RiparianRiparian Zone Retreat Zone Retreatand population studiesand population studies

Missy StickneyMissy Stickney

Honors Biology IIHonors Biology II

Period 1Period 1

Weasel or Mustelidae• Mustelidae can be found almost anywhere. The habitats they can be found in

are polar, temperate, tropical, terrestrial, marine, or freshwater.

• Weasels breed seasonally which lasts for about three to four months. Weasels usually will undergo delayed implantation which is when the fertilized egg will take up to 10 months to implant in the uterus. Gestation will last anywhere between 30-65 days. Females will give birth only once per season. They will have 1-14 pups per litter. The pups are usually born blind and very small they will need a lot of attention from their mother. The pups will reach sexual maturity anywhere from eight months to two years. The females will protect the territory and keep the pups in a burrow or den.

• Weasels usually eat rodents, eggs, mollusks, and sometimes plant material.

• Weasels will hunt at anytime of day. Weasels will crawl through holes, climb trees, run after their prey, and basically anything to kill their prey. Weasels will kill more then they need to. For example, weasels will get into a chicken coop and kill all of the chickens when it can’t even finish eating one of the chickens. Weasels’ fur color changes with the seasons. It will become white with a black tip on the tail in the winter. In the warmer seasons it will be different shades of brown.

Factors which Affect Birth Rate of Assigned Animal

• Weasels mate once per year– They mate during the summer

• Weasels can reproduce twice per year but they usually only conceive once.– The second litter has a high death rate.

• Gestation Period: 30-50 days• 1-7 pups will be born in each litter• The mother will watch her pups closely in the den that she has lined with fur

from animals that she has killed. In about five weeks the pups eyes will open. They can begin to hunt at the age of two months. Until then the mother will provide food for the pups and protection.

• Female weasels can begin to reproduce at the age of two months but males can’t reproduce until the age of eight months. They can reproduce their whole life.

Factors Which Affect the Death Rate of Assigned Animal

• Weasels have few predators, two predators would be the horned owl and marten. Both species are apparently agile enough to occasionally catch weasels. Hawks, foxes, coyotes, and lynx also kill weasels, but this happens rarely.

• Speed, ferocity, and the ability to fit into tight spaces help the weasel to cope with these larger predators. A weasel's color changes also provide natural camouflage. The weasel benefits both as the hunter and as the hunted. In winter, predator may only see the black tip of the tail moving against the white snow. If the predator strikes at this black spot, it will miss the weasel's body. As a last resort, weasels can emit an odor which is as pungent as that of a skunk.

• Weasels will boldly confront animals much larger than themselves. They've been known to attack humans who come between them and their food. A severe winter with insufficient food is their worst enemy.

Factors Which Affect the Death Rate of Assigned

Animal Cont.

•Weasels biggest predator would be humans. Humans kill weasels for their fur. •Weasels live up to three years•Pneumocystis carinii is a very common parasite found in weasels. It is a form of pneumonia. Another common parasite would be fleas.•Overpopulation of weasels will result in more diseases and parasites.

Food Chain of Assigned OrganismThe grass is the producer which they chicken will eat. The chicken is the primary consumer and a herbivore. The weasel will eat the chicken. The weasel is the secondary consumer and a carnivore. The tertiary consumer and carnivore is the horned owl.

Producer

Autotroph

Primary Consumer

HerbivoreSecondary Consumer

Carnivore

Tertiary Consumer

Carnivore

Food web of Assigned Organism

Herbivore

Producer Omnivore

CarnivoreCarnivore

ProducerCarnivore

Omnivore

Producer Herbivore

Population Sampling Techniques

• Ecologists will use tagging, measuring land, keeping animals in reservoirs, mark and recapture, and predator-prey technique. The techniques do not harm the animals it just allows ecologists to know approximately the population size.

• Predator-prey technique because it shows how weasels depend on food to be able to live and reproduce. It will show how as the prey population goes up the weasel population will also increase because it will have more to eat. If the number of prey decreases then the weasel population will also decrease because there won’t be as much to eat.

Stream Quality Data & AnalysisStream Quality Data & Analysis• By looking at the graph one can tell

that the stream is very healthy. It has a excellent stream quality.

• Most of the organisms are from class one this shows that the stream has excellent stream quality. Class one organisms must have very healthy water conditions. They must have a high dissolved oxygen level, neutral pH, and low nitrates and phosphates.

• The weasel drinks the water and if it drinks bad water then it will affect it.

• The animals that eat weasels will be affected because if the weasel is drinking bad water then it will get ill and die. If an animal eats a weasel that is sick it also will get sick.

Water Testing Data & AnalysisWater Testing Data & Analysis• The nitrate and phosphate levels should be low

because if they are high it will kill the organisms. It will cause an overgrowth of algae and the plants in the water will not be able to complete photosynthesis. The dissolved oxygen levels should be high, between 10 and 15, because this allows the organisms to breath. pH should be neutral or near neutral, 6.5-7.5, because acidic water will kill class one organisms.

• Marsh areas will usually have a high nitrate level, slightly higher phosphate level, basic pH level, and a lower dissolved oxygen level. A mine area will have an acidic pH level, some nitrates, little phosphates, and a low dissolved oxygen level.

• The weasel depends on other animals to prey on. If there is poor stream quality then there will be less animals that the weasel can prey on. This will result in death of the weasel because it has nothing to eat. The weasel also depends on water to drink so if the water conditions are not healthy the weasel will suffer.

• The turbidity of water should be low so that the organisms will be able to see for shelter and so that it does not interfere with their predator-prey relationships. The temperature should be low but not freezing. Low temperatures will create more dissolved oxygen and the animals will be able to breathe without troubles.

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50

100

150StreamMarshMine

Soil Testing & AnalysisSoil Testing & Analysis

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1

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Riparian School Site

• Phosphorus, nitrogen, and potash levels are needed in order for the plants to be able to grow and fight of diseases. pH will allow the plants to grow and absorb nutrients.

• The pH level should be anywhere between 4 and 7. A good pH level will let the plants to absorb nutrients properly. The potash level will help the plants grow and it should be at a high level. The nitrate and phosphate levels should be low they will help the plants to grow and fight diseases.

• If the pH, nitrogen, phosphorus, and potash levels are out of range it will kill the plants. If the plants die the herbivores and carnivores will have nothing to eat and slowly ruin the food chain.

Positive and Negative Factors• Good water quality will positively affect the weasel. By having good water quality everything that depends on the water including the weasel will thrive and make a good, solid food web. Poor water quality, such as the marsh and mine water, will negatively affect the weasel. It depends on water for drinking purposes and the weasel’s prey that depend on the water.

• The good soil quality will positively affect the weasel. By having good soil quality this will allow for a lot of vegetation. Most of the weasel’s prey are omnivores so if there is poor soil quality then the weasel will have nothing to eat because the omnivores will die.

• Most PA streams have many trees that protect them from too much sunlight. If the stream received too much sunlight then the temperature would be too hot and this would kill the organisms in the water. The water temperature should stay under 65 degrees Fahrenheit. Farmland run-off is a common source of pollution in PA streams. This can be easily corrected many ways, for example using cement water barrels or keeping livestock out of streams. Anything that affects the water will affect the weasel because it depends on the water.

Conclusion

• I learned that every little element of water affects the water quality. The number of organisms in the different classes will show one the water quality. The pH, dissolved oxygen, and nitrate and phosphate levels will show one just by looking at the numbers the stream quality.

• I think that weasels will fight animals much bigger then them is very interesting. Weasels are very small animals and the fact that they will fight bears and porcupines astonishes me. I never realized how brave they can be.

• The number of organisms in a certain class would be interesting to research further because it is weird how the organisms can tell one what the stream quality is.

Works Cited

•http://www.biokids.umich.edu/critters/Mustela_nivalis/

•http://www.saskschools.ca/~gregory/animals/weasel.html

•http://www.adfg.state.ak.us/pubs/notebook/furbear/weasels.php

• Online Encyclopedia http://www.questia.com/library/encyclopedia/weasel.jsp