the number of insects thus food for birds and other prey for the bobcats, thus increasing their food supply.
The bobcat would be indirectly harmed if the majority of organisms were Class III. The number and diversity of aquatic organisms would decrease drastically changing the food chain, eventually hurting the bobcat carnivore, because of the decline in prey.
Water Testing Data & Analysis
Nitrate and phosphate levels indicate how much of those nutrients have entered the stream, for example through agricultural and waste run-off, high levels of these nutrients are bad for the ecosystem. The ideal numbers of nitrates and phosphates in the water at Powdermill are 0 mg/L. High levels of these nutrients can directly kill organisms because they are toxic at high levels. These nutrients can also cause an increase in the density of photosynthetic organisms, such as in eutrophication. As these plants die and are decomposed oxygen is used which can kill stream organisms if the dissolved oxygen falls below there threshold for life.
pH is how alkaline or acidic the water is. Values close to 7, neutral, are best for the ecosystem, and are the ideal value for Powdermill; high or low pH don’t support the widest array of life, because some organisms cant survive outside of a nearly neutral pH range. So if the pH range increases or decreases too much many organisms will die. The dissolved oxygen level is a measure of the oxygen in the water, higher level especially over 10 mg/L are best for the ecosystem and Powdermill; many organisms cannot survive at lower levels, because they will not get enough oxygen to function.
Water Testing Data & Analysis cont.
The bobcat would survive better near the stream, because it would be a healthier ecosystem, with a complete food web. The marsh waters contain too much nitrogen and the mine waters have too much pH and too little oxygen for the survival of many organisms, thus severing parts of the food chain, hurting the bobcats chance of survival because the populations of its prey would decrease. Describe how you organism would survive (using both direct and indirect evidence) if its habitat is close to the stream versus the marsh, and mine waters.
The temperature of the water affects the dissolved oxygen level, cooler waters retain more oxygen. Organisms also can only survive at certain temperatures. Turbidity is also important to stream quality, a very turbid stream causes debris to build up in organisms gills, and effects predator prey relationships because creatures cannot see.
Soil Testing & Analysis
pH controls how well plants utilize nutrients. Potash, Nitrogen and Phosphorus all play a role in plant growth and metabolism. Describe the importance of pH, potash, phosphorus, & nitrogen levels in the soil.
The ideal pH range depends on the plants in the area but pH levels near 7 are generally ideal. The ideal ranges for phosphorus and nitrogen are not to exceed the critical load, the amount that can be absorbed by plants without harming the ecosystem by leaching into waterways. Potash is needed in high levels and usually does not harm the ecosystem if there is too much present in the soil.
pH ranges that are too acidic or basic can stunt plant growth or just kill plants. High levels of nitrogen and phosphorus are very hazardous for the ecosystem. If levels of these nutrients are above the critical load, they will run-off into streams which can have cataclysmic effects on the ecosystem. Very low levels of potash can slow plant development and the production of sugars which can ultimately kill plants.
Positive and Negative Factors
The Stream water would benefit the bobcat because it is of pristine quality and supports a healthy ecosystem, therefore aiding the amount of prey for the bobcat. The Acidic mine water has too low of a pH value and little dissolved oxygen impairing nearly all stream life, thus hurting the food chain and the bobcat. The high nitrate levels in the marsh waters would cause eutrophication and can be toxic to life, both of which would sever the food chain.
The soil conditions in the riparian zone are nearly ideal for the area. They are adequate for plant growth and do not exceed the critical load of nutrients that could impact stream health. This growth of producers and healthy environment create an ecosystem that allows the bobcat’s prey to thrive helping the bobcats survive.
Agricultural run-off and abandoned mine drainage are the major sources of pollution on PA streams. This pollution can cause eutrophication, toxic levels of nutrients, and other factors ruining stream quality. These adverse stream conditions would negatively impact the bobcat because they would alter the food web decreasing the bobcats food source. Nutrient levels under the critical load in the soil, streams protected by buffer zones, and treated abandon mine drainage, can positively affect stream quality. These conservation techniques can benefit the entire ecosystem, creating a healthy food web, which also aid the bobcat.
During this project a learned about how streams were classified using both species richness and diversity, as well as the chemicals and composition of a stream.
I found the organisms that we caught and researched at Powdermill to be fascinating. Especially how the different classes of species can only live in certain stream environments and the roles they play in their habitat.
One environmental topic I would enjoy researching further would be the treatment of abandon mine drainage through the use of wetlands and SAPS.
Works Cited Banfield, A. W. F. "Bobcat." Encyclopedia Americana . 2010. Grolier Online. 14 Apr. 2010 <http://ea.grolier.com/article?id=0051950-00>. Campbell, Neil, and Jane Reece. Biology Sixth Edition . N.p.: Benjamin Cummings, 2002. N. pag. Print. University of Michigan. "Lynx Rufus." Animal Diversity Web . N.p., n.d. Web. 12 May 2010. <http://animaldiversity.ummz.umich.edu/site/index.html>.