Riparian Zone Retreat and population studies Cody Gaynor Honor Biology II, Period 1.
Eastern Gray Squirrel Sciurus carolinensis
The Eastern Gray Squirrel likes a woodland habitat and is comfortable with about 105 acres of land. Squirrels will chose an area with more trees for food in the winter.
The Gray Squirrel eats mostly nuts, flowers and buds of more than 24 species of oaks, 10 species of hickory, pecan, walnut and beech tree species. Maple, mulberry, hackberry, and elm. The seeds of certain trees such as cedar, hemlock, pine, and spruce are another food source. Crops, such as corn and wheat, are eaten, particularly during the cold winter months. Insects are eaten in the summer and are probably especially important for juveniles. Cannibalism has been reported, and squirrels may also eat bones, bird eggs and nestlings, and frogs. They also burry some food for the winter. They recover these items with the help of memory and smell.
Squirrels are omnivores and usually only eat insects. There are rare cases where cannibalism occurs.
Gray Squirrel Reproduction
Mating occurs in May-June and December-February
Usually squirrels mate twice per year and have an average gestation period of 44 days.
Female start the reproductive cycle at about 1.25 years old, some as early as five and a half months start the cycle.
Male reach maturity at about 11 months.
About 2-4 offspring are born per litter. But there have been cases where 8 have been born.
Squirrels have hair-like whiskers to feel with around their face when they are born.
The average weight for newborn squirrels is 13-18 grams
Factors Which Affect the Death Rate of Assigned Animal
Eastern gray squirrels are preyed on by numerous predators. American mink, other weasels, red foxes, bobcats, grey wolves, coyotes, lynx, and birds of prey, for example red-tailed hawks are some of the few predators squirrels deal with. They emit warning calls to warn neighboring squirrels of the presence of predators. Their extreme agility in the trees makes them difficult to capture.
Squirrels live an average of 12.5 years in the wild. In captivity the average life span is 23.5 years.
Squirrels host fleas, ticks, lice, roundworms, and other parasites.
Food Chain Producer Autotroph Oak Tree Primary Consumer Omnivore Eastern Gray Squirrel Secondary Consumer Carnivore Weasel Tertiary Consumer Carnivore Coyote
Food web of Gray Squirrel All of these organisms are found in the same habitat as the gray squirrel. The carnivores, bear and the hawk are on the top and they eat what is below them in the web. Herbivore Producer Omnivore Carnivore Carnivore Producer Carnivore Herbivore Herbivore Omnivore Producer
Population Sampling Techniques
First catch as many of the species as possible in one area. Next mark them with something. Then return them all. Then later catch as many of the same species as possible again. Now count how many were caught before, ones with some kind of a mark that was put on them, then count how many don’t have a mark. This should give a good idea of the population size.
The mark and release capture method is the best for gray squirrels and there is no other way used.
Stream Quality Data & Analysis
The stream is a very health stream indicated by the number of Class I organisms found in it.
Since there is an overwhelming number of Class I organisms and not very many from Class II or III, we can determine the stream is very healthy.
The squirrel benefits from this in many ways. If the stream is healthy the water is healthy. That mean the oak tree can grow better acorns. If there are more acorns, the squirrel will have more of a food supply and a greater chance to survive the winter.
If the majority of the organisms found were in Class III this would mean the water is of poor quality and this again affects the trees that grow near the stream, and the acorns produced that the squirrels use for a food supply.
Water Testing Data & Analysis
For a healthy ecosystem, the nitrates should be low, the phosphorus should be too. The pH should be as close to seven as possible. An the dissolved oxygen needs to be high to support the fish. If the levels are outside of this range the organisms could die off because they aren’t tolerant of the high level of pollutants and the low levels of oxygen.
If the squirrels live close to the stream they will have a healthy and more plentiful food supply. The food will grow better with the higher quality water.
If the temperature is too high the dissolved oxygen in the water will too low, and if the turbidity is high the gills of the fish will get clogged and. If the gills get clogged the fish will die.
Soil Testing & Analysis
The pH and levels of the different nutrients are essential for the plants to grow. Too high or too low of each of the nutrients or pH will result in the plant not growing to it’s full potential or not growing at all.
The pH level is 7, but that rarely occurs in nature by itself. The ideal range for pH is about 4 to 8. The other level need to be kept high enough to benefit the plants, but not too high that it exceeds the critical load of the plant.
If it exceeds the critical load of the plants, runoff will occur and runoff is bad. This will contribute to pollution of local streams and could potentially kill off all the living organisms.
Positive and Negative Factors
The Stream would be an ideal habitat for the squirrel to live around. All of the level in the stream are at a level to support the gray squirrel.
If the soil is not at an acceptable level the plants will not grow. If the plants aren’t growing, there will be no food supply for the organisms in that habitat.
The riparian zone is positively affected by conservationists trying to save the habitat. There are some negative things for the zone. The farmland and golf course runoff impact the zone the most. The next negative factor is abandoned mine drainage. Without these levels in check the food supply for the gray squirrel will eventually disappear.
I learned the two majors sources of pollution in PA are runoff from farmland and golf courses. The number two source of pollution in PA is Abandoned Mine Drainage.
I found that if the levels of N, K, and or P are just a little too high or a little too low it can have a major affect on the riparian zone.
I would like to research more about the farmland runoff.