The document summarizes a lab experiment that examined the effects of different contaminants on groundwater. Beakers of water were contaminated with oil, vinegar, or laundry detergent. Observations were made of each beaker's smell, color, clarity, and presence of bubbles or soil. Based on the results, hypotheses were formed about each contaminant and whether they would be accepted or rejected. Oil caused the water to become thick and allow soil to filter through. Vinegar cleaned the water and prevented soil. Laundry detergent significantly changed the color and added bubbles to the water. The detergent seemed to have the most impact on contaminating the water.
Python Notes for mca i year students osmania university.docx
Running Head SAMPLE FINAL LAB REPORT 1 Sa.docx
1. Running Head: SAMPLE FINAL LAB REPORT 1
Sample Lab Report (The Optimal Foraging Theory)
Name
SCI 207 Dependence of Man on the Environment
Instructor
Date
2. SAMPLE FINAL LAB REPORT 2
Sample Lab Report
Abstract
The theory of optimal foraging and its relation to
central foraging was examined by using
the beaver as a model. Beaver food choice was examined by
noting the species of woody
vegetation, status (chewed vs. not-chewed), distance from the
water, and circumference of trees
near a beaver pond in North Carolina. Beavers avoided certain
species of trees and preferred
trees that were close to the water. No preference for tree
circumference was noted. These data
suggest that beaver food choice concurs with the optimal
foraging theory.
Introduction
In this lab, we explore the theory of optimal foraging and the
theory of central place
foraging using beavers as the model animal. Foraging refers to
the mammalian behavior
3. associated with searching for food. The optimal foraging theory
assumes that animals feed in a
way that maximizes their net rate of energy intake per unit time
(Pyke et al., 1977). An animal
may either maximize its daily energy intake (energy maximizer)
or minimize the time spent
feeding (time minimizer) in order to meet minimum
requirements. Herbivores commonly behave
as energy maximizers (Belovsky, 1986) and accomplish this
maximizing behavior by choosing
food that is of high quality and has low-search and low-
handling time (Pyke et al., 1977).
The central place theory is used to describe animals that
collect food and store it in a
fixed location in their home range, the central place (Jenkins,
1980). The factors associated with
the optimal foraging theory also apply to the central place
theory. The central place theory
predicts that retrieval costs increase linearly with distance of
the resource from the central place
SAMPLE FINAL LAB REPORT 3
4. (Rockwood and Hubbell, 1987). Central place feeders are very
selective when choosing food
that is far from the central place since they have to spend time
and energy hauling it back to the
storage site (Schoener, 1979).
The main objective of this lab was to determine beaver
(Castor canadensis) food selection
based on tree species, size, and distance. Since beavers are
energy maximizers (Jenkins, 1980;
Belovsky, 1984) and central place feeders (McGinley &
Whitam, 1985), they make an excellent
test animal for the optimal foraging theory. Beavers eat several
kinds of herbaceous plants as
well as the leaves, twigs, and bark of most species of woody
plants that grow near water (Jenkins
& Busher, 1979). By examining the trees that are chewed or
not-chewed in the beavers' home
range, an accurate assessment of food preferences among tree
species may be gained (Jenkins,
1975). The purpose of this lab was to learn about the optimal
foraging theory. We wanted to
know if beavers put the optimal foraging theory into action
when selecting food.
We hypothesized that the beavers in this study will
5. choose trees that are small in
circumference and closest to the water. Since the energy yield
of tree species may vary
significantly, we also hypothesized that beavers will show a
preference for some species of trees
over others regardless of circumference size or distance from
the central area. The optimal
foraging theory and central place theory lead us to predict that
beavers, like most herbivores,
will maximize their net rate of energy intake per unit time. In
order to maximize energy, beavers
will choose trees that are closest to their central place (the
water) and require the least retrieval
cost. Since beavers are trying to maximize energy, we
hypothesized that they will tend to select
some species of trees over others on the basis of nutritional
value.
Methods
This study was conducted at Yates Mill Pond, a research area
owned by the North
SAMPLE FINAL LAB REPORT 4
6. Carolina State University, on October 25th, 1996. Our research
area was located along the edge
of the pond and was approximately 100 m in length and 28 m in
width. There was no beaver
activity observed beyond this width. The circumference, the
species, status (chewed or not-
chewed), and distance from the water were recorded for each
tree in the study area. Due to the
large number of trees sampled, the work was evenly divided
among four groups of students
working in quadrants. Each group contributed to the overall
data collected.
We conducted a chi-squared test to analyze the data with
respect to beaver selection of
certain tree species. We conducted t-tests to determine (1) if
avoided trees were significantly
farther from the water than selected trees, and (2) if chewed
trees were significantly larger or
smaller than not chewed trees. Mean tree distance from the
water and mean tree circumference
were also recorded.
Results
7. SAMPLE FINAL LAB REPORT 5
Overall, beavers showed a preference for certain species of
trees, and their preference
was based on distance from the central place. Measurements
taken at the study site show that
SAMPLE FINAL LAB REPORT 6
beavers avoided oaks and musclewood (Fig. 1) and show a
significant food preference. No
avoidance or particular preference was observed for the other
tree species. The mean distance of
8.42 m away from the water for not-chewed trees was
significantly greater than the mean
distance of 6.13 m for chewed trees (Fig. 2). The tree species
that were avoided were not
significantly farther from the water than selected trees. For the
selected tree species, no
significant difference in circumference was found between trees
that were not chewed
8. (mean=16.03 cm) and chewed (mean=12.80 cm) (Fig. 3).
Discussion
Although beavers are described as generalized herbivores, the
finding in this study
related to species selection suggests that beavers are selective
in their food choice. This finding
agrees with our hypothesis that beavers are likely to show a
preference for certain tree species.
Although beaver selection of certain species of trees may be
related to the nutritional value,
additional information is needed to determine why beavers
select some tree species over others.
Other studies suggested that beavers avoid trees that have
chemical defenses that make the tree
unpalatable to beavers (Muller-Schawarze et al., 1994). These
studies also suggested that
beavers prefer trees with soft wood, which could possibly
explain the observed avoidance of
musclewood and oak in our study.
The result that chewed trees were closer to the water accounts
for the time and energy
spent gathering and hauling. This is in accordance with the
optimal foraging theory and agrees
9. with our hypothesis that beavers will choose trees that are close
to the water. As distance from
the water increases, a tree's net energy yield decreases because
food that is farther away is more
likely to increase search and retrieval time. This finding is
similar to Belovskyís finding of an
SAMPLE FINAL LAB REPORT 7
inverse relationship between distance from the water and
percentage of plants cut.
The lack of any observed difference in mean circumference
between chewed and not
chewed trees does not agree with our hypothesis that beavers
will prefer smaller trees to larger
ones. Our hypothesis was based on the idea that branches from
smaller trees will require less
energy to cut and haul than those from larger trees. Our finding
is in accordance with other
studies (Schoener, 1979), which have suggested that the value
of all trees should decrease with
distance from the water but that beavers would benefit from
choosing large branches from large
trees at all distances. This would explain why there was no
10. significant difference in
circumference between chewed and not-chewed trees.
This lab gave us the opportunity to observe how a specific
mammal selects foods that
maximize energy gains in accordance with the optimal foraging
theory. Although beavers adhere
to the optimal foraging theory, without additional information
on relative nutritional value of
tree species and the time and energy costs of cutting certain tree
species, no optimal diet
predictions may be made. Other information is also needed
about predatory risk and its role in
food selection. Also, due to the large number of students taking
samples in the field, there may
have been errors which may have affected the accuracy and
precision of our measurements. In
order to corroborate our findings, we suggest that this study be
repeated by others.
Conclusion
The purpose of this lab was to learn about the optimal foraging
theory by measuring tree
selection in beavers. We now know that the optimal foraging
theory allows us to predict food-
11. seeking behavior in beavers with respect to distance from their
central place and, to a certain
extent, to variations in tree species. We also learned that
foraging behaviors and food selection is
SAMPLE FINAL LAB REPORT 8
not always straightforward. For instance, beavers selected large
branches at any distance from
the water even though cutting large branches may increase
energy requirements. There seems to
be a fine line between energy intake and energy expenditure in
beavers that is not so easily
predicted by any given theory.
12. SAMPLE FINAL LAB REPORT 9
References
Belovsky, G.E. (1984). Summer diet optimization by beaver.
The American Midland Naturalist.
111: 209-222.
Belovsky, G.E. (1986). Optimal foraging and community
structure: implications for a guild of
generalist grassland herbivores. Oecologia. 70: 35-52.
Jenkins, S.H. (1975). Food selection by beavers:› a
multidimensional contingency table analysis.
Oecologia. 21: 157-173.
Jenkins, S.H. (1980). A size-distance relation in food selection
by beavers. Ecology. 61: 740-
746.
Jenkins, S.H., & P.E. Busher. (1979). Castor canadensis.
Mammalian Species. 120: 1-8.
McGinly, M.A., & T.G. Whitham. (1985). Central place
13. foraging by beavers (Castor
Canadensis): a test of foraging predictions and the
impact of selective feeding on the
growth form of cottonwoods (Populus fremontii).
Oecologia. 66: 558-562.
Muller-Schwarze, B.A. Schulte, L. Sun, A. Muller-Schhwarze,
& C. Muller-Schwarze. (1994).
Red Maple (Acer rubrum) inhibits feeding behavior by
beaver (Castor canadensis).
Journal of Chemical Ecology. 20: 2021-2033.
Pyke, G.H., H.R. Pulliman, E.L. Charnov. (1977). Optimal
foraging. The Quarterly Review of
Biology. 52: 137-154.
Rockwood, L.L., & S.P. Hubbell. (1987). Host-plant selection,
diet diversity, and optimal
foraging in a tropical leaf-cutting ant. Oecologia. 74:
55-61.
Schoener, T.W. (1979). Generality of the size-distance relation
in models of optimal feeding.
The American Naturalist. 114: 902-912.
SAMPLE FINAL LAB REPORT 10
14. *Note: This document was modified from the work of Selena
Bauer, Miriam Ferzli, and Vanessa
Sorensen, NCSU.
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16. 6
Water is brown without any soil.
7
Water is almost clear with no soil
8
Water is dark brown
POST LAB QUESTIONS
1. Develop hypotheses on the ability of oil, vinegar, and laundry
detergent to contaminate groundwater.
a. Oil hypothesis = Oil contaminates water causing it to be
thick and lumpy while allowing soil to filter through.
b. Vinegar hypothesis = Vinegar cleans ground water by
allowing little to no soil filter through but causes an odor
c. Laundry detergent hypothesis = Laundry detergent will
significantly change the color the water and contaminate with
water with bubbles.
2. Based on the results of your experiment, would you reject or
accept each hypothesis that you produced in question 1?
Explain how you determined this.
a. Oil hypothesis accept/reject = Accept, contaminates water by
allowing soil to filter through
b. Vinegar hypothesis accept/reject = Accept, vinegar cleans
ground water helps it to rid the soil
c. Laundry detergent hypothesis accept/reject = Accept,
contaminates water with soap bubbles.
3. What affects did each of the contaminants have on the water
in the experiment? Which contaminant seemed to have the most
potent effect on the water?
Answer = Each contaminate changed the color and thickness of
the water during the experiment. The most potent effect to me
was the smell of the vinegar.
4. Using at least 1 scholarly source, discuss what type of affects
these contaminants (oil, vinegar, detergent) might have on a
town’s water source and the people who drank the water?
Answer = According to studies chronic exposures to arsenic via
17. drinking water has caused adverse health impact on humans.
Tens of millions of people are at risk for health effects due to
ground water arsenic levels.
5. Describe what type of human activity would cause
contaminants like oil, acid and detergents to flow into the water
supply? Additionally, what other items within your house do
you believe could contaminate the water supply if you were to
dump them onto the ground?
Answer = A large number of widespread waste come from
household products that are released into the ground through
septic systems. Typical sources of potential ground water
contaminates such as oil, vinegar and detergent come from
natural sources and numerous human activities.
Experiment 2: Water Treatment
POST LAB QUESTIONS
1. Develop a hypothesis on the ability of your filtration
technique to remove contaminants.
Hypothesis = The filtration technique using charcoal, sand and
gravel will clean the water and remove the contaminates.
2. Based on the results of your experiment, would you reject or
accept the hypothesis that you produced in question 1? Explain
how you determined this.
Accept/Reject = Accept, The coagulants removed the particles
and cleared the contaminated from the water.
3. What are the differences in color, smell, visibility, etc.
between the “contaminated” water and the “treated” water?
Answer = The treated water was clear and odor free versus the
contaminated water.
4. From the introduction to this lab, you know that there are
typically five steps involved in the water treatment process.
Identify the processes (e.g., coagulation) that were used in this
lab and describe how they were performed.
Answer = Separating the soil from the water, Allow time to
separate, use rocks to separate the large particles, use sand and
charcoal to separate small particles and finally0 use chemicals
18. to decontaminate the water
Experiment 3: Drinking Water Quality
Table 2: Ammonia Test Results
Water Sample
Test Results
Tap Water
0
Dasani® Bottled Water
0
Fiji® Bottled Water
0
Table 3: Chloride Test Results
Water Sample
Test Results
Tap Water
500
Dasani® Bottled Water
0
Fiji® Bottled Water
0
Table 4: 4 in 1 Test Results
Water Sample
pH
Total Alkalinity
Total Chlorine
Total Hardness
Tap Water
5
120
0.3
50
Dasani® Bottled Water
3
40
0
0
19. Fiji® Bottled Water
6
180
0
0
Table 5: Phosphate Test Results
Water Sample
Test Results
Tap Water
10 ppm
Dasani® Bottled Water
25 ppm
Fiji® Bottled Water
50 pp
Table 6: Iron Test Results
Water Sample
Test Results
Tap Water
0.10
Dasani® Bottled Water
0
Fiji® Bottled Water
0
POST LAB QUESTIONS
1. Develop a hypothesis on which water source you believe will
contain the most and least contaminants.
Hypothesis = I think that the Tap water will contain the most
contaminates and the Dasani water will have the least amount of
contaminates.
2. Based on the results of your experiment, would you reject or
accept the hypothesis that you produced in question 1? Explain
how you determined this.
Accept/reject = Accept, Being that Tap water is the least
filtered it has the more contaminates and Dasani is filtered
more.
