Araaa Aquarian
Biology
Colleen Dunning
Thursday, October 4, 2012
Amphibian population estimates and ecosystem assessment on the Durango Nature Studies Property
Introduction
Durango Nature Studies (DNS) is an non-profit organization that brings thousands of children to their property to teach them fieldwork for biology and science. DNS is located in between Southwest Colorado and Northwest New Mexico . It was acquired in June 1998. Altogether there are 140 acres on the DNS property. The DNS property contains trails, meadows, oak woodlands, pinon-juniper forests, and desert arroyos.
The status of Rana catesbeiana ( bullfrogs) in Colorado are, invasive. Colorado is experiencing problems with the bullfrogs due to them being introduced to the population. One concern is, bullfrogs occasionally invade fish hatchery ponds and their larvae are caught along the fishes that are regularly stocked in the ponds. The bullfrog, being an invasive specimen, are also a concern because they take over native species like the Rana pipiens ( leopard frogs). bullfrogs and Lepomis macrochirus (bluegills) are dangerous to leopard frogs because, unknowingly, the bullfrogs and bluegills work together to get rid of the leopard frogs. The bullfrogs kick the leopard frogs out of their marsh around the pond. They force them into the open water where the bluegills eat them. This harms the population of the leopard frogs. The current status of the leopard frog in Colorado is, “ state species of special concern”.
Natural History:
In order to survive, leopard frogs need fresh water that meets land. Such as, marshes, ponds, lakes, rivers, or streams. leopard frogs need their food. They eat algae, bugs, smaller frogs, tadpoles, and earthworms. The life cycle of the leopard frog is, they breed from late April to early June. They lay their eggs in ponds or streams or small lakes. Each female can lay up tp 5,000 eggs. The eggs can hatch in 5 to 7 days. The tadpoles turn into froglets after 60 days of being a tadpole.
The bullfrogs need fresh water also. The bullfrogs can survive on almost anything. They will ambush and eat just about anything including insects, mice, fish, birds and snakes. The female bullfrog can lay up to 20,000 to 25,000 eggs at one time. Most eggs are eaten before they can hatch. The ones that do hatch spend their first winter as tadpoles. Bullfrogs are an aggressive generalist predator.
Methods and Materials
4 pitfall traps were set by the pond. The pitfall traps were checked daily over a 4 day time period. When frogs were caught, they were tagged with pink elastomer and then were released back into the pond. Samples from the pond were taken in order to test/know the nitrate, phosphate, dissolved oxygen and the PH levels. These samples were brought to Animas High School and tested. Macroinvertebrates were collected from were collected from the pond by using a dip net. The net was pushed to the bottom of the pond and brought up and put into test tubes. Macroinvertebrates were also collected from the river. They were collected by a person standing in the river facing upstream and holding a net out in front of them. After the macroinvertebrates were collected, they were also brought back to Animas High School and were sorted through.
Results
The diversity in the DNS pond was found to be 0.99 and the diversity was found to be 1.03 in the Florida River. In 2012, the diversity for the pond was 1.22 and for the Florida River it was 0.88. The ponds pH was found to be alkaline, the nitrate and phosphate were high. The dissolved oxygen was low and the water tested positive for coliform. The water quality for the river was almost the same. The pH was alkaline and the phosphate, nitrate and dissolved oxygen were high. The coliform was also positive for the river. Using the population formula, the found population of leopard frogs on the DNS property was estimated to be 15. Based on the visual encounter, the population of leopard frogs on the DNS property was found to be 11. For the bullfrogs it was found to be 1.
Conclusion and Discussion
Based on population estimates, it can be concluded that bullfrogs are not yet invasive on the DNS property. Last year, the population for bullfrogs were found to be 2. According to Durango Nature Studies staff, one bullfrog was caught and removed. DNS is working on keeping the bullfrog population down before they become invasive. However, in other parts of Colorado, bullfrogs eat native frogs, outcompete them for food, and spread infectious diseases like chytridiomycosis. Chytridiomycosis is an infectious disease of amphibians caused by the chytrid Batrachochytrium. This has driven 100 frog species to complete extinction. Over 5 million bullfrogs are imported to San Francisco, New York and Los Angeles to get tested for the Chytridiomycosis. 62% of the frogs tested positive for carrying deadly chytrid fungus. Even though bullfrogs are becoming a big problem, it is still legal to sell tadpoles in the Western part of the United States. This problem can be solved in a few different ways. One, you can donate $20 to Save The Frogs ( the non-profit organization) to help institute the law against selling bullfrog tadpoles.
The water quality is a major factor in the ecosystem. The water qualities for Nitrate and phosphate levels were high and the pH was alkaline in the pond. The pond tested positive for coliform. Coliform is extremely bad for the pond because it raises the nitrate and phosphate levels and the nitrate and phosphate levels start algal blooms which kill all living things in the pond.
Next year more pitfall traps should be set up so that there are more chances of catching invasive species. Also, there should be a stronger focus on catching the one bullfrog in order to limit the chances of the bullfrog becoming invasive on the DNS property. More leopard frogs should be brought to the DNS property in order to keep the population going and to keep the population strong.
Sources:
http://www.biokids.umich.edu
http://ndis.nrel.colostate.edu
http://www.ehow.com
http://www.naturenorth.com
http://animals.nationalgeographic.com
http://www.savethefrogs.com
http://www.bullfrogs.com
Biology
Colleen Dunning
Thursday, October 4, 2012
Amphibian population estimates and ecosystem assessment on the Durango Nature Studies Property
Introduction
Durango Nature Studies (DNS) is an non-profit organization that brings thousands of children to their property to teach them fieldwork for biology and science. DNS is located in between Southwest Colorado and Northwest New Mexico . It was acquired in June 1998. Altogether there are 140 acres on the DNS property. The DNS property contains trails, meadows, oak woodlands, pinon-juniper forests, and desert arroyos.
The status of Rana catesbeiana ( bullfrogs) in Colorado are, invasive. Colorado is experiencing problems with the bullfrogs due to them being introduced to the population. One concern is, bullfrogs occasionally invade fish hatchery ponds and their larvae are caught along the fishes that are regularly stocked in the ponds. The bullfrog, being an invasive specimen, are also a concern because they take over native species like the Rana pipiens ( leopard frogs). bullfrogs and Lepomis macrochirus (bluegills) are dangerous to leopard frogs because, unknowingly, the bullfrogs and bluegills work together to get rid of the leopard frogs. The bullfrogs kick the leopard frogs out of their marsh around the pond. They force them into the open water where the bluegills eat them. This harms the population of the leopard frogs. The current status of the leopard frog in Colorado is, “ state species of special concern”.
Natural History:
In order to survive, leopard frogs need fresh water that meets land. Such as, marshes, ponds, lakes, rivers, or streams. leopard frogs need their food. They eat algae, bugs, smaller frogs, tadpoles, and earthworms. The life cycle of the leopard frog is, they breed from late April to early June. They lay their eggs in ponds or streams or small lakes. Each female can lay up tp 5,000 eggs. The eggs can hatch in 5 to 7 days. The tadpoles turn into froglets after 60 days of being a tadpole.
The bullfrogs need fresh water also. The bullfrogs can survive on almost anything. They will ambush and eat just about anything including insects, mice, fish, birds and snakes. The female bullfrog can lay up to 20,000 to 25,000 eggs at one time. Most eggs are eaten before they can hatch. The ones that do hatch spend their first winter as tadpoles. Bullfrogs are an aggressive generalist predator.
Methods and Materials
4 pitfall traps were set by the pond. The pitfall traps were checked daily over a 4 day time period. When frogs were caught, they were tagged with pink elastomer and then were released back into the pond. Samples from the pond were taken in order to test/know the nitrate, phosphate, dissolved oxygen and the PH levels. These samples were brought to Animas High School and tested. Macroinvertebrates were collected from were collected from the pond by using a dip net. The net was pushed to the bottom of the pond and brought up and put into test tubes. Macroinvertebrates were also collected from the river. They were collected by a person standing in the river facing upstream and holding a net out in front of them. After the macroinvertebrates were collected, they were also brought back to Animas High School and were sorted through.
Results
The diversity in the DNS pond was found to be 0.99 and the diversity was found to be 1.03 in the Florida River. In 2012, the diversity for the pond was 1.22 and for the Florida River it was 0.88. The ponds pH was found to be alkaline, the nitrate and phosphate were high. The dissolved oxygen was low and the water tested positive for coliform. The water quality for the river was almost the same. The pH was alkaline and the phosphate, nitrate and dissolved oxygen were high. The coliform was also positive for the river. Using the population formula, the found population of leopard frogs on the DNS property was estimated to be 15. Based on the visual encounter, the population of leopard frogs on the DNS property was found to be 11. For the bullfrogs it was found to be 1.
Conclusion and Discussion
Based on population estimates, it can be concluded that bullfrogs are not yet invasive on the DNS property. Last year, the population for bullfrogs were found to be 2. According to Durango Nature Studies staff, one bullfrog was caught and removed. DNS is working on keeping the bullfrog population down before they become invasive. However, in other parts of Colorado, bullfrogs eat native frogs, outcompete them for food, and spread infectious diseases like chytridiomycosis. Chytridiomycosis is an infectious disease of amphibians caused by the chytrid Batrachochytrium. This has driven 100 frog species to complete extinction. Over 5 million bullfrogs are imported to San Francisco, New York and Los Angeles to get tested for the Chytridiomycosis. 62% of the frogs tested positive for carrying deadly chytrid fungus. Even though bullfrogs are becoming a big problem, it is still legal to sell tadpoles in the Western part of the United States. This problem can be solved in a few different ways. One, you can donate $20 to Save The Frogs ( the non-profit organization) to help institute the law against selling bullfrog tadpoles.
The water quality is a major factor in the ecosystem. The water qualities for Nitrate and phosphate levels were high and the pH was alkaline in the pond. The pond tested positive for coliform. Coliform is extremely bad for the pond because it raises the nitrate and phosphate levels and the nitrate and phosphate levels start algal blooms which kill all living things in the pond.
Next year more pitfall traps should be set up so that there are more chances of catching invasive species. Also, there should be a stronger focus on catching the one bullfrog in order to limit the chances of the bullfrog becoming invasive on the DNS property. More leopard frogs should be brought to the DNS property in order to keep the population going and to keep the population strong.
Sources:
http://www.biokids.umich.edu
http://ndis.nrel.colostate.edu
http://www.ehow.com
http://www.naturenorth.com
http://animals.nationalgeographic.com
http://www.savethefrogs.com
http://www.bullfrogs.com